[FFmpeg-devel] [RFC] dc value 0 legal for flv?

Reimar Döffinger Reimar.Doeffinger
Sun Sep 13 00:21:09 CEST 2009

On Sat, Sep 12, 2009 at 11:41:19PM +0200, Michael Niedermayer wrote:
> On Sat, Sep 12, 2009 at 10:40:20PM +0200, Reimar D?ffinger wrote:
> > I'd sure expect so (I do not use flash player), though that doesn't really
> > tell if the file is valid (if not, at least the warning should stay).
> in h.263 such 0 values can lead to start code emulation, they are thus not
> valid.
> the flv spec i have which might not be the latest does not hint at any change
> of dc coding
> flv ver2 does replace the ac escape coding with a different one but it does
> also explicitly list 0 as forbidden in the new table

Hm, ok. It's a bit of an issue since MPlayer uses -er 2 as default but I
guess it's better to think a bit longer about it.
Maybe the original reporter responds (I asked if he know what
application created it, though probably he had nothing to do with
it and doesn't know...).

> btw, you did not mention it but does the file play correctly with your patch?

For what I can tell yes, even though quality is still bad.
It also works with ffplay by default, only if -er is 2 or greater there
is an issue.

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