public EncodingInfo Read( Stream raf ) {
EncodingInfo info = new EncodingInfo();
long oldPos = 0;
//Reads the file encoding infos -----------------------------------
raf.Seek( 0 , SeekOrigin.Begin);
double PCMSamplesNumber = -1;
raf.Seek( raf.Length-2, SeekOrigin.Begin);
while(raf.Position >= 4) {
if(raf.ReadByte()==0x53) {
raf.Seek( raf.Position - 4, SeekOrigin.Begin);
byte[] ogg = new byte[3];
raf.Read(ogg, 0, 3);
if(ogg[0]==0x4F && ogg[1]==0x67 && ogg[2]==0x67) {
raf.Seek( raf.Position - 3, SeekOrigin.Begin);
oldPos = raf.Position;
raf.Seek(raf.Position + 26, SeekOrigin.Begin);
int _pageSegments = raf.ReadByte()&0xFF; //Unsigned
raf.Seek( oldPos , SeekOrigin.Begin);
byte[] _b = new byte[27 + _pageSegments];
raf.Read( _b, 0, _b.Length );
OggPageHeader _pageHeader = new OggPageHeader( _b );
raf.Seek(0, SeekOrigin.Begin);
PCMSamplesNumber = _pageHeader.AbsoluteGranulePosition;
break;
}
}
raf.Seek( raf.Position - 2, SeekOrigin.Begin);
}
if(PCMSamplesNumber == -1){
throw new CannotReadException("Error: Could not find the Ogg Setup block");
}
//Supposing 1st page = codec infos
// 2nd page = comment+decode info
//...Extracting 1st page
byte[] b = new byte[4];
oldPos = raf.Position;
raf.Seek(26, SeekOrigin.Begin);
int pageSegments = raf.ReadByte()&0xFF; //Unsigned
raf.Seek( oldPos , SeekOrigin.Begin);
b = new byte[27 + pageSegments];
raf.Read( b , 0, b .Length);
OggPageHeader pageHeader = new OggPageHeader( b );
byte[] vorbisData = new byte[pageHeader.PageLength];
raf.Read( vorbisData , 0, vorbisData.Length);
VorbisCodecHeader vorbisCodecHeader = new VorbisCodecHeader( vorbisData );
//Populates encodingInfo----------------------------------------------------
info.Duration = new TimeSpan((long)(PCMSamplesNumber / vorbisCodecHeader.SamplingRate) * TimeSpan.TicksPerSecond);
info.ChannelNumber = vorbisCodecHeader.ChannelNumber;
info.SamplingRate = vorbisCodecHeader.SamplingRate;
info.EncodingType = vorbisCodecHeader.EncodingType;
info.ExtraEncodingInfos = "";
if(vorbisCodecHeader.NominalBitrate != 0
&& vorbisCodecHeader.MaxBitrate == vorbisCodecHeader.NominalBitrate
&& vorbisCodecHeader.MinBitrate == vorbisCodecHeader.NominalBitrate) {
//CBR
info.Bitrate = vorbisCodecHeader.NominalBitrate;
info.Vbr = false;
}
else if(vorbisCodecHeader.NominalBitrate != 0
&& vorbisCodecHeader.MaxBitrate == 0
&& vorbisCodecHeader.MinBitrate == 0) {
//Average vbr
info.Bitrate = vorbisCodecHeader.NominalBitrate;
info.Vbr = true;
}
else {
info.Bitrate = ComputeBitrate( (int)info.Duration.TotalSeconds, raf.Length );
info.Vbr = true;
}
return info;
}
public EncodingInfo Read(Stream raf)
{
EncodingInfo info = new EncodingInfo();
long oldPos = 0;
//Reads the file encoding infos -----------------------------------
raf.Seek(0, SeekOrigin.Begin);
double PCMSamplesNumber = -1;
raf.Seek(raf.Length - 2, SeekOrigin.Begin);
while (raf.Position >= 4)
{
if (raf.ReadByte() == 0x53)
{
raf.Seek(raf.Position - 4, SeekOrigin.Begin);
byte[] ogg = new byte[3];
raf.Read(ogg, 0, 3);
if (ogg[0] == 0x4F && ogg[1] == 0x67 && ogg[2] == 0x67)
{
raf.Seek(raf.Position - 3, SeekOrigin.Begin);
oldPos = raf.Position;
raf.Seek(raf.Position + 26, SeekOrigin.Begin);
int _pageSegments = raf.ReadByte() & 0xFF; //Unsigned
raf.Seek(oldPos, SeekOrigin.Begin);
byte[] _b = new byte[27 + _pageSegments];
raf.Read(_b, 0, _b.Length);
OggPageHeader _pageHeader = new OggPageHeader(_b);
raf.Seek(0, SeekOrigin.Begin);
PCMSamplesNumber = _pageHeader.AbsoluteGranulePosition;
break;
}
}
raf.Seek(raf.Position - 2, SeekOrigin.Begin);
}
if (PCMSamplesNumber == -1)
{
throw new CannotReadException("Error: Could not find the Ogg Setup block");
}
//Supposing 1st page = codec infos
// 2nd page = comment+decode info
//...Extracting 1st page
byte[] b = new byte[4];
oldPos = raf.Position;
raf.Seek(26, SeekOrigin.Begin);
int pageSegments = raf.ReadByte() & 0xFF; //Unsigned
raf.Seek(oldPos, SeekOrigin.Begin);
b = new byte[27 + pageSegments];
raf.Read(b, 0, b.Length);
OggPageHeader pageHeader = new OggPageHeader(b);
byte[] vorbisData = new byte[pageHeader.PageLength];
raf.Read(vorbisData, 0, vorbisData.Length);
VorbisCodecHeader vorbisCodecHeader = new VorbisCodecHeader(vorbisData);
//Populates encodingInfo----------------------------------------------------
info.Duration = new TimeSpan((long)(PCMSamplesNumber / vorbisCodecHeader.SamplingRate) * TimeSpan.TicksPerSecond);
info.ChannelNumber = vorbisCodecHeader.ChannelNumber;
info.SamplingRate = vorbisCodecHeader.SamplingRate;
info.EncodingType = vorbisCodecHeader.EncodingType;
info.ExtraEncodingInfos = "";
if (vorbisCodecHeader.NominalBitrate != 0 &&
vorbisCodecHeader.MaxBitrate == vorbisCodecHeader.NominalBitrate &&
vorbisCodecHeader.MinBitrate == vorbisCodecHeader.NominalBitrate)
{
//CBR
info.Bitrate = vorbisCodecHeader.NominalBitrate;
info.Vbr = false;
}
else if (vorbisCodecHeader.NominalBitrate != 0 &&
vorbisCodecHeader.MaxBitrate == 0 &&
vorbisCodecHeader.MinBitrate == 0)
{
//Average vbr
info.Bitrate = vorbisCodecHeader.NominalBitrate;
info.Vbr = true;
}
else
{
info.Bitrate = ComputeBitrate((int)info.Duration.TotalSeconds, raf.Length);
info.Vbr = true;
}
return(info);
}
