private unsafe void DecodeAVIHeader(RiffParser rp, int unpaddedLength, int length)
{
//if (length < sizeof(AVIMAINHEADER))
//{
// throw new RiffParserException(String.Format("Header size mismatch. Needed {0} but only have {1}",
// sizeof(AVIMAINHEADER), length));
//}
byte[] ba = new byte[length];
if (rp.ReadData(ba, 0, length) != length)
{
throw new RiffParserException("Problem reading AVI header.");
}
fixed(Byte *bp = &ba[0])
{
AVIMAINHEADER *avi = (AVIMAINHEADER *)bp;
m_frameRate = avi->dwMicroSecPerFrame;
m_height = avi->dwHeight;
m_maxBitRate = avi->dwMaxBytesPerSec;
m_numStreams = avi->dwStreams;
m_totalFrames = avi->dwTotalFrames;
m_width = avi->dwWidth;
}
}
/// <summary>
/// Handle chunk elements found in the AVI file. Ignores unknown chunks and
/// </summary>
/// <param name="rp"></param>
/// <param name="FourCC"></param>
/// <param name="unpaddedLength"></param>
/// <param name="paddedLength"></param>
private void ProcessAVIChunk(RiffParser rp, int FourCC, int unpaddedLength, int paddedLength)
{
if (AviRiffData.ckidMainAVIHeader == FourCC)
{
// Main AVI header
DecodeAVIHeader(rp, unpaddedLength, paddedLength);
}
else if (AviRiffData.ckidAVIStreamHeader == FourCC)
{
// Stream header
DecodeAVIStream(rp, unpaddedLength, paddedLength);
}
else if (AviRiffData.ckidAVIISFT == FourCC)
{
Byte[] ba = new byte[paddedLength];
rp.ReadData(ba, 0, paddedLength);
StringBuilder sb = new StringBuilder(unpaddedLength);
for (int i = 0; i < unpaddedLength; ++i)
{
if (0 != ba[i])
{
sb.Append((char)ba[i]);
}
}
m_isft = sb.ToString();
}
else
{
// Unknon chunk - skip
rp.SkipData(paddedLength);
}
}
private unsafe void DecodeAVIStream(RiffParser rp, int unpaddedLength, int length)
{
byte[] ba = new byte[length];
if (rp.ReadData(ba, 0, length) != length)
{
throw new RiffParserException("Problem reading AVI header.");
}
fixed(Byte *bp = &ba[0])
{
AVISTREAMHEADER *avi = (AVISTREAMHEADER *)bp;
if (AviRiffData.streamtypeVIDEO == avi->fccType)
{
m_vidHandler = RiffParser.FromFourCC(avi->fccHandler);
if (avi->dwScale > 0)
{
m_vidDataRate = (double)avi->dwRate / (double)avi->dwScale;
}
else
{
m_vidDataRate = 0.0;
}
}
else if (AviRiffData.streamtypeAUDIO == avi->fccType)
{
if (AviRiffData.ckidMP3 == avi->fccHandler)
{
m_audHandler = "MP3";
}
else
{
m_audHandler = RiffParser.FromFourCC(avi->fccHandler);
}
if (avi->dwScale > 0)
{
m_audDataRate = 8.0 * (double)avi->dwRate / (double)avi->dwScale;
if (avi->dwSampleSize > 0)
{
m_audDataRate /= (double)avi->dwSampleSize;
}
}
else
{
m_audDataRate = 0.0;
}
}
}
}
private unsafe void DecodeWave(RiffParser rp, int length)
{
byte[] ba = new byte[length];
rp.ReadData(ba, 0, length);
fixed(byte *bp = &ba[0])
{
WAVEFORMATEX *wave = (WAVEFORMATEX *)bp;
m_numChannels = wave->nChannels;
m_bitsPerSec = wave->nAvgBytesPerSec;
m_bitsPerSample = wave->wBitsPerSample;
m_samplesPerSec = wave->nSamplesPerSec;
}
}
