[FFmpeg-devel] [PATCH] AC3 decoder CRC check

Michael Niedermayer michaelni
Mon Sep 3 00:21:18 CEST 2007


Hi

On Sun, Sep 02, 2007 at 11:12:42PM +0200, Reimar D?ffinger wrote:
> Hello,
> On Sun, Sep 02, 2007 at 01:53:15PM -0700, Trent Piepho wrote:
> [...]
> > If the crc is bad, the frame is useless.  It's a CRC, not Reed-Solomon, you
> > can't correct the bits.
> 
> That's nonsense. I do no know the details of AC-3 to know how likely it
> is, but the damage might be completely irrelevant (e.g. one of the 16
> bits of the CRC damaged and nothing else) or at least hardly noticable.

also all data before the damage is ok, in video codecs its much better to
guess where the error is and discard the data afterwards instead of discarding
the whole slice
and like reimar i dunno the details of ac3 ...

and to correct errors with crcs see
http://guru.multimedia.cx/index.php?s=crc

[...]
-- 
Michael     GnuPG fingerprint: 9FF2128B147EF6730BADF133611EC787040B0FAB

Everything should be made as simple as possible, but not simpler.
-- Albert Einstein
-------------- 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/20070903/4aaf72b8/attachment.pgp>



More information about the ffmpeg-devel mailing list