[FFmpeg-devel] [PATCH] ffv1enc: Make ffv1.3 non experimental

wm4 nfxjfg at googlemail.com
Sat Aug 17 15:27:43 CEST 2013

On Sat, 17 Aug 2013 13:33:27 +0200
Michael Niedermayer <michaelni at gmx.at> wrote:

> On Sat, Aug 17, 2013 at 08:27:14AM +0200, Reimar Döffinger wrote:
> > On 17.08.2013, at 05:00, Michael Niedermayer <michaelni at gmx.at> wrote:
> > 
> > > The fate tests change as they used 1.2 previously
> > 
> > It's fairly minimal, but is it expected that every single frame becomes larger?
> 1.3 adds 32bit CRCs per slice by default (can be disabled),
> it adds slice headers to allow decoding one slice without the others
> an additional slice size field is added to make it possible to find
> slices within corrupted surroundings.
> these add up to about 57bit per slice more
> at 50 frames and 4 slices thats 1425 byte which comes close to the
> actual difference, so i would say that explains the difference

I'm just curious: isn't CRC a pretty slow checksum algorithm? Why are
checksums needed at all, isn't that the responsibility of the
container, if it should be inside the file at all?

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