public MainPage()
{
this.InitializeComponent();
var videoProperties = VideoEncodingProperties.CreateH264();//.CreateUncompressed(MediaEncodingSubtypes.H264, 720, 480);
var vd = VideoEncodingProperties.CreateUncompressed(MediaEncodingSubtypes.H264, 720, 480);
videoDesc = new VideoStreamDescriptor(videoProperties);
videoDesc.EncodingProperties.FrameRate.Numerator = 29970;
videoDesc.EncodingProperties.FrameRate.Denominator = 1000;
videoDesc.EncodingProperties.Width = 720;
videoDesc.EncodingProperties.Height = 480;
mss = new MediaStreamSource(videoDesc);
mss.CanSeek = false;
//mss.BufferTime = new TimeSpan(0, 0, 0, 0, 250);
mss.Starting += mss_Starting;
mss.SampleRequested += Mss_SampleRequested;
mss.SampleRendered += Mss_SampleRendered;
//initialize some buffers
buff = new Windows.Storage.Streams.Buffer(1024 * 4);
bStream = buff.AsStream();
//this seems needed for start-up
threadSync = new System.Threading.AutoResetEvent(false);
//get the frame time in ms
double ms = 1000.0 * videoDesc.EncodingProperties.FrameRate.Denominator / videoDesc.EncodingProperties.FrameRate.Numerator;
//get the frame time in ticks
T0 = System.TimeSpan.FromTicks((long)(ms * System.TimeSpan.TicksPerMillisecond));
//our demuxer
extractor = new MpegTS.BufferExtractor();
running = true;
//give the file IO a head start
Task.Run(() => RunreadFromFile());
}
private void Mss_SampleRequested(MediaStreamSource sender, MediaStreamSourceSampleRequestedEventArgs args)
{
if (!(args.Request.StreamDescriptor is VideoStreamDescriptor))
{
return;
}
Debug.WriteLine("requesting sample");
MediaStreamSourceSampleRequest request = args.Request;
MpegTS.VideoSample rawSample = null;
MediaStreamSourceSampleRequestDeferral deferal = request.GetDeferral();
try
{
//block here for signal from mpegTS parser that a sample is ready
//if (extractor.SampleCount == 0)
// threadSync.WaitOne();
//dequeue the raw sample here
if (!foundKeyFrame)
{
do
{
threadSync.WaitOne();
rawSample = extractor.DequeueNextSample(false);
}while (rawSample == null || extractor.SampleCount == 0);
}
else
{
if (extractor.SampleCount > 0)
{
rawSample = extractor.DequeueNextSample(false);
}
if (rawSample == null)
{
request.Sample = emptySample;
deferal.Complete();
return;
}
}
//if (!gotT0)
//{
// gotT0 = true;
// //T0.TotalMilliseconds = 33.3667;
//}
//check max size of current buffer, increase if needed.
if (buff.Capacity < rawSample.Length)
{
buff = new Windows.Storage.Streams.Buffer((uint)rawSample.Length);
bStream.Dispose();
//bStream = sample.Buffer.AsStream();
bStream = buff.AsStream();
}
//create our sample here may need to keep initial time stamp for relative time?
sample = MediaStreamSample.CreateFromBuffer(buff, new TimeSpan(T0.Ticks * frameCount));
bStream.Position = 0;
//write the raw sample to the reqest sample stream;
rawSample.WriteToStream(bStream);
sample.Buffer.Length = (uint)rawSample.Length;
Debug.WriteLine("sample length: {0}", rawSample.Length);
//sample.DecodeTimestamp = new TimeSpan(T0.Ticks * frameCount);
sample.Duration = T0;
sample.KeyFrame = ScanForKeyframe(bStream);//rawSample.Length > 3000;//
//not sure if this is correct...
sample.Discontinuous = !lastFrame;
//this just tells us if the MpegTS Continuity Counter
//for all Mpeg packets in the sample were in order. (0-15)
lastFrame = rawSample.IsComplete;
//if (!foundKeyFrame)
// sample = emptySample;
//else
++frameCount;
// create the MediaStreamSample and assign to the request object.
// You could also create the MediaStreamSample using createFromBuffer(...)
//MediaStreamSample sample = await MediaStreamSample.CreateFromStreamAsync(inputStream, sampleSize, timeOffset);
//sample.Duration = sampleDuration;
//sample.KeyFrame = true;
// increment the time and byte offset
//byteOffset += sampleSize;
//timeOffset = timeOffset.Add(sampleDuration);
request.Sample = sample;
}
catch (Exception ex)
{
var exStr = ex.ToString();
}
finally
{
deferal.Complete();
}
Debug.WriteLine("exit request sample");
}
