[FFmpeg-devel] [PATCH] mxf umid generation

Michael Niedermayer michaelni
Sat Mar 7 04:44:55 CET 2009

On Fri, Mar 06, 2009 at 07:28:55PM -0800, Baptiste Coudurier wrote:
> Hi,
> It seems some products really check umid and base themself on its
> uniqueness, so it seems better to actually try to generate a unique number.
> Is the approach in the patch acceptable ? If no, 

> any other suggestion ?

yes, add a random_seed.c/h
that does:
1. try to get a uint32 from reading /dev/(u)random
2. try to get a uint32 from LSB of rdtsc (and similar for ppc/bfin see 
3. md5 or sha1 of the first frame or extradata

Michael     GnuPG fingerprint: 9FF2128B147EF6730BADF133611EC787040B0FAB

Let us carefully observe those good qualities wherein our enemies excel us
and endeavor to excel them, by avoiding what is faulty, and imitating what
is excellent in them. -- Plutarch
-------------- next part --------------
A non-text attachment was scrubbed...
Name: not available
Type: application/pgp-signature
Size: 189 bytes
Desc: Digital signature
URL: <http://lists.mplayerhq.hu/pipermail/ffmpeg-devel/attachments/20090307/83b91590/attachment.pgp>

More information about the ffmpeg-devel mailing list