Reimar Döffinger <b...@reimardoeffinger.de> added the comment: On Sat, Jan 15, 2011 at 03:57:08PM +0000, ami_stuff wrote: > > New submission from ami_stuff <ami_st...@o2.pl>: > > it's painfully slow and the output avi file have insane big size > > this happens for most of the codecs I have tested, here is a qt cinepak as an > axample > > C:\>ffmpeg -i C:\QT-Cinepak.mov -t 1 -an -vcodec copy C:\QT-Cinepak.avi > FFmpeg version SVN-r26325, Copyright (c) 2000-2011 the FFmpeg developers > built on Jan 13 2011 04:13:55 with gcc 4.4.2 > configuration: --enable-gpl --enable-version3 --enable-libgsm > --enable-libvorb > is --enable-libtheora --enable-libspeex --enable-libmp3lame > --enable-libopenjpeg > --enable-libschroedinger --enable-libopencore_amrwb > --enable-libopencore_amrnb > --enable-libvpx --disable-decoder=libvpx --arch=x86 > --enable-runtime-cpudetect - > -enable-libxvid --enable-libx264 --enable-librtmp --extra-libs='-lrtmp > -lpolarss > l -lws2_32 -lwinmm' --target-os=mingw32 --enable-avisynth --enable-w32threads > -- > cross-prefix=i686-mingw32- --cc='ccache i686-mingw32-gcc' > --enable-memalign-hack > > libavutil 50.36. 0 / 50.36. 0 > libavcore 0.16. 1 / 0.16. 1 > libavcodec 52.108. 0 / 52.108. 0 > libavformat 52.92. 0 / 52.92. 0 > libavdevice 52. 2. 3 / 52. 2. 3 > libavfilter 1.73. 1 / 1.73. 1 > libswscale 0.12. 0 / 0.12. 0 > > Seems stream 1 codec frame rate differs from container frame rate: 1000000.00 > (1 > 000000/1) -> 24.00 (1000000/41667) > Input #0, mov,mp4,m4a,3gp,3g2,mj2, from 'C:\QT-Cinepak.mov': > Metadata: > creation_time : 2002-10-02 22:28:55 > Duration: 00:00:05.95, start: 0.000000, bitrate: 783 kb/s > Stream #0.0(eng): Audio: adpcm_ima_qt, 11025 Hz, 2 channels, s16 > Metadata: > creation_time : 2002-10-02 22:28:55 > Stream #0.1(eng): Video: cinepak, yuv420p, 192x128, 687 kb/s, 24 fps, 24 > tbr > , 1000k tbn, 1000k tbc
Timebase of the input format is 1/1000000 s > Metadata: > creation_time : 2002-10-02 22:28:55 > Output #0, avi, to 'C:\QT-Cinepak.avi': > Metadata: > creation_time : 2002-10-02 22:28:55 > ISFT : Lavf52.92.0 > Stream #0.0(eng): Video: cvid / 0x64697663, yuv420p, 192x128, q=2-31, 687 > kb > /s, 1000k tbn, 1000k tbc Trying to mux that into AVI results in > video:81kB audio:0kB global headers:0kB muxing overhead 27746.017656% This massive overhead. You absolutely need to specify a desired output frame-rate. I suspect that in this case FFmpeg should probably detect that 1/24 is a sufficient time-base (assuming it really is for this format), and probably it should print a big warning when it can't use a reasonable one with a format where this causes issues. The problem is that teh AVI muxer is currently AVFMT_VARIABLE_FPS, while technically correct we should probably have a flag that indicates timebase >> fps will cause massive overhead (as is the case for AVI) and warn in that case. ---------- title: Remuxing Cinepak from qt to avi -> something is wrong with transcode of qt to avi ________________________________________________ FFmpeg issue tracker <iss...@roundup.ffmpeg.org> <https://roundup.ffmpeg.org/issue2549> ________________________________________________
