Audio / video out of sync for custom capture pipeline

[Chris Tapp]

I'm trying to use a pipeline to capture a video stream so that I can display the frames in a custom app whilst the audio streams in the background. I've been using pipelines of the form:

gst-launch playbin2 uri=sintel.webm audio-sink="alsasink" video-sink="videorate ! ffmpegcolorspace ! videoscale add-borders=true ! video/x-raw-rgb, bpp=32, pixel-aspect-ratio=1/1, width=800, height=500 ! appsink drop=1 max-buffers=1"

I then use the 'last-buffer' of the appsink to grab the most-recent video frame to render.

This works great one system, but on another the audio gets ahead of the video and eventually breaks up.

What do I need to change in the pipeline so the audio keeps running real-time and the 'last-buffer' in the appsink is in step with it?

Chris Tapp

opensource at keylevel.com
www.keylevel.com