[MEncoder-users] Need help fixing/decoding a recovered h264 file

[Marc MERLIN]

On Tue, Feb 23, 2010 at 11:59:47PM -0800, RC wrote:
> On Tue, 23 Feb 2010 23:49:16 -0800
> Marc MERLIN <marc_mplayer at merlins.org> wrote:
> 
> > The problem is that the file I recovered isn't quite playable and I
> > don't know h264/avc1 file formats well enough to see if there is an
> > easy fix or if my file is just hosed and gone.
> > I actually tried to take the h264 file header from the good file shown
> > below and attach the possibly broken file to that, but didn't get far
> > since I just don't know the h264 headers.
> 
> Unless they were intended for streaming, MP4/MOV files default to having
> the index at the END of the file, NOT the start.  What you may need to
> do is trucate it until you find approximately the right file length. 
> Looking at the bits at the end of a working MP4 will probably help.

So, I was wondering if that was the case, thanks for pointing that out.
But this is why I took 
ftp://marc.merlins.org/GOPR0001.MP4
and I truncated it myself (with dd, just removing all the bits) to 10MB
ftp://marc.merlins.org/GOPR0001_short.MP4
and it still plays fine.
So, my conclusion was that the GoPro HD MP4s had to be of the streaming
format then?

In that case, it would be good news for me, but yet, something is wrong in
ftp://marc.merlins.org/sd_short.mov
then that it doesn't have enough headers to play.

Is there a way to get more debugging out of mplayer/mencoder to see where
it's looking for headers and which one it's missing?

> For a less clumsy undelete option, try PhotoRec:
> www.cgsecurity.org/wiki/PhotoRec

Yes, that's a good tip. I actually have and use PhotoRec, it's a great piece
of software. Unfortunately it doesn't quite know how to restore avc1 mp4s
yet (I've been working with Christophe GRENIER on it, but no success yet).
 
Marc
-- 
"A mouse is a device used to point at the xterm you want to type in" - A.S.R.
Microsoft is to operating systems & security ....
                                      .... what McDonalds is to gourmet cooking
Home page: http://marc.merlins.org/