[FFmpeg-devel] [PATCH] Implement PAFF in H.264

Martin Zlomek martin.zlomek
Mon Oct 15 00:39:40 CEST 2007

I have discovered that h264_loop_filter_strength_mmx2(), used for
'bS' calculation in inter predicted macroblocks, gives wrong output
when used in fields (compared with the reference decoder).
Attached patch is temporary not-optimized solution giving correct

I would like to ask Loren Merritt for help - could you look at this,
please? Learning MMX instructions and understanding your code would
not take me a while...

On Sun, 14 Oct 2007 21:17:00 +0200, Martin Zlomek <martin.zlomek at email.cz>  
> There is special case for deblocking top- and left-most macroblocks
> in the ffmpeg implementation. The problem is in the condition, which
> tests macroblock y-coordinate for equation to 0, and in y-coordinate
> of top-most macroblocks in bottom fields, where the coordinate is 1.
> The attached patch fixes this problem - the condition is fulfilled
> for top-most macroblocks in both top and bottom fields.
> Decoded I-frames (fields in fact) should be equivalent to those
> decoded by the reference decoder now.
> P-frames are still different...
> On Thu, 11 Oct 2007 17:23:59 +0200, Martin Zlomek  
> <martin.zlomek at email.cz>
> wrote:
>> I have discovered that the PAFF implementation still produces different
>> color values of several pixels in comparision with the reference  
>> decoder,
>> even in I-frames. I use the following sample for testing:
>> http://ftp3.itu.ch/av-arch/jvt-site/draft_conformance/FI1_Sony_E.zip
>> and I am working on solution...

Martin Zlomek
martin.zlomek at email.cz
-------------- next part --------------
A non-text attachment was scrubbed...
Name: paff-deblock-notoptimized.patch
Type: text/x-patch
Size: 1213 bytes
Desc: not available
URL: <http://lists.mplayerhq.hu/pipermail/ffmpeg-devel/attachments/20071015/85450841/attachment.bin>

More information about the ffmpeg-devel mailing list