private void CalculateBitrate(Stream stream, CInterestedFrames InterestedFrames)
{
int totalTagSize = ID3v2.GetTagSize(stream);
totalTagSize += ID3v1.GetTagSize(stream);
totalTagSize += APEv2.GetTagSize(stream);
Int64 audioLength = stream.Length - totalTagSize;
_bitrate = 0;
_isVBR = null;
_frames = 0;
_totalSeconds = 0;
String step = "";
try
{
int BR, Padding;
int FrameSize;
int TotalBR = 0;
int FrameOffset = 0;
//Int64 TagOffset = 0;
bool bTrusting = true;
bool ignoreall = false;
Byte[] FH = new Byte[4];
bool mPerfect = true;
stream.Position = _headerOffset;
// if (_headerOffset > 0)
// {
// TagOffset = _headerOffset;
// }
int offset = 0;
int frameCount = 0;
int FirstBR = 0;
int audioDataSize = (int)(stream.Length - _headerOffset);
Byte[] audioData = new Byte[audioDataSize];
//Int64 startoffset = stream.Position;
int BufLen = stream.Read(audioData, 0, audioDataSize);
while (offset < BufLen - 16 && !ignoreall)
{
bool reservedlayer = false;
// Find FrameSync
if (FindFrameSync(FH, audioData, BufLen, ref FrameOffset, ref offset, ref mPerfect, ref ignoreall, ref bTrusting, ref reservedlayer))
{
FrameOffset = 0;
int bitrateIndex = FH[2] >> 4;
if (bitrateIndex <= 0 || bitrateIndex >= 15)
{
offset -= 3;
continue;
}
Padding = (FH[2] >> 1) & 0x01;
BR = GetBitrate(_mpegVersion, _mpegLayer, bitrateIndex);
if (BR == 0 || BR % 8 != 0)
{
offset -= 3;
continue;
}
//step = "last good frame @ " + String(startoffset + offset - 4) + ", frame " +
// String(_frames + 1);
// todo: put back later
/*if (InterestedFrames != NULL)
{
if (((_frames + 1) * _samplesperframe / (float)_Frequency) * 75.0 >= InterestedFrames->CurrentFrame())
{
if (_frames == 0 || InterestedFrames->NoAccomodation)
{
InterestedFrames->SetCurrentByteOffset(startoffset + offset - 4);
InterestedFrames->SetCurrentFrameOffset(_frames);
}
InterestedFrames->SetCurrentByteEndOffset(startoffset + offset - 4);
InterestedFrames->Cur += 1;
}
else
{
InterestedFrames->SetCurrentByteOffset(startoffset + offset - 4);
InterestedFrames->SetCurrentFrameOffset(_frames);
}
}*/
if (_isVBR != true)
{
if (TotalBR == 0)
{
FirstBR = BR;
}
else if (BR != FirstBR)
{
_isVBR = true;
}
}
TotalBR += BR;
FrameSize = (int)(BR * _frameSizeConst + Padding * _paddingSizeConst);
offset += FrameSize - 4;
frameCount++;
}
}// end while
if (frameCount == 0)
{
throw new InvalidDataException(String.Format("No frames found in {0}", _fileName));
}
_frames = frameCount;
if (_isVBR == null)
{
_bitrate = FirstBR;
_isVBR = false;
}
else
{
_bitrate = TotalBR / _frames;
}
if (_bitrate == 0)
{
throw new InvalidDataException(String.Format("Error determining bitrate: {0}", _fileName));
}
_totalSeconds = (audioLength / 125.0m) / _bitrate;
}
catch (Exception ex)
{
throw new Exception(String.Format("Error calculating bitrate; {0}", step), ex);
}
}
private void CalculateBitrate(Stream stream, CInterestedFrames InterestedFrames)
{
int totalTagSize = ID3v2.GetTagSize(stream);
totalTagSize += ID3v1.GetTagSize(stream);
totalTagSize += APEv2.GetTagSize(stream);
Int64 audioLength = stream.Length - totalTagSize;
_bitrate = 0;
_isVBR = null;
_frames = 0;
_totalSeconds = 0;
String step = "";
try
{
int BR, Padding;
int FrameSize;
int TotalBR = 0;
int FrameOffset = 0;
//Int64 TagOffset = 0;
bool bTrusting = true;
bool ignoreall = false;
Byte[] FH = new Byte[4];
bool mPerfect = true;
stream.Position = _headerOffset;
// if (_headerOffset > 0)
// {
// TagOffset = _headerOffset;
// }
int offset = 0;
int frameCount = 0;
int FirstBR = 0;
int audioDataSize = (int)(stream.Length - _headerOffset);
Byte[] audioData = new Byte[audioDataSize];
//Int64 startoffset = stream.Position;
int BufLen = stream.Read(audioData, 0, audioDataSize);
while (offset < BufLen - 16 && !ignoreall)
{
bool reservedlayer = false;
// Find FrameSync
if (FindFrameSync(FH, audioData, BufLen, ref FrameOffset, ref offset, ref mPerfect, ref ignoreall, ref bTrusting, ref reservedlayer))
{
FrameOffset = 0;
int bitrateIndex = FH[2] >> 4;
if (bitrateIndex <= 0 || bitrateIndex >= 15)
{
offset -= 3;
continue;
}
Padding = (FH[2] >> 1) & 0x01;
BR = GetBitrate(_mpegVersion, _mpegLayer, bitrateIndex);
if (BR == 0 || BR % 8 != 0)
{
offset -= 3;
continue;
}
//step = "last good frame @ " + String(startoffset + offset - 4) + ", frame " +
// String(_frames + 1);
// todo: put back later
/*if (InterestedFrames != NULL)
* {
* if (((_frames + 1) * _samplesperframe / (float)_Frequency) * 75.0 >= InterestedFrames->CurrentFrame())
* {
* if (_frames == 0 || InterestedFrames->NoAccomodation)
* {
* InterestedFrames->SetCurrentByteOffset(startoffset + offset - 4);
* InterestedFrames->SetCurrentFrameOffset(_frames);
* }
* InterestedFrames->SetCurrentByteEndOffset(startoffset + offset - 4);
* InterestedFrames->Cur += 1;
* }
* else
* {
* InterestedFrames->SetCurrentByteOffset(startoffset + offset - 4);
* InterestedFrames->SetCurrentFrameOffset(_frames);
* }
* }*/
if (_isVBR != true)
{
if (TotalBR == 0)
{
FirstBR = BR;
}
else if (BR != FirstBR)
{
_isVBR = true;
}
}
TotalBR += BR;
FrameSize = (int)(BR * _frameSizeConst + Padding * _paddingSizeConst);
offset += FrameSize - 4;
frameCount++;
}
}// end while
if (frameCount == 0)
{
throw new InvalidDataException(String.Format("No frames found in {0}", _fileName));
}
_frames = frameCount;
if (_isVBR == null)
{
_bitrate = FirstBR;
_isVBR = false;
}
else
{
_bitrate = TotalBR / _frames;
}
if (_bitrate == 0)
{
throw new InvalidDataException(String.Format("Error determining bitrate: {0}", _fileName));
}
_totalSeconds = (audioLength / 125.0m) / _bitrate;
}
catch (Exception ex)
{
throw new Exception(String.Format("Error calculating bitrate; {0}", step), ex);
}
}
