private static async Task StartFfmpegListener(string sdpPath, CancellationToken cancel)
{
while (!File.Exists(FFMPEG_SDP_FILE) && !cancel.IsCancellationRequested)
{
await Task.Delay(500);
}
if (!cancel.IsCancellationRequested)
{
var sdp = SDP.ParseSDPDescription(File.ReadAllText(FFMPEG_SDP_FILE));
// The SDP is only expected to contain a single video media announcement.
var videoAnn = sdp.Media.Single(x => x.Media == SDPMediaTypesEnum.video);
_ffmpegVideoFormat = videoAnn.MediaFormats.Values.First();
_ffmpegListener = new RTPSession(false, false, false, IPAddress.Loopback, FFMPEG_DEFAULT_RTP_PORT);
_ffmpegListener.AcceptRtpFromAny = true;
MediaStreamTrack videoTrack = new MediaStreamTrack(SDPMediaTypesEnum.video, false, new List <SDPAudioVideoMediaFormat> {
_ffmpegVideoFormat
}, MediaStreamStatusEnum.RecvOnly);
_ffmpegListener.addTrack(videoTrack);
_ffmpegListener.SetRemoteDescription(SIP.App.SdpType.answer, sdp);
// Set a dummy destination end point or the RTP session will end up sending RTCP reports
// to itself.
var dummyIPEndPoint = new IPEndPoint(IPAddress.Loopback, 0);
_ffmpegListener.SetDestination(SDPMediaTypesEnum.video, dummyIPEndPoint, dummyIPEndPoint);
await _ffmpegListener.Start();
}
}
private static RTPSession CreateRtpSession(List <SDPAudioVideoMediaFormat> audioFormats, List <SDPAudioVideoMediaFormat> videoFormats)
{
var rtpSession = new RTPSession(false, false, false, IPAddress.Loopback);
bool hasAudio = false;
bool hasVideo = false;
if (audioFormats != null && audioFormats.Count > 0)
{
MediaStreamTrack audioTrack = new MediaStreamTrack(SDPMediaTypesEnum.audio, false, audioFormats, MediaStreamStatusEnum.SendRecv);
rtpSession.addTrack(audioTrack);
hasAudio = true;
}
if (videoFormats != null && videoFormats.Count > 0)
{
MediaStreamTrack videoTrack = new MediaStreamTrack(SDPMediaTypesEnum.video, false, videoFormats, MediaStreamStatusEnum.SendRecv);
rtpSession.addTrack(videoTrack);
hasVideo = true;
}
var sdpOffer = rtpSession.CreateOffer(null);
// Because the SDP being written to the file is the input to ffplay the connection ports need to be changed
// to the ones ffplay will be listening on.
if (hasAudio)
{
sdpOffer.Media.Single(x => x.Media == SDPMediaTypesEnum.audio).Port = FFPLAY_DEFAULT_AUDIO_PORT;
}
if (hasVideo)
{
sdpOffer.Media.Single(x => x.Media == SDPMediaTypesEnum.video).Port = FFPLAY_DEFAULT_VIDEO_PORT;
}
Console.WriteLine(sdpOffer);
using (StreamWriter sw = new StreamWriter(FFPLAY_DEFAULT_SDP_PATH))
{
sw.Write(sdpOffer);
}
string ffplayCommand = String.Format(FFPLAY_DEFAULT_COMMAND, FFPLAY_DEFAULT_SDP_PATH);
Console.WriteLine($"Start ffplay using the command below:");
Console.WriteLine(ffplayCommand);
Console.WriteLine($"To request the remote peer to send a video key frame press 'k'");
rtpSession.Start();
rtpSession.SetDestination(SDPMediaTypesEnum.audio, new IPEndPoint(IPAddress.Loopback, FFPLAY_DEFAULT_AUDIO_PORT), new IPEndPoint(IPAddress.Loopback, FFPLAY_DEFAULT_AUDIO_PORT + 1));
rtpSession.SetDestination(SDPMediaTypesEnum.video, new IPEndPoint(IPAddress.Loopback, FFPLAY_DEFAULT_VIDEO_PORT), new IPEndPoint(IPAddress.Loopback, FFPLAY_DEFAULT_VIDEO_PORT + 1));
return(rtpSession);
}
