[FFmpeg-devel] FFV1 Specification

Peter B. pb at das-werkstatt.com
Sun Apr 8 22:16:35 CEST 2012

On 04/08/2012 05:33 PM, Michael Niedermayer wrote:
> pushed some code to allow easy testing of 1.2, before you had to edit
> the source to enable it.
Does this mean there's a commandline switch now?
If so: How to enable v1.2?
(I used to change the version in the code and recompiled, just like you
told me)

> also to get good compression with gop=1 you need to use some statistics
> generated by -pass 1 though these dont need to be from teh same file
> as the actual encoding uses.
You mean I can (or even should) do multipass with FFv1?

Unfortunately, we're still bound to use Windows on the capture clients,
so I'm using ffdshow-tryouts to capture using FFv1 in realtime. They're
not really supporting encoding, so I'm lucky that it works at all.
However, I was always wondering about the "keyframe interval" option in
their FFv1 settings. It defaults to 10, but I set it to 1 (just to be
sure) - so I assume that all videos we've recording in the last 2 years
were GOP=1. And I can't complain.

> if someone wants to test ffv1.2, especially with diverse raw material,
> this would be quite interresting. Especially knowing where it performs
> poorly ...
That's still on my TODO-list.
Just a side-note, regarding diverse material and FFv1:
I found it very surprising (and very interesting), that compressing VHS
material ends up with ~350 MB/Min, but if the source was DigiBeta, it's
about ~650 MB/Min (FFv1, not v1.2 yet) - at the same resolution
(720x576, 8bit YUV422)

I would have expected the "dirtier" VHS to need more space, due to the
entropy of noise, but seems I was wrong :)


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