[FFmpeg-devel] [PATCH] parser: error out if the codec doesn't match

[Michael Niedermayer]

On Tue, Jan 05, 2016 at 12:48:10PM +0100, Andreas Cadhalpun wrote:
> On 05.01.2016 12:18, Michael Niedermayer wrote:
> > On Tue, Jan 05, 2016 at 12:02:29PM +0100, Andreas Cadhalpun wrote:
> >> That wouldn't work, as the codec id wasn't changed in force_codec_ids,
> >> but in the API using program.
> >> To reiterate, the problematic steps were:
> >>  * call avformat_find_stream_info, which detects a codec and initializes
> >>    a parser for it
> >>  * afterwards change the codec id in the API using program, so it
> >>    doesn't match with the parser
> >>
> >> Thus I think the only reliable way to detect this is a check in av_parser_parse2.
> > 
> > shouldnt this be a av_assert1/2() then ?
> > i mean this is a programming error in the user app not a error
> > condition that should happen that way in correct usage
> > IMHO if we need 5 extra checks thats fine but if this is just to
> > detect a user app bug then iam not sure these checks should be run
> > for every packet
> 
> I would prefer av_assert0, but if you think that could cause relevant slowdowns,
> I'm also fine with av_assert1. Patch for that attached.
> 
> Best regards,
> Andreas
> 

>  parser.c |    7 +++++++
>  1 file changed, 7 insertions(+)
> 1a29aebd63e39c82039cddb1239de415b1da43df  0001-parser-add-av_assert1-to-make-sure-the-codec-matches.patch
> From 80f6baa6d091807538461bab28656e3cf7303a2d Mon Sep 17 00:00:00 2001
> From: Andreas Cadhalpun <Andreas.Cadhalpun at googlemail.com>
> Date: Mon, 4 Jan 2016 23:52:20 +0100
> Subject: [PATCH] parser: add av_assert1 to make sure the codec matches
> 
> Otherwise this can have some surprising effects (crashes), so let's
> better not allow it.
> 
> Signed-off-by: Andreas Cadhalpun <Andreas.Cadhalpun at googlemail.com>

LGTM

thx

[...]

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Michael     GnuPG fingerprint: 9FF2128B147EF6730BADF133611EC787040B0FAB

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