internal byte[] ConvertSamples(byte[] pvInSamples)
{
short[] data = null;
short[] array = AudioFormatConverter.Convert(pvInSamples, _iInFormatType, AudioCodec.PCM16);
if (_inWavFormat.nChannels == 2 && _outWavFormat.nChannels == 1)
{
data = Resample(_inWavFormat, _outWavFormat, Stereo2Mono(array), _leftMemory);
}
else if (_inWavFormat.nChannels == 1 && _outWavFormat.nChannels == 2)
{
data = Mono2Stereo(Resample(_inWavFormat, _outWavFormat, array, _leftMemory));
}
if (_inWavFormat.nChannels == 2 && _outWavFormat.nChannels == 2)
{
if (_inWavFormat.nSamplesPerSec != _outWavFormat.nSamplesPerSec)
{
short[] leftSamples;
short[] rightSamples;
SplitStereo(array, out leftSamples, out rightSamples);
data = MergeStereo(Resample(_inWavFormat, _outWavFormat, leftSamples, _leftMemory), Resample(_inWavFormat, _outWavFormat, rightSamples, _rightMemory));
}
else
{
data = array;
}
}
if (_inWavFormat.nChannels == 1 && _outWavFormat.nChannels == 1)
{
data = Resample(_inWavFormat, _outWavFormat, array, _leftMemory);
}
_eChunkStatus = Block.Middle;
return(AudioFormatConverter.Convert(data, AudioCodec.PCM16, _iOutFormatType));
}
internal bool PrepareConverter(ref WAVEFORMATEX inWavFormat, ref WAVEFORMATEX outWavFormat)
{
bool result = true;
if (inWavFormat.nSamplesPerSec <= 0 || inWavFormat.nChannels > 2 || inWavFormat.nChannels <= 0 || outWavFormat.nChannels <= 0 || outWavFormat.nSamplesPerSec <= 0 || outWavFormat.nChannels > 2)
{
throw new FormatException();
}
_iInFormatType = AudioFormatConverter.TypeOf(inWavFormat);
_iOutFormatType = AudioFormatConverter.TypeOf(outWavFormat);
if (_iInFormatType < AudioCodec.G711U || _iOutFormatType < AudioCodec.G711U)
{
throw new FormatException();
}
if (outWavFormat.nSamplesPerSec == inWavFormat.nSamplesPerSec && _iOutFormatType == _iInFormatType && outWavFormat.nChannels == inWavFormat.nChannels)
{
result = false;
}
else
{
if (inWavFormat.nSamplesPerSec != outWavFormat.nSamplesPerSec)
{
CreateResamplingFilter(inWavFormat.nSamplesPerSec, outWavFormat.nSamplesPerSec);
}
_inWavFormat = inWavFormat;
_outWavFormat = outWavFormat;
}
return(result);
}
/// <summary>
/// Description:
/// first read samples into VAPI_PCM16, then judge cases :
/// 1. STEREO -> mono + resampling
/// STEREO -> 1 mono -> reSampling
/// 2. mono -> STEREO + resampling
/// mono -> reSampling -> STEREO
/// 3. STEREO -> STEREO + resampling
/// STEREO -> 2 MONO - > reSampling -> 2 MONO -> STEREO
/// 4. mono -> mono + resampling
/// mono -> reSampling -> mono
/// </summary>
internal byte[] ConvertSamples(byte[] pvInSamples)
{
short[] pnBuff = null;
//--- Convert samples to VAPI_PCM16
short[] inSamples = AudioFormatConverter.Convert(pvInSamples, _iInFormatType, AudioCodec.PCM16);
//--- case 1
if (_inWavFormat.nChannels == 2 && _outWavFormat.nChannels == 1)
{
pnBuff = Resample(_inWavFormat, _outWavFormat, Stereo2Mono(inSamples), _leftMemory);
}
//--- case 2
else if (_inWavFormat.nChannels == 1 && _outWavFormat.nChannels == 2)
{
//--- resampling
pnBuff = Mono2Stereo(Resample(_inWavFormat, _outWavFormat, inSamples, _leftMemory));
}
//--- case 3
if (_inWavFormat.nChannels == 2 && _outWavFormat.nChannels == 2)
{
if (_inWavFormat.nSamplesPerSec != _outWavFormat.nSamplesPerSec)
{
short[] leftChannel;
short[] rightChannel;
SplitStereo(inSamples, out leftChannel, out rightChannel);
pnBuff = MergeStereo(Resample(_inWavFormat, _outWavFormat, leftChannel, _leftMemory), Resample(_inWavFormat, _outWavFormat, rightChannel, _rightMemory));
}
else
{
pnBuff = inSamples;
}
}
//--- case 4
if (_inWavFormat.nChannels == 1 && _outWavFormat.nChannels == 1)
{
pnBuff = Resample(_inWavFormat, _outWavFormat, inSamples, _leftMemory);
}
_eChunkStatus = Block.Middle;
//---Convert samples to output format
return(AudioFormatConverter.Convert(pnBuff, AudioCodec.PCM16, _iOutFormatType));
}
/// <summary>
/// Description:
/// first read samples into VAPI_PCM16, then judge cases :
/// 1. STEREO -> mono + resampling
/// STEREO -> 1 mono -> reSampling
/// 2. mono -> STEREO + resampling
/// mono -> reSampling -> STEREO
/// 3. STEREO -> STEREO + resampling
/// STEREO -> 2 MONO - > reSampling -> 2 MONO -> STEREO
/// 4. mono -> mono + resampling
/// mono -> reSampling -> mono
/// </summary>
internal bool PrepareConverter(ref WAVEFORMATEX inWavFormat, ref WAVEFORMATEX outWavFormat)
{
bool convert = true;
// Check if we can deal with the format
if (!(inWavFormat.nSamplesPerSec > 0 && inWavFormat.nChannels <= 2 && inWavFormat.nChannels > 0 && outWavFormat.nChannels > 0 && outWavFormat.nSamplesPerSec > 0 && outWavFormat.nChannels <= 2))
{
throw new FormatException();
}
_iInFormatType = AudioFormatConverter.TypeOf(inWavFormat);
_iOutFormatType = AudioFormatConverter.TypeOf(outWavFormat);
if (_iInFormatType < 0 || _iOutFormatType < 0)
{
throw new FormatException();
}
// Check if Format in == Format out
if (outWavFormat.nSamplesPerSec == inWavFormat.nSamplesPerSec && _iOutFormatType == _iInFormatType && outWavFormat.nChannels == inWavFormat.nChannels)
{
convert = false;
}
else
{
//--- need reset filter
if (inWavFormat.nSamplesPerSec != outWavFormat.nSamplesPerSec)
{
CreateResamplingFilter(inWavFormat.nSamplesPerSec, outWavFormat.nSamplesPerSec);
}
// Keep a reference to the WaveHeaderformat
_inWavFormat = inWavFormat;
_outWavFormat = outWavFormat;
}
return(convert);
}
