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

Christophe Gisquet christophe.gisquet at gmail.com
Wed May 4 09:52:51 CEST 2016


2016-05-04 3:06 GMT+02:00 Rostislav Pehlivanov <atomnuker at gmail.com>:
> vc2hqencode is not the reference encoder, vc2-reference is. It's even worse
> though.

Sorry, I thought authoritative could mean "from the authors", so I
didn't mean it as "the" reference/"the authority". Just a good
reference in case the specs are not clear or don't mention it. If
vc2-reference or "the" reference dirac codec do it differently, then
those should be followed.

> Also, the commit message still says 0 instead of 0xff.

I'm getting confused: neither version of the patch does. On a side
note, maybe I should retract the "standardized value" for the padding.

The commit message does mention 0 for the prefix, because I didn't see
any reference as what should be there. Anything I've seen uses 0
prefix bytes.

> 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).

Yeah, that's what I meant with the rationale. Classical reason to
choose a value for a padding.
Not a big deal, but isn't the specific codeword for 0 '1'?

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

Will come later today, and I may wait for your other patch to vc2enc.

And sorry I haven't followed the style of the file.

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

I haven't tested but I take your word on it.

Best regards,

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