New submission from herve <[email protected]>: Hi, the conversion to pix_fmt yuvj420p or yuvj422p produces "points/white holes" in the darkest part of videos. I tried to understand its reason but failed. my impression is: JPG YUV range (aka yuvj, ala full range, 0-255) produces "holes", yuv range does not produce them (16-235) - if the output is YUV (range 16-235), no concern - if the output is mjpeg (range 0-255), artefacts. The concern only exists IF YOU RESCALE the video (no artifact without rescale) This "bug"(?) is not new, it already occured before the new scale/libavfilter
how to reproduce them: you will find screenshot and an input file here: http://www.whynotflores.com/_PRIVATE/FFmpeg/index.php (PS: the bug is not related to this MTS file, I encountered it with Xvid/AVI and other formats) the best way to see it is to deinterlace the file (to avoid blended fields in output) cli: ffmpeg -v 1 -deinterlace -i /Users/herve/Desktop/yuvjArtefacts.mts -vf "scale=1280:720" -vcodec mjpeg -an -y /Users/herve/Desktop/yuvjArtefacts.mov eg (command line with full output): hard/software: uname -a Darwin iMac-de-Herve.local 10.4.0 Darwin Kernel Version 10.4.0: Fri Apr 23 18:28:53 PDT 2010; root:xnu-1504.7.4~1/RELEASE_I386 i386 iMac-de-Herve:~ herve$ ffmpeg -v 1 -deinterlace -i /Users/herve/Desktop/yuvjArtefacts.mts -vf "scale=1280:720" -vcodec mjpeg -an -y /Users/herve/Desktop/yuvjArtefacts.mov FFmpeg version SVN-r24716, Copyright (c) 2000-2010 the FFmpeg developers built on Aug 12 2010 15:23:58 with gcc 4.2.1 (Apple Inc. build 5664) configuration: --enable-postproc --enable-gpl --enable-pthreads -- enable-static --disable-shared --enable-gray --enable-libx264 --enable- libmp3lame libavutil 50.23. 0 / 50.23. 0 libavcore 0. 3. 0 / 0. 3. 0 libavcodec 52.84. 3 / 52.84. 3 libavformat 52.78. 0 / 52.78. 0 libavdevice 52. 2. 1 / 52. 2. 1 libavfilter 1.27. 1 / 1.27. 1 libswscale 0.11. 0 / 0.11. 0 libpostproc 51. 2. 0 / 51. 2. 0 Seems stream 0 codec frame rate differs from container frame rate: 50.00 (50/1) -> 50.00 (50/1) Input #0, mpegts, from '/Users/herve/Desktop/yuvjArtefacts.mts': Duration: 00:00:03.65, start: 1.000033, bitrate: 7528 kb/s Program 1 Stream #0.0[0x1011]: Video: h264, yuv420p, 1440x1080 [PAR 4:3 DAR 16:9], 50 fps, 50 tbr, 90k tbn, 50 tbc Stream #0.1[0x1100]: Audio: ac3, 48000 Hz, 5.1, s16, 448 kb/s [buffer @ 0x100d02290] w:1440 h:1080 pixfmt:yuv420p [scale @ 0x100d02620] w:1440 h:1080 fmt:yuv420p -> w:1280 h:720 fmt:yuvj420p flags:0xa0000004 Output #0, mov, to '/Users/herve/Desktop/yuvjArtefacts.mov': Metadata: encoder : Lavf52.78.0 Stream #0.0: Video: mjpeg, yuvj420p, 1280x720 [PAR 4:3 DAR 64:27], q=2-31, 200 kb/s, 50 tbn, 50 tbc Stream mapping: Stream #0.0 -> #0.0 Press [q] to stop encoding frame= 91 fps= 27 q=24.8 Lsize= 2830kB time=3.66 bitrate=6335.4kbits/s video:2829kB audio:0kB global headers:0kB muxing overhead 0.048671% iMac-de-Herve:~ herve$ thanks for your attention bye ---------- messages: 11674 priority: normal status: new substatus: new title: mjpeg (yuvj4…p) produces artefacts type: bug ________________________________________________ FFmpeg issue tracker <[email protected]> <https://roundup.ffmpeg.org/issue2165> ________________________________________________
