[MPlayer-users] help w/ AVI format please

Dark Avenger adonis at linuxmail.org
Fri Feb 21 15:27:13 CET 2003


I recently had a AVI format movie deleted from my hard drive. I have
managed to recover the unallocated blocks (4096 bytes each), but in
RANDOM ORDER. The reason for this is that the linkage of block to
block for the file was lost. Therefore I have a 600MB file made up of
4k blocks containing movie data. Unfortunately there's also some
other non-movie data, but it's minimal, as the disk was full at the
time the movie was deleted.

What I want to do is recontruct the movie by "testing" to
see which 4k block is after which one so that it gives a "longer
run without errors".

Now, what I really want is someone to point me to some good sites
where I can learn about the AVI format (i know a little, but not
enough), so that I can maybe use this information to chase down the
"next good block". I realize that there are a lot of
permutations with 160,000 4kb blocks, but as far as I can tell only 1
is the correct one, which will also yield the original movie. I'm
willing to let my CPU's crunch on this for even a year 24/hours a
day. I don't care.

Any information on the AVI format would be appreciated!

For info: my first attempt was this: I found the first 4 4kb blocks
of the movie and put them together myself. Then I picked another 4kb
piece and attached it at the end and tested to see if the movie had
more "frames" in it (with a small avi parser based on the
opensource code). Unfortunately this failed (got stuck in infinite
loops, plus even if it didn't I'm sure some chunks are more than 4kb
and it would be next to impossible to find out their correct

Now I have read through the source and from what I can figure out
each video packet is marked as a "chunk". I'm thinking that
maybe there's a way to identify these chunks and play with that..
But I am not sure how i'm gonna "TEST" my concantenated
chuncks...meanign how to tell if this sequence of 4kb blocks A-B-C-D
is more correct than B-C-D-A let's say.

Is there an error metric that anyone can think of ?

Thanks in advance

PS. please CC me as I'm not subscribed to the list
Now with e-mail forwarding for only US$5.95/yr

Powered by Outblaze
-------------- next part --------------
An embedded message was scrubbed...
From: "Dark Avenger" <adonis at linuxmail.org>
Subject: help w/ AVI format please
Date: Fri, 21 Feb 2003 16:05:08 +0200
Size: 2772
URL: <http://lists.mplayerhq.hu/pipermail/mplayer-users/attachments/20030221/97d7a0e1/attachment.eml>

More information about the MPlayer-users mailing list