[FFmpeg-devel] ancient avi compatibility? (was: vintage avi type 1...)

[u-owvm at aetey.se]

On Sat, Jan 25, 2014 at 03:42:14PM +0100, Michael Niedermayer wrote:
> > What I am looking for is the pre-1996 avi format without extensions.
> > 
> > (I was referring to "AVI 2.0" which Wikipedia says the format is called
> > with the extensions, so I assumed that the former format would be called
> > "AVI 1.x")
> 
> what is the difference or rather which things that we write / dont
> write cause a problem ?

I do not know exactly, it is a matter of observation: a program which
is happily playing samples from http://samples.mplayerhq.hu/V-codecs/CVID/
becomes unhappy with corresponding avi files produced by ffmpeg by
"-c:v copy" avi to avi (or generated by ffmpeg).

It is a DOS program from 1998 which seems to go looping when given a
"modern" avi file.
(http://www.multimediaware.com/qv/dnreal.htm)

I wonder if ffmpeg can produce avi files without OpenDML extensions
which is probably what is making the difference for the old program.

> and where is the spec for the old format ?

According to http://wiki.multimedia.cx/index.php?title=AVI
there is
 http://msdn.microsoft.com/en-us/library/ms779636%28VS.85%29.aspx
and
 http://www.alexander-noe.com/video/documentation/avi.pdf
the latter looking more useful.

> also, i have a bad feeling about using wikipedia as reference here

At that moment I did not new any better.

> and opendml AVI had its first release 1995 not 1996 according to the
> opendml spec if thats what you refer to by AVI 2.0

The pdf mentioned above states that the OpenDML extensions are dated
28/02/1996 as version 1.02. The version before this is called there
"1.0".

This is otherwise a non-issue, the old video players are far from being
critical. The "pro" 32-bit version of the same program released 2007
can play ffmpeg's avi files just fine.

On the other side, why not let an owner of a 286 play videos on it? :)

Regards,
Rl