[FFmpeg-devel] [PATCH] Dynamic plugins loading

Alexander Strange astrange
Tue Nov 2 23:14:43 CET 2010

On Nov 2, 2010, at 6:05 PM, Nicolas George wrote:

> Le duodi 12 brumaire, an CCXIX, Michael Niedermayer a ?crit :
>> I think debuging the differences would be usefull
>> is it caused by quantization, motion estimation, scenechange detection
>> macroblock decisison ?
>> both we and xvid could benefit from knowing this
> I had been told, at the time, that the main difference was that XviD uses a
> higher quantizer for B-frames, while the native encoder, in fixed-quantizer
> mode, does not without specific options. But I had not been able to find the
> relevant options.
> That is why I am not claiming that XviD is better, but asking: does someone
> know how to tune the native encoder to be better than XviD?

That particular setting is -b_qoffset <something>.
More interesting options would start off with "-bidir_refine 1 -brd_scale 1 -bf 4 -b_strategy 2".

Given x264's success with MB-Tree (which obsoletes I/P offset and P/B offsets) and trellis frametype (b_strategy 2 is IIRC exponential) I think some improvement in algorithms would work better than options tuning here, but it would take a lot of effort and ASP is not really worth it.

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