public void GotVideoRtp(IPEndPoint remoteEndPoint, uint ssrc, uint seqnum, uint timestamp, int payloadID, bool marker, byte[] payload)
{
//logger.LogDebug($"rtp video, seqnum {seqnum}, ts {timestamp}, marker {marker}, payload {payload.Length}.");
if (_currVideoFramePosn + payload.Length >= _currVideoFrame.Length)
{
// Something has gone very wrong. Clear the buffer.
_currVideoFramePosn = 0;
}
// New frames must have the VP8 Payload Descriptor Start bit set.
// The tracking of the current video frame position is to deal with a VP8 frame being split across multiple RTP packets
// as per https://tools.ietf.org/html/rfc7741#section-4.4.
if (_currVideoFramePosn > 0 || (payload[0] & 0x10) > 0)
{
RtpVP8Header vp8Header = RtpVP8Header.GetVP8Header(payload);
Buffer.BlockCopy(payload, vp8Header.Length, _currVideoFrame, _currVideoFramePosn, payload.Length - vp8Header.Length);
_currVideoFramePosn += payload.Length - vp8Header.Length;
if (marker)
{
DateTime startTime = DateTime.Now;
List <byte[]> decodedFrames = _vp8Decoder.Decode(_currVideoFrame, _currVideoFramePosn, out var width, out var height);
if (decodedFrames == null)
{
logger.LogWarning("VPX decode of video sample failed.");
}
else
{
foreach (var decodedFrame in decodedFrames)
{
byte[] rgb = PixelConverter.I420toRGB(decodedFrame, (int)width, (int)height);
//Console.WriteLine($"VP8 decode took {DateTime.Now.Subtract(startTime).TotalMilliseconds}ms.");
OnVideoSinkDecodedSample(rgb, width, height, (int)(width * 3));
}
}
_currVideoFramePosn = 0;
}
}
else
{
logger.LogWarning("Discarding RTP packet, VP8 header Start bit not set.");
logger.LogWarning($"rtp video, seqnum {seqnum}, ts {timestamp}, marker {marker}, payload {payload.Length}.");
}
}
public static RtpVP8Header GetVP8Header(byte[] rtpPayload)
{
RtpVP8Header vp8Header = new RtpVP8Header();
int payloadHeaderStartIndex = 1;
// First byte of payload descriptor.
vp8Header.ExtendedControlBitsPresent = ((rtpPayload[0] >> 7) & 0x01) == 1;
vp8Header.StartOfVP8Partition = ((rtpPayload[0] >> 4) & 0x01) == 1;
vp8Header._length = 1;
// Is second byte being used.
if (vp8Header.ExtendedControlBitsPresent)
{
vp8Header.IsPictureIDPresent = ((rtpPayload[1] >> 7) & 0x01) == 1;
vp8Header._length = 2;
payloadHeaderStartIndex = 2;
}
// Is the picture ID being used.
if (vp8Header.IsPictureIDPresent)
{
if (((rtpPayload[2] >> 7) & 0x01) == 1)
{
// The Picture ID is using two bytes.
vp8Header._length = 4;
payloadHeaderStartIndex = 4;
vp8Header.PictureID = BitConverter.ToUInt16(rtpPayload, 2);
}
else
{
// The picture ID is using one byte.
vp8Header.PictureID = rtpPayload[2];
vp8Header._length = 3;
payloadHeaderStartIndex = 3;
}
}
vp8Header._payloadDescriptorLength = payloadHeaderStartIndex;
return(vp8Header);
}
