[FFmpeg-devel] FFV1.3

Tim Nicholson nichot20 at yahoo.com
Mon Apr 23 14:04:15 CEST 2012

On 20/04/12 14:50, Michael Niedermayer wrote:
> Hi
> Ive just commited some changes to the ffv1 codec v1.3
> Whats new:
> mandatory CRC on the global header

Sounds good.

> optional CRC on slices (The optionality is for discussion, we can make
> it mandatory if theres consens that this would be better, it would
> slow the encoder down a bit, bitrate wise it probably is negligible)
> many fields have been moved from the frame header to the slice header,
> this is needed so one slice can be decoded when the others are damaged
> or lost

This all sounds good from the point of robustness, and if ffv1 is
considered as a good archiving format (which is what I presume has
prompted these tweaks) then I would opt for per slice CRC and live with
the encoder overhead. However an option would give other users the
choice, so how about the default being on with the option to disable it?

> aspect ratio, top field first and interlace fields added, these could
> be droped again but i think they are better in ffv1 than the container
> because not all containers have these fields and thouse which do
> cant always change them mid file while mixed progressive/interlaced
> content exists and we want to support losslessly preserving it

I think having this information in the stream, rather than the
container, is preferable for all the reasons you outline.

> Comments welcome



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