[MPlayer-users] Get dimensions and duration of raw h.264 video

[Reimar Döffinger]

On Tue, Feb 07, 2012 at 01:43:25PM -0800, Marlon Smith wrote:
> Thanks for the help.  ffmpeg does determine the correct dimensions, and
> gives me this:
> 
> Seems stream 0 codec frame rate differs from container frame rate: 60.00
> (60/1) -> 30.00 (60/2)
> Input #0, h264, from './input.264':
>   Duration: N/A, bitrate: N/A
>     Stream #0.0: Video: h264, yuv420p, 800x480 [PAR 533:400 DAR
> 533:240], 30 fps, 30 tbr, 1200k tbn, 60 tbc
> 
> I created this video with mencoder, and it looks like mencoder didn't
> write the container info properly?  Ideally, I'd like to use mplayer to
> parse the information, since I want to include it with an application
> I'm writing.  Is there a way I can get mencoder to properly write this
> data with the video so that mplayer can read it back?  The video is
> 800x480, but mplayer shows it as 533x400.  I see those numbers in the
> output, but I don't understand what PAR and DAR are.

They are the aspect values, i.e. when a video should be displayed
in a different format than it was decoded.
There seems to be a bug (for which I just sent a patch to the
-dev-eng list) that MPlayer would overwrite and print the
aspect values instead of the actual video dimension when using
unusual aspect values.
One option to avoid it is to make mencoder use one of the
standard aspect values like 4:3 or 16:9...
(or compile a MPlayer with the patch I sent applied).