[FFmpeg-devel] [PATCH] H264: Fix deblocking for first row in fields

[Martin Zlomek]

I suppose that one more condition (in filter_mb()) should be fixed - see my
patch  
http://lists.mplayerhq.hu/pipermail/ffmpeg-devel/2007-October/036746.html


On Wed, 07 Nov 2007 21:05:29 +0100, Jeff Downs <heydowns at borg.com> wrote:

> H264 PAFF implementation is missing a change to filter_mb_fast to
> check for deblocking on the first row of a bottom field.  Without this
> check, filter_mb_fast might be called for the first row, which (from what
> I understand in a read of the existing code) is not appropriate.  In
> particular, a run through valgrind will show that the access to
> qscale_table[h->top_mb_xy] goes out of bounds (top_mb_xy is negative for
> first row).
>
> This augments the existing check to look for row 1 in bottom fields.
>
> Benchmarks here with non-interlaced content showed no real speed impact
> (overhead of the check), which is surprising to me; if anyone else wants
> to check that, please feel free.
>
> Old:
> User: avg: 6.222  stddev: 0.007  med: 6.222
>
> New:
> User: avg: 6.212  stddev: 0.007  med: 6.216
>
> 	-Jeff



-- 
Martin Zlomek
martin.zlomek at email.cz