[FFmpeg-devel] [PATCH 4/4] avcodec: loongson optimized h264pred with mmi

[Michael Niedermayer]

On Sun, Jul 12, 2015 at 05:46:46PM +0200, Michael Niedermayer wrote:
> On Sun, Jul 12, 2015 at 09:13:18PM +0800, 周晓勇 wrote:
> > 
> > 
> > 
> > > -----原始邮件-----
> > > 发件人: "Michael Niedermayer" <michael at niedermayer.cc>
> > > 发送时间: 2015年7月12日 星期日
> > > 收件人: "FFmpeg development discussions and patches" <ffmpeg-devel at ffmpeg.org>
> > > 抄送: 
> > > 主题: Re: [FFmpeg-devel] [PATCH 4/4] avcodec: loongson optimized h264pred with mmi
> > > 
> > > On Sat, Jul 11, 2015 at 09:02:51PM +0200, Michael Niedermayer wrote:
> > > > On Sun, Jul 05, 2015 at 11:43:37PM +0200, Michael Niedermayer wrote:
> > > > > On Sat, Jul 04, 2015 at 12:14:51PM +0800, 周晓勇 wrote:
> > > > > > i will offer a download source of Fedora21 OS next Monday.
> > > > > > i will run yum-builddep ffmpeg-xxx.src.rpm for preparing devel environment.
> > > > > >  what else do you need to install, because it maybe slow for downloading other packages abroad.
> > > > > > the new FC21 build with mips64el N64 API and mips64r2(-march=loongson3a) isa, and enabled ARCH_MIPS64 after ffmpeg configure.
> > > > > > the FC19-O32 was slow, so aborted.
> > > > > 
> > > > > other things hmm
> > > > > ccache, dash, screen
> > > > 
> > > > with dash configure finished in 1minute instead of 4 with bash (on loongson)
> > > 
> > > fate no longer passes after installing Fedora21
> > > 
> > > with
> > > dash ./configure --enable-gpl --cc='ccache gcc' --enable-pthreads --samples=/home/loongson/fate/ --enable-nonfree  --enable-version3 --assert-level=2
> > > i get failure due to illegal instructions
> > > 
> > > with
> > > dash ./configure --enable-gpl --cc='ccache gcc' --enable-pthreads --samples=/home/loongson/fate/ --enable-nonfree  --enable-version3 --assert-level=2  --cpu=loongson3a --enable-loongson3
> > > it fails in dca tests:
> > > 
> > > TEST    dca-core
> > > TEST    dca-xll
> > > stddev:  853.28 PSNR: 37.71 MAXDIFF:11651 bytes:  1554432/   700416
> > > MAXDIFF: |11651 - 0| >= 1
> > > size: |1554432 - 700416| >= 0
> > > Test dca-core failed. Look at tests/data/fate/dca-core.err for details.
> > > tests/Makefile:202: recipe for target 'fate-dca-core' failed
> > > make: *** [fate-dca-core] Error 1
> > > make: *** Waiting for unfinished jobs....
> > > stddev:  219.18 PSNR: 49.51 MAXDIFF: 2483 bytes:  8994816/  1073152
> > > MAXDIFF: |2483 - 0| >= 1
> > > size: |8994816 - 1073152| >= 0
> > > Test dca-xll failed. Look at tests/data/fate/dca-xll.err for details.
> > > tests/Makefile:202: recipe for target 'fate-dca-xll' failed
> > > make: *** [fate-dca-xll] Error 1
> > > 
> > 
> > yes, i got this dca failure too. i have encountered many other errors in fate test.
> 
> > why do you think it's due to illegal instructions? 
> 
> when --cpu=loongson3a --enable-loongson3 is not added then make fate
> fails and displays "illegal instruction"
> 
> this worked before the upgrade to Fedora21
> 
> 
> > i have no idea because ffmpeg or ffplay could decode and play the media data regularly only with wrong decoding.
> > if there is illegal instructions, when run ffmpeg or ffplay commands it will show illegal instruction caution.
> > in addition, with no optimization fate failed as well.
> 
> so what is the plan to continue ?
> you suggested to upgrade to Fedora21 but fate does not pass after the
> upgrade
> 
> you should have tested this before suggesting an upgrade!
> 
> i cannot test your patches if fate does not pass
> 
> will you fix the failures in Fedora21 or is there some other solution
> so we can continue to test and apply patches for loongson
> ?

building libavcodec/dca_parser.c with
-O0
fixes the fate-dca-core and fate-dca-xll failure


[...]

-- 
Michael     GnuPG fingerprint: 9FF2128B147EF6730BADF133611EC787040B0FAB

It is dangerous to be right in matters on which the established authorities
are wrong. -- Voltaire
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