Public bug reported: Binary package hint: ffmpeg
using ffmpeg comming with ubuntu jaunty (which is FFmpeg version 0.5=-svn17737+3:0.svn20090303-1ubuntu4); usage of the -qscale rather then -b doesn't change the end result file size. In fact; coding a flv video five times with qscale going from 1 to 5 has no effect; using 25 doesn't quite make the video any smaller or less nice to watch. Originally found this with trying to transcode vob mpeg to a theora; trying -qmin, -qmax -sameq seems to have the same effect. I guess the default of 200kb/s for the bitrate setting is taking precedence over what's set for the quantizer Here's some command line session which shows the problem. This isn't limited to vob -> flv; qscale doesn't work for theora->theora as well, (and probably a lot more, if not everything). 0 n...@toad:~/ for x in 1 2 3 4 5; do ffmpeg -y -i HARRY_POTTER_GOBLET_OF_FIRE1.vob -croptop 80 -cropbottom 80 -t 00:01:00 -ss 00:00:00 -an -sameq -f flv -qscale $x video$x.flv; done FFmpeg version 0.5-svn17737+3:0.svn20090303-1ubuntu4, Copyright (c) 2000-2009 Fabrice Bellard, et al. configuration: --enable-gpl --enable-postproc --enable-swscale --enable-x11grab --extra-version=svn17737+3:0.svn20090303-1ubuntu4 --prefix=/usr --enable-avfilter --enable-avfilter-lavf --enable-libgsm --enable-libschroedinger --enable-libspeex --enable-libtheora --enable-libvorbis --enable-pthreads --disable-stripping --disable-vhook --enable-libdc1394 --enable-shared --disable-static libavutil 49.15. 0 / 49.15. 0 libavcodec 52.20. 0 / 52.20. 0 libavformat 52.31. 0 / 52.31. 0 libavdevice 52. 1. 0 / 52. 1. 0 libavfilter 0. 4. 0 / 0. 4. 0 libswscale 0. 7. 1 / 0. 7. 1 libpostproc 51. 2. 0 / 51. 2. 0 built on Mar 23 2009 07:13:25, gcc: 4.3.3 Seems stream 0 codec frame rate differs from container frame rate: 50.00 (50/1) -> 25.00 (25/1) Input #0, mpeg, from 'HARRY_POTTER_GOBLET_OF_FIRE1.vob': Duration: 01:15:42.86, start: 0.052000, bitrate: 12699 kb/s Stream #0.0[0x1e0]: Video: mpeg2video, yuv420p, 720x576 [PAR 64:45 DAR 16:9], 7500 kb/s, 25 tbr, 90k tbn, 50 tbc Stream #0.1[0x80]: Audio: ac3, 48000 Hz, 5.1, s16, 384 kb/s Stream #0.2[0x81]: Audio: ac3, 0 channels, s16 Output #0, flv, to 'video1.flv': Stream #0.0: Video: flv, yuv420p, 720x416 [PAR 227:221 DAR 10215:5746], q=2-31, 200 kb/s, 90k tbn, 25 tbc Stream mapping: Stream #0.0 -> #0.0 Press [q] to stop encoding frame= 1501 fps=103 q=0.0 Lsize= 12920kB time=60.04 bitrate=1762.8kbits/s video:12896kB audio:0kB global headers:0kB muxing overhead 0.183273% FFmpeg version 0.5-svn17737+3:0.svn20090303-1ubuntu4, Copyright (c) 2000-2009 Fabrice Bellard, et al. configuration: --enable-gpl --enable-postproc --enable-swscale --enable-x11grab --extra-version=svn17737+3:0.svn20090303-1ubuntu4 --prefix=/usr --enable-avfilter --enable-avfilter-lavf --enable-libgsm --enable-libschroedinger --enable-libspeex --enable-libtheora --enable-libvorbis --enable-pthreads --disable-stripping --disable-vhook --enable-libdc1394 --enable-shared --disable-static libavutil 49.15. 0 / 49.15. 0 libavcodec 52.20. 0 / 52.20. 0 libavformat 52.31. 0 / 52.31. 0 libavdevice 52. 1. 0 / 52. 1. 0 libavfilter 0. 4. 0 / 0. 4. 0 libswscale 0. 7. 1 / 0. 7. 1 libpostproc 51. 2. 0 / 51. 2. 0 built on Mar 23 2009 07:13:25, gcc: 4.3.3 Seems stream 0 codec frame rate differs from container frame rate: 50.00 (50/1) -> 25.00 (25/1) Input #0, mpeg, from 'HARRY_POTTER_GOBLET_OF_FIRE1.vob': Duration: 01:15:42.86, start: 0.052000, bitrate: 12699 kb/s Stream #0.0[0x1e0]: Video: mpeg2video, yuv420p, 720x576 [PAR 64:45 DAR 16:9], 7500 kb/s, 25 tbr, 90k tbn, 50 tbc Stream #0.1[0x80]: Audio: ac3, 48000 Hz, 5.1, s16, 384 kb/s Stream #0.2[0x81]: Audio: ac3, 0 channels, s16 Output #0, flv, to 'video2.flv': Stream #0.0: Video: flv, yuv420p, 720x416 [PAR 227:221 DAR 10215:5746], q=2-31, 200 kb/s, 90k tbn, 25 tbc Stream mapping: Stream #0.0 -> #0.0 Press [q] to stop encoding frame= 1501 fps= 98 q=0.0 Lsize= 12920kB time=60.04 bitrate=1762.8kbits/s video:12896kB audio:0kB global headers:0kB muxing overhead 0.183273% FFmpeg version 0.5-svn17737+3:0.svn20090303-1ubuntu4, Copyright (c) 2000-2009 Fabrice Bellard, et al. configuration: --enable-gpl --enable-postproc --enable-swscale --enable-x11grab --extra-version=svn17737+3:0.svn20090303-1ubuntu4 --prefix=/usr --enable-avfilter --enable-avfilter-lavf --enable-libgsm --enable-libschroedinger --enable-libspeex --enable-libtheora --enable-libvorbis --enable-pthreads --disable-stripping --disable-vhook --enable-libdc1394 --enable-shared --disable-static libavutil 49.15. 0 / 49.15. 0 libavcodec 52.20. 0 / 52.20. 0 libavformat 52.31. 0 / 52.31. 0 libavdevice 52. 1. 0 / 52. 1. 0 libavfilter 0. 4. 0 / 0. 4. 0 libswscale 0. 7. 1 / 0. 7. 1 libpostproc 51. 2. 0 / 51. 2. 0 built on Mar 23 2009 07:13:25, gcc: 4.3.3 Seems stream 0 codec frame rate differs from container frame rate: 50.00 (50/1) -> 25.00 (25/1) Input #0, mpeg, from 'HARRY_POTTER_GOBLET_OF_FIRE1.vob': Duration: 01:15:42.86, start: 0.052000, bitrate: 12699 kb/s Stream #0.0[0x1e0]: Video: mpeg2video, yuv420p, 720x576 [PAR 64:45 DAR 16:9], 7500 kb/s, 25 tbr, 90k tbn, 50 tbc Stream #0.1[0x80]: Audio: ac3, 48000 Hz, 5.1, s16, 384 kb/s Stream #0.2[0x81]: Audio: ac3, 0 channels, s16 Output #0, flv, to 'video3.flv': Stream #0.0: Video: flv, yuv420p, 720x416 [PAR 227:221 DAR 10215:5746], q=2-31, 200 kb/s, 90k tbn, 25 tbc Stream mapping: Stream #0.0 -> #0.0 Press [q] to stop encoding frame= 1501 fps= 99 q=0.0 Lsize= 12920kB time=60.04 bitrate=1762.8kbits/s video:12896kB audio:0kB global headers:0kB muxing overhead 0.183273% FFmpeg version 0.5-svn17737+3:0.svn20090303-1ubuntu4, Copyright (c) 2000-2009 Fabrice Bellard, et al. configuration: --enable-gpl --enable-postproc --enable-swscale --enable-x11grab --extra-version=svn17737+3:0.svn20090303-1ubuntu4 --prefix=/usr --enable-avfilter --enable-avfilter-lavf --enable-libgsm --enable-libschroedinger --enable-libspeex --enable-libtheora --enable-libvorbis --enable-pthreads --disable-stripping --disable-vhook --enable-libdc1394 --enable-shared --disable-static libavutil 49.15. 0 / 49.15. 0 libavcodec 52.20. 0 / 52.20. 0 libavformat 52.31. 0 / 52.31. 0 libavdevice 52. 1. 0 / 52. 1. 0 libavfilter 0. 4. 0 / 0. 4. 0 libswscale 0. 7. 1 / 0. 7. 1 libpostproc 51. 2. 0 / 51. 2. 0 built on Mar 23 2009 07:13:25, gcc: 4.3.3 Seems stream 0 codec frame rate differs from container frame rate: 50.00 (50/1) -> 25.00 (25/1) Input #0, mpeg, from 'HARRY_POTTER_GOBLET_OF_FIRE1.vob': Duration: 01:15:42.86, start: 0.052000, bitrate: 12699 kb/s Stream #0.0[0x1e0]: Video: mpeg2video, yuv420p, 720x576 [PAR 64:45 DAR 16:9], 7500 kb/s, 25 tbr, 90k tbn, 50 tbc Stream #0.1[0x80]: Audio: ac3, 48000 Hz, 5.1, s16, 384 kb/s Stream #0.2[0x81]: Audio: ac3, 0 channels, s16 Output #0, flv, to 'video4.flv': Stream #0.0: Video: flv, yuv420p, 720x416 [PAR 227:221 DAR 10215:5746], q=2-31, 200 kb/s, 90k tbn, 25 tbc Stream mapping: Stream #0.0 -> #0.0 Press [q] to stop encoding frame= 1501 fps=103 q=0.0 Lsize= 12920kB time=60.04 bitrate=1762.8kbits/s video:12896kB audio:0kB global headers:0kB muxing overhead 0.183273% FFmpeg version 0.5-svn17737+3:0.svn20090303-1ubuntu4, Copyright (c) 2000-2009 Fabrice Bellard, et al. configuration: --enable-gpl --enable-postproc --enable-swscale --enable-x11grab --extra-version=svn17737+3:0.svn20090303-1ubuntu4 --prefix=/usr --enable-avfilter --enable-avfilter-lavf --enable-libgsm --enable-libschroedinger --enable-libspeex --enable-libtheora --enable-libvorbis --enable-pthreads --disable-stripping --disable-vhook --enable-libdc1394 --enable-shared --disable-static libavutil 49.15. 0 / 49.15. 0 libavcodec 52.20. 0 / 52.20. 0 libavformat 52.31. 0 / 52.31. 0 libavdevice 52. 1. 0 / 52. 1. 0 libavfilter 0. 4. 0 / 0. 4. 0 libswscale 0. 7. 1 / 0. 7. 1 libpostproc 51. 2. 0 / 51. 2. 0 built on Mar 23 2009 07:13:25, gcc: 4.3.3 Seems stream 0 codec frame rate differs from container frame rate: 50.00 (50/1) -> 25.00 (25/1) Input #0, mpeg, from 'HARRY_POTTER_GOBLET_OF_FIRE1.vob': Duration: 01:15:42.86, start: 0.052000, bitrate: 12699 kb/s Stream #0.0[0x1e0]: Video: mpeg2video, yuv420p, 720x576 [PAR 64:45 DAR 16:9], 7500 kb/s, 25 tbr, 90k tbn, 50 tbc Stream #0.1[0x80]: Audio: ac3, 48000 Hz, 5.1, s16, 384 kb/s Stream #0.2[0x81]: Audio: ac3, 0 channels, s16 Output #0, flv, to 'video5.flv': Stream #0.0: Video: flv, yuv420p, 720x416 [PAR 227:221 DAR 10215:5746], q=2-31, 200 kb/s, 90k tbn, 25 tbc Stream mapping: Stream #0.0 -> #0.0 Press [q] to stop encoding frame= 1501 fps=104 q=0.0 Lsize= 12920kB time=60.04 bitrate=1762.8kbits/s video:12896kB audio:0kB global headers:0kB muxing overhead 0.183273% 0 n...@toad:~/ ls -la video[12345].flv -rw-r--r-- 1 nido nido 13230180 2009-04-02 14:00 video1.flv -rw-r--r-- 1 nido nido 13230180 2009-04-02 14:00 video2.flv -rw-r--r-- 1 nido nido 13230180 2009-04-02 14:00 video3.flv -rw-r--r-- 1 nido nido 13230180 2009-04-02 14:00 video4.flv -rw-r--r-- 1 nido nido 13230180 2009-04-02 14:01 video5.flv ** Affects: ffmpeg (Ubuntu) Importance: Undecided Status: New -- using -qscale in ffmpeg doesn't have any effect on coding https://bugs.launchpad.net/bugs/356322 You received this bug notification because you are a member of Ubuntu Bugs, which is subscribed to Ubuntu. -- ubuntu-bugs mailing list ubuntu-bugs@lists.ubuntu.com https://lists.ubuntu.com/mailman/listinfo/ubuntu-bugs