Programming Information for WiNRADiO G33DDC HF receiver.

The G33DDC API SDK is implemented as a dynamic library (libg33ddcapi.so) for 32-bit i386 and 64-bit x86_64 platforms. It provides object-oriented and non-object-oriented interface to control the G33DDC device. This document describes the object-oriented interface. The libg33ddcapi.so library provides several object types that make it possible to control G33DDC receivers.

The API is not fully thread-safe so preferrably it should be used in single-threaded applications. It can be used in multi-threaded applications as well, but with some care: One G33DDC receiver can be controlled from a single user thread only.

A C/C++ header file g33ddcapi.h is a part of the SDK.

Block diagram of G33DDC processing chain

Simplified block diagram of G33DDC processing chain
Attenuator Preselectors Preamplifier ADC Noise blanker IF DDC1 frequency shift DDC1 DDC1 stream DDC2 frequency shift DDC2 DDC2 stream DDC2 noise blanker Demodulator filter Signal level Notch filter Gain Pre-processed DDC2 stream Demodulator Audio gain Audio stream Audio filter Volume DDC2 frequency shift DDC2 DDC2 stream DDC2 noise blanker Demodulator filter Signal level Notch filter Gain Pre-processed DDC2 stream Demodulator Audio gain Audio stream Audio filter Volume DDC2 frequency shift DDC2 DDC2 stream DDC2 noise blanker Demodulator filter Signal level Notch filter Gain Pre-processed DDC2 stream Demodulator Audio gain Audio stream Audio filter Volume Simplified block diagram of G33DDC processing chain

Using WiNRADiO G33DDC API

Loading API

The lib35ddcapi.so library can be loaded to the application using the dlopen function of dynamic linking loader (link with -ldl). After the library is loaded, it is required to get addresses of exported functions. When the API is no longer required in the memory, the dlclose function can be used to unload the API. Before the dlclose is called, all the objects created using CreateInstance function must be freed releasing their interfaces using the Release method, otherwise the application can enter an unpredictable state. The following source code shows how to load the API:

 
#include <stdio.h>
#include <dlfcn.h>
#include "g33ddcapi.h"

G33DDCAPI_CREATE_INSTANCE CreateInstance;
void *API;

int main(void)
{  
    //Loading the API
    API=dlopen("libg33ddcapi.so",RTLD_LAZY);

    if(API!=NULL)
    {
        //Retrieving addresses of CreateInstance functions
        CreateInstance=(G33DDCAPI_CREATE_INSTANCE)dlsym(API,"CreateInstance");

        //Here place code that uses the API

        dlclose(API);
    }
    else
    {
        //If the dlopen fails
        printf("Failed to load libg33ddcapi.so. %s\n",dlerror());
    }
    
    return 0;
} 

Enumerating available G33DDC devices

To enumerate available G33DDC devices the API provides an enumeration object. The object has to be created using the CreateInstance function. The following source code in C++ produces list of serial numbers of available G33DDC devices:

#include <stdio.h>
#include <dlfcn.h>
#include <errno.h>
#include "g33ddcapi.h"

int main(void)
{
 G33DDCAPI_CREATE_INSTANCE CreateInstance;
 void *API;
 IG33DDCDeviceEnumerator *Enumerator=NULL;
 G33DDC_DEVICE_INFO DevInfo;
 uint32_t Index;
 uint32_t Count;

    API=dlopen("libg33ddcapi.so",RTLD_LAZY);

    if(API!=NULL)
    {
        CreateInstance=(G33DDCAPI_CREATE_INSTANCE)dlsym(API,"CreateInstance");

        if(CreateInstance(G33DDC_CLASS_ID_DEVICE_ENUMERATOR,(void**)&Enumerator))
        {
            Enumerator->Enumerate();

            Count=Enumerator->GetCount();
            
            if(Count!=0)
            {
                printf("Available G33DDC devices count=%d:\n",Count);

                for(Index=0;Index<Count;Index++)
                {
                    Enumerator->GetDeviceInfo(Index,&DevInfo,sizeof(DevInfo));
                    printf("%d. SN: %s\n",Index,DevInfo.SerialNumber);
                }
            }
            else
            {
                printf("No available G33DDC device found.\n");
            }

            Enumerator->Release();
        }
        else
        {
            printf("Failed to create enumerator object. Error code=%d\n",errno);
        }

        dlclose(API);
    }
    else
    {
        printf("Failed to load libg33ddcapi.so. %s\n",dlerror());
    }

    printf("Press enter to exit\n");
    getchar();
    
    return 0;
} 

Opening G33DDC device

The API provides an object to control the G33DDC device. Before the device is open, the object has to be created using the CreateInstance function. The following source code in C++ shows how to open the first available G33DDC device.

#include <stdio.h>
#include <dlfcn.h>
#include <errno.h>
#include "g33ddcapi.h"


int main(void)
{  
 G33DDCAPI_CREATE_INSTANCE CreateInstance;
 void *API;
 IG33DDCDevice *Device;
 
    //Loading the API
    API=dlopen("libg33ddcapi.so",RTLD_LAZY);

    if(API!=NULL)
    {
        //Retrieving address of the CreateInstance API functions
        CreateInstance=(G33DDCAPI_CREATE_INSTANCE)dlsym(API,"CreateInstance");
        
        //Creating instance of the device object
        if(CreateInstance(G33DDC_CLASS_ID_DEVICE,(void**)&Device))
        {
            //Opening the first available G33DDC device using predefined G3XDDC_OPEN_FIRST constant            
            if(Device->Open(G3XDDC_OPEN_FIRST))
            {            
                //Here place code that works with the open G33DDC device            
                
                //Closing device
                Device->Close();
            }
            else
            {
                printf("Failed to open device. Error code=%d\n",errno);
            }
            
            //Release interface of device object
            Device->Release();
        }
        else
        {
            printf("Failed to create device object. Error code=%d\n",errno);
        }        

        dlclose(API);
    }
    else
    {
        //If the dlopen fails
        printf("Failed to load libg33ddcapi.so. %s\n",dlerror());
    }
    
    return 0;
} 

CreateInstance

Creates single object of the specified class and returns interface of the object.

C/C++ declaration

int32_t  CreateInstance(uint32_t ClassId,Pvoid *Interface);

Address retrieval

G33DDCAPI_CREATE_INSTANCE CreateInstance=(G33DDCAPI_CREATE_INSTANCE)dlsym(API,"CreateInstance");

Parameters

ClassId
[in] Specifies class identifier of the object to be created. This parameter must be one of the following:

ValueMeaning
G33DDC_CLASS_ID_DEVICE_ENUMERATORClass identifier of the enumerator object. When the function finished successfully, IG33DDCDeviceEnumerator interface is stored to a variable pointed to by the Interface parameter.
G33DDC_CLASS_ID_DEVICEClass identifier of the device object. When the function finished successfully, IG33DDCDevice interface is stored to variable pointed to by the Interface parameter.

Interface
[out] Pointer to a variable that receives interface to newly created object of specified class. This parameter cannot be NULL.

Return value

If the function succeeds, the return value is non-zero.
If the function fails, the return value is zero. To get extended error information, check errno.

Remarks

All the objects created using CreateInstance must be freed releasing their interfaces using Release method before the API is unloaded using the FreeLibrary function.

The CreateInstance function can be called in any user-thread. Returned interface can be used only in the same thread in which its object was created, otherwise the application can become to unpredictable state.


IG33DDCDeviceEnumerator interface

IG33DDCDeviceEnumerator interface is the interface of the enumerator object that is created using the CreateInstance function and that provides enumeration mechanism of available G33DDC devices.


IG33DDCDeviceEnumerator::AddRef

Increases the reference count to the enumerator object.

C/C++ declaration

uint32_t AddRef(void);

Parameters

None

Return value

The method returns resulting reference count.

Remarks

Initial reference count of an object created using CreateInstance function is 1.

IG33DDCDeviceEnumerator::Release

Decrements the reference count of the object. When the reference count reaches zero, the object and all the resources allocated by them are freed and the interface is no longer usable.

C/C++ declaration

uint32_t Release(void);

Parameters

None

Return value

The method returns resulting reference count. If the return value is zero, the object was freed.

IG33DDCDeviceEnumerator::Enumerate

Performs enumeration of available G33DDC devices.

C/C++ declaration

int Enumerate(void);

Parameters

None

Return value

If the method succeeds, the return value is non-zero.
If the method fails, the return value is zero. To get extended error information, check errno.

IG33DDCDeviceEnumerator::GetCount

Retrieves number of available G33DDC devices enumerated using the IG33DDCDeviceEnumerator::Enumerate method.

C/C++ declaration

uint32_t GetCount(void);

Parameters

None

Return value

The method returns number of available G33DDC devices.

IG33DDCDeviceEnumerator::GetDeviceInfo

Retrieves information about available G33DDC device.

C/C++ declaration

int  GetDeviceInfo(uint32_t DeviceIndex,G33DDC_DEVICE_INFO *DeviceInfo,uint32_t BufferLength);

Parameters

DeviceIndex
[in] Specifies index of the device. It can vary from zero to one less than the value returned by the IG33DDCDeviceEnumerator::GetCount method.
DeviceInfo
[out] Pointer to a G33DDC_DEVICE_INFO structure to be filled with information about the the device.
BufferLength
[in] Size, in bytes, of the G33DDC_DEVICE_INFO structure.

Return value

If the method succeeds, the return value is non-zero.
If the method fails, the return value is zero. To get extended error information, check errno.

IG33DDCDevice interface

IG33DDCDevice interface is an interface of the device object that is created using the CreateInstance function. This interface allows to control selected G33DDC device.


IG33DDCDevice::AddRef

Increases the reference count to the device object.

C/C++ declaration

uint32_t  AddRef(void);

Parameters

None

Return value

The method returns resulting reference count.

Remarks

Initial reference count of an object created using CreateInstance function is 1.

IG33DDCDevice::Release

Decrements the reference count of the object. When the reference count reaches zero, the object and all the resources allocated by them are freed and the interface is no longer usable.

C/C++ declaration

uint32_t  Release(void);

Parameters

None

Return value

The method returns resulting reference count. If the return value is zero, the object was freed.

IG33DDCDevice::Open

Opens G33DDC device by its system path and associates the device with the device object given by its interface pointer.

C/C++ declaration

int  Open(const char *DevicePath);

Parameters

DevicePath
[in] Pointer to a null-terminated string that specifies the system path of the G33DDC device to open. The system device path of the device can be obtained from the G33DDC_DEVICE_INFO structure filled by the IG33DDCDeviceEnumerator::GetDeviceInfo method. Instead of the system path, it can be used one of the following values:

ValueMeaning
G3XDDC_OPEN_FIRSTThe method opens first available G33DDC device.
G3XDDC_OPEN_DEMOThe method opens demo G33DDC device. This allows to work with the API without physical G33DDC device.

Return value

If the method succeeds, the return value non-zero.
If the method fails, the return value is zero. To get extended error information, check errno.

Remarks

Use the IG33DDCDevice::Close method to close currently open G33DDC device associated with the device object.


IG33DDCDevice::Close

Closes currently open G33DDC device associated with the device object and makes the object available for use with another G33DDC device.

C/C++ declaration

void  Close(void);

Parameters

None

Return value

None

Remarks

If no open G33DDC device is associated with the object, the Close method does nothing.

IG33DDCDevice::IsOpen

Checks if a device is associated with the device object.

C/C++ declaration

int  IsOpen(void);

Parameters

None

Return value

The method returns non-zero value if a device is associated with the device object (using the IG33DDCDevice::Open method) and it can be controlled using methods of the device object interface.
The method returns zero,if no device is associated with the device object.

IG33DDCDevice::IsConnected

Checks if the device is still connected to the computer.

C/C++ declaration

int  IsConnected(void);

Parameters

None

Return value

The method returns non-zero value if the device is still connected.
If the device is disconnected or the method fails return value is zero. To determine if the method failed, check errno. errno returns 0 if the device is disconnected or another error code if IsConnected failed.

Remarks

If it is determined the device is disconnected, the IG33DDCDevice::Close should be used.

IG33DDCDevice::GetDeviceInfo

Retrieves information about the G33DDC device.

C/C++ declaration

int  GetDeviceInfo(G33DDC_DEVICE_INFO *Info,uint32_t BufferLength);

Parameters

Info
[out] Pointer to a G33DDC_DEVICE_INFO structure to be filled with information about the device. This parameter cannot be NULL.
BufferLength
[in] Size in bytes of the G33DDC_DEVICE_INFO structure.

Return value

If the method succeeds, the return value is non-zero.
If the method fails, the return value is zero. To get extended error information, check errno.

IG33DDCDevice::SetPower

Turns the G33DDC device on or off.

C/C++ declaration

int  SetPower(int Power);

Parameters

Power
[in] Specifies whether to turn on or off the device. If this parameter is non-zero the device is turned on, if it is zero the device is turned off.

Return value

If the method succeeds, the return value is non-zero.
If the method fails, the return value is zero. To get extended error information, check errno.

Remarks

If SetPower turns the device off, all the running streams are stopped.

Use the IG33DDCDevice::GetPower method to determine the current power state of the device.


IG33DDCDevice::GetPower

Determines whether the device is turned on or off.

C/C++ declaration

int  GetPower(int *Power);

Parameters

Power
[out] Pointer to a variable that receives the current power state of the device. If it is non-zero, the device is turned on. If it is zero the device is turned off. This parameter cannot be NULL.

Return value

If the method succeeds, the return value is non-zero.
If the method fails, the return value is zero. To get extended error information, check errno.

IG33DDCDevice::SetExternalReference

Enables or disables the use of external reference as the clock source.

C/C++ declaration

int  SetExternalReference(int Enabled);

Parameters

Enabled
[in] Specifies the desired clock source: nonzero - external reference, zero - internal.

Return value

If the method succeeds, the return value is non-zero.
If the method fails, the return value is zero. To get extended error information, check errno.

Remarks

External reference is optional. If the receiver does not support external reference, IG33DDCDevice::SetExternalReference fails. The following example shows how to determine the receiver supports external reference:
    G33DDC_DEVICE_INFO DeviceInfo;
    IG33DDCDevice *Device;  //Interface of G33DDC device object, created using the CreateInstance function
    
    Device->GetDeviceInfo(&DeviceInfo,sizeof(DeviceInfo));
    
    if(DeviceInfo.Flags & G33DDC_FLAGS_EXTERNAL_REFERENCE_100MHZ)
    {
        //the receiver supports external 100MHz reference
    }
    else if(DeviceInfo.Flags & G33DDC_FLAGS_EXTERNAL_REFERENCE_10MHZ)
    {
        //the receiver supports external 10MHz reference
    }
    else
    {
        //the receiver does not support external reference
    }

IG33DDCDevice::GetExternalReference

Retrieves the current clock source.

C/C++ declaration

int  GetExternalReference(int *Enabled);

Parameters

Enabled
[out] Pointer to a variable that receives information about the current clock source. If it is non-zero, external reference is used, if it is zero, internal reference is used. This parameter cannot be NULL.

Return value

If the method succeeds, the return value is non-zero.
If the method fails, the return value is zero. To get extended error information, check errno.

IG33DDCDevice::SetAttenuator

Sets input attenuator.

C/C++ declaration

int  SetAttenuator(uint32_t Attenuator);

Parameters

Attenuator
[in] Value that specifies attenuation level in dB. Possible values are: 0, 3, 6, 9, 12, 15, 18, 21. If the value is not from the list, the SetAttenuator method rounds the value to nearest lower one.

Return value

If the method succeeds, the return value is non-zero.
If the method fails, the return value is zero. To get extended error information, check errno.

Remarks

Use the IG33DDCDevice::GetAttenuator method to determine the current setting of the attenuator.

IG33DDCDevice::SetDithering

Enables or disables ADC dithering.

C/C++ declaration

int  SetDithering(int Enable);

Parameters

Enable
[in] Specifies whether to enable or disable ADC dithering. If this parameter is non-zero, dithering is enabled. If the parameter is zero, dithering is disabled.

Return value

If the method succeeds, the return value is non-zero.
If the method fails, the return value is zero. To get extended error information, check errno.

Remarks

Use the IG33DDCDevice::GetDithering method to determine the current setting of dithering.

IG33DDCDevice::GetAttenuator

Retrieves current setting of the attenuator.

C/C++ declaration

int  GetAttenuator(uint32_t *Attenuator);

Parameters

Attenuator
[out] Pointer to a variable that receives the current attenuation level. This parameter cannot be NULL.

Return value

If the method succeeds, the return value is non-zero.
If the method fails, the return value is zero. To get extended error information, check errno.

IG33DDCDevice::GetDithering

Retrieves current setting of dithering.

C/C++ declaration

int  GetDithering(int *Enable);

Parameters

Enable
[out] Pointer to a variable that receives the current dithering setting. This parameter cannot be NULL.

Return value

If the method succeeds, the return value is non-zero.
If the method fails, the return value is zero. To get extended error information, check errno.

IG33DDCDevice::SetPreselectors

Controls the band pass filter at input.

C/C++ declaration

int  SetPreselectors(uint32_t Low,uint32_t High);

Parameters

Low
[in] Specifies cut-off low frequency of the filter in Hz. Possible values are : 700000,1200000,2000000,2900000,4000000,5100000,5600000,8300000, 9200000, 9500000, 13300000, 14600000, 16100000, 21600000.
High
[in] Specifies cut-off high frequency of the filter in Hz. Possible values are: 2200000,2700000,4000000,4900000,6200000,7400000,9400000,10700000, 12900000, 14600000, 18900000, 23400000, 25800000, 32100000, 50000000. If the value is not from the list, the method rounds it to nearest one.

Return value

If the method succeeds, the return value is non-zero.
If the method fails, the return value is zero. To get extended error information, check errno.

Remarks

Value of the Low parameter must not be higher than the value of the High parameter, otherwise the method fails.

Use the IG33DDCDevice::GetPreselectors method to determine the current setting of the preselectors.


IG33DDCDevice::GetPreselectors

Retrieves current setting of input band pass filter.

C/C++ declaration

int  GetPreselectors(uint32_t *Low,uint32_t *High);

Parameters

Low
[out] Pointer to a variable that receives the current cut-off low frequency of the filter in Hz. This parameter can be NULL if the application does not require this information.
High
[out] Pointer to a variable that receives the current cut-off high frequency of the filter in Hz. This parameter can be NULL if the application does not require this information.

Return value

If the method succeeds, the return value is non-zero.
If the method fails, the return value is zero. To get extended error information, check errno.

IG33DDCDevice::SetPreamp

Enables or disables input preamplifier.

C/C++ declaration

int  SetPreamp(int Preamp);

Parameters

Preamp
[in] Specifies whether to enable or disable preamplifier. If this parameter is non-zero, the preamplifier is enabled. If the parameter is zero, the preamplifier is disabled.

Return value

If the method succeeds, the return value is non-zero.
If the method fails, the return value is zero. To get extended error information, check errno.

Remarks

Use the IG33DDCDevice::GetPreamp method to determine the current state of the preamplifier.


IG33DDCDevice::GetPreamp

Retrieves current state of input preamplifier.

C/C++ declaration

int  GetPreamp(int *Preamp);

Parameters

Preamp
[out] Pointer to a variable that receives the current state of the preamplifier. The value is non-zero if the preamplifier is enabled and zero if it is disabled. This parameter cannot be NULL.

Return value

If the method succeeds, the return value is non-zero.
If the method fails, the return value is zero. To get extended error information, check errno.

IG33DDCDevice::SetADCNoiseBlanker

Enables or disables noise blanker on ADC stream.

C/C++ declaration

int  SetADCNoiseBlanker(int Enabled);

Parameters

Enabled
[in] Specifies whether to enable or disable noise blanker. If this parameter is non-zero, noise blanker is enabled. If the parameter is zero, noise blanker is disabled.

Return value

If the method succeeds, the return value is non-zero.
If the method fails, the return value is zero. To get extended error information, check errno.

Remarks

Use the IG33DDCDevice::GetADCNoiseBlanker method to determine the current state of the noise blanker.

IG33DDCDevice::GetADCNoiseBlanker

Retrieves current ADC noise blanker state.

C/C++ declaration

int  GetADCNoiseBlanker(int *Enabled);

Parameters

Enabled
[out] Pointer to a variable that receives the current state of noise blanker. The value is non-zero if noise blanker is enabled and zero if it is disabled. This parameter cannot be NULL.

Return value

If the method succeeds, the return value is non-zero.
If the method fails, the return value is zero. To get extended error information, check errno.

IG33DDCDevice::SetADCNoiseBlankerThreshold

Specifies ADC noise blanker threshold.

C/C++ declaration

int  SetADCNoiseBlankerThreshold(uint16_t Threshold);

Parameters

Threshold
[in] Specifies the maximum acceptable input signal. Maximum possible value of threshold is 32767, in this case the noise blanker has no effect even it is enabled using the IG33DDCDevice::SetADCNoiseBlanker method.

Return value

If the method succeeds, the return value is non-zero.
If the method fails, the return value is zero. To get extended error information, check errno.

Remarks

Use the IG33DDCDevice::GetADCNoiseBlankerThreshold method to retrieve the current threshold of the noise blanker.

IG33DDCDevice::GetADCNoiseBlankerThreshold

Determines ADC noise blanker threshold.

C/C++ declaration

int  GetADCNoiseBlankerThreshold(uint16_t *Threshold);

Parameters

Threshold
[out] Pointer to a variable that receives threshold of ADC noise blanker. This parameter cannot be NULL.

Return value

If the method succeeds, the return value is non-zero.
If the method fails, the return value is zero. To get extended error information, check errno.

IG33DDCDevice::StartIF

Starts sending of IF snapshots.

C/C++ declaration

int  StartIF(uint16_t Period);

Parameters

Period
[in] Specifies time interval in milliseconds how often the IF snapshots are sent to IG33DDCDeviceCallback::G33DDC_IFCallback callback.

Return value

If the method succeeds, the return value is non-zero.
If the method fails, the return value is zero. To get extended error information, check errno.

Remarks

The G33DDC device has to be turned on using the IG33DDCDevice::SetPower method before use of StartIF, otherwise the StartIF method fails.

Too low value of the Period parameter can dramatically increase data flow through USB wich could cause breaking of running streaming.


IG33DDCDevice::StopIF

Stops sending of IF snapshots.

C/C++ declaration

int  StopIF(void);

Parameters

None

Return value

If the method succeeds, the return value is non-zero.
If the method fails, the return value is zero. To get extended error information, check errno.

Remarks

The IG33DDCDeviceCallback::G33DDC_IFCallback callback is not called after StopIF returns.


IG33DDCDevice::SetInverted

Enables or disables frequency spectrum inversion.

C/C++ declaration

int  SetInverted(int Inverted);

Parameters

Inverted
[in] Specifies whether to enable or disable frequency spectrum inversion. If this parameter is non-zero, IF spectrum is inverted.

Return value

If the method succeeds, the return value is non-zero.
If the method fails, the return value is zero. To get extended error information, check errno.

IG33DDCDevice::GetInverted

Retrieves current frequency spectrum inversion setting.

C/C++ declaration

int  GetInverted(int *Inverted);

Parameters

Inverted
[out] Pointer to a variable that receives non-zero value if the frequency spectrum inversion is enabled, and zero if the inversion is disabled. This parameter cannot be NULL.

Return value

If the method succeeds, the return value is non-zero.
If the method fails, the return value is zero. To get extended error information, check errno.

IG33DDCDevice::GetDDCInfo

Retrieves information about DDC format.

C/C++ declaration

int  GetDDCInfo(uint32_t DDCTypeIndex,G3XDDC_DDC_INFO *Info);

Parameters

DDCTypeIndex
[in] Specifies index of DDC type. For more information, see remarks.
Info
[out] Pointer to a G3XDDC_DDC_INFO structure to be filled with information about DDC type.

Return value

If the method succeeds, the return value is non-zero.
If the method fails, the return value is zero. To get extended error information, check errno.

Remarks

Use the IG33DDCDevice::GetDDC1Count method to determine the number of possible DDC types of DDC1. In this case the DDCTypeIndex parameter can vary from zero to one less than the number determined by IG33DDCDevice::GetDDC1Count.

Use the IG33DDCDevice::GetDDC1 method to determine the current DDC type index of DDC1 and the IG33DDCDevice::GetDDC2 method to determine the current DDC type of DDC2.


IG33DDCDevice::GetDDC1Count

Retrieves number of DDC types supported by DDC1.

C/C++ declaration

int  GetDDC1Count(uint32_t *Count);

Parameters

Count
[out] Pointer to a variable that receives number of DDC types supported by the DDC1. This parameter cannot be NULL.

Return value

If the method succeeds, the return value is non-zero.
If the method fails, the return value is zero. To get extended error information, check errno.

IG33DDCDevice::SetDDC1

Sets current DDC type of DDC1.

C/C++ declaration

int  SetDDC1(uint32_t DDCTypeIndex);

Parameters

DDCTypeIndex
[in] Specifies index of DDC type to be used in DDC1. It can vary from zero to one less than number of DDC types of the DDC1.

Return value

If the method succeeds, the return value is non-zero.
If the method fails, the return value is zero. To get extended error information, check errno.

Remarks

Use the IG33DDCDevice::GetDDC1Count method to determine the number of possible DDC types of DDC1. The DDCTypeIndex parameter can vary from zero to one less than the number determined by IG33DDCDevice::GetDDC1Count.

DDC1 streaming must not run when calling SetDDC1. In other words, DDC1 streaming that is started using the IG33DDCDevice::StartDDC1 method has to be stopped using the IG33DDCDevice::StopDDC1 method before calling of SetDDC1, otherwise SetDDC1 fails. The SetDDC1 method does not start and stop DDC1 streaming, just changes DDC type of DDC1.

Calling of SetDDC1 can change the current DDC type of DDC2 and the current bandwidth of demodulator filter, so it is useful to call the IG33DDCDevice::GetDDC2 and IG33DDCDevice::GetDemodulatorFilterBandwidth methods immediately after SetDDC1 to determine the current DDC type of DDC2 and the current bandwidth of demodulator filter.

Use the IG33DDCDevice::GetDDC1 method to determine the current DDC type of the DDC1.


IG33DDCDevice::GetDDC1

Retrieves information about the current DDC type of the DDC1.

C/C++ declaration

int  GetDDC1(uint32_t *DDCTypeIndex,G3XDDC_DDC_INFO *DDCInfo);

Parameters

DDCTypeIndex
[out] Pointer to a variable that receives index of the current DDC type of the DDC1. This parameter can be NULL if the application does not require this information.
DDCInfo
[out] Pointer to a G3XDDC_DDC_INFO structure to be filled with information about the current DDC type of the DDC1. This parameter can be NULL if the application does not require this information.

Return value

If the method succeeds, the return value is non-zero.
If the method fails, the return value is zero. To get extended error information, check errno.

Remarks

Returned DDCTypeIndex can be passed to the IG33DDCDevice::GetDDCInfo method.

IG33DDCDevice::SetDDC1Frequency

Sets DDC1 center frequency.

C/C++ declaration

int  SetDDC1Frequency(uint32_t Frequency);

Parameters

Frequency
[in] Specifies new center frequency of DDC1 in Hz.

Return value

If the method succeeds, the return value is non-zero.
If the method fails, the return value is zero. To get extended error information, check errno.

Remarks

Changing of DDC1 frequency causes change of absolute frequency of the DDC2 and demodulator in each channel.

Use the IG33DDCDevice::GetDDC1Frequency method to determine the current center frequency of DDC1.


IG33DDCDevice::GetDDC1Frequency

Retrieves the current center frequency of DDC1.

C/C++ declaration

int  GetDDC1Frequency(uint32_t *Frequency);

Parameters

Frequency
[out] Pointer to a variable that receives the current center frequency of DDC1 in Hz. This parameter cannot be NULL.

Return value

If the method succeeds, the return value is non-zero.
If the method fails, the return value is zero. To get extended error information, check errno.

IG33DDCDevice::StartDDC1

Starts DDC1 streaming.

C/C++ declaration

int  StartDDC1(uint32_t SamplesPerBuffer);

Parameters

SamplesPerBuffer
[in] Specifies number of I/Q sample sets in each buffer passed to the the DDC1StreamCallback callback method. The value has to be a multiple of 64 greater than zero. If it is zero, the StartDDC1 method fails. If it is not a multiple of 64 the method rounds it up to nearest a multiple of 64.

Return value

If the method succeeds, the return value is non-zero.
If the method fails, the return value is zero. To get extended error information, check errno.

Remarks

The G33DDC device has to be turned on using the IG33DDCDevice::SetPower method before StartDDC1 is used. Otherwise StartDDC1 fails.

If the DDC1 streaming is already running before use of StartDDC1, StartDDC1 restarts the streaming except it was previously started with the same SamplesPerBuffer parameter. In this case StartDDC1 does nothing. Restart of DDC1 streaming stops DDC2 and audio streaming in each channel. StartDDC1 does not restart DDC2 and audio streaming.

If DDC1 playback is running (started using IG33DDCDevice::StartDDC1Playback method) before use of StartDDC1, StartDDC1 stops it and starts DDC1 streaming from the device.

Use the IG33DDCDevice::StopDDC1 method to stop DDC1 streaming.

Decreasing the value of the SamplesPerBuffer parameter decreases latency and may increase CPU usage. Increasing the value of the SamplesPerBuffer parameter increases latency and it may decrease CPU usage.


IG33DDCDevice::StopDDC1

Stops DDC1 streaming.

C/C++ declaration

int  StopDDC1(void);

Parameters

None

Return value

If the method succeeds, the return value is non-zero.
If the method fails, the return value is zero. To get extended error information, check errno.

Remarks

If DDC1 playback is running (started using IG33DDCDevice::StartDDC1Playback) before use of StopDDC1, the StopDDC1 method stops it.

The StopDDC1 method stops all the streaming beyond the DDC1 in processing chain (DDC2 and audio streaming in all the channels).

The IG33DDCDeviceCallback::G33DDC_DDC1StreamCallback and IG33DDCDeviceCallback::G33DDC_DDC1PlaybackStreamCallback callback methods are not called after StopDDC1 returns.


IG33DDCDevice::StartDDC1Playback

Starts DDC1 playback. It allows to pass previously recorded DDC1 I/Q samples to the processing chain instead of the samples received from the device.

C/C++ declaration

int  StartDDC1Playback(uint32_t SamplesPerBuffer,uint32_t BitsPerSample);

Parameters

SamplesPerBuffer
[in] Specifies number of I/Q sample sets in each buffer passed to the IG33DDCDeviceCallback::G33DDC_DDC1PlaybackStreamCallback callback to fill the buffer by the application and to the IG33DDCDeviceCallback::G33DDC_DDC1StreamCallback callback. The value has to be a multiple of 64 greater than zero. If it is zero, the StartDDC1Playback method fails. If it is not a multiple of 64 the method rounds it up to nearest a multiple of 64.
BitsPerSample
[in] Specifies number of bits per I and Q samples. It is used for both IG33DDCDeviceCallback::G33DDC_DDC1PlaybackStreamCallback and IG33DDCDeviceCallback::G33DDC_DDC1StreamCallback callback methods. The possible value is one of the following:

ValueMeaning
0I and Q samples have default number of bits. It is given by by BitsPerSample member of the G3XDDC_DDC_INFO structure which can be retrieved using the GetDDC1 or IG33DDCDevice::GetDDCInfo method. Possible values are 16 or 32 bits per sample, signed, little endian.
16I and Q samples have 16 bit (16 bits per I, 16 bits per Q), signed, little endian.
32I and Q samples have 32 bit (32 bits per I, 32 bits per Q), signed, little endian.

Return value

If the method succeeds, the return value is non-zero.
If the method fails, the return value is zero. To get extended error information, check errno.

Remarks

The G33DDC device has to be turned on using IG33DDCDevice::SetPower method before use of StartDDC1Playback.

The StartDDC1Playback method stops DDC1 streaming that was previously started by the IG33DDCDevice::StartDDC1 or StartDDC1Playback methods and starts DDC1 playback with new parameters. Stopping of DDC1 streaming stops DDC2 and audio steaming in each channel. StartDDC1Playback does not restart DDC2 and audio streaming.

Use the IG33DDCDevice::StopDDC1 method to stop DDC1 playback.


IG33DDCDevice::PauseDDC1Playback

Pauses DDC1 playback.

C/C++ declaration

int  PauseDDC1Playback(void);

Parameters

None

Return value

If the method succeeds, the return value is non-zero.
If the method fails, the return value is zero. To get extended error information, check errno.

Remarks

If DDC1 playback is not active or it is already paused, PauseDDC1Playback does nothing.

The IG33DDCDeviceCallback::G33DDC_DDC1PlaybackStreamCallback and IG33DDCDeviceCallback::G33DDC_DDC1StreamCallback callback methods can be called by the API once after PauseDDC1Playback returns. Then they are not called until playback is resumed using the IG33DDCDevice::ResumeDDC1Playback method.


IG33DDCDevice::ResumeDDC1Playback

Resumes paused DDC1 playback.

C/C++ declaration

int  ResumeDDC1Playback(void);

Parameters

None

Return value

If the method succeeds, the return value is non-zero.
If the method fails, the return value is zero. To get extended error information, check errno.

Remarks

If DDC1 playback is not active or it is not paused, ResumeDDC1Playback does nothing.


IG33DDCDevice::GetDDC2

Retrieves information about the current DDC type of the DDC2.

C/C++ declaration

int  GetDDC2(uint32_t *DDCTypeIndex,G3XDDC_DDC_INFO *DDCInfo);

Parameters

DDCTypeIndex
[out] Pointer to a variable that receives index of the current DDC type of the DDC2. This parameter can be NULL if the application does not require this information.
DDCInfo
[out] Pointer to a G3XDDC_DDC_INFO structure to be filled with information about the current DDC type of the DDC2. This parameter can be NULL if the application does not require this information.

Return value

If the method succeeds, the return value is non-zero.
If the method fails, the return value is zero. To get extended error information, check errno.

Remarks

Each channel has its own DDC2, see the block diagram. DDC type of each DDC2 is the same and it depends on DDC type of DDC1, it cannot be changed by the application directly. DDC type of DDC2 is equal to DDC type of DDC1 if DDC type index of DDC1 is less than or equal to 5 (sample rate: 80 kHz, bandwidth: 64 kHz, bits per sample: 32). If DDC type index of DDC1 is above 5, DDC type index of DDC2 is always 5. Changing of DDC type of DDC1 can cause change of DDC type of DDC2, so it is useful to call GetDDC2 immediately after the SetDDC1 method to determine the current DDC type of DDC2 if the application needs to know parameters of DDC2.

The BitsPerSample member of the G3XDDC_DDC_INFO structure is not used and it can be ignored for DDC2. I and Q samples in buffers passed to the IG33DDCDeviceCallback::G33DDC_DDC2StreamCallback and IG33DDCDeviceCallback::G33DDC_DDC2PreprocessedStreamCallback DDC2 callback methods are always in IEEE float (32 bit, little endian) format.

Returned DDCTypeIndex can be passed to the IG33DDCDevice::GetDDCInfo method.


IG33DDCDevice::SetDDC2Frequency

Sets relative center frequency of DDC2 for given channel.

C/C++ declaration

int  SetDDC2Frequency(uint32_t Channel,int32_t Frequency);

Parameters

Channel
[in] Specifies channel index. Possible values are: 0, 1, 2.
Frequency
[in] Specifies new center frequency of DDC2 in Hz.

Return value

If the method succeeds, the return value is non-zero.
If the method fails, the return value is zero. To get extended error information, check errno.

Remarks

Value of the Frequency parameter is center frequency of the DDC2 relative to center of the DDC1. The value can be negative.

Absolute frequency of the DDC2 is given by the following formula:

faDDC2[i] = fDDC1 + frDDC2[i]

Where faDDC2[i] is absolute center frequency of DDC2 of i-th channel in Hz, fDDC1 is center frequency of the DDC1 in Hz (set using the IG33DDCDevice::SetDDC1Frequency method) and frDDC2[i] is relative center frequency of DDC2 of i-th channel in Hz (set using SetDDC2Frequency).

Changing of DDC2 relative frequency changes absolute frequency of the DDC2 and demodulator in the specified channel.

Use the IG33DDCDevice::GetDDC2Frequency method to determine the current relative center frequency of the DDC2 for given channel.

The following example shows three methods how it is possible to set absolute DDC2 center frequency of channel 0 to 11.01 MHz:

IG33DDCDevice *Device; //Interface of the G33DDC device object, created using CreateInstance function

//1. method
Device->SetDDC1Frequency(11010000);
Device->SetDDC2Frequency(0,0);

//2. method, it can be used if bandwidth of DDC2 is less than bandwidth of DDC1
Device->SetDDC1Frequency(11000000);
Device->SetDDC2Frequency(0,10000);

//3. method, it can be used if bandwidth of DDC2 is less than bandwidth of DDC1
Device->SetDDC1Frequency(11020000);
Device->SetDDC2Frequency(0,-10000);

IG33DDCDevice::GetDDC2Frequency

Retrieves the current relative center frequency of DDC2.

C/C++ declaration

int  GetDDC2Frequency(uint32_t Channel,int32_t *Frequency);

Parameters

Channel
[in] Specifies channel index. Possible values are: 0, 1, 2.
Frequency
[out] Pointer to a variable that receives the current relative center frequency of DDC2 in Hz. The returned value can be negative. See remarks of the SetDDC2Frequency for information how to calculate absolute center frequency of DDC2. This parameter cannot be NULL.

Return value

If the method succeeds, the return value is non-zero.
If the method fails, the return value is zero. To get extended error information, check errno.

IG33DDCDevice::StartDDC2

Starts DDC2 streaming for given channel.

C/C++ declaration

int  StartDDC2(uint32_t Channel,uint32_t SamplesPerBuffer);

Parameters

Channel
[in] Specifies channel index. Possible values are: 0, 1, 2.
SamplesPerBuffer
[in] Specifies number of I/Q sample sets in each buffer passed to the the IG33DDCDeviceCallback::G33DDC_DDC2StreamCallback and IG33DDCDeviceCallback::G33DDC_DDC2PreprocessedStreamCallback callback methods. The value has to be a multiple of 64 greater than zero. If it is zero, the StartDDC2 method fails. If it is not a multiple of 64 the method rounds it up to nearest a multiple of 64.

Return value

If the method succeeds, the return value is non-zero.
If the method fails, the return value is zero. To get extended error information, check errno.

Remarks

Before StartDDC2 is used, the G33DDC device has to be turned on using the IG33DDCDevice::SetPower method and DDC1 streaming has to be started using the IG33DDCDevice::StartDDC1 or IG33DDCDevice::StartDDC1Playback method, otherwise StartDDC2 fails.

If the DDC2 streaming for given channel is already running, StartDDC2 restarts it except the streaming was previously started with the same SamplesPerBuffer parameter. In this case StartDDC2 does nothing. Restart of the DDC2 streaming stops audio streaming for give channel. StartDDC2 does not restart audio streaming.

Use the IG33DDCDevice::StopDDC2 method to stop DDC2 streaming.

Decreasing value of the SamplesPerBuffer parameter decreases latency and it may increase CPU usage. Increasing the value of the SamplesPerBuffer parameter increases latency and may decrease CPU usage.


IG33DDCDevice::StopDDC2

Stops DDC2 streaming for given channel.

C/C++ declaration

int  StopDDC2(uint32_t Channel);

Parameters

Channel
[in] Specifies channel index. Possible values are: 0, 1, 2.

Return value

If the method succeeds, the return value is non-zero.
If the method fails, the return value is zero. To get extended error information, check errno.

Remarks

If audio streaming for given channel is running, it is stopped too.

If DDC2 streaming is not active, StopDDC2 does nothing.

The IG33DDCDeviceCallback::G33DDC_DDC2StreamCallback and IG33DDCDeviceCallback::G33DDC_DDC2PreprocessedStreamCallback callback methods are not called after StopDDC2 returns.


IG33DDCDevice::SetDDC2NoiseBlanker

Enables or disables noise blanker on DDC2 stream.

C/C++ declaration

int  SetDDC2NoiseBlanker(uint32_t Channel,int Enabled);

Parameters

Channel
[in] Specifies channel index. Possible values are: 0, 1, 2.
Enabled
[in] Specifies whether to enable or disable noise blanker. If this parameter is non-zero, noise blanker is enabled. If the parameter is zero, noise blanker is disabled.

Return value

If the method succeeds, the return value is non-zero.
If the method fails, the return value is zero. To get extended error information, check errno.

Remarks

Use the IG33DDCDevice::GetDDC2NoiseBlanker method to determine the current state of the noise blanker.

IG33DDCDevice::GetDDC2NoiseBlanker

Retrieves the current DDC2 noise blanker state.

C/C++ declaration

int  GetDDC2NoiseBlanker(uint32_t Channel,int *Enabled);

Parameters

Channel
[in] Specifies channel index. Possible values are: 0, 1, 2.
Enabled
[out] Pointer to a variable that receives the current state of noise blanker. The value is non-zero if noise blanker is enabled and zero if it is disabled. This parameter cannot be NULL.

Return value

If the method succeeds, the return value is non-zero.
If the method fails, the return value is zero. To get extended error information, check errno.

IG33DDCDevice::SetDDC2NoiseBlankerThreshold

Specifies DDC2 noise blanker threshold.

C/C++ declaration

int  SetDDC2NoiseBlankerThreshold(uint32_t Channel,double Threshold);

Parameters

Channel
[in] Specifies channel index. Possible values are: 0, 1, 2.
Threshold
[in] Specifies threshold in %.

Return value

If the method succeeds, the return value is non-zero.
If the method fails, the return value is zero. To get extended error information, check errno.

Remarks

Use the IG33DDCDevice::GetDDC2NoiseBlankerThreshold method to retrieve the current threshold of the noise blanker.

IG33DDCDevice::GetDDC2NoiseBlankerThreshold

Retrieves DDC2 noise blanker threshold.

C/C++ declaration

int  GetDDC2NoiseBlankerThreshold(uint32_t Channel,double *Threshold);

Parameters

Channel
[in] Specifies channel index. Possible values are: 0, 1, 2.
Threshold
[out] Pointer to a variable that receives threshold of the noise blanker. This parameter cannot be NULL.

Return value

If the method succeeds, the return value is non-zero.
If the method fails, the return value is zero. To get extended error information, check errno.

IG33DDCDevice::GetDDC2NoiseBlankerExcessValue

Determines value which indicates percentage ratio between short time average signal level and maximum level.

C/C++ declaration

int  GetDDC2NoiseBlankerExcessValue(uint32_t Channel,double *Value);

Parameters

Channel
[in] Specifies channel index. Possible values are: 0, 1, 2.
Value
[out] Pointer to a variable that receives the current excess value in %. This parameter cannot be NULL.

Return value

If the method succeeds, the return value is non-zero.
If the method fails, the return value is zero. To get extended error information, check errno.

IG33DDCDevice::GetSignalLevel

Determines the current signal level for given channel.

C/C++ declaration

int  GetSignalLevel(uint32_t Channel,float *Peak,float *RMS);

Parameters

Channel
[in] Specifies channel index. Possible values are: 0, 1, 2.
Peak
[out] Pointer to a variable that receives the current signal level (peak) in Volts. This parameter can be NULL if the application does not require this information.
RMS
[out] Pointer to a variable that receives the current signal level (RMS) in Volts. This parameter can be NULL if the application does not require this information.

Return value

If the method succeeds, the return value is non-zero.
If the method fails, the return value is zero. To get extended error information, check errno.

Remarks

DDC2 streaming has to be active (started using the IG33DDCDevice::StartDDC2 method) before calling of GetSignalLevel, otherwise returned peak and RMS signal levels are zero.

Signal level is evaluated from signal after the demodulator filter and before the notch filter (see block diagram), the signal is selected by the demodulator filter.

Signal level is evaluated for each buffer that processed by the demoduletor filter. Buffer size (signal level evaluation rate) is given by the SamplesPerBuffer parameter of the IG33DDCDevice::StartDDC2 method.

The IG33DDCDeviceCallback::G33DDC_DDC2PreprocessedStreamCallback callback method provides signal level for each buffer passed the callback, i.e. for each buffer used in signal level evaluation. This provides way to get signal level from each processed buffer without need of pulling it using GetSignalLevel.

To convert RMS signal level in Volts to power in dBm use the following formulas:

P[W] = (VRMS)2 / R = (VRMS)2 / 50

P[dBm]= 10 * log10( P[W] * 1000 )

Where VRMS is RMS signal level in Volts obtained by GetSignalLevel, R is G33DDC receiver input impedance (50 Ω), P[W] is power in Watts, P[dBm] is power in dBm and 1000 is conversion coefficient W -> mW.

The following example shows how to obtain the current signal level in dBm from channel 0:

#include <stdio.h>
#include <math.h>

IG33DDCDevice *Device; //Interface of G33DDC device object, created using the CreateInstance function
float P_dBm,V_RMS;

Device->GetSignalLevel(0,NULL,&V_RMS);

P_dBm=10.0*log10(V_RMS*V_RMS*(1000.0/50.0));

printf("Current signal level [RMS]: %.1f dBm\n",P_dBm);

IG33DDCDevice::SetNotchFilter

Enables or disables notch filter for given channel.

C/C++ declaration

int  SetNotchFilter(uint32_t Channel,uint32_t NotchFilterIndex,int Enabled);

Parameters

Channel
[in] Specifies channel index. Possible values are: 0, 1, 2.
NotchFilterIndex
[in] Specifies notch filter index. Possible values are: 0, 1.
Enabled
[in] Specifies whether to enable or disable notch filter. If this parameter is non-zero, the filter is enabled. If the parameter is zero, the filter is disabled.

Return value

If the method succeeds, the return value is non-zero.
If the method fails, the return value is zero. To get extended error information, check errno.

Remarks

Use the IG33DDCDevice::GetNotchFilter method to determine whether the filter is enabled or disabled.

IG33DDCDevice::GetNotchFilter

Retrieves the current notch filter state for given channel.

C/C++ declaration

int  GetNotchFilter(uint32_t Channel,uint32_t NotchFilterIndex,int *Enabled);

Parameters

Channel
[in] Specifies channel index. Possible values are: 0, 1, 2.
NotchFilterIndex
[in] Specifies notch filter index. Possible values are: 0, 1.
Enabled
[out] Pointer to a variable that receives the current state of the notch filter. The value is non-zero if the filter is enabled and zero if it is disabled. This parameter cannot be NULL.

Return value

If the method succeeds, the return value is non-zero.
If the method fails, the return value is zero. To get extended error information, check errno.

IG33DDCDevice::SetNotchFilterFrequency

Specifies relative center frequency of the notch filter for given channel.

C/C++ declaration

int  SetNotchFilterFrequency(uint32_t Channel,uint32_t NotchFilterIndex,int32_t Frequency);

Parameters

Channel
[in] Specifies channel index. Possible values are: 0, 1, 2.
NotchFilterIndex
[in] Specifies notch filter index. Possible values are: 0, 1.
Frequency
[in] Specifies new center frequency of the notch filter in Hz.

Return value

If the method succeeds, the return value is non-zero.
If the method fails, the return value is zero. To get extended error information, check errno.

Remarks

Value of the Frequency parameter is new center frequency of the notch filter relative to center of the DDC2 (see the IG33DDCDevice::SetDDC2Frequency method). The value can be negative.

Use the IG33DDCDevice::GetNotchFilterFrequency method to retrieve the current center frequency of the notch filter.


IG33DDCDevice::GetNotchFilterFrequency

Retrieves the current relative center frequency of the notch filter.

C/C++ declaration

int  GetNotchFilterFrequency(uint32_t Channel,uint32_t NotchFilterIndex,int32_t *Frequency);

Parameters

Channel
[in] Specifies channel index. Possible values are: 0, 1, 2.
NotchFilterIndex
[in] Specifies notch filter index. Possible values are: 0, 1.
Frequency
[out] Pointer to a variable that receives the current center frequency of the notch filter. This parameter cannot be NULL.

Return value

If the method succeeds, the return value is non-zero.
If the method fails, the return value is zero. To get extended error information, check errno.

IG33DDCDevice::SetNotchFilterBandwidth

Specifies bandwidth of the notch filter for given channel.

C/C++ declaration

int  SetNotchFilterBandwidth(uint32_t Channel,uint32_t NotchFilterIndex,uint32_t Bandwidth);

Parameters

Channel
[in] Specifies channel index. Possible values are: 0, 1, 2.
NotchFilterIndex
[in] Specifies notch filter index. Possible values are: 0, 1.
Bandwidth
[in] Specifies new bandwidth of the notch filter in Hz. The bandwidth can be in the range of 1 - 3000 Hz.

Return value

If the method succeeds, the return value is non-zero.
If the method fails, the return value is zero. To get extended error information, check errno.

Remarks

Use the IG33DDCDevice::GetNotchFilterBandwidth method to retrieve the current bandwidth of the notch filter.


IG33DDCDevice::GetNotchFilterBandwidth

Retrieves the current bandwidth of the notch filter for given channel.

C/C++ declaration

int  GetNotchFilterBandwidth(uint32_t Channel,uint32_t NotchFilterIndex,uint32_t *Bandwidth);

Parameters

Channel
[in] Specifies channel index. Possible values are: 0, 1, 2.
NotchFilterIndex
[in] Specifies notch filter index. Possible values are: 0, 1.
Bandwidth
[out] Pointer to a variable that receives the current bandwidth of the notch filter. This parameter cannot be NULL.

Return value

If the method succeeds, the return value is non-zero.
If the method fails, the return value is zero. To get extended error information, check errno.

IG33DDCDevice::SetNotchFilterLength

Specifies notch filter length for given channel. The notch filter is implemented as FIR filter. This method specifies number of coefficients used in filtration procedure.

C/C++ declaration

int  SetNotchFilterLength(uint32_t Channel,uint32_t NotchFilterIndex,uint32_t Length);

Parameters

Channel
[in] Specifies channel index. Possible values are: 0, 1, 2.
NotchFilterIndex
[in] Specifies notch filter index. Possible values are: 0, 1.
Length
[in] Specifies length of the notch filter. The value has to be a multiple of 64, greater than or equal to 64 and less than or equal to 32768. If it is not a multiple of 64 the method rounds it up to nearest a multiple of 64.

Return value

If the method succeeds, the return value is non-zero.
If the method fails, the return value is zero. To get extended error information, check errno.

Remarks

Increasing the filter length increases filter steepness and it may increase CPU usage.

Use the IG33DDCDevice::GetNotchFilterLength method to determine the current length of the notch filter.


IG33DDCDevice::GetNotchFilterLength

Retrieves the current notch filter length for given channel.

C/C++ declaration

int  GetNotchFilterLength(uint32_t Channel,uint32_t NotchFilterIndex,uint32_t *Length);

Parameters

Channel
[in] Specifies channel index. Possible values are: 0, 1, 2.
NotchFilterIndex
[in] Specifies notch filter index. Possible values are: 0, 1.
Length
[out] Pointer to a variable that receives the current length of the notch filter. This parameter cannot be NULL.

Return value

If the method succeeds, the return value is non-zero.
If the method fails, the return value is zero. To get extended error information, check errno.

IG33DDCDevice::SetAGC

Enables or disables AGC for given channel.

C/C++ declaration

int  SetAGC(uint32_t Channel,int Enabled);

Parameters

Channel
[in] Specifies channel index. Possible values are: 0, 1, 2.
Enabled
[in] Specifies whether to enable or disable AGC. If this parameter is non-zero, the AGC is enabled. If the parameter is zero, the AGC is disabled.

Return value

If the method succeeds, the return value is non-zero.
If the method fails, the return value is zero. To get extended error information, check errno.

Remarks

If the AGC is disabled, the signal is affected by fixed gain specified using the IG33DDCDevice::SetGain method.

Use the IG33DDCDevice::GetAGC method to determine the current state of the AGC.


IG33DDCDevice::GetAGC

Retrieves the current state of the AGC for given channel.

C/C++ declaration

int  GetAGC(uint32_t Channel,int *Enabled);

Parameters

Channel
[in] Specifies channel index. Possible values are: 0, 1, 2.
Enabled
[out] Pointer to a variable that receives the current state of the AGC. The value is non-zero if the AGC is enabled and zero if it is disabled. This parameter cannot be NULL.

Return value

If the method succeeds, the return value is non-zero.
If the method fails, the return value is zero. To get extended error information, check errno.

IG33DDCDevice::SetAGCParams

Sets parameters of the AGC for given channel.

C/C++ declaration

int  SetAGCParams(uint32_t Channel,double AttackTime,double DecayTime,double ReferenceLevel);

Parameters

Channel
[in] Specifies channel index. Possible values are: 0, 1, 2.
AttackTime
[in] Specifies new attack time of the AGC in seconds.
DecayTime
[in] Specifies new decay time of the AGC in seconds.
ReferenceLevel
[in] Specifies new reference level of the AGC in dB.

Return value

If the method succeeds, the return value is non-zero.
If the method fails, the return value is zero. To get extended error information, check errno.

Remarks

Use the IG33DDCDevice::GetAGCParams method to determine the current parameters of the AGC.


IG33DDCDevice::GetAGCParams

Retrieves the current parameters of the AGC for given channel.

C/C++ declaration

int  GetAGCParams(uint32_t Channel,double *AttackTime,double *DecayTime,double *ReferenceLevel);

Parameters

Channel
[in] Specifies channel index. Possible values are: 0, 1, 2.
AttackTime
[out] Pointer to a variable that receives the current attack time of the AGC in seconds. This parameter can be NULL if the application does not require this information.
DecayTime
[out] Pointer to a variable that receives the current decay time of the AGC in seconds. This parameter can be NULL if the application does not require this information.
ReferenceLevel
[out] Pointer to a variable that receives the current reference level of the AGC in dB. This parameter can be NULL if the application does not require this information.

Return value

If the method succeeds, the return value is non-zero.
If the method fails, the return value is zero. To get extended error information, check errno.

IG33DDCDevice::SetMaxAGCGain

Sets maximum gain of the AGC for given channel.

C/C++ declaration

int  SetMaxAGCGain(uint32_t Channel,double MaxGain);

Parameters

Channel
[in] Specifies channel index. Possible values are: 0, 1, 2.
MaxGain
[in] Specifies new maximum gain of the AGC in dB.

Return value

If the method succeeds, the return value is non-zero.
If the method fails, the return value is zero. To get extended error information, check errno.

Remarks

Use the IG33DDCDevice::GetMaxAGCGain method to determine maximum gain of the AGC.


IG33DDCDevice::GetMaxAGCGain

Retrieves the current maximum gain of the AGC for given channel.

C/C++ declaration

int  GetMaxAGCGain(uint32_t Channel,double *MaxGain);

Parameters

Channel
[in] Specifies channel index. Possible values are: 0, 1, 2.
MaxGain
[out] Pointer to a variable that receives the current maximum gain of the AGC in dB. This parameter cannot be NULL.

Return value

If the method succeeds, the return value is non-zero.
If the method fails, the return value is zero. To get extended error information, check errno.

IG33DDCDevice::SetGain

Sets fixed gain for given channel. This gain is applied to I/Q signal if the AGC is disabled, otherwise it is not used.

C/C++ declaration

int  SetGain(uint32_t Channel,double Gain);

Parameters

Channel
[in] Specifies channel index. Possible values are: 0, 1, 2.
Gain
[in] Specifies new fixed gain in dB.

Return value

If the method succeeds, the return value is non-zero.
If the method fails, the return value is zero. To get extended error information, check errno.

Remarks

Use the IG33DDCDevice::GetGain method to determine the current fixed gain.


IG33DDCDevice::GetGain

Retrieves the current fixed gain for given channel.

C/C++ declaration

int  GetGain(uint32_t Channel,double *Gain);

Parameters

Channel
[in] Specifies channel index. Possible values are: 0, 1, 2.
Gain
[out] Pointer to a variable that receives the current fixed gain in dB. This parameter cannot be NULL.

Return value

If the method succeeds, the return value is non-zero.
If the method fails, the return value is zero. To get extended error information, check errno.

IG33DDCDevice::GetCurrentGain

Retrieves the current gain that is applied to I/Q signal.

C/C++ declaration

int  GetCurrentGain(uint32_t Channel,double *CurrentGain);

Parameters

Channel
[in] Specifies channel index. Possible values are: 0, 1, 2.
CurrentGain
[out] Pointer to a variable that receives the current gain in dB. This parameter cannot be NULL.

Return value

If the method succeeds, the return value is non-zero.
If the method fails, the return value is zero. To get extended error information, check errno.

Remarks

If the AGC is enabled (using the IG33DDCDevice::SetAGC method), the variable pointed to by the CurrentGain parameter is filled by the current gain of the AGC. If the AGC is disabled, the variable pointed to by the CurrentGain parameter is filled by fixed gain that is specified using the IG33DDCDevice::SetGain method.

IG33DDCDevice::SetDemodulatorFilterBandwidth

Sets bandwidth of the demodulator filter for given channel.

C/C++ declaration

int  SetDemodulatorFilterBandwidth(uint32_t Channel,uint32_t Bandwidth);

Parameters

Channel
[in] Specifies channel index. Possible values are: 0, 1, 2.
Bandwidth
[in] Specified new bandwidth of the demodulator filter in Hz. Possible values are from the range 1 Hz to the current DDC2 bandwidth. Use the IG33DDCDevice::GetDDC2 method to retrieve information about the current DDC type of DDC2.

Return value

If the method succeeds, the return value is non-zero.
If the method fails, the return value is zero. To get extended error information, check errno.

Remarks

The demodulator filter bandwidth can be changed using the IG33DDCDevice::SetDDC1 method. It can change DDC type of DDC2 and if the current demodulator filter bandwidth is greater than new bandwidth of DDC2, the demodulator filter bandwidth is reduced. So it is useful to call the IG33DDCDevice::GetDemodulatorFilterBandwidth method immediately after IG33DDCDevice::SetDDC1.

IG33DDCDevice::GetDemodulatorFilterBandwidth

Retrieves the current demodulator filter bandwidth for given channel.

C/C++ declaration

int  GetDemodulatorFilterBandwidth(uint32_t Channel,uint32_t *Bandwidth);

Parameters

Channel
[in] Specifies channel index. Possible values are: 0, 1, 2.
Bandwidth
[out] Pointer to a variable that receives the current demodulator filter bandwidth. This parameter cannot be NULL.

Return value

If the method succeeds, the return value is non-zero.
If the method fails, the return value is zero. To get extended error information, check errno.

IG33DDCDevice::SetDemodulatorFilterShift

Sets demodulator filter shift for given channel.

C/C++ declaration

int  SetDemodulatorFilterShift(uint32_t Channel,int32_t Shift);

Parameters

Channel
[in] Specifies channel index. Possible values are: 0, 1, 2.
Shift
[in] Specified new shift of the demodulator filter in Hz.

Return value

If the method succeeds, the return value is non-zero.
If the method fails, the return value is zero. To get extended error information, check errno.

Remarks

Value of the Shift parameter is shift in Hz relative to center of the demodulator. This value can be negative.

This method does not change demodulator frequency just shift the filter from demodulator's centre.

Use the IG33DDCDevice::GetDemodulatorFilterShift method to determine the current demodulator filter shift.


IG33DDCDevice::GetDemodulatorFilterShift

Retrieves the current shift of the demodulator filter for given channel.

C/C++ declaration

int  GetDemodulatorFilterShift(uint32_t Channel,int32_t *Shift);

Parameters

Channel
[in] Specifies channel index. Possible values are: 0, 1, 2.
Shift
[out] Pointer to a variable that receives the current shift of the demodulator. This parameter cannot be NULL.

Return value

If the method succeeds, the return value is non-zero.
If the method fails, the return value is zero. To get extended error information, check errno.

IG33DDCDevice::SetDemodulatorFilterLength

Specifies demodulator filter length for given channel. The demodulator filter is implemented as FIR filter. This method specifies number of coefficients used in filtration procedure.

C/C++ declaration

int  SetDemodulatorFilterLength(uint32_t Channel,uint32_t Length);

Parameters

Channel
[in] Specifies channel index. Possible values are: 0, 1, 2.
Length
[in] Specifies length of the demodulator filter. The value has to be a multiple of 64, greater than or equal to 64 and less than or equal to 32768. If it is not a multiple of 64 the method rounds it up to nearest a multiple of 64.

Return value

If the method succeeds, the return value is non-zero.
If the method fails, the return value is zero. To get extended error information, check errno.

Remarks

Increasing the filter length increases filter steepness and it may increase CPU usage.

Use the IG33DDCDevice::GetDemodulatorFilterLength method to determine the current length of the demodulator filter.


IG33DDCDevice::GetDemodulatorFilterLength

Retrieves the current length of the demodulator filter for given channel.

C/C++ declaration

int  GetDemodulatorFilterLength(uint32_t Channel,uint32_t *Length);

Parameters

Channel
[in] Specifies channel index. Possible values are: 0, 1, 2.
Length
[out] Pointer to a variable that receives the current demodulator filter length. This parameter cannot be NULL.

Return value

If the method succeeds, the return value is non-zero.
If the method fails, the return value is zero. To get extended error information, check errno.

IG33DDCDevice::SetDemodulatorMode

Sets demodulator mode for given channel.

C/C++ declaration

int  SetDemodulatorMode(uint32_t Channel,uint32_t Mode);

Parameters

Channel
[in] Specifies channel index. Possible values are: 0, 1, 2.
Mode
[in] Specifies new demodulator mode. This value can be one of the following:

ValueMeaning
G3XDDC_MODE_CWContinuous wave
G3XDDC_MODE_AMAmplitude modulation
G3XDDC_MODE_FMFrequency modulation
G3XDDC_MODE_LSBLower sideband modulation
G3XDDC_MODE_USBUpper sideband modulation
G3XDDC_MODE_AMSAmplitude modulation
G3XDDC_MODE_DSBDouble sideband modulation
G3XDDC_MODE_ISBIndependent sideband modulation

Return value

If the method succeeds, the return value is non-zero.
If the method fails, the return value is zero. To get extended error information, check errno.

IG33DDCDevice::GetDemodulatorMode

Retrieves the current demodulator mode for given channel.

C/C++ declaration

int  GetDemodulatorMode(uint32_t Channel,uint32_t *Mode);

Parameters

Channel
[in] Specifies channel index. Possible values are: 0, 1, 2.
Mode
[out] Pointer to a variable that receives the current demodulator mode. This parameter cannot be NULL.

Return value

If the method succeeds, the return value is non-zero.
If the method fails, the return value is zero. To get extended error information, check errno.

IG33DDCDevice::SetDemodulatorFrequency

Sets relative center frequency of demodulator for given channel.

C/C++ declaration

int  SetDemodulatorFrequency(uint32_t Channel,int32_t Frequency);

Parameters

Channel
[in] Specifies channel index. Possible values are: 0, 1, 2.
Frequency
[in] Specified new center frequency of the demodulator in Hz.

Return value

If the method succeeds, the return value is non-zero.
If the method fails, the return value is zero. To get extended error information, check errno.

Remarks

Value of the Frequency parameter is center frequency of the demodulator relative to center of the DDC2. The value can be negative.

Absolute frequency of the demodulator is given by the following formula:

faDEM[i] = fDDC1 + frDDC2[i] + frDEM[i]

Where faDEM[i] is absolute center frequency of the demodulator of i-th channel in Hz, fDDC1 is center frequency of the DDC1 in Hz (set using the IG33DDCDevice::SetDDC1Frequency method), frDDC2[i] is relative center frequency of DDC2 of i-th channel in Hz (set using the IG33DDCDevice::SetDDC2Frequency) and frDEM[i] is relative center frequency of the demodulator of i-th channel in Hz (set using SetDemodulatorFrequency).

Absolute center frequency of the demodulator is the real-world frequency that you are listening to.

Use the IG33DDCDevice::GetDemodulatorFrequency method to determine the current relative center frequency of the demodulator for given channel.

The following example shows four methods how it is possible to set absolute demodulator center frequency of channel 0 to 11.01 MHz:

IG33DDCDevice *Device; //Interface of G33DDC device object, created using the CreateInstance function

//1. method
Device->SetDDC1Frequency(11010000);
Device->SetDDC2Frequency(0,0);
Device->SetDemodulatorFrequency(0,0);

//2. method, usable if DDC2 bandwidth is less than DDC1 bandwidth
Device->SetDDC1Frequency(11000000);
Device->SetDDC2Frequency(0,10000);
Device->SetDemodulatorFrequency(0,0);

//3. method, usable if DDC2 bandwidth is less than DDC1 bandwidth,
//and demodulator filter bandwidth is less than DDC2 bandwidth
Device->SetDDC1Frequency(11020000);
Device->SetDDC2Frequency(0,-5000);
Device->SetDemodulatorFrequency(0,-5000);

//4. method
Device->SetFrequency(0,11010000); 
//The SetFrequency method sets DDC1, DDC2 and demodulator
//center frequencies so that demodulator's absolute frequency is set to the required frequency

IG33DDCDevice::GetDemodulatorFrequency

Retrieves the current relative center frequency of the demodulator for given channel.

C/C++ declaration

int  GetDemodulatorFrequency(uint32_t Channel,int32_t *Frequency);

Parameters

Channel
[in] Specifies channel index. Possible values are: 0, 1, 2.
Frequency
[out] Pointer to a variable that receives the current center frequency of the demodulator. This parameter cannot be NULL.

Return value

If the method succeeds, the return value is non-zero.
If the method fails, the return value is zero. To get extended error information, check errno.

IG33DDCDevice::SetDemodulatorParam

Sets a parameter of the demodulation for given channel.

C/C++ declaration

int  SetDemodulatorParam(uint32_t Channel,uint32_t Code,const void *Buffer,uint32_t BufferSize);

Parameters

Channel
[in] Specifies channel index. Possible values are: 0, 1, 2.
Code
[in] Specifies code of the demodulator parameter to be set by the method. The code can be one of the following:

ValueMeaning
G3XDDC_DEMODULATOR_PARAM_AMS_SIDE_BAND

Side band for synchronous AM demodulation.

The Buffer parameter has to be a pointer to an uint32_t variable, and the BufferSize parameter has to be sizeof(Uint32_t).

Value of the variable pointed to by the Buffer parameter can be one of the following:

G3XDDC_SIDE_BAND_LOWER
AMS demodulator will use lower sideband

G3XDDC_SIDE_BAND_UPPER
AMS demodulator will use upper sideband

G3XDDC_SIDE_BAND_BOTH
AMS demodulator will use both side bands.

G3XDDC_DEMODULATOR_PARAM_AMS_CAPTURE_RANGE

Capture range of synchronous AM demodulator.

The Buffer parameter has to be a pointer to a G3XDDC_AMS_CAPTURE_RANGE structure, and the BufferSize parameter has to be sizeof(G3XDDC_AMS_CAPTURE_RANGE).

G3XDDC_DEMODULATOR_PARAM_CW_FREQUENCY

CW tone frequency

The Buffer parameter has to be a pointer to an int32_t variable, and the BufferSize parameter has to be sizeof(int32_t).

Value of the variable pointed to by the Buffer parameter is CW tone frequency in Hz.

G3XDDC_DEMODULATOR_PARAM_DSB_SIDE_BAND

Side band for DSB demodulation.

The Buffer parameter has to be a pointer to an uint32_t variable, and the BufferSize parameter has to be sizeof(Uint32_t).

Value of the variable pointed to by the Buffer parameter can be one of the following:

G3XDDC_SIDE_BAND_LOWER
DSB demodulator will use lower sideband

G3XDDC_SIDE_BAND_UPPER
DSB demodulator will use upper sideband

G3XDDC_SIDE_BAND_BOTH
DSB demodulator will use both side bands.

G3XDDC_DEMODULATOR_PARAM_ISB_SIDE_BAND

Side band for ISB demodulation.

The Buffer parameter has to be a pointer to an uint32_t variable, and the BufferSize parameter has to be sizeof(Uint32_t).

Value of the variable pointed to by the Buffer parameter can be one of the following:

G3XDDC_SIDE_BAND_LOWER
ISB demodulator will use lower sideband

G3XDDC_SIDE_BAND_UPPER
ISB demodulator will use upper sideband

G3XDDC_SIDE_BAND_BOTH
ISB demodulator will use both side bands.

Buffer
[in] Pointer to a buffer containing value of the demodulator parameter the method will set. This parameter cannot be NULL.
BufferSize
[in] Specifies the size of the buffer.

Return value

If the method succeeds, the return value is non-zero.
If the method fails, the return value is zero. To get extended error information, check errno.

IG33DDCDevice::GetDemodulatorParam

Retrieves a parameter of the demodulation for given channel.

C/C++ declaration

int  GetDemodulatorParam(uint32_t Channel,uint32_t Code,void *Buffer,uint32_t BufferSize);

Parameters

Channel
[in] Specifies channel index. Possible values are: 0, 1, 2.
Code
[in] Specifies code of the demodulator parameter to be retrieved. For detailed information about available codes see IG33DDCDevice::SetDemodulatorParam.
Buffer
[out] Pointer to a buffer that receives requested parameter. This parameter cannot be NULL.
BufferSize
[in] Specifies the size of the buffer.

Return value

If the method succeeds, the return value is non-zero.
If the method fails, the return value is zero. To get extended error information, check errno.

IG33DDCDevice::GetDemodulatorState

Retrieves information about the current demodulator state for given channel.

C/C++ declaration

int  GetDemodulatorState(uint32_t Channel,uint32_t Code,void *Buffer,uint32_t BufferSize);

Parameters

Channel
[in] Specifies channel index. Possible values are: 0, 1, 2.
Code
[in] Specifies code of the demodulator state to be retrieved. It can be one of the following:

ValueMeaning
G3XDDC_DEMODULATOR_STATE_AMS_LOCK

Lock state of synchronous AM demodulation.

The Buffer parameter has to be a pointer to an int variable, and the BufferSize parameter has to be sizeof(BOOL).

Received value is non-zero if synchronous AM demodulator is locked to signal, and zero if it is not locked.

G3XDDC_DEMODULATOR_STATE_AMS_FREQUENCY

Frequency in Hz which synchronous AM demodulator is locked to. It is relative to center of the demodulator. It can be negative.

The Buffer parameter has to be a pointer to a double variable, and the BufferSize parameter has to be sizeof(double).

G3XDDC_DEMODULATOR_STATE_AM_DEPTH

Depth of AM modulation in %.

The Buffer parameter has to be a pointer to a double variable, and the BufferSize parameter has to be sizeof(double).

G3XDDC_DEMODULATOR_STATE_DSB_LOCK

Lock state of DSB demodulation.

The Buffer parameter has to be a pointer to an int variable, and the BufferSize parameter has to be sizeof(BOOL).

Received value is non-zero if DSB demodulator is locked to signal, and zero if it is not locked.

G3XDDC_DEMODULATOR_STATE_DSB_FREQUENCY

Frequency in Hz which DSB demodulator is locked to. It is relative to center of the demodulator. It can be negative.

The Buffer parameter has to be a pointer to a double variable, and the BufferSize parameter has to be sizeof(double).

G3XDDC_DEMODULATOR_STATE_TUNE_ERROR

Estimated tune error in Hz.

The Buffer parameter has to be a pointer to an int32_t variable, and the BufferSize parameter has to be sizeof(int32_t).

Received value is difference between demodulator frequency and frequency of received signal. Subtract the returned tune error from demodulator frequency to get frequency of the received signal. Tune error is relative to center of the demodulator and it can be negative.

G3XDDC_DEMODULATOR_STATE_FM_DEVIATION

Estimated frequency deviation in Hz.

The Buffer parameter has to be a pointer to an uint32_t variable, and the BufferSize parameter has to be sizeof(Uint32_t).

Buffer
[out] Pointer to a buffer that receives requested information. This parameter cannot be NULL.
BufferSize
[in] Specifies the size of the buffer.

Return value

If the method succeeds, the return value is non-zero.
If the method fails, the return value is zero. To get extended error information, check errno.

IG33DDCDevice::StartAudio

Starts audio streaming for given channel.

C/C++ declaration

int  StartAudio(uint32_t Channel,uint32_t SamplesPerBuffer);

Parameters

Channel
[in] Specifies channel index. Possible values are: 0, 1, 2.
SamplesPerBuffer
[in] Specifies number of samples in each buffer passed to the the IG33DDCDeviceCallback::G33DDC_AudioStreamCallback callback method. The value has to be a multiple of 64 greater than zero. If it is zero, the StartAudio method fails. If it is not a multiple of 64 the method rounds it up to nearest a multiple of 64.

Return value

If the method succeeds, the return value is non-zero.
If the method fails, the return value is zero. To get extended error information, check errno.

Remarks

Before StartAudio is used, the G33DDC device has to be turned on using the IG33DDCDevice::SetPower method and DDC1 streaming has to be started using the IG33DDCDevice::StartDDC1 or IG33DDCDevice::StartDDC1Playback method and DDC2 streaming has to be started using the IG33DDCDevice::StartDDC2 method, otherwise StartAudio fails.

If the audio streaming for given channel is already running, StartAudio restarts it except the streaming was previously started with the same SamplesPerBuffer parameter. In this case StartAudio does nothing.

Use the IG33DDCDevice::StopAudio method to stop audio streaming.

Decreasing value of the SamplesPerBuffer parameter decreases latency and it may increase CPU usage. Increasing the value of the SamplesPerBuffer parameter increases latency and may decrease CPU usage.


IG33DDCDevice::StopAudio

Stops audio streaming for given channel.

C/C++ declaration

int  StopAudio(uint32_t Channel);

Parameters

Channel
[in] Specifies channel index. Possible values are: 0, 1, 2.

Return value

If the method succeeds, the return value is non-zero.
If the method fails, the return value is zero. To get extended error information, check errno.

Remarks

If audio streaming is not active, StopAudio does nothing.

If audio playback (started using the IG33DDCDevice::StartAudioPlayback method) is active, StopAudio stops it.

The IG33DDCDeviceCallback::G33DDC_AudioStreamCallback and IG33DDCDeviceCallback::G33DDC_AudioPlaybackStreamCallback callback methods are not called after StopAudio returns.


IG33DDCDevice::StartAudioPlayback

Starts audio playback for given channel. It allows to pass previously recorded audio samples to the processing chain instead of the samples from the demodulator.

C/C++ declaration

int  StartAudioPlayback(uint32_t Channel,uint32_t SamplesPerBuffer);

Parameters

Channel
[in] Specifies channel index. Possible values are: 0, 1, 2.
SamplesPerBuffer
[in] Specifies number of samples in each buffer passed to the IG33DDCDeviceCallback::G33DDC_AudioPlaybackStreamCallback callback to fill the buffer by the application and to the IG33DDCDeviceCallback::G33DDC_AudioStreamCallback callback methods. The value has to be a multiple of 64 greater than zero. If it is zero, the StartAudioPlayback method fails. If it is not a multiple of 64 the method rounds it up to nearest a multiple of 64.

Return value

If the method succeeds, the return value is non-zero.
If the method fails, the return value is zero. To get extended error information, check errno.

Remarks

The G33DDC device has to be turned on using IG33DDCDevice::SetPower method before use of StartDDC1Playback.

The StartDDC1Playback method stops audio streaming that was previously started by the IG33DDCDevice::StartAudio or IG33DDCDevice::StartAudioPlayback method and starts audio playback with new parameters.

Use the IG33DDCDevice::StopAudio method to stop audio playback.


IG33DDCDevice::PauseAudioPlayback

Pauses audio playback for given channel.

C/C++ declaration

int  PauseAudioPlayback(UINT23 Channel);

Parameters

Channel
[in] Specifies channel index. Possible values are: 0, 1, 2.

Return value

If the method succeeds, the return value is non-zero.
If the method fails, the return value is zero. To get extended error information, check errno.

Remarks

If audio playback is not active or it is already paused, PauseAudioPlayback does nothing.

The IG33DDCDeviceCallback::G33DDC_AudioPlaybackStreamCallback and IG33DDCDeviceCallback::G33DDC_AudioStreamCallback callback methods can be called once after PauseAudioPlayback returns. Then they are not called until playback is resumed using the IG33DDCDevice::ResumeAudioPlayback method.


IG33DDCDevice::ResumeAudioPlayback

Resumes paused audio playback for given channel.

C/C++ declaration

int  ResumeAudioPlayback(uint32_t Channel);

Parameters

Channel
[in] Specifies channel index. Possible values are: 0, 1, 2.

Return value

If the method succeeds, the return value is non-zero.
If the method fails, the return value is zero. To get extended error information, check errno.

Remarks

If audio playback is not active or it is not paused, ResumeAudioPlayback does nothing.


IG33DDCDevice::SetAudioGain

Sets fixed audio gain for given channel.

C/C++ declaration

int  SetAudioGain(uint32_t Channel,double Gain);

Parameters

Channel
[in] Specifies channel index. Possible values are: 0, 1, 2.
Gain
[in] Specifies new fixed audio gain in dB.

Return value

If the method succeeds, the return value is non-zero.
If the method fails, the return value is zero. To get extended error information, check errno.

Remarks

Use the IG33DDCDevice::GetAudioGain method to retrieve the current audio gain.

IG33DDCDevice::GetAudioGain

Retrieves the current fixed audio gain for given channel.

C/C++ declaration

int  GetAudioGain(uint32_t Channel,double *Gain);

Parameters

Channel
[in] Specifies channel index. Possible values are: 0, 1, 2.
Gain
[out] Pointer to a variable that receives the current fixed gain in dB. This parameter cannot be NULL.

Return value

If the method succeeds, the return value is non-zero.
If the method fails, the return value is zero. To get extended error information, check errno.

IG33DDCDevice::SetAudioFilter

Enabled or disables audio filter for given channel.

C/C++ declaration

int  SetAudioFilter(uint32_t Channel,int Enabled);

Parameters

Channel
[in] Specifies channel index. Possible values are: 0, 1, 2.
Enabled
[in] Specifies whether to enable or disable audio filter. If this parameter is non-zero, the filter is enabled. If the parameter is zero, the filter is disabled.

Return value

If the method succeeds, the return value is non-zero.
If the method fails, the return value is zero. To get extended error information, check errno.

Remarks

Use the IG33DDCDevice::GetAudioFiler method to retrieve the current state of the audio filter.

IG33DDCDevice::GetAudioFilter

Retrieves the current state of the audio filter for given channel.

C/C++ declaration

int  GetAudioFilter(uint32_t Channel,int *Enabled);

Parameters

Channel
[in] Specifies channel index. Possible values are: 0, 1, 2.
Enabled
[out] Pointer to a variable that receives the current state of the audio filter. The value is non-zero if the filter is enabled and zero if it is disabled. This parameter cannot be NULL.

Return value

If the method succeeds, the return value is non-zero.
If the method fails, the return value is zero. To get extended error information, check errno.

IG33DDCDevice::SetAudioFilterParams

Sets parameters of the audio filter for given channel.

C/C++ declaration

int  SetAudioFilterParams(uint32_t Channel,uint32_t CutOffLow,uint32_t CutOffHigh,double Deemphasis);

Parameters

Channel
[in] Specifies channel index. Possible values are: 0, 1, 2.
CutOffLow
[in] Specifies cut-off low frequency of the filter in Hz. This is the start frequency of filter's passband, it can be in the range of 0 to 23999 Hz. The value has to be less then the cut-off high frequency specified by the CutOffHigh parameter.
CutOffHigh
[in] Specifies cut-off high frequency of the filter in Hz. This is the end frequency of filter's passband it can be in the range of 1 - 24000 Hz. The value has to be greater than the cut-off low frequency specified by the CutOffLow parameter.
Deemphasis
[in] Specifies de-emphasis the filter in dB per octave. De-emphasis starts at cut-off low frequency of the filter. This value can be in the range -9.9 to 0.0 dB/octave. Zero means the de-emphasis is disabled.

Return value

If the method succeeds, the return value is non-zero.
If the method fails, the return value is zero. To get extended error information, check errno.

Remarks

Use the IG33DDCDevice::GetAudioFilerParams method to retrieve the current parameters of the audio filter.

IG33DDCDevice::GetAudioFilterParams

Retrieves the current parameters of the audio filter for given channel.

C/C++ declaration

int  GetAudioFilterParams(uint32_t Channel,uint32_t *CutOffLow,uint32_t *CutOffHigh,double *Deemphasis);

Parameters

Channel
[in] Specifies channel index. Possible values are: 0, 1, 2.
CutOffLow
[out] Pointer to a variable that receives the current cut-off low frequency of the filter. This parameter can be NULL if the application does not require this information.
CutOffHigh
[out] Pointer to a variable that receives the current cut-off high frequency of the filter. This parameter can be NULL if the application does not require this information.
Deemphasis
[out] Pointer to a variable that receives the current de-emphasis setting of the filter. This parameter can be NULL if the application does not require this information.

Return value

If the method succeeds, the return value is non-zero.
If the method fails, the return value is zero. To get extended error information, check errno.

IG33DDCDevice::SetAudioFilterLength

Specifies audio filter length for given channel. The audio filter is implemented as FIR filter. This method specifies number of coefficients used in filtration procedure.

C/C++ declaration

int  SetAudioFilterLength(uint32_t Channel,uint32_t Length);

Parameters

Channel
[in] Specifies channel index. Possible values are: 0, 1, 2.
Length
[in] Specifies length of the audio filter. The value has to be a multiple of 64, greater than or equal to 64 and less than or equal to 32768. If it is not a multiple of 64 the method rounds it up to nearest a multiple of 64.

Return value

If the method succeeds, the return value is non-zero.
If the method fails, the return value is zero. To get extended error information, check errno.

Remarks

Increasing the filter length increases filter steepness and may increase CPU usage.

Use the IG33DDCDevice::GetAudioFilterLength method to determine the current length of the audio filter.


IG33DDCDevice::GetAudioFilterLength

Retrieves the current audio filter length for given channel.

C/C++ declaration

int  GetAudioFilterLength(uint32_t Channel,uint32_t *Length);

Parameters

Channel
[in] Specifies channel index. Possible values are: 0, 1, 2.
Length
[out] Pointer to a variable that receives the current length of the audio filter. This parameter cannot be NULL.

Return value

If the method succeeds, the return value is non-zero.
If the method fails, the return value is zero. To get extended error information, check errno.

IG33DDCDevice::SetVolume

Sets audio volume for given channel.

C/C++ declaration

int  SetVolume(uint32_t Channel,uint8_t Volume);

Parameters

Channel
[in] Specifies channel index. Possible values are: 0, 1, 2.
Volume
[in] Specifies new volume. The value can vary from 0 to 31, where 31 means maximum volume.

Return value

If the method succeeds, the return value is non-zero.
If the method fails, the return value is zero. To get extended error information, check errno.

Remarks

Use the IG33DDCDevice::GetVolume method to retrieve the current volume.


IG33DDCDevice::GetVolume

Retrieve the current volume for given channel.

C/C++ declaration

int  GetVolume(uint32_t Channel,uint8_t *Volume);

Parameters

Channel
[in] Specifies channel index. Possible values are: 0, 1, 2.
Volume
[out] Pointer to a variable that receives the current volume. This parameter cannot be NULL.

Return value

If the method succeeds, the return value is non-zero.
If the method fails, the return value is zero. To get extended error information, check errno.

IG33DDCDevice::SetMute

Mutes or unmutes audio.

C/C++ declaration

int  SetMute(uint32_t Channel,int Mute);

Parameters

Channel
[in] Specifies channel index. Possible values are: 0, 1, 2.
Mute
[in] Specifies whether to mute or unmute audio. If this parameter is non-zero, the audio is muted. If the parameter is zero, the audio is unmuted.

Return value

If the method succeeds, the return value is non-zero.
If the method fails, the return value is zero. To get extended error information, check errno.

Remarks

Use the IG33DDCDevice::GetMute method to retrieve the current mute state.


IG33DDCDevice::GetMute

Retrieves the current mute state for given channel.

C/C++ declaration

int  GetMute(uint32_t Channel,int *Mute);

Parameters

Channel
[in] Specifies channel index. Possible values are: 0, 1, 2.
Mute
[out] Pointer to a variable that receives the current mute state. This parameter cannot be NULL.

Return value

If the method succeeds, the return value is non-zero.
If the method fails, the return value is zero. To get extended error information, check errno.

IG33DDCDevice::SetFrequency

Sets absolute frequency of the demodulator for given channel.

C/C++ declaration

int  SetFrequency(uint32_t Channel,uint32_t Frequency);

Parameters

Channel
[in] Specifies channel index. Possible values are: 0, 1, 2.
Frequency
[in] Specifies new absolute frequency of the demodulator in Hz.

Return value

If the method succeeds, the return value is non-zero.
If the method fails, the return value is zero. To get extended error information, check errno.

Remarks

The method sets DDC1, DDC2 and demodulator frequencies so that new absolute frequency of the demodulator is the required one.

Absolute frequency of the demodulator is given by the following formula:

faDEM[i] = fDDC1 + frDDC2[i] + frDEM[i]

Where faDEM[i] is absolute center frequency of the demodulator of i-th channel in Hz, fDDC1 is center frequency of the DDC1 in Hz (set using the IG33DDCDevice::SetDDC1Frequency method), frDDC2[i] is relative center frequency of DDC2 of i-th channel in Hz (set using the IG33DDCDevice::SetDDC2Frequency) and frDEM[i] is relative center frequency of the demodulator of i-th channel in Hz (set using the IG33DDCDevice::SetDemodulatorFrequency method).

Absolute center frequency of the demodulator is the real-world frequency that you are listening to.

Use the IG33DDCDevice::GetFrequency method to retrieve the current absolute frequency of the demodulator.


IG33DDCDevice::GetFrequency

Determines absolute frequency of the demodulator for given channel.

C/C++ declaration

int  GetFrequency(uint32_t Channel,uint32_t *Frequency);

Parameters

Channel
[in] Specifies channel index. Possible values are: 0, 1, 2.
Frequency
[out] Pointer to a variable that receives the current absolute frequency of the demodulator. This parameter cannot be NULL.

Return value

If the method succeeds, the return value is non-zero.
If the method fails, the return value is zero. To get extended error information, check errno.

Remarks

Returned value of the variable pointed to by the Frequency parameter is sum of DDC1, DDC2 and demodulator relative frequency. For more information, see remarks of the IG33DDCDevice::SetFrequency method.

IG33DDCDevice::GetSpectrumCompensation

Determines compensation data for frequency spectrum computed from DDC1 or DDC2 signal. It is used to convert relative amplitudes in dB to absolutes ones in dBm.

C/C++ declaration

int  GetSpectrumCompensation(uint64_t CenterFrequency,uint32_t Width,float *Buffer,uint32_t Count);

Parameters

CenterFrequency
[in] Specifies absolute center frequency of requested compensation data in Hz.
Width
[in] Specifies width of requested compensation data in Hz.
Buffer
[out] Pointer to a buffer to be filled with compensation data. This parameter cannot be NULL.
Count
[in] Specifies number of float items in the buffer pointed to by the Buffer parameter.

Return value

If the method succeeds, the return value is non-zero.
If the method fails, the return value is zero. To get extended error information, check errno.

Remarks

The following example shows how to use the GetSpectrumCompensation method in IG33DDCDeviceCallback::G33DDC_DDC2StreamCallback callback:

//Let the following is prototype of a function which computes FFT from I/Q signal stored in
//the buffer pointed to be the Input parameter. Result is stored in complex form in the buffer
//pointed to by the Output parameter. Size of the FFT is given be the Size parameter.
//The example uses 2048 bins FFT.
void FFT(float *Output,const float *Input,int Size);

IG33DDCDevice *Device; //Interface to G33DDC device object
uint32_t AbsDDC2Frequency; //Absolute frequency of the DDC2
int32_t RelDDC2Frequency; //Relative frequency of the DDC2
uint32_t DDC1Frequency; //DDC1 frequency
G3XDDC_DDC_INFO DDC2Info; //Information about the current DDC type of the DDC2
float FFTBuffer[2*2048]; //Buffer for FFT result
float Compensation[2048]; //Buffer for compensation data
uint32_t FirstBin,LastBin; //the first and last bins in the FFT of useful DDC2 band
MY_CALLBACK_OBJECT MyCallbackObject; //User defined callback object implementing methods of IG33DDCDeviceCallback interface

Code before...

//Retrieve frequency of the DDC1
Device->GetDDC1Frequency(&DDC1Frequency);

//Retrieve relative frequency of the DDC2 for channel 0
Device->GetDDC2Frequency(0,&RelDDC2Frequency);

//Calculate absolute frequency of the DDC2
AbsDDC2Frequency=(int32_t)DDC1Frequency+RelDDC2Frequency;

//Retrieve DDC type information of the DDC2
Device->GetDDC2(NULL,&DDC2Info);

//Retrieve compensation data
Device->GetSpectrumCompensation(AbsDDC2Frequency,DDC2Info.SampleRate,Compensation,2048);
//In this case the Width parameter is equal to sample rate, because we need compensation data
//for whole DDC2 band.
//Compensation data have to be updated after change of absolute DDC2 frequency using
//the IG33DDCDevice::SetDDC1Frequency or IG33DDCDevice::SetDDC2Frequency method.
//In this case a mutual-exclusion synchronization method (for example critical section) should be used 
//if the Compensation buffer would be modified outside the G33DDC_DDC2StreamCallback callback.

FirstBin=2048*(DDC2Info.SampleRate-DDC2Info.Bandwidth)/2/DDC2Info.SampleRate;
LastBin=2048*(DDC2Info.SampleRate+DDC2Info.Bandwidth)/2/DDC2Info.SampleRate;

//Register callback object
Device->SetCallback(&MyCallbackObject);

//Start DDC2 streaming for channel 0
//The SamplesPerBuffer parameter is set to 2048 which is size of the FFT to simplify
//the example.
Device->StartDDC2(0,2048);

Code after...
    
void  MY_CALLBACK_OBJECT::G33DDC_DDC2StreamCallback(IG33DDCDevice *Device,uint32_t Channel,const float *Buffer,uint32_t NumberOfSamples)
{
 uint32_t i;
 
    //Compute FFT
    FFT(FFTBuffer,Buffer,2048);
    
    //Converts complex FFT result to dB
    for(i=0;i<2048;i++)
    {
        FFTBuffer[i]=(FLOAT)(10.0*log10(FFTBuffer[i*2]*FFTBuffer[i*2]+FFTBuffer[i*2+1]*FFTBuffer[i*2+1]));
    }
    
    //Apply compensation data to get amplitudes in frequency spectrum in dBm
    for(i=0;i<2048;i++)
    {
        FFTBuffer[i]+=Compensation[i];
    }
    
    //now the FFTBuffer contains amplitudes in dBm
    //Useful band starts at the bin given by the FirstBin variable
    //and ends at the bin given by the LastBin variable.
}


IG33DDCDevice::SetCallback

Registers user-defined callback object given by its interface. The API calls methods of the object to pass samples to the application. The object has to implement methods of the IG33DDCDeviceCallback interface.

C/C++ declaration

int  SetCallback(IG33DDCDeviceCallback *Callback);

Parameters

Callback
[in] Interface to user-defined object to be registered as callback object. If this parameter is NULL, the current callback object is unregistered, the API will not call any callback after SetCallback returns.

Return value

If the method succeeds, the return value is non-zero.
If the method fails, the return value is zero. To get extended error information, check errno.

IG33DDCDevice::GetCallback

Returns a pointer to the current user-defined callback object.

C/C++ declaration

IG33DDCDeviceCallback*  GetCallback(void);

Parameters

None

Return value

The method returns a pointer to the current user-defined callback object, previously set by the IG33DDCDevice::SetCallback method.

IG33DDCDeviceCallback interface

IG33DDCDeviceCallback interface is an interface of application-defined object that implements methods of the interface. The object is used to receive streamed buffers from the G33DDC device object. See IG33DDCDevice::SetCallback.

Each method of the interface is called in context of thread created by the API. If some shared data are accessed inside callback methods, it is recommended to use a mutual-exclusion synchronization method. The application should not call any G33DDC API function/method from inside method of this interface, otherwise it can cause deadlock or the application can become to unpredictable state.


IG33DDCDeviceCallback::G33DDC_IFCallback

It is called by the API to pass IF snapshots to the application. Sending of IF snapshots is started using the IG33DDCDevice::StartIF method.

C/C++ declaration

void  G33DDC_IFCallback(IG33DDCDevice *Device,const int16_t *Buffer,uint32_t NumberOfSamples,uint16_t MaxADCAmplitude,uint32_t ADCSamplingRate);

Parameters

Device
Interface of the device object which called the method.
Buffer
Pointer to the buffer which contains samples directly received from ADC. Sample rate is 100 MHz, sample is 16bit signed little endian.
NumberOfSamples
Specifies number of samples in the buffer pointed to be the Buffer parameter. This is usually 65536.
MaxADCAmplitude
Specifies maximum amplitude. Measurement of the maximum is started at the end of the previous snapshot to the current one. The possible value is 0 to 32767.
ADCSamplingRate
Specifies sample rate of the ADC in Hz. It can vary a little bit because of temperature instability.

IG33DDCDeviceCallback::G33DDC_DDC1StreamCallback

It is called by the API to pass I/Q samples from DDC1 to the application. The DDC1 streaming can be started using the IG33DDCDevice::StartDDC1 or IG33DDCDevice::StartDDC1Playback method.

C/C++ declaration

void  G33DDC_DDC1StreamCallback(IG33DDCDevice *Device,const void *Buffer,uint32_t NumberOfSamples,uint32_t BitsPerSample);

Parameters

Device
Interface of the device object which called the method.
Buffer
Pointer to the buffer which contains I/Q sample sets from DDC1. Sample rate and bits per sample is given by used DDC type, see the IG33DDCDevice::SetDDC1 method. One I/Q sample set consists of two samples.
NumberOfSamples
Specifies number of I/Q sample sets in the buffer pointed to by the Buffer parameter. This value is equal to value of the SamplesPerBuffer parameter of the IG33DDCDevice::StartDDC1 or IG33DDCDevice::StartDDC1Playback method.
BitsPerSample
Specifies number of bits per sample. It is given by DDC type used for DDC1 and it can be 16 or 32. If it is 16, sample is 16bit integer (32bits per I/Q sample set), signed, little endian, in the range of -32768 to 32767. If it is 32, sample is 32bit integer (64bits per I/Q sample set), signed, little endian, in the range -2147483648 to 2147483647.

IG33DDCDeviceCallback::G33DDC_DDC1PlaybackStreamCallback

It is called by the API to fill the buffer with I/Q samples by the applcation. The DDC1 playback can be started using the IG33DDCDevice::StartDDC1Playback method.

C/C++ declaration

int  G33DDC_DDC1PlaybackStreamCallback(IG33DDCDevice *Device,void *Buffer,uint32_t NumberOfSamples,uint32_t BitsPerSample);

Parameters

Device
Interface of the device object which called the method.
Buffer
Pointer to the buffer to be filled with I/Q sample sets. Sample rate and bits per sample is given by used DDC type, see the IG33DDCDevice::SetDDC1 method.
NumberOfSamples
Specifies number of I/Q sample sets to be stored to the buffer pointed to by the Buffer parameter. This value is equal to value of the SamplesPerBuffer parameter of the IG33DDCDevice::StartDDC1Playback method. If the application does not have requested number of sample sets, it has to fill the buffer with zeros. One I/Q sample set consists of two samples.
BitsPerSample
Specifies number of bits per sample. It is given by DDC type used for DDC1 and it can be 16 or 32. If it is 16, sample is 16bit integer (32bits per I/Q sample set), signed, little endian, in the range -32768 to 32767. If it is 32, sample is 32bit integer (64bits per I/Q sample set), signed, little endian, in the range -2147483648 to 2147483647.

Return value

The application should return non-zero to continue playback. The application should return zero to stop the API to call G33DDC_DDC1PlaybackStreamCallback again. This does not stop DDC1 playback, it has to be done explicitly by the application calling the IG33DDCDevice::StopDDC1 method from the thread in which the device object was created using the CreateInstance function. IG33DDCDevice::StopDDC1 must not be called from inside the callback.

IG33DDCDeviceCallback::G33DDC_DDC2StreamCallback

It is called by the API to pass I/Q samples from DDC2 to the application. The DDC2 streaming can be started using the IG33DDCDevice::StartDDC2 method.

C/C++ declaration

void  G33DDC_DDC2StreamCallback(IG33DDCDevice *Device,uint32_t Channel,const float *Buffer,uint32_t NumberOfSamples);

Parameters

Device
Interface of the device object which called the method.
Channel
Specifies channel index. It can be 0, 1, 2.
Buffer
Pointer to the buffer which contains I/Q sample sets from DDC2. Sample rate is given by the DDC type of the DDC2. Use the IG33DDCDevice::GetDDC2 method to determine the current DDC type of the DDC2. Sample is 32bit IEEE float in the range -1.0 to 1.0. One I/Q sample set consists of two samples.
NumberOfSamples
Specifies number of I/Q sample sets in the buffer pointed to by the Buffer parameter. This value is equal to value of the SamplesPerBuffer parameter of the IG33DDCDevice::StartDDC2 method.

IG33DDCDeviceCallback::G33DDC_DDC2PreprocessedStreamCallback

It is called by the API to pass preprocessed I/Q samples from DDC2 to the application. The samples are filtered by the demodulator filter, notch filter and affected by AGC or fixed gain. The DDC2 streaming can be started using the IG33DDCDevice::StartDDC2 method.

C/C++ declaration

void  G33DDC_DDC2PreprocessedStreamCallback(IG33DDCDevice *Device,uint32_t Channel,const float *Buffer,
    uint32_t NumberOfSamples,float SlevelPeak,float SlevelRMS);

Parameters

Device
Interface of the device object which called the method.
Channel
Specifies channel index. It can be 0, 1, 2.
Buffer
Pointer to the buffer which contains preprocessed I/Q sample sets from DDC2. Sample rate is given by the DDC type of the DDC2. Use the IG33DDCDevice::GetDDC2 method to determine the current DDC type of the DDC2. Sample is 32bit IEEE float in the range -1.0 to 1.0. One I/Q sample set consists of two samples.
NumberOfSamples
Specifies number of I/Q sample sets in the buffer pointed to by the Buffer parameter. This value is equal to value of the SamplesPerBuffer parameter of the IG33DDCDevice::StartDDC2 method.
SlevelPeak
Specifies peak signal level in Volts evaluated from samples stored in the buffer pointed to by the Buffer parameter.
SlevelRMS
Specifies RMS signal level in Volts evaluated from samples stored in the buffer pointed to by the Buffer parameter. For detailed information how to convert RMS signal level to dBm, see remarks of the IG33DDCDevice::GetSignalLevel method.

IG33DDCDeviceCallback::G33DDC_AudioStreamCallback

It is called by the API to pass audio samples to the application. The audio streaming can be started using the IG33DDCDevice::StartAudio or IG33DDCDevice::StartAudioPlayback method.

C/C++ declaration

void  G33DDC_AudioStreamCallback(IG33DDCDevice *Device,uint32_t Channel,uint32_t Type,const float *Buffer,uint32_t NumberOfSamples);

Parameters

Device
Interface of the device object which called the method.
Channel
Specifies channel index. It can be 0, 1, 2.
Type
Specifies type (stage) of audio samples stored in the buffer pointed to by the Buffer parameter. Value of this parameter can be one of the following:

ValueMeaning
0The buffer contains audio samples affected by audio gain (see IG33DDCDevice::SetAudioGain).
1The buffer contains audio samples affected by audio gain and audio filter (see IG33DDCDevice::SetAudioGain and IG33DDCDevice::SetAudioFilter).
2The buffer contains audio samples affected by audio gain, audio filter and volume (see IG33DDCDevice::SetAudioGain, IG33DDCDevice::SetAudioFilter, IG33DDCDevice::SetVolume and IG33DDCDevice::SetMute).
Buffer
Pointer to the buffer which contains samples of audio signal. The signal is mono, sample rate is 48000 Hz, sample is 32bit IEEE float in the range -1.0 to 1.0.
NumberOfSamples
Specifies number of samples stored in the buffer pointed to by the Buffer parameter. This value is equal to value of the SamplesPerBuffer parameter of the IG33DDCDevice::StartAudio or IG33DDCDevice::StartAudioPlayback method.

IG33DDCDeviceCallback::G33DDC_AudioPlaybackStreamCallback

It is called by the API to fill the buffer with audio samples by the application. The audio playback can be started using the IG33DDCDevice::StartAudioPlayback method.

C/C++ declaration

int  G33DDC_AudioPlaybackStreamCallback(IG33DDCDevice *Device,uint32_t Channel,float *Buffer,uint32_t NumberOfSamples);

Parameters

Device
Interface of the device object which called the method.
Channel
Specifies channel index. It can be 0, 1, 2.
Buffer
Pointer to the buffer to by filled with audio samples. The audio signal is mono, sample rate is 48000 Hz, sample is 32bit IEEE float in the range -1.0 to 1.0.
NumberOfSamples
Specifies number of samples in the buffer pointed to by the Buffer parameter. This value is equal to value of the SamplesPerBuffer parameter of the IG33DDCDevice::StartAudioPlayback method. If the application does not have requested number of samples, the application has to fill the buffer with zeros.

Return value

The application should return non-zero to continue playback. The application should return zero to stop the API to call G33DDC_AudioPlaybackStreamCallback again. This does not stop audio playback, it has to be done explicitly by the application calling the IG33DDCDevice::StopAudio method from the thread in which the device object was created using the CreateInstance function. IG33DDCDevice::StopAudio must not be called from inside the callback.

Structures

G33DDC_DEVICE_INFO

Contains information about G33DDC device.

C/C++ declaration

#pragma pack(push,1)

typedef struct
{
    char        DevicePath[MAX_PATH];
    uint8_t        InterfaceType;
    char        SerialNumber[9];
    uint16_t    HWVersion;
    uint16_t    FWVersion;
    uint8_t        EEPROMVersion;    
    uint32_t      Flags;
    uint32_t      ChannelCount;
    uint32_t      DDCTypeCount;   
} G33DDC_DEVICE_INFO;

#pragma pack(pop

Members

DevicePath
Device system path in a null-terminated string. It is used to open the device using object interface.
InterfaceType

Device interface type. The value can be one of the following:

G3XDDC_INTERFACE_TYPE_PCIE
The device is connected to the computer via PCI express.

G3XDDC_INTERFACE_TYPE_USB
The device is connected to the computer via USB.

SerialNumber
Serial number in null-terminated string.
HWVersion
Version of the hardware.
FWVersion
Version of the firmware.
EEPROMVersion
EEPROM structure version.
Flags
Hardware configuration flags. It can be combination of the following values:

ValueMeaning
G33DDC_FLAGS_EXTERNAL_REFERENCE_100MHZThe device supports external 100MHz reference.
G33DDC_FLAGS_EXTERNAL_REFERENCE_10MHZThe device supports external 10MHz reference.
G33DDC_FLAGS_COHERENTThe device supports coherent mode.

ChannelCount
Number of channels.
DDCTypeCount
Number of DDC types supported by the DDC1.

G3XDDC_DDC_INFO

Contains information about DDC type.

C/C++ declaration

#pragma pack(push,1)

typedef struct
{
    uint32_t  SampleRate;
    uint32_t  Bandwidth;
    uint32_t  BitsPerSample;
} G3XDDC_DDC_INFO;

#pragma pack(pop

Members

SampleRate
Sample rate of I/Q signal in Hz.
Bandwidth
Useful bandwidth in Hz.
BitsPerSample
Number of bits per sample. It can be 16 or 32. It is used to determine bits per sample for DDC1.

G3XDDC_AMS_CAPTURE_RANGE

Contains information about DDC type.

C/C++ declaration

#pragma pack(push,1)

typedef struct
{
    uint32_t  Tune;
    uint32_t  Lock;
} G3XDDC_AMS_CAPTURE_RANGE;

#pragma pack(pop

Members

Tune
Initial capture range in Hz.
Lock
Capture range (in Hz) used when AMS demodulator is locked.