/// <summary>
/// Video resolution changed event handler.
/// </summary>
/// <param name="width">The new video frame width.</param>
/// <param name="height">The new video frame height.</param>
/// <param name="stride">The new video frame stride.</param>
private static void OnVideoResolutionChanged(uint width, uint height, uint stride)
{
try
{
if (_vpxEncoder == null ||
(_vpxEncoder.GetWidth() != width || _vpxEncoder.GetHeight() != height || _vpxEncoder.GetStride() != stride))
{
if (_vpxEncoder != null)
{
_vpxEncoder.Dispose();
}
_vpxEncoder = new VpxEncoder();
_vpxEncoder.InitEncoder(width, height, stride);
logger.LogInformation($"VPX encoder initialised with width {width}, height {height} and stride {stride}.");
}
}
catch (Exception excp)
{
logger.LogWarning("Exception OnVideoResolutionChangedEvent. " + excp.Message);
}
}
/// <summary>
/// Starts the Media Foundation sampling.
/// </summary>
unsafe private void SampleMp4Media()
{
try
{
logger.LogDebug("Starting mp4 media sampling thread.");
_isMp4Sampling = true;
VpxEncoder vpxEncoder = null;
uint vp8Timestamp = 0;
uint mulawTimestamp = 0;
while (!_exit)
{
if (OnMp4MediaSampleReady == null)
{
logger.LogDebug("No active clients, media sampling paused.");
break;
}
else
{
byte[] sampleBuffer = null;
var sample = _mediaSource.GetSample(ref sampleBuffer);
if (sample != null && sample.HasVideoSample)
{
if (vpxEncoder == null ||
(vpxEncoder.GetWidth() != sample.Width || vpxEncoder.GetHeight() != sample.Height || vpxEncoder.GetStride() != sample.Stride))
{
if (vpxEncoder != null)
{
vpxEncoder.Dispose();
}
vpxEncoder = InitialiseVpxEncoder((uint)sample.Width, (uint)sample.Height, (uint)sample.Stride);
}
byte[] vpxEncodedBuffer = null;
unsafe
{
fixed(byte *p = sampleBuffer)
{
int encodeResult = vpxEncoder.Encode(p, sampleBuffer.Length, 1, ref vpxEncodedBuffer);
if (encodeResult != 0)
{
logger.LogWarning("VPX encode of video sample failed.");
}
}
}
OnMp4MediaSampleReady?.Invoke(SDPMediaTypesEnum.video, vp8Timestamp, vpxEncodedBuffer);
//Console.WriteLine($"Video SeqNum {videoSeqNum}, timestamp {videoTimestamp}, buffer length {vpxEncodedBuffer.Length}, frame count {sampleProps.FrameCount}.");
vp8Timestamp += VP8_TIMESTAMP_SPACING;
}
else if (sample != null && sample.HasAudioSample)
{
uint sampleDuration = (uint)(sampleBuffer.Length / 2);
byte[] mulawSample = new byte[sampleDuration];
int sampleIndex = 0;
for (int index = 0; index < sampleBuffer.Length; index += 2)
{
var ulawByte = MuLawEncoder.LinearToMuLawSample(BitConverter.ToInt16(sampleBuffer, index));
mulawSample[sampleIndex++] = ulawByte;
}
OnMp4MediaSampleReady?.Invoke(SDPMediaTypesEnum.audio, mulawTimestamp, mulawSample);
//Console.WriteLine($"Audio SeqNum {audioSeqNum}, timestamp {audioTimestamp}, buffer length {mulawSample.Length}.");
mulawTimestamp += sampleDuration;
}
}
}
vpxEncoder.Dispose();
}
catch (Exception excp)
{
logger.LogWarning("Exception SampleMp4Media. " + excp.Message);
}
finally
{
logger.LogDebug("mp4 sampling thread stopped.");
_isMp4Sampling = false;
}
}