Re: [Cellar] FFV1: FFmpeg default version is "0"?

["Peter B." <[e-mail]>]

Thanks Jérôme!



On 08.11.22 12:49, Jerome Martinez wrote:
> Actually it depends on the count of pixels (trigger is if > 720x576)

Thanks! Forgot about that.


> It is a "political" choice from FFmpeg, also for the count of slices 
> by default (always 4, either 720x577 or 4096x2160).
>
> I personally don't care much because I have the count of slices in my 
> scripts so version is defaulted to 3, but now that HD is common and 
> FFV1.3 is supported for a long time, it may be interesting to change 
> the default settings, true.

+1
Don't know about your experiences, but 24 slices has turned out to be 
nice overall default for SD-to-HD.
Opinions?


>
> IMO if the default version is changed, the default count of slices 
> should be changed too (change in FFV1 version would already have an 
> impact with 4 slices if more than 352x288; as the current default 
> setting for FFV1.3 is based on check on 352x288, we could do 4 for SD 
> including the ones with extra VBI so 720x608, 12 for HDReady, 16 for 
> HD/2K, 64 for UHD/4K, 256 for 8K, for having a similar pixel size of 
> slices whatever is the image pixel width).

If auto-default of slices per resolution would be possible, that'd be 
great! :)


I was mainly asking, because in trainings and presentations I've noticed 
that it's definitely nice (especially for FFV1-beginners) if FFmpeg's 
default settings would match the 
somewhat-de-facto-and-proven-to-be-useful values already in use in a 
professional context.

So introducing FFV1 with "-c:v ffv1" is sufficient and proper to start 
with, would be awesome IMO.

Right now, I have the feeling that many archivists feel overwhelmed when 
I mention "oh, please use these parameters that you have no idea yet 
what they're for" :P


>
> Note that changing default version has also an impact on compression 
> ratio (less compression with 4 slices than with the current 1 for SD 
> content).

Got any (rough) compression size benchmarks for this?



Thanks again,
Peter