[FFmpeg-devel] [PATCHv3] On2 VP7 decoder

[Vittorio Giovara]

On Tue, Mar 25, 2014 at 1:25 PM, Michael Niedermayer <michaelni at gmx.at> wrote:
> On Tue, Feb 18, 2014 at 09:52:30PM +1100, Peter Ross wrote:
>> Signed-off-by: Peter Ross <pross at xvid.org>
>> ---
>> Here is my first attempt at addressing the VP8 performance regressions
>> introduced by the VP7 decoder.
>>
>> This uses 'always inline & static template' approach to generate vp7_ and
>> vp8_ variants of performance critical functions. Every function containing
>> an 'if vp7' branch below vp8_decode_mb_row_sliced is duplicated.
>>
>> As a sanity check --disable-decoder=vp7 makes the resulting vp8.o binary is
>> virtually identical to the current vp8.o file. The only difference being the
>> use of function pointers for decode_mb_row_no_filter and filter_mb_row.
>>
>> user times from VP8 'A_4K_Video_Reel_by_Bright_Side_Network_Inc..webm' on
>> Core2 Q9400. In seconds.
>> VP8 only: 82.013 82.049 82.059 82.089 82.095  : AVERAGE 82.061
>> VP7+VP8:  82.206 82.234 82.249 82.253 82.261  : AVERAGE 82.241
>> VP8 only: 82.056 82.065 82.114 82.211 82.224  : AVERAGE 82.134
>> VP7+VP8:  82.257 82.339 82.356 82.391 82.482  : AVERAGE 82.365
>>
>> There is a fairly consistent ~0.25% performance drop for this input. It would
>> be nice to get performance data on other platforms where VP8 is popular. ARM
>> especially.
>>
>> Other changes in PATCHv3:
>> - combine fade operation with gold frame preservation
>> - optimise inter_predict_dc usage
>> - described vp7_calculate_mb_offset
>> - dont bother zeroing block/block_dc as done by idct now
>>
>> Thanks to Ronald and Jason for their thorough reviews. Cheers,
>>
>>  Changelog                            |   1 +
>>  doc/general.texi                     |   2 +
>>  libavcodec/Makefile                  |   1 +
>>  libavcodec/allcodecs.c               |   1 +
>>  libavcodec/arm/h264pred_init_arm.c   |   6 +-
>>  libavcodec/arm/vp8.h                 |   2 +-
>>  libavcodec/avcodec.h                 |   1 +
>>  libavcodec/codec_desc.c              |   7 +
>>  libavcodec/h264pred.c                |  16 +-
>>  libavcodec/vp8.c                     | 759 +++++++++++++++++++++++++++++------
>>  libavcodec/vp8.h                     |  26 ++
>>  libavcodec/vp8data.h                 | 138 ++++++-
>>  libavcodec/x86/Makefile              |   3 +
>>  libavcodec/x86/h264_intrapred_init.c |  10 +-
>>  14 files changed, 829 insertions(+), 144 deletions(-)
>
> applied
>

Hi,

the decoder doesn't compile standalone.
Also lacks a lavc MINOR version bump.
Furthermore it introduces at least a possible NULL pointer
dereferences in vp7_decode_frame_header() when prev_frame is NULL.

Cheers,
-- 
Vittorio