[FFmpeg-devel] [PATCH] avformat/framehash: Add more information to the output

James Almer jamrial at gmail.com
Sat Apr 2 07:45:05 CEST 2016

On 3/30/2016 5:54 PM, Michael Niedermayer wrote:
> Signed-off-by: Michael Niedermayer <michael at niedermayer.cc>
> ---
>  libavformat/framehash.c                            |   13 +++++++++++++

Since you're pretty much rewriting every ref file, this may be a good chance
to turn framecrc into an alias for framemd5, hardcoding its AVHash context to

framecrc is using zero as initial value for the checksum, and i recall you once
saying that it should be non-zero. AVHash and thus framemd5's adler32 uses 1 as
initial value.
It would also allow us to move the framecrc stream extradata checksum code to
ff_framehash_write_header() to be used by framemd5 without having to duplicate
code. Same with the packet side data checks.

Somebody recently sent a patch to rename framemd5 and probably also framecrc
into framehash (keeping the old names as aliases for compat reason). Maybe the
efforts could be combined.

For that matter, would this require MD5Context.format_version to be bumped? Be
it your patch as is or with any of the above suggestions.

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