I'm trying to record and play some sound with Portaudio, the objective is to create a simple voip app, so i'm trying to transfer recorded data from the first client to a second client. The problem is when it comes to play the recorded sound, i either have no sound played, of a very buzzy sound, let me explain :
here are my record and play callback functions :
int recordCallback(const void *inputBuffer, void *outputBuffer, unsigned long framesPerBuffer, const PaStreamCallbackTimeInfo* timeInfo,
PaStreamCallbackFlags statusFlags, void *userData)
{
paTestData *data = (paTestData*)userData;
const SAMPLE *rptr = (const SAMPLE*)inputBuffer;
SAMPLE *wptr = &data->recordedSamples[data->frameIndex * NUM_CHANNELS];
long framesToCalc;
long i;
int finished;
unsigned long framesLeft = data->maxFrameIndex - data->frameIndex;
(void) outputBuffer;
(void) timeInfo;
(void) statusFlags;
(void) userData;
if (framesLeft < framesPerBuffer) {
framesToCalc = framesLeft;
finished = paComplete;
} else {
framesToCalc = framesPerBuffer;
finished = paContinue;
} if (inputBuffer == NULL) {
for (i = 0; i<framesToCalc; i++) {
*wptr++ = SAMPLE_SILENCE;
if (NUM_CHANNELS == 2 ) *wptr++ = SAMPLE_SILENCE;
}
} else {
for(i = 0; i<framesToCalc; i++) {
*wptr++ = *rptr++;
if( NUM_CHANNELS == 2 ) *wptr++ = *rptr++;
}
}
data->frameIndex += framesToCalc;
return finished;
}
int playCallback( const void *inputBuffer, void *outputBuffer, unsigned long framesPerBuffer, const PaStreamCallbackTimeInfo* timeInfo,
PaStreamCallbackFlags statusFlags, void *userData )
{
paTestData *data = (paTestData*)userData;
data->frameIndex = 1;
SAMPLE *rptr = &data->recordedSamples[data->frameIndex * NUM_CHANNELS];
SAMPLE *wptr = (SAMPLE*)outputBuffer;
unsigned int i = 0;
int finished;
unsigned int framesLeft = data->maxFrameIndex - data->frameIndex;
(void) inputBuffer; /* Prevent unused variable warnings. */
(void) timeInfo;
(void) statusFlags;
(void) userData;
if (framesLeft < framesPerBuffer) {
for (i = 0; i < framesLeft; i++) {
*wptr++ = *rptr++;
if (NUM_CHANNELS == 2) *wptr++ = *rptr++;
} for (; i < framesPerBuffer; i++) {
*wptr++ = 0;
if (NUM_CHANNELS == 2) *wptr++ = 0;
}
data->frameIndex += framesLeft;
finished = paComplete;
} else {
for (i = 0; i < framesPerBuffer; i++) {
*wptr++ = *rptr++;
if (NUM_CHANNELS == 2) *wptr++ = *rptr++;
}
data->frameIndex += framesPerBuffer;
finished = paContinue;
}
return finished;
}
then here are my init, record and play functions :
PortAudio::PortAudio()
{
_err = paNoError;
PaStreamParameters baseParameters = {.channelCount = 1, .sampleFormat = PA_SAMPLE_TYPE, .hostApiSpecificStreamInfo = NULL};
init();
_inputParameters = baseParameters;
_inputParameters.device = Pa_GetDefaultInputDevice();
_inputParameters.suggestedLatency = Pa_GetDeviceInfo(_inputParameters.device)->defaultLowInputLatency;
_outputParameters = baseParameters;
_outputParameters.channelCount = 2;
_outputParameters.device = Pa_GetDefaultOutputDevice();
_outputParameters.suggestedLatency = Pa_GetDeviceInfo(_outputParameters.device)->defaultLowInputLatency;
}
int PortAudio::init()
{
int i = 0;
_data.maxFrameIndex = _totalFrames = NUM_SECONDS * SAMPLE_RATE;
_data.frameIndex = 0;
_numSamples = _totalFrames * NUM_CHANNELS;
_numBytes = _numSamples * sizeof(SAMPLE);
_data.recordedSamples = (SAMPLE *) malloc(_numBytes);
if (_data.recordedSamples == NULL) {
printf("Could not allocate record array.\n");
goto Error;
} for(i = 0; i < _numSamples; i++) _data.recordedSamples[i] = 0;
_err = Pa_Initialize();
if (_err != paNoError) goto Error;
if (_inputParameters.device == paNoDevice) {
fprintf(stderr,"Error: No default input device.\n");
goto Error;
}
return 0;
Error:
return quit();
}
paTestData PortAudio::record()
{
int i = 0;
_err = Pa_OpenStream(&_stream, &_inputParameters, NULL, SAMPLE_RATE, FRAMES_PER_BUFFER, paClipOff, recordCallback, &_data);
if (_err != paNoError) goto done;
_err = Pa_StartStream(_stream);
if (_err != paNoError) goto done;
while ((_err = Pa_IsStreamActive(_stream)) == 1)
Pa_Sleep(1000);
if (_err < 0) goto done;
_err = Pa_CloseStream(_stream);
if (_err != paNoError) goto done;
_max = 0;
_average = 0.0;
for (i = 0; i< _numSamples; i++ ) {
_val = _data.recordedSamples[i];
if (_val < 0) _val = -_val;
if (_val > _max) {
_max = _val;
}
_average += _val;
}
_average = _average / (double)_numSamples;
return _data;
done:
return _data;
}
int PortAudio::play(paTestData Audio)
{
_data.frameIndex = 0;
_data = Audio;
if (_outputParameters.device == paNoDevice) {
fprintf(stderr,"Error: No default output device.\n");
goto done;
}
_err = Pa_OpenStream(
&_stream,
NULL,
&_outputParameters,
SAMPLE_RATE,
FRAMES_PER_BUFFER,
paClipOff,
playCallback,
&_data );
if (_err != paNoError) goto done;
if (_stream) {
_err = Pa_StartStream(_stream);
if (_err != paNoError ) goto done;
while ((_err = Pa_IsStreamActive(_stream)) == 1) Pa_Sleep(100);
if (_err < 0) goto done;
_err = Pa_CloseStream(_stream);
if (_err != paNoError) goto done;
}
return 0;
done:
return quit();
}
now what I'm doing to try to transfer the data is in my main :
int main(void)
{
PortAudio *audio = new PortAudio;
audio->init();
paTestData data = audio->record();
audio->play(data);
return 0;
}
Once record() returned data, the frameIndex value is the same as maxFrameIndex, when running the binary this way, it's records but nothing is played. If i try to set frameIndex to any value, it will play a horrible buzzing sound, i can't seem to find what's wrong with this.
I can't seem to find what's wrong, but I messed up something, ended up cutting the example again and it worked.