[MPlayer-users] Problem with -ao pcm:file option

[Reimar Döffinger]

On Thu, May 14, 2009 at 01:03:00PM +1000, Matthew Kwan wrote:
> We then tried using FIFOs to capture the decoded audio and video, using
> mplayer -ao pcm:file=audio-fifo -vo yuv4mpeg:file=video-fifo
> 
> The behaviour we're seeing is that it connects and buffers correctly,
> but that it passes through the audio and video in bursts. It does nothing
> for about four seconds, then writes all the accumulated audio and video
> in one hit, waits another four seconds, and so on. That's no good for us.

A large -autosync value should make the video smooth.
audio will always be written in chunks of 64 kB. While it's silly you
could change the audio to 2 channels / 48kHz and you'd get a piece of
audio about every 0.6 seconds.

> Is there any way to fix this problem?

Change ao_pcm to calculate get_delay correctly would make the video
smooth (but as said, -autosync should do that already).
Or you could probably use e.g. ao_jack and grab the audio via that
framework.
Lastly, you could provide a sample so the FFmpeg bug can be fixed and
you can use that.