Audio / video out of sync for custom capture pipeline

[Chris Tapp]

Hi Tim,

On 30 Aug 2013, at 07:39, Tim-Philipp Müller wrote:

> Hi Chris,
> 
> ----- Original message -----
>> 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?
>> 
> 
> Have you tried setting sync=true on appsink?


Yes, I've tried that and it makes no difference.

I think I need to make the video sink bin lossy so that it drops frames. Does that makes sense? If so, how can I get that behaviour? I though the 'drop=1' should do the job.

Chris Tapp

opensource at keylevel.com
www.keylevel.com