[FFmpeg-user] A/V sync problems with h264/aac video fragment

Konrad Karl kk_konrad at gmx.at
Sat Apr 14 10:45:36 CEST 2012

On Fri, Apr 13, 2012 at 04:24:46PM +0000, Carl Eugen Hoyos wrote:
> Because your hardware is not fast enough.
> Or are you able to reproduce the problem with mplayer -speed 0.2 ?
> (It works fine here with 0.1 on very slow hardware.)

Carl Eugen, you are completely right (shame on me, did not even think
about trying -speed :-(

It seems I need to go down to speed 0.7 on my hardware
(Intel(R) Core(TM)2 CPU 6400 @ 2.13GHz / GeForce 450 GTS)
to be able to play w/o A/V fluctuations. The other parts of the 
movie play OK at -speed 1.15 so the margin was quite small.

To watch the decoding speed in real time I tried also (after
removing the audio track):

mplayer -speed 5 test1-wo-audio.mp4  

and just looking at the V: values the progress suddenly slows down
quite a lot at the elephant. 

I guess now it is time to ask the x264 folks now about how to avoid this

Before that I will try a two-pass encode and see what happens.
Unfortunately encoding is quite slow, this movie takes about 1.5 hours
to render.

My final goal is to have this movie playing properly on the WD TV Live.

Thanks for actually looking at the video, appreciated,


More information about the ffmpeg-user mailing list