[FFmpeg-devel] [PATCH] avcodec/x86: add an 8-bit simple IDCT function based on the x86-64 high depth functions

[Paul B Mahol]

On 6/16/17, James Darnley <jdarnley at obe.tv> wrote:
> On 2017-06-16 03:58, Michael Niedermayer wrote:
>> On Thu, Jun 15, 2017 at 05:08:33PM +0200, James Darnley wrote:
>>> Includes add/put functions
>>>
>>> Rounding contributed by Ronald S. Bultje
>>> ---
>>> I must be stupid.  I dropped the stack space change somewhere.
>>>
>>>  libavcodec/tests/x86/dct.c       |  2 +
>>>  libavcodec/x86/idctdsp_init.c    | 23 ++++++++++
>>>  libavcodec/x86/simple_idct.h     |  9 ++++
>>>  libavcodec/x86/simple_idct10.asm | 94
>>> ++++++++++++++++++++++++++++++++++++++++
>>>  4 files changed, 128 insertions(+)
>>
>> theres something wrong with this
>> it totally breaks this:
>> make -j12 ffmpeg && ./ffmpeg -ss 1 -i cache:matrixbench_mpeg2.mpg -t 2 -y
>> test.avi
>> ./ffplay test.avi
>>
>> (totally as in bitstream errors not some idct artifacts)
>
> How did you manage to break it that much?  I don't touch avformat.  I
> don't touch the rest of the decoder.
>
> I don't have that file to test with and the cut down version which I
> think is in fate is only 0.96 seconds long.  However trying your command
> on that file successfully decodes 1 frame from it.  I made decoding it
> with the new functions the fate test I added.  All the other fate
> samples in mpeg2/ decode seemingly fine with no extra messages.

File is in samples.ffmpeg.org/benchmark/testsuite1/matrixbench_mpeg2.mpg

Michael failed to write that.