音频和视频不同步？

Question

I'm using nVLC as vlc wrapper to render rtsp video stream to memory, and then raise events for NewFrame (audio and Video). in the class that capture those events. I've used Accord.Video.FFMPEG.VideoFileWriter to write the frame, and audio bytes (or signal). but unfortunately I keep having delay between audio and video. I've tried to trace that delay and come up with the following:

1- the delay is different from stream to stream. ie for one stream it's about 1800 ms (audio leads), for another one it's about 3000 ms(audio leads too).

2- the delay is independent of the delay between capturing frames and capturing audio signals.

3- the delay is independent of the delay between capturing video NewFrame event and capturing audio NewFrame event.

4- delay is independent of the internet connection speed.

any help in solving this problem would be appreciated.

Thanks

Answer 1

The best shot I've got was by using the audio stream as the leading stream ie never record frames from video stream until the frame time is greater than or equals the first recorded audio frame. the PTS (Presentation Time Stamp) of sound frame as is when capture, but the PTS of image is calculated depending on the player.Time (ms) and by using a stopwatch which is reset every time the player.Time has changed (in TimeChanged event).