bool CopyWavChannel(ModSample &sample, const FileReader &file, size_t channelIndex, size_t numChannels, SampleConversion conv = SampleConversion())
{
MPT_ASSERT(sample.GetNumChannels() == 1);
MPT_ASSERT(sample.GetElementarySampleSize() == sizeof(typename SampleConversion::output_t));
const size_t offset = channelIndex * sizeof(typename SampleConversion::input_t) * SampleConversion::input_inc;
if(sample.AllocateSample() == 0 || !file.CanRead(offset))
{
return false;
}
const mpt::byte *inBuf = file.GetRawData<mpt::byte>();
CopySample<SampleConversion>(reinterpret_cast<typename SampleConversion::output_t*>(sample.pSample), sample.nLength, 1, inBuf + offset, file.BytesLeft() - offset, numChannels, conv);
return true;
}
// Remove DC offset
float RemoveDCOffset(ModSample &smp,
SmpLength iStart,
SmpLength iEnd,
const MODTYPE modtype,
CSoundFile &sndFile)
//---------------------------------------
{
if(smp.pSample == nullptr || smp.nLength < 1)
return 0;
if (iEnd > smp.nLength) iEnd = smp.nLength;
if (iStart > iEnd) iStart = iEnd;
if (iStart == iEnd)
{
iStart = 0;
iEnd = smp.nLength;
}
iStart *= smp.GetNumChannels();
iEnd *= smp.GetNumChannels();
const double dMaxAmplitude = (smp.GetElementarySampleSize() == 2) ? GetMaxAmplitude<int16>() : GetMaxAmplitude<int8>();
// step 1: Calculate offset.
OffsetData oData = {0,0,0};
if(smp.GetElementarySampleSize() == 2)
oData = CalculateOffset(static_cast<int16 *>(smp.pSample) + iStart, iEnd - iStart);
else if(smp.GetElementarySampleSize() == 1)
oData = CalculateOffset(static_cast<int8*>(smp.pSample) + iStart, iEnd - iStart);
double dMin = oData.dMin, dMax = oData.dMax, dOffset = oData.dOffset;
const float fReportOffset = (float)dOffset;
if((int)(dOffset * dMaxAmplitude) == 0)
return 0;
// those will be changed...
dMax += dOffset;
dMin += dOffset;
// ... and that might cause distortion, so we will normalize this.
const double dAmplify = 1 / MAX(dMax, -dMin);
// step 2: centralize + normalize sample
dOffset *= dMaxAmplitude * dAmplify;
if(smp.GetElementarySampleSize() == 2)
RemoveOffsetAndNormalize( static_cast<int16 *>(smp.pSample) + iStart, iEnd - iStart, dOffset, dAmplify);
else if(smp.GetElementarySampleSize() == 1)
RemoveOffsetAndNormalize( static_cast<int8 *>(smp.pSample) + iStart, iEnd - iStart, dOffset, dAmplify);
// step 3: adjust global vol (if available)
if((modtype & (MOD_TYPE_IT | MOD_TYPE_MPT)) && (iStart == 0) && (iEnd == smp.nLength * smp.GetNumChannels()))
{
CriticalSection cs;
smp.nGlobalVol = std::min((uint16)(smp.nGlobalVol / dAmplify), uint16(64));
for (CHANNELINDEX i = 0; i < MAX_CHANNELS; i++)
{
if(sndFile.m_PlayState.Chn[i].pModSample == &smp)
{
sndFile.m_PlayState.Chn[i].nInsVol = smp.nGlobalVol;
if(sndFile.m_PlayState.Chn[i].pModInstrument)
{
sndFile.m_PlayState.Chn[i].nInsVol = (smp.nGlobalVol * sndFile.m_PlayState.Chn[i].pModInstrument->nGlobalVol) >> 6;
}
}
