[MPlayer-users] Detected unknown aspect_ratio_information

[Giacomo Comes]

On Sat, Mar 12, 2005 at 03:35:08AM +0300, Vladimir Mosgalin wrote:
> A friend gave me mpeg2 file which mplayer plays back with wrong aspect
> ratio. It was ripped from 480x480 NTSC SVCD, the correct aspect ratio
> should be 4/3, however mplayer sets 1:1 aspect and prints this message
> upon playback:
> 
> Detected unknown aspect_ratio_information in mpeg sequence header.
> Please report the aspect value (14) along with the movie type
> (VGA,PAL,NTSC,SECAM) and the movie resolution
> (720x576,352x240,480x480,...) to the MPlayer developers, so that we can
> add support for it!
> Assuming 1:1 aspect for now.
> VIDEO:  MPEG2  480x480  (aspect 14)  23.976 fps  2518.0 kbps (314.8
> kbyte/s)
> [V] filefmt:2  fourcc:0x10000002  size:480x480  fps:23.98  ftime:=0.0417
> 
> 
> Right now I remuxed the file with -mpegopts vaspect=4/3, however I
> wonder if original file had wrong aspect ratio or 14 is some meaningful
> yet unrecognised by mplayer value.

I think the enocoder or the muxer used to create the movie did a mess.
mpeg2 defines only 4 aspect ratio: 1 to 4 corresponding to 1, 4/3, 16/9, 2.21
mpeg1 defines more values because of a different definition of the aspect ratio
(I dont remember exactly the details now).
So I you have an mpeg2 with an aspect not being 1-4 the mpeg is broken.
The correct thing to do is to remux it as you did.

Giacomo