#7124: Unexpected results from YUV-RGB color space conversion optimization on POWER8/LE -------------------------------------+------------------------------------ Reporter: seiko | Owner: Type: defect | Status: reopened Priority: normal | Component: swscale Version: git-master | Resolution: Keywords: ppc altivec | Blocked By: Blocking: | Reproduced by developer: 1 Analyzed by developer: 0 | -------------------------------------+------------------------------------ Changes (by cehoyos):
* keywords: ppc => ppc altivec * status: closed => reopened * version: unspecified => git-master * resolution: worksforme => * reproduced: 0 => 1 Comment: Replying to [comment:3 seiko]: > It's not about the performance but the sanity of conversion. Sorry, I realized that by now. Allow me to repeat that the original report was just invalid, post all necessary information including the command line you tested together with the complete, uncut console output here in the ticket, do not use external resources except for large source files. {{{ $ ffmpeg -lavfi testsrc2,format=yuv420p -pix_fmt rgb24 -vcodec png -t 10 out.nut ffmpeg version N-90615-g53688b6 Copyright (c) 2000-2018 the FFmpeg developers built with gcc 6.3.1 (GCC) 20170515 (Advance-Toolchain-at10.0) IBM AT 10 branch, based on subversion id 248065. configuration: --enable-gpl --cpu=power8 --cc=/opt/at10.0/bin/gcc libavutil 56. 13.100 / 56. 13.100 libavcodec 58. 17.100 / 58. 17.100 libavformat 58. 10.100 / 58. 10.100 libavdevice 58. 2.100 / 58. 2.100 libavfilter 7. 14.100 / 7. 14.100 libswscale 5. 0.102 / 5. 0.102 libswresample 3. 0.101 / 3. 0.101 libpostproc 55. 0.100 / 55. 0.100 Stream mapping: format -> Stream #0:0 (png) Press [q] to stop, [?] for help [swscaler @ 0x10019995be0] ALTIVEC: Color Space RGB24 Output #0, nut, to 'out.nut': Metadata: encoder : Lavf58.10.100 Stream #0:0: Video: png (MPNG / 0x474E504D), rgb24, 320x240 [SAR 1:1 DAR 4:3], q=2-31, 200 kb/s, 25 fps, 51200 tbn, 25 tbc (default) Metadata: encoder : Lavc58.17.100 png frame= 250 fps=0.0 q=-0.0 Lsize= 2289kB time=00:00:09.96 bitrate=1882.4kbits/s speed=56.6x video:2286kB audio:0kB subtitle:0kB other streams:0kB global headers:0kB muxing overhead: 0.130058% }}} The output file is clearly recognizable but looks broken. I tested a few of the libavcodec altivec optimizations and they work fine on le (and are tested by fate), this is indeed a specific issue in libswscale. -- Ticket URL: <https://trac.ffmpeg.org/ticket/7124#comment:4> FFmpeg <https://ffmpeg.org> FFmpeg issue tracker _______________________________________________ FFmpeg-trac mailing list FFmpeg-trac@avcodec.org http://ffmpeg.org/mailman/listinfo/ffmpeg-trac