[FFmpeg-user] FFv1: newer ffmpeg builds create larger files?

Peter B. pb at das-werkstatt.com
Mon Jun 18 09:50:58 CEST 2012


Quoting Michael Niedermayer <michaelni at gmx.at>:

> On Mon, Jun 04, 2012 at 07:31:34PM +0200, Peter B. wrote:
>> On 06/04/2012 02:56 AM, Michael Niedermayer wrote:
>> > On Mon, Jun 04, 2012 at 01:22:27AM +0200, Peter B. wrote:
>> >> Hm... I don't see any information about the bitstream parameters.
>> >> I've tried 2 things with "-debug 1":
>> >> 1) calling ffprobe on the original
>> >> 2) transcoding the original as before
>> > [...]
>> >> Is there something I've misunderstood/overlooked?
>> > ffmpeg -debug 1 -i ffv1file -f null -
>> >
>> Thank you! Interesting commandline :)
>>
>> Interestingly, this showed "coder:0" for the original (=smallest) file,
>> whereas using "-coder 0" resulted in larger files than "-coder 1" in my
>> tests.
>>
>> When I checked files encoded with "-coder 1", the above command output
>> "coder:2" - I've verified this behavior, and all files encoded with
>> "-coder 1" are being shown with "-coder 2". Why is that?
>
> The difference between coder type 1 and 2 are documented in the spec
> coder type 2 performs better than 1 in all cases i remember
> so its used by default when range coding is requested

I think there's a misunderstanding here:
I thought that the valid values for "-coder" are "0" and "1", not "1"  
and "2". Correct me if I'm wrong.

Secondly, the puzzling part is, that the ffv1-files I'm getting from  
the realtime encoding during capture (using ffdshow-tryouts with ffv1  
version 1), are way smaller than *any* ffv1-encoded version of the  
same content, transcoded with the current git-version(s) of ffmpeg.

Why is it that I'm unable to reproduce these small files - regardless  
which parameters I use?

Thanks,
Pb



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