[FFmpeg-devel] [PATCH] avcodec/x86: add an 8-bit simple IDCT function based on the x86-64 high depth functions
michael at niedermayer.cc
Fri Jun 16 15:24:47 EEST 2017
On Fri, Jun 16, 2017 at 12:09:27PM +0200, James Darnley 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.
i retested and it does fail with this patch.
looking at the code changing the perm_type alone is enough to trigger
see dct_quantize() in libavcodec/x86/mpegvideoenc_template.c
it seems this lacks support for TRANSPOSE
Michael GnuPG fingerprint: 9FF2128B147EF6730BADF133611EC787040B0FAB
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