/// <summary>
/// Processes a NAL.
/// </summary>
/// <param name="nal">The NAL to be processed.</param>
/// <returns>Type of NAL.</returns>
private int ProcessNal(Nal nal)
{
// get the NAL type
int nalType = -1;
if (nal.Buffer.Length > 4)
{
byte[] header = new byte[5];
nal.Buffer.CopyTo(0, header, 0, 5);
nalType = (header[0] == 0 && header[1] == 0 && header[2] == 0 && header[3] == 1) ? (header[4] & 0x1F) : -1;
}
//Log.Verbose("NAL: type = {0}, len = {1}", nalType, nal.Buffer.Length);
// process the first SPS record we encounter
if (nalType == 7 && !isDecoding)
{
byte[] sps = new byte[nal.Buffer.Length];
nal.Buffer.CopyTo(sps);
SpsParser parser = new SpsParser(sps, (int)nal.Buffer.Length);
//Log.Verbose("SPS: {0}x{1} @ {2}", parser.width, parser.height, parser.fps);
VideoEncodingProperties properties = VideoEncodingProperties.CreateH264();
properties.ProfileId = H264ProfileIds.High;
properties.Width = (uint)parser.width;
properties.Height = (uint)parser.height;
streamSource = new MediaStreamSource(new VideoStreamDescriptor(properties));
streamSource.BufferTime = TimeSpan.Zero;
streamSource.CanSeek = false;
streamSource.Duration = TimeSpan.Zero;
streamSource.SampleRequested += HandleSampleRequested;
var action = Dispatcher.RunAsync(Windows.UI.Core.CoreDispatcherPriority.High, () =>
{
statusTextBlock.Visibility = Visibility.Collapsed;
media.SetMediaStreamSource(streamSource);
media.Play();
storyboard.Begin();
});
isDecoding = true;
}
// queue the frame
if (nalType > 0 && isDecoding)
{
if (deferral != null)
{
request.Sample = MediaStreamSample.CreateFromBuffer(nal.Buffer, new TimeSpan(0));
lock (availableNals)
{
//Log.Verbose("availableNals.Enqueue");
availableNals.Enqueue(nal);
}
deferral.Complete();
deferral = null;
request = null;
//Log.Verbose("Deferral Complete");
}
else
{
//Log.Verbose("usedNals.Enqueue");
lock (usedNals)
{
usedNals.Enqueue(nal);
}
}
}
// return the NAL type
return(isDecoding ? nalType : -1);
}
/// <summary>
/// Reads bytes form the socket and parses them into NALs.
/// </summary>
/// <returns>The asynchronous task.</returns>
private async Task ReadSocketAsync()
{
Log.Info("+VideoPage.ReadSocketAsync");
Nal nal = availableNals.Dequeue();
int numZeroes = 0;
int numReadErrors = 0;
bool gotHeader = false;
// look for a TCP/IP connection
try
{
// try to connect to the device
socket = new StreamSocket();
HostName hostName = new HostName(camera.Address);
CancellationTokenSource tokenSource = new CancellationTokenSource();
tokenSource.CancelAfter(settings.ScanTimeout);
await socket.ConnectAsync(hostName, camera.Port.ToString()).AsTask(tokenSource.Token);
// if we get here, we opened the socket
isConnected = true;
DataReader reader = new DataReader(socket.InputStream);
reader.InputStreamOptions = InputStreamOptions.Partial;
while (!isCancelled)
{
uint len = await reader.LoadAsync(BUFFER_SIZE);
//Log.Verbose("numBytes = {0}", len);
if (nal == null)
{
lock (availableNals)
{
//Log.Verbose("availableNals.Dequeue: {0}", availableNals.Count);
nal = (availableNals.Count > 0) ? availableNals.Dequeue() : null;
}
}
// process the input buffer
if (nal == null)
{
if (len > 0)
{
reader.ReadBuffer(len);
}
}
else if (len > 0)
{
numReadErrors = 0;
for (int i = 0; i < len && nal != null && !isCancelled; i++)
{
// resize the NAL if necessary
if (nal.Stream.Length == nal.Buffer.Capacity)
{
nal.Resize(nal.Buffer.Capacity + NAL_SIZE_INC);
}
// add the byte to the NAL
byte b = reader.ReadByte();
nal.Stream.WriteByte(b);
// look for a header
if (b == 0)
{
numZeroes++;
}
else
{
if (b == 1 && numZeroes == 3)
{
if (nal.Stream.Length > 4)
{
if (gotHeader)
{
nal.Buffer.Length = (uint)nal.Stream.Length - 4;
int nalType = ProcessNal(nal);
if (isCancelled)
{
break;
}
if (nalType != -1)
{
lock (availableNals)
{
//Log.Verbose("availableNals.Dequeue: {0}", availableNals.Count);
nal = (availableNals.Count > 0) ? availableNals.Dequeue() : null;
}
}
}
if (nal != null)
{
nal.Stream.Seek(0, SeekOrigin.Begin);
nal.Stream.SetLength(0);
nal.Stream.WriteByte(0);
nal.Stream.WriteByte(0);
nal.Stream.WriteByte(0);
nal.Stream.WriteByte(1);
}
else
{
//Log.Verbose("null");
}
}
gotHeader = true;
}
numZeroes = 0;
}
}
}
else
{
numReadErrors++;
if (numReadErrors >= MAX_READ_ERRORS)
{
DisplayStatusMessage(Res.Error.LostConnection);
break;
}
}
}
reader.Dispose();
socket.Dispose();
isDecoding = false;
isConnected = false;
await Dispatcher.RunAsync(Windows.UI.Core.CoreDispatcherPriority.Normal, () =>
{
media.Stop();
Frame.GoBack();
});
}
catch (Exception ex)
{
DisplayStatusMessage(isConnected ? Res.Error.LostConnection : Res.Error.CouldntConnect);
Log.Error("EXCEPTION: {0}", ex.ToString());
isConnected = false;
return;
}
Log.Info("-VideoPage.ReadSocketAsync");
}
