[FFmpeg-devel] [PATCH] Dynamic plugins loading

Jason Garrett-Glaser darkshikari
Wed Nov 3 06:04:27 CET 2010


On Tue, Nov 2, 2010 at 7:19 PM, Michael Niedermayer <michaelni at gmx.at> wrote:
> On Tue, Nov 02, 2010 at 06:14:43PM -0400, Alexander Strange wrote:
>>
>> 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.
>
> long term, we will likely start using x264s encoding core for
> mpeg1/2/4/h261/2/3. That way we would get all the improvments in x264 for free

Well, mpeg-2 for sure: http://github.com/kierank/x262 :)

Dark Shikari



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