public static void Scan(
TSAudioStream stream,
TSStreamBuffer buffer,
ref string tag)
{
if (stream.IsInitialized &&
stream.CoreStream != null &&
stream.CoreStream.IsInitialized)
{
return;
}
bool syncFound = false;
uint sync = 0;
for (int i = 0; i < buffer.Length; i++)
{
sync = (sync << 8) + buffer.ReadByte();
if (sync == 0xF8726FBA)
{
syncFound = true;
break;
}
}
if (!syncFound)
{
tag = "CORE";
if (stream.CoreStream == null)
{
stream.CoreStream = new TSAudioStream();
stream.CoreStream.StreamType = TSStreamType.AC3_AUDIO;
}
if (!stream.CoreStream.IsInitialized)
{
buffer.BeginRead();
TSCodecAC3.Scan(stream.CoreStream, buffer, ref tag);
}
return;
}
tag = "HD";
int ratebits = buffer.ReadBits(4);
if (ratebits != 0xF)
{
stream.SampleRate =
(((ratebits & 8) > 0 ? 44100 : 48000) << (ratebits & 7));
}
int temp1 = buffer.ReadBits(8);
int channels_thd_stream1 = buffer.ReadBits(5);
int temp2 = buffer.ReadBits(2);
stream.ChannelCount = 0;
stream.LFE = 0;
int c_LFE2 = buffer.ReadBits(1);
if (c_LFE2 == 1)
{
stream.LFE += 1;
}
int c_Cvh = buffer.ReadBits(1);
if (c_Cvh == 1)
{
stream.ChannelCount += 1;
}
int c_LRw = buffer.ReadBits(1);
if (c_LRw == 1)
{
stream.ChannelCount += 2;
}
int c_LRsd = buffer.ReadBits(1);
if (c_LRsd == 1)
{
stream.ChannelCount += 2;
}
int c_Ts = buffer.ReadBits(1);
if (c_Ts == 1)
{
stream.ChannelCount += 1;
}
int c_Cs = buffer.ReadBits(1);
if (c_Cs == 1)
{
stream.ChannelCount += 1;
}
int c_LRrs = buffer.ReadBits(1);
if (c_LRrs == 1)
{
stream.ChannelCount += 2;
}
int c_LRc = buffer.ReadBits(1);
if (c_LRc == 1)
{
stream.ChannelCount += 2;
}
int c_LRvh = buffer.ReadBits(1);
if (c_LRvh == 1)
{
stream.ChannelCount += 2;
}
int c_LRs = buffer.ReadBits(1);
if (c_LRs == 1)
{
stream.ChannelCount += 2;
}
int c_LFE = buffer.ReadBits(1);
if (c_LFE == 1)
{
stream.LFE += 1;
}
int c_C = buffer.ReadBits(1);
if (c_C == 1)
{
stream.ChannelCount += 1;
}
int c_LR = buffer.ReadBits(1);
if (c_LR == 1)
{
stream.ChannelCount += 2;
}
int access_unit_size = 40 << (ratebits & 7);
int access_unit_size_pow2 = 64 << (ratebits & 7);
int a1 = buffer.ReadBits(16);
int a2 = buffer.ReadBits(16);
int a3 = buffer.ReadBits(16);
int is_vbr = buffer.ReadBits(1);
int peak_bitrate = buffer.ReadBits(15);
peak_bitrate = (peak_bitrate * stream.SampleRate) >> 4;
double peak_bitdepth =
(double)peak_bitrate /
(stream.ChannelCount + stream.LFE) /
stream.SampleRate;
if (peak_bitdepth > 14)
{
stream.BitDepth = 24;
}
else
{
stream.BitDepth = 16;
}
#if DEBUG
System.Diagnostics.Debug.WriteLine(string.Format(
"{0}\t{1}\t{2:F2}",
stream.PID, peak_bitrate, peak_bitdepth));
#endif
/*
* // TODO: Get THD dialnorm from metadata
* if (stream.CoreStream != null)
* {
* TSAudioStream coreStream = (TSAudioStream)stream.CoreStream;
* if (coreStream.DialNorm != 0)
* {
* stream.DialNorm = coreStream.DialNorm;
* }
* }
*/
stream.IsVBR = true;
stream.IsInitialized = true;
}