void CAudioEncoder::Initialize (void)
{
// called from derived classes init function from the start function
// in the media flow
m_audioSrcFrameNumber = 0;
m_audioDstFrameNumber = 0;
m_audioDstSampleNumber = 0;
m_audioSrcElapsedDuration = 0;
m_audioDstElapsedDuration = 0;
// destination parameters are from the audio profile
m_audioDstType = GetFrameType();
m_audioDstSampleRate = m_pConfig->GetIntegerValue(CFG_AUDIO_SAMPLE_RATE);
m_audioDstChannels = m_pConfig->GetIntegerValue(CFG_AUDIO_CHANNELS);
m_audioDstSamplesPerFrame = GetSamplesPerFrame();
// if we need to resample
if (m_audioDstSampleRate != m_audioSrcSampleRate) {
// create a resampler for each audio destination channel -
// we will combine the channels before resampling
m_audioResample = (resample_t *)malloc(sizeof(resample_t) *
m_audioDstChannels);
for (int ix = 0; ix < m_audioDstChannels; ix++) {
m_audioResample[ix] = st_resample_start(m_audioSrcSampleRate,
m_audioDstSampleRate);
}
}
// this calculation doesn't take into consideration the resampling
// size of the src. 4 times might not be enough - we need most likely
// 2 times the max of the src samples and the dest samples
m_audioPreEncodingBufferLength = 0;
m_audioPreEncodingBufferMaxLength =
4 * DstSamplesToBytes(m_audioDstSamplesPerFrame);
m_audioPreEncodingBuffer = (u_int8_t*)realloc(
m_audioPreEncodingBuffer,
m_audioPreEncodingBufferMaxLength);
}
bool CMediaSource::SetAudioSrc(
MediaType srcType,
u_int8_t srcChannels,
u_int32_t srcSampleRate)
{
// audio source info
m_audioSrcType = srcType;
m_audioSrcChannels = srcChannels;
m_audioSrcSampleRate = srcSampleRate;
m_audioSrcSamplesPerFrame = 0; // unknown, presumed variable
// init audio encoder
delete m_audioEncoder;
m_audioEncoder = AudioEncoderCreate(
m_pConfig->GetStringValue(CONFIG_AUDIO_ENCODER));
if (m_audioEncoder == NULL) {
return false;
}
if (!m_audioEncoder->Init(m_pConfig, m_sourceRealTime)) {
delete m_audioEncoder;
m_audioEncoder = NULL;
return false;
}
m_audioDstType = m_audioEncoder->GetFrameType();
m_audioDstSamplesPerFrame =
m_audioEncoder->GetSamplesPerFrame();
// if we need to resample
if (m_audioDstSampleRate != m_audioSrcSampleRate) {
// create a resampler for each audio destination channel -
// we will combine the channels before resampling
m_audioResample = (resample_t *)malloc(sizeof(resample_t) *
m_audioDstChannels);
for (int ix = 0; ix <= m_audioDstChannels; ix++) {
m_audioResample[ix] = st_resample_start(m_audioSrcSampleRate,
m_audioDstSampleRate);
}
}
// this calculation doesn't take into consideration the resampling
// size of the src. 4 times might not be enough - we need most likely
// 2 times the max of the src samples and the dest samples
m_audioPreEncodingBufferLength = 0;
m_audioPreEncodingBufferMaxLength =
4 * DstSamplesToBytes(m_audioDstSamplesPerFrame);
m_audioPreEncodingBuffer = (u_int8_t*)realloc(
m_audioPreEncodingBuffer,
m_audioPreEncodingBufferMaxLength);
if (m_audioPreEncodingBuffer == NULL) {
delete m_audioEncoder;
m_audioEncoder = NULL;
return false;
}
return true;
}
