one more question about avi file's pixel aspect ratio

[compusic]

as I have learned before that avi file does not support par other than 1:1, since avi was first coined for video on computer. the link is below:
https://forum.videohelp.com/topic324305.html


if a avi file with other par is played back on pc, nearly all the players will suppose a 1:1 par, and won't make adjusting for the display, quick time's mov file has the same problem. I don't remember clearly at that time what codec those avi and mov files used, maybe in uncompressed format and some other codecs.

but now I just encounter a problem. when I play back avi file with dv codec ( par is 1.067), I find that the displayed frame aspect is correct, that means the players make adjusting for the par! the players I use are media player classic and windows media player 9. and I use quick time player 7 to play back mov file with dv codec, the fame ratio is correct too!

then I play back some other umcompressed avi with different par, the dar is not correct!

how can it be? the problem makes me crazy! nearly 99 out of 100 times, I'm not sure whether the avi file can be displayed correctly on the computer.

[jagabo]

I was wrong about AVI not supporting display aspect ratios. The original AVI spec had no provision for it but the ODL extensions (used by most programs these days) do have a frame aspect ratio (same as display aspect ratio) setting. Unfortunately its usage is sporadic so you can't rely on it.

The safest bet is assume DV (4:3 or 16:9) will display properly and that most other AVI files are square pixel (DAR = SAR).

Of course any file can be displayed correctly if you use a player that lets you specify the DAR (and most do).

[celtic_druid]

mplayer is I think about the only app that respects ODML AR settings. DV I would think contains its own AR info in the DV stream itself. Like with MPEG-4. So it would work irrespective of the container.