private void NALUnitParse()
{
//3. NumBytesInNALunit is set equal to the number of bytes starting with the byte at the current position in the byte
//stream up to and including the last byte that precedes the location of any of the following:
//– A subsequent byte-aligned three-byte sequence equal to 0x000000,
//– A subsequent byte-aligned three-byte sequence equal to 0x000001,
//– The end of the byte stream, as determined by unspecified means.
//4. NumBytesInNALunit bytes are removed from the bitstream and the current position in the byte stream is
//advanced by NumBytesInNALunit bytes. This sequence of bytes is nal_unit( NumBytesInNALunit ) and is
//decoded using the NAL unit decoding process.
//5. When the current position in the byte stream is not at the end of the byte stream (as determined by unspecified
//means) and the next bytes in the byte stream do not start with a three-byte sequence equal to 0x000001 and the
//next bytes in the byte stream do not start with a four byte sequence equal to 0x00000001, the decoder extracts
//and discards each trailing_zero_8bits syntax element, moving the current position in the byte stream forward
//one byte at a time, until the current position in the byte stream is such that the next bytes in the byte stream form
//the four-byte sequence 0x00000001 or the end of the byte stream has been encountered (as determined by
//unspecified means).
NALUnit cNALUnitAudio = null;
NALUnit cNALUnitVideo = new NALUnit();
cNALUnitVideo.nStart = _cStream.Position - 3;
bool bNALStart = false;
byte nStepVideo = 0, nStepAudio = 0;
int nByte = 0;
//_cStream.ReadByte();
//int nByteType = _cStream.ReadByte();
//if (0 > nByteType)
// throw new Exception();
while (true)
{
if (_cStream.Position >= nDataSize + nDataStart || 0 > (nByte = _cStream.ReadByte()))
{
throw new Exception();
}
if (0x00 == nByte)
{
nStepAudio = 0;
nStepVideo++;
if (2 < nStepVideo)
{
bNALStart = true;
}
}
else if (0x01 == nByte)
{
nStepAudio = 0;
if (1 < nStepVideo)
{
bNALStart = true;
}
else
{
nStepVideo = 0;
}
}
else
{
nStepVideo = 0;
if (0xFF == nByte)
{
nStepAudio = 1;
}
else if (0xFB == nByte && 1 == nStepAudio)
{
nStepAudio++;
}
else if (_nAudioMP3ControlByte == nByte && 2 == nStepAudio)
{
nStepAudio++;
}
else if ((0x64 == nByte || 0x44 == nByte) && 3 == nStepAudio)
{
long nPosition = _cStream.Position;
_cStream.Position += _cMP3WaveFormat.BlockSize - 4;
nByte = _cStream.ReadByte();
if ((0 == nByte && 0 == _cStream.ReadByte() && 0 == _cStream.ReadByte()) || (0xFF == nByte && 0xFB == _cStream.ReadByte() && _nAudioMP3ControlByte == _cStream.ReadByte()))
{
if (null != cNALUnitVideo)
{
cNALUnitVideo.nBytesQty = nPosition - cNALUnitVideo.nStart - 4;
cNALUnitVideo.bFrameStart = true;
NALUnitVideoAdd(cNALUnitVideo);
lock (_cSyncRoot)
_aFramesOffsets.Add(new FrameOffset(_aAudioNALs.Count + 1, _aVideoNALs.Count));
cNALUnitVideo = null;
}
cNALUnitAudio = new NALUnit();
cNALUnitAudio.nStart = nPosition - 4;
cNALUnitAudio.nBytesQty = (long)_cMP3WaveFormat.BlockSize;
NALUnitAudioAdd(cNALUnitAudio);
_cStream.Position -= 3;
}
else
{
_cStream.Position = nPosition;
}
nStepAudio = 0;
}
else
{
nStepAudio = 0;
}
}
if (bNALStart)
{
if (null != cNALUnitVideo)
{
cNALUnitVideo.nBytesQty = _cStream.Position - cNALUnitVideo.nStart - 2;
NALUnitVideoAdd(cNALUnitVideo);
}
return;
}
}
}
private void ResponseCallback(IAsyncResult iAsynchronousResult)
{
try
{
_ahMediaSourceAttributes = null;
_aMediaStreamDescriptions = null;
_cMP3WaveFormat = null;
_cStream = new MediaStream(((HttpWebResponse)_cHttpWebRequest.EndGetResponse(iAsynchronousResult)).GetResponseStream());
_cStream.Position = 0;
// Initialize data structures to pass to the Media pipeline via the MediaStreamSource
_ahMediaSourceAttributes = new Dictionary<MediaSourceAttributesKeys, string>();
_aMediaStreamDescriptions = new List<MediaStreamDescription>();
Dictionary<MediaStreamAttributeKeys, string> ahMediaStreamAttributes = new Dictionary<MediaStreamAttributeKeys, string>();
ahMediaStreamAttributes[MediaStreamAttributeKeys.VideoFourCC] = "H264";
ahMediaStreamAttributes[MediaStreamAttributeKeys.Width] = _nVideoFrameWidth.ToString();
ahMediaStreamAttributes[MediaStreamAttributeKeys.Height] = _nVideoFrameHeight.ToString();
_nCurrentFrameVideo = 0;
_nCurrentFrameAudio = 0;
_cMediaStreamVideoDescription = new MediaStreamDescription(MediaStreamType.Video, ahMediaStreamAttributes);
_aMediaStreamDescriptions.Add(_cMediaStreamVideoDescription);
FileTypeCompatibility cFtyp = (FileTypeCompatibility)Atom.Read(_cStream);
Wide cWide = (Wide)cFtyp.cNext;
MovieData cMdat = (MovieData)cWide.cNext;
nDataStart = cMdat.DataOffsetGet();
nDataSize = cMdat.DataSizeGet();
//1. When the next four bytes in the bitstream form the four-byte sequence 0x00000001, the next byte in the byte
//stream (which is a zero_byte syntax element) is extracted and discarded and the current position in the byte
//stream is set equal to the position of the byte following this discarded byte.
while (true)
{
if (0 == _cStream.ReadByte() && 0 == _cStream.ReadByte() && 0 == _cStream.ReadByte() && 1 == _cStream.ReadByte())
{
break;
}
}
//2. The next three-byte sequence in the byte stream (which is a start_code_prefix_one_3bytes) is extracted and
//discarded and the current position in the byte stream is set equal to the position of the byte following this
//three-byte sequence.
_cMP3WaveFormat = new MpegLayer3WaveFormat();
_cMP3WaveFormat.WaveFormatEx = new WaveFormatEx();
_cMP3WaveFormat.WaveFormatEx.FormatTag = WaveFormatEx.FormatMP3;
//_cMP3WaveFormat.WaveFormatEx.Channels = (short)((mpegLayer3Frame.Channels == MediaParsers.Channel.SingleChannel) ? 1 : 2);
_cMP3WaveFormat.WaveFormatEx.Channels = (short)2;
//_cMP3WaveFormat.WaveFormatEx.SamplesPerSec = mpegLayer3Frame.SamplingRate;
_cMP3WaveFormat.WaveFormatEx.SamplesPerSec = _nAudioSampleRate;
//_cMP3WaveFormat.WaveFormatEx.AvgBytesPerSec = mpegLayer3Frame.Bitrate / 8;
_cMP3WaveFormat.WaveFormatEx.AvgBytesPerSec = _nAudioBitRate / 8;
_cMP3WaveFormat.WaveFormatEx.BlockAlign = 1;
_cMP3WaveFormat.WaveFormatEx.BitsPerSample = 0;
_cMP3WaveFormat.WaveFormatEx.Size = 12;
_cMP3WaveFormat.Id = 1;
_cMP3WaveFormat.BitratePaddingMode = 0;
_cMP3WaveFormat.FramesPerBlock = 1;
//_cMP3WaveFormat.BlockSize = (short)mpegLayer3Frame.FrameSize; //(short)(144 * nBitRate / _nAudioSampleRate + _cMP3WaveFormat.BitratePaddingMode);
_cMP3WaveFormat.BlockSize = (short)(144 * _nAudioBitRate / _nAudioSampleRate + _cMP3WaveFormat.BitratePaddingMode);
_cMP3WaveFormat.CodecDelay = 0;
ahMediaStreamAttributes = new Dictionary<MediaStreamAttributeKeys, string>();
ahMediaStreamAttributes[MediaStreamAttributeKeys.CodecPrivateData] = _cMP3WaveFormat.ToHexString();
_cMediaStreamAudioDescription = new MediaStreamDescription(MediaStreamType.Audio, ahMediaStreamAttributes);
_aMediaStreamDescriptions.Add(_cMediaStreamAudioDescription);
switch (_nAudioBitRate)
{
case 64000:
_nAudioMP3ControlByte = 0x54;
break;
case 128000:
_nAudioMP3ControlByte = 0x94;
break;
default:
throw new Exception("unsupported audio bit rate:" + _nAudioBitRate);
}
_aFramesOffsets.Add(new FrameOffset(0, 0));
_nFrameDuration = TimeSpan.FromSeconds((double)1 / 25).Ticks; //FPS
_nSampleDuration = TimeSpan.FromSeconds(((double)1 / _nAudioSampleRate) * 1152).Ticks;
try
{
long nBufferTicks = TimeSpan.FromSeconds(_nBufferSeconds).Ticks;
while ((ulong)_nBufferSeconds > _nFramesQty || nBufferTicks > (_aAudioNALs.Count * _nSampleDuration)) //если длительность меньше буфера, то крутим до исключения, по которому и выйдем из цикла
NALUnitParse();
_cThread = new System.Threading.Thread(NALUnitsReceive);
_cThread.Start();
}
catch
{
_bCached = true;
}
TimeSpan tsDuration;
if (1 > _nFramesQty)
{
lock (_cSyncRoot)
{
long nDurationAudio = (long)(_aAudioNALs.Count * _nSampleDuration);
long nDurationVideo = (long)(_aVideoNALs.Count(row => row.bFrameStart) * _nFrameDuration);
tsDuration = TimeSpan.FromTicks(nDurationAudio > nDurationVideo ? nDurationAudio : nDurationVideo);
}
}
else
tsDuration = TimeSpan.FromMilliseconds(_nFramesQty * 40); //FPS
_ahMediaSourceAttributes[MediaSourceAttributesKeys.Duration] = tsDuration.Ticks.ToString(System.Globalization.CultureInfo.InvariantCulture);
_ahMediaSourceAttributes[MediaSourceAttributesKeys.CanSeek] = true.ToString();
ReportOpenMediaCompleted(_ahMediaSourceAttributes, _aMediaStreamDescriptions);
}
catch (WebException e)
{
// Need to handle the exception
}
}
private void ResponseCallback(IAsyncResult iAsynchronousResult)
{
try
{
_ahMediaSourceAttributes = null;
_aMediaStreamDescriptions = null;
_cMP3WaveFormat = null;
_cStream = new MediaStream(((HttpWebResponse)_cHttpWebRequest.EndGetResponse(iAsynchronousResult)).GetResponseStream());
_cStream.Position = 0;
// Initialize data structures to pass to the Media pipeline via the MediaStreamSource
_ahMediaSourceAttributes = new Dictionary <MediaSourceAttributesKeys, string>();
_aMediaStreamDescriptions = new List <MediaStreamDescription>();
Dictionary <MediaStreamAttributeKeys, string> ahMediaStreamAttributes = new Dictionary <MediaStreamAttributeKeys, string>();
ahMediaStreamAttributes[MediaStreamAttributeKeys.VideoFourCC] = "H264";
ahMediaStreamAttributes[MediaStreamAttributeKeys.Width] = _nVideoFrameWidth.ToString();
ahMediaStreamAttributes[MediaStreamAttributeKeys.Height] = _nVideoFrameHeight.ToString();
_nCurrentFrameVideo = 0;
_nCurrentFrameAudio = 0;
_cMediaStreamVideoDescription = new MediaStreamDescription(MediaStreamType.Video, ahMediaStreamAttributes);
_aMediaStreamDescriptions.Add(_cMediaStreamVideoDescription);
FileTypeCompatibility cFtyp = (FileTypeCompatibility)Atom.Read(_cStream);
Wide cWide = (Wide)cFtyp.cNext;
MovieData cMdat = (MovieData)cWide.cNext;
nDataStart = cMdat.DataOffsetGet();
nDataSize = cMdat.DataSizeGet();
//1. When the next four bytes in the bitstream form the four-byte sequence 0x00000001, the next byte in the byte
//stream (which is a zero_byte syntax element) is extracted and discarded and the current position in the byte
//stream is set equal to the position of the byte following this discarded byte.
while (true)
{
if (0 == _cStream.ReadByte() && 0 == _cStream.ReadByte() && 0 == _cStream.ReadByte() && 1 == _cStream.ReadByte())
{
break;
}
}
//2. The next three-byte sequence in the byte stream (which is a start_code_prefix_one_3bytes) is extracted and
//discarded and the current position in the byte stream is set equal to the position of the byte following this
//three-byte sequence.
_cMP3WaveFormat = new MpegLayer3WaveFormat();
_cMP3WaveFormat.WaveFormatEx = new WaveFormatEx();
_cMP3WaveFormat.WaveFormatEx.FormatTag = WaveFormatEx.FormatMP3;
//_cMP3WaveFormat.WaveFormatEx.Channels = (short)((mpegLayer3Frame.Channels == MediaParsers.Channel.SingleChannel) ? 1 : 2);
_cMP3WaveFormat.WaveFormatEx.Channels = (short)2;
//_cMP3WaveFormat.WaveFormatEx.SamplesPerSec = mpegLayer3Frame.SamplingRate;
_cMP3WaveFormat.WaveFormatEx.SamplesPerSec = _nAudioSampleRate;
//_cMP3WaveFormat.WaveFormatEx.AvgBytesPerSec = mpegLayer3Frame.Bitrate / 8;
_cMP3WaveFormat.WaveFormatEx.AvgBytesPerSec = _nAudioBitRate / 8;
_cMP3WaveFormat.WaveFormatEx.BlockAlign = 1;
_cMP3WaveFormat.WaveFormatEx.BitsPerSample = 0;
_cMP3WaveFormat.WaveFormatEx.Size = 12;
_cMP3WaveFormat.Id = 1;
_cMP3WaveFormat.BitratePaddingMode = 0;
_cMP3WaveFormat.FramesPerBlock = 1;
//_cMP3WaveFormat.BlockSize = (short)mpegLayer3Frame.FrameSize; //(short)(144 * nBitRate / _nAudioSampleRate + _cMP3WaveFormat.BitratePaddingMode);
_cMP3WaveFormat.BlockSize = (short)(144 * _nAudioBitRate / _nAudioSampleRate + _cMP3WaveFormat.BitratePaddingMode);
_cMP3WaveFormat.CodecDelay = 0;
ahMediaStreamAttributes = new Dictionary <MediaStreamAttributeKeys, string>();
ahMediaStreamAttributes[MediaStreamAttributeKeys.CodecPrivateData] = _cMP3WaveFormat.ToHexString();
_cMediaStreamAudioDescription = new MediaStreamDescription(MediaStreamType.Audio, ahMediaStreamAttributes);
_aMediaStreamDescriptions.Add(_cMediaStreamAudioDescription);
switch (_nAudioBitRate)
{
case 64000:
_nAudioMP3ControlByte = 0x54;
break;
case 128000:
_nAudioMP3ControlByte = 0x94;
break;
default:
throw new Exception("unsupported audio bit rate:" + _nAudioBitRate);
}
_aFramesOffsets.Add(new FrameOffset(0, 0));
_nFrameDuration = TimeSpan.FromSeconds((double)1 / 25).Ticks; //FPS
_nSampleDuration = TimeSpan.FromSeconds(((double)1 / _nAudioSampleRate) * 1152).Ticks;
try
{
long nBufferTicks = TimeSpan.FromSeconds(_nBufferSeconds).Ticks;
while ((ulong)_nBufferSeconds > _nFramesQty || nBufferTicks > (_aAudioNALs.Count * _nSampleDuration)) //если длительность меньше буфера, то крутим до исключения, по которому и выйдем из цикла
{
NALUnitParse();
}
_cThread = new System.Threading.Thread(NALUnitsReceive);
_cThread.Start();
}
catch
{
_bCached = true;
}
TimeSpan tsDuration;
if (1 > _nFramesQty)
{
lock (_cSyncRoot)
{
long nDurationAudio = (long)(_aAudioNALs.Count * _nSampleDuration);
long nDurationVideo = (long)(_aVideoNALs.Count(row => row.bFrameStart) * _nFrameDuration);
tsDuration = TimeSpan.FromTicks(nDurationAudio > nDurationVideo ? nDurationAudio : nDurationVideo);
}
}
else
{
tsDuration = TimeSpan.FromMilliseconds(_nFramesQty * 40); //FPS
}
_ahMediaSourceAttributes[MediaSourceAttributesKeys.Duration] = tsDuration.Ticks.ToString(System.Globalization.CultureInfo.InvariantCulture);
_ahMediaSourceAttributes[MediaSourceAttributesKeys.CanSeek] = true.ToString();
ReportOpenMediaCompleted(_ahMediaSourceAttributes, _aMediaStreamDescriptions);
}
catch (WebException e)
{
// Need to handle the exception
}
}
