[Ffmpeg-devel] [PATCH] tunable vb_strategy=1

Corey Hickey bugfood-ml
Thu Jun 1 18:48:53 CEST 2006

Matthias Wieser wrote:
> Corey Hickey wrote:
>> Corey Hickey wrote:
>>> It seems to me that vb_strategy=1 is fundamentally a good idea, but
>>> it's too sensitive. I looked in the code and found a number: 40. If
>>> that number were lower, lavc would use more B-frames. I made it tunable
>>> and ran some tests. All results are for the second pass (except
>>> first-pass encoding time), and each test had vmax_b_frames=2.
>> Would anybody object if I applied this? If nobody speaks up, then I'll
>> apply it in one day.
> I'm not a developer but I have done some tests and lower numbers at least do 
> not look worse and give better PSNR (hello Rich).

Thanks for testing. Can you please describe your source video(s) a bit? 
Specifically, I'm curious whether or not you tried animated material, 
and how much motion there was. Also, what other encoding parameters did 
you use?

> So it would be nice if you would not only apply the patch but also adjust 
> the default to some lower number, e.g. 10. It's all about sane defaults.

Eventually I would like to do that. Some testing of a variety of samples 
is in order.


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