Audio and Video Timestamp or Offset Problems

William Metcalf wmetcalf at
Tue Jul 19 11:50:58 PDT 2011

Hello all,

I am reading in Raw Audio and Raw Video from capture cards, and then 
rendering them directly to my computer.  I am able to do this fine, but 
the resulting video is ahead of the audio.  My initial thought was to 
start the Audio pipeline, and then wait 2 seconds and start the video 
pipeline.  When I executed this code the audio began playing sooner than 
the video as it should, but then the video just played faster until it 
was ahead of the audio again.  I then tried pausing 5 seconds before I 
started the video pipeline just to see what would happen, and that time 
the video did the same thing.  Because the video always plays ahead of 
the audio at the same rate, I am now thinking this problem is a 
timestamp or offset issue of some sort.  Is there any way to adjust the 
Video/Audio offset, or is there a better way to delay the video so that 
it will not speed up and pass the audio?

Here are my pipelines:
video - appsrc max-bytes = 0 is-live=true typefind=true ! 
"video/x-raw-yuv,format=UYVY,width=720,height=486,framerate=30/1" ! 
audio - appsrc max-bytes=0 is-live=true typefind=true ! audioparse ! 

Thank you for any help you can offer,

More information about the gstreamer-devel mailing list