[FFmpeg-devel] [PATCH] Fix de/selection of libx264 I-partitions

Loren Merritt lorenm
Fri Jul 27 04:13:10 CEST 2007

On Thu, 26 Jul 2007, Panagiotis Issaris wrote:

> I've noticed that when using ffmpeg, using -partitions -parti4x4 doesn't
> work as I had expected. Although I was trying to disable the generations
> of 4x4 blocks, the output of ffmpeg would still contain:
> ...
> mb I  I16..4: 59.1%  0.0% 40.9%
> ...
> The attached patch fixes the selection and deselection of the usage of
> certain blocksizes when using libx264.

ffmpeg is currently consistent with mencoder and x264cli: the "partitions" 
option affects only P- and B-frames, while I-frames always use all 
available partitions. Because the only reason for disabling partitions is 
speed, and intra partitions in I-frames gain much more compression per 
cpu-time than in P- and B-frames.

If you want some way to disable partitions in I-frames, that's another 
question. But don't change the meaning of an existing option.

--Loren Merritt

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