[FFmpeg-devel] [PATCH] h264 - don't warn about deblocking type 1 without multiple slices

Michael Niedermayer michaelni
Wed Oct 31 18:09:49 CET 2007


On Sun, Oct 28, 2007 at 01:18:57PM -0400, Alexander Strange wrote:
> On Oct 27, 2007, at 3:18 PM, Michael Niedermayer wrote:
>> Hi
>> On Fri, Oct 26, 2007 at 05:40:01PM -0400, Alexander Strange wrote:
>>> If you enable multithreaded decoding for h.264, you get the warning
>>> "Cannot parallelize deblocking type 1, decoding such frames in sequential
>>> order",
>>> even if the video has only one slice and can't be parallelized anyway.
>>> This patch disables that bit of code for the first slice in a frame. I
>>> tested it on
>>> single-slice (that it can't parallelize) and multi-slice (that it can), 
>>> but
>>> not on
>>> type 1 + multi-slice since I can't find any. Is there any on mplayerhq?
>> this patch is wrong, it will disable the CODEC_FLAG2_FAST behavior of
>> deblocking_filter == 1 slices
>> [...]
> Looking at the h264 spec, deblocking_filter 1 is the same as 2 on 
> single-slice,
> so I think it's safe to make that change on everything.

no, this is still wrong
now the code would change to deblocking_filter = 2 (=incorrect decoding)
even if no multithreading (=no speed gain) is possible

Michael     GnuPG fingerprint: 9FF2128B147EF6730BADF133611EC787040B0FAB

I count him braver who overcomes his desires than him who conquers his
enemies for the hardest victory is over self. -- Aristotle
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