[FFmpeg-devel] [PATCH]: One line fix for https://roundup.ffmpeg.org/issue2343

[Michael Niedermayer]

On Thu, Dec 09, 2010 at 08:34:52PM -0800, Jason Garrett-Glaser wrote:
> On Thu, Dec 9, 2010 at 8:05 PM, Michael Niedermayer <michaelni at gmx.at> wrote:
> > On Thu, Dec 09, 2010 at 05:06:05PM -0800, Jason Garrett-Glaser wrote:
> >> On Thu, Dec 9, 2010 at 3:58 PM, Joey Geralnik <jgeralnik at gmail.com> wrote:
> >> > Um, yes, it is silly to file a bug with the solution built into the question
> >> > but if it is already filed might as well patch it.
> >> > --Joey
> >>
> >> 1. ?Stop top-posting.
> >>
> >> 2. ?Read my message again and again until you understand why your
> >> patch does literally the exact opposite of fixing the problem.
> >
> > i dont want to disturb your discussion but,
> > what problem?
> > a bug involves user vissible (wrong) behavior.
> > What kind of wrong behavior does this cause?
> 
> As far as I can tell, the bug is that the error code doesn't get
> checked.  Therefore, an error could occur in the function as a result
> of failed parsing, but then be ignored, causing ffmpeg to continue
> parsing anyways even when it shouldn't.

do you know of a case where this causes a actual problem (crash,
exploit, anything?). In mjpeg similar cases are problematic and must be checked
Ive not investigated this case now but i remember when writing this code that
my reasoning was that if a file has extradata we should try to parse it for
headers and if it fails just ignore and try normal header parsing.
My reasoning behind this was that with all the odd avi mpeg4 files out there
there likely would be some with extradata that is not valid mpeg4 headers.


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

Incandescent light bulbs waste a lot of energy as heat so the EU forbids them.
Their replacement, compact fluorescent lamps, much more expensive, dont fit in
many old lamps, flicker, contain toxic mercury, produce a fraction of the light
that is claimed and in a unnatural spectrum rendering colors different than
in natural light. Ah and we now need to turn the heaters up more in winter to
compensate the lower wasted heat. Who wins? Not the environment, thats for sure
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