[FFmpeg-devel] [PATCH 1/2] vc2enc: prevent random data

Rostislav Pehlivanov atomnuker at gmail.com
Wed May 4 03:06:05 CEST 2016


On 3 May 2016 at 18:25, Christophe Gisquet <christophe.gisquet at gmail.com>
wrote:

> 2016-05-03 19:06 GMT+02:00 Christophe Gisquet <
> christophe.gisquet at gmail.com>:
> > +        memset(pb->buf_ptr, 0, pad_c);
>
> Commit squashing fail, attached patch should fix that. This
> unfortunately requires updating the fate tests as I generated them
> from this squashing.
>
> --
> Christophe
>
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>
vc2hqencode is not the reference encoder, vc2-reference is. It's even worse
though.
Also vc2hqencode shouldn't even be considered a reliable source of
correctness. We beat it in quality, stability, features and correctness
(their bitstream wasn't entirely correct until I pointed it out). Speed is
pending. And vc2hqdecode is a stability (and compliance w.r.t.
non-broadcast features) disaster.

Also, the commit message still says 0 instead of 0xff. btw the value 0xff
makes sense since that's the golomb code for 0. Would make reading broken
files a little more robust (instead of reading a ton of zeroes, losing
bitstream sync and causing trouble elsewhere).

Could you make the comment a C89 style like the rest of the encoder?

Other than that the patch is okay. Slice padding is usually very small, so
no real performance degradation.

Thanks


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