[FFmpeg-devel] [PATCH] Stricter TMV probe

Reimar Döffinger Reimar.Doeffinger
Mon Sep 14 22:37:01 CEST 2009


On Mon, Sep 14, 2009 at 10:30:13PM +0200, Vitor Sessak wrote:
> Reimar D?ffinger wrote:
> > On Mon, Sep 14, 2009 at 04:05:34PM -0400, Ronald S. Bultje wrote:
> >> Hi,
> >>
> >> On Mon, Sep 14, 2009 at 3:51 PM, Reimar D?ffinger
> >> <Reimar.Doeffinger at gmx.de> wrote:
> >>> Not really related to this specific patch, just because every probe
> >>> function checks sample_rate:
> >>> A lot of demuxers (including that one) do not validate it in
> >>> read_header, ending up with 1/0 as time base. That really is not ok (and
> >>> as said, I have the impression a lot of demuxers do that).
> >> I think just checking for != 0 isn't enough. A samplerate of 1 might
> >> be valid, but isn't. I mean, it wouldn't produce anything audible. A
> >> min. samplerate of e.g. 1000 seems appropriate, and for many gaming
> >> formats, a max of e.g. 192000 might also be useful.
> >>
> >> Similar restrictions might apply to other properties.
> > 
> > Checking for != 0 is certainly enough to avoid division by 0
> 
> I don't think the probing code is the best place to avoid crashes later 
> (think about someone correctly forcing the format for a broken file)...

Then we were misunderstanding each other, I wrote "do not validate it in
read_header", and I was only talking about that, not about probing.



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