On Tue, Oct 13, 2015 at 6:04 PM, Michael Niedermayer <mich...@niedermayer.cc> wrote: > On Tue, Oct 13, 2015 at 09:21:40PM +0200, Christophe Gisquet wrote: >> Results for omse on the 3 idct dct-test. >> >> C: 0.16915859 0.11848359 0.12913125 >> x86: 0.16883281 0.11849063 0.19041875 >> >> Using 14 and 17 as shifts subtantially improve those, but actually >> cause overflows and incorrect decoding of 12bpp content. >> --- >> libavcodec/simple_idct_template.c | 17 ++++------------- >> libavcodec/x86/idctdsp_init.c | 8 +++----- >> libavcodec/x86/simple_idct10.asm | 7 +++---- >> 3 files changed, 10 insertions(+), 22 deletions(-) > > dct-test -i changes > IDCT SIMPLE-C12: max_err=1 omse=0.11856094 ome=0.00286875 syserr=0.02590000 > maxout=288 blockSumErr=64 > to > IDCT SIMPLE-C12: max_err=1 omse=0.11825703 ome=0.01024297 syserr=0.05225000 > maxout=288 blockSumErr=64 > > dct-test -i 2 > 58 2571 1334 1334 1334 1334 58 2571 > 2571 58 1334 1334 1334 1334 2571 58 > 58 2571 3805 -1156 3805 -1156 58 2571 > 2571 58 -1156 3805 -1156 3805 2571 58 > 58 2571 3805 -1156 3805 -1156 58 2571 > 2571 58 -1156 3805 -1156 3805 2571 58 > 58 2571 1334 1334 1334 1334 58 2571 > 2571 58 1334 1334 1334 1334 2571 58 > IDCT SIMPLE-C12: max_err=1 omse=0.12911875 ome=0.06609375 syserr=0.19025000 > maxout=256 blockSumErr=64 > to > 2560 5073 2560 2560 2560 2560 2560 5073 > 5073 2560 2560 2560 2560 2560 5073 2560 > 2560 5073 5031 70 5031 70 2560 5073 > 5073 2560 70 5031 70 5031 5073 2560 > 2560 5073 5031 70 5031 70 2560 5073 > 5073 2560 70 5031 70 5031 5073 2560 > 2560 5073 2560 2560 2560 2560 2560 5073 > 5073 2560 2560 2560 2560 2560 5073 2560 > IDCT SIMPLE-C12: max_err=1 omse=0.19041875 ome=0.15929375 syserr=0.25365000 > maxout=256 blockSumErr=64 > > the ome and syserr values worsen by this > > iam not objecting to this if thats what people want, just want to > make sure its not missed
I do not object if there is a good reason for why keeping the error bars the same is not feasible. As a percentage of the original errors, these changes do not look negligible. This should be documented as (preferably) commit message + comment, or at the least in the commit message. > > also IIUC this is just to make C and x86 match, so it could just be > skiped with no ill effects except that tnen x86 and C would not be > bitexact matches ? > > > [...] > -- > Michael GnuPG fingerprint: 9FF2128B147EF6730BADF133611EC787040B0FAB > > I have often repented speaking, but never of holding my tongue. > -- Xenocrates > > _______________________________________________ > ffmpeg-devel mailing list > ffmpeg-devel@ffmpeg.org > http://ffmpeg.org/mailman/listinfo/ffmpeg-devel > _______________________________________________ ffmpeg-devel mailing list ffmpeg-devel@ffmpeg.org http://ffmpeg.org/mailman/listinfo/ffmpeg-devel
