id summary reporter owner description type status priority component version resolution keywords cc blockedby blocking reproduced analyzed 2245 Speed difference when using -ss on similar MKVs when extracting frame image eelco "Summary of the bug: When using -ss on the input file, some MKVs are significantly slower than others, while they’re the same resolution. I would expect a small speed difference due to encoding differences, but in this case it’s about 6-8 times. How to reproduce: {{{ > time ./ffmpeg ""-ss"" ""10"" ""-i"" ~/Desktop/ffmpeg-ss-bug/slow-ss.mkv ""-f"" ""image2"" ""-vframes"" ""1"" /dev/null ffmpeg version N-49666-g4745194 Copyright (c) 2000-2013 the FFmpeg developers built on Feb 7 2013 10:22:14 with llvm-gcc 4.2.1 (LLVM build 2336.11.00) configuration: --prefix=/Users/eelco/Projects/Beamer/FFmpeg/build --enable-gpl --enable-version3 --enable-libx264 --disable-shared --enable-static --enable-libtheora --enable-libvorbis --enable-libvo-aacenc --disable-doc --extra-cflags='-DMACOSX_DEPLOYMENT_TARGET=10.6 -isysroot /Applications/Xcode.app/Contents/Developer/Platforms/MacOSX.platform/Developer/SDKs/MacOSX10.8.sdk -mmacosx-version-min=10.6 -I/Users/eelco/Projects/Beamer/FFmpeg/build/include' --extra-ldflags='-isysroot /Applications/Xcode.app/Contents/Developer/Platforms/MacOSX.platform/Developer/SDKs/MacOSX10.8.sdk -mmacosx-version-min=10.6 -L/Users/eelco/Projects/Beamer/FFmpeg/build/lib' libavutil 52. 17.101 / 52. 17.101 libavcodec 54. 91.101 / 54. 91.101 libavformat 54. 61.104 / 54. 61.104 libavdevice 54. 3.103 / 54. 3.103 libavfilter 3. 35.101 / 3. 35.101 libswscale 2. 2.100 / 2. 2.100 libswresample 0. 17.102 / 0. 17.102 libpostproc 52. 2.100 / 52. 2.100 Input #0, matroska,webm, from '/Users/eelco/Desktop/ffmpeg-ss-bug/slow-ss.mkv': Metadata: ENCODER : Lavf54.59.106 Duration: 00:00:11.22, start: 0.000000, bitrate: 9890 kb/s Chapter #0.0: start 0.000000, end 11.000000 Metadata: title : 00:00:00.000 Stream #0:0(eng): Video: h264 (High), yuv420p, 1920x1080, SAR 1:1 DAR 16:9, 23.98 fps, 23.98 tbr, 1k tbn, 47.95 tbc (default) Stream #0:1(eng): Audio: truehd, 48000 Hz, 7.1, s32 (default) Metadata: title : English TRUE-HD LANGUAGE : eng Output #0, image2, to '/dev/null': Metadata: encoder : Lavf54.61.104 Chapter #0.0: start 0.000000, end 1.000000 Metadata: title : 00:00:00.000 Stream #0:0(eng): Video: mjpeg, yuvj420p, 1920x1080 [SAR 1:1 DAR 16:9], q=2-31, 200 kb/s, 90k tbn, 23.98 tbc (default) Stream mapping: Stream #0:0 -> #0:0 (h264 -> mjpeg) Press [q] to stop, [?] for help frame= 1 fps=0.4 q=0.0 Lsize=N/A time=00:00:00.04 bitrate=N/A dup=0 drop=236 video:50kB audio:0kB subtitle:0 global headers:0kB muxing overhead -100.043320% 2.41 real 5.94 user 0.10 sys }}} VS. {{{ > time ./ffmpeg ""-ss"" ""10"" ""-i"" ~/Desktop/ffmpeg-ss-bug/fast-ss.mkv ""-f"" ""image2"" ""-vframes"" ""1"" /dev/null ffmpeg version N-49666-g4745194 Copyright (c) 2000-2013 the FFmpeg developers built on Feb 7 2013 10:22:14 with llvm-gcc 4.2.1 (LLVM build 2336.11.00) configuration: --prefix=/Users/eelco/Projects/Beamer/FFmpeg/build --enable-gpl --enable-version3 --enable-libx264 --disable-shared --enable-static --enable-libtheora --enable-libvorbis --enable-libvo-aacenc --disable-doc --extra-cflags='-DMACOSX_DEPLOYMENT_TARGET=10.6 -isysroot /Applications/Xcode.app/Contents/Developer/Platforms/MacOSX.platform/Developer/SDKs/MacOSX10.8.sdk -mmacosx-version-min=10.6 -I/Users/eelco/Projects/Beamer/FFmpeg/build/include' --extra-ldflags='-isysroot /Applications/Xcode.app/Contents/Developer/Platforms/MacOSX.platform/Developer/SDKs/MacOSX10.8.sdk -mmacosx-version-min=10.6 -L/Users/eelco/Projects/Beamer/FFmpeg/build/lib' libavutil 52. 17.101 / 52. 17.101 libavcodec 54. 91.101 / 54. 91.101 libavformat 54. 61.104 / 54. 61.104 libavdevice 54. 3.103 / 54. 3.103 libavfilter 3. 35.101 / 3. 35.101 libswscale 2. 2.100 / 2. 2.100 libswresample 0. 17.102 / 0. 17.102 libpostproc 52. 2.100 / 52. 2.100 Input #0, matroska,webm, from '/Users/eelco/Desktop/ffmpeg-ss-bug/fast-ss.mkv': Metadata: MAJOR_BRAND : qt MINOR_VERSION : 537199360 COMPATIBLE_BRANDS: qt TIMECODE : 00:00:00:00 ENCODER : Lavf54.59.106 Duration: 00:00:11.08, start: 0.000000, bitrate: 14054 kb/s Stream #0:0(eng): Video: h264 (Main), yuv420p, 1920x1080, SAR 1:1 DAR 16:9, 24 fps, 24 tbr, 1k tbn, 2k tbc (default) Metadata: CREATION_TIME : 2008-05-27 18:40:35 LANGUAGE : eng HANDLER_NAME : Apple Alias Data Handler Stream #0:1(eng): Audio: aac, 48000 Hz, 5.1, fltp (default) Metadata: CREATION_TIME : 2008-05-27 18:40:35 LANGUAGE : eng HANDLER_NAME : Apple Alias Data Handler Output #0, image2, to '/dev/null': Metadata: MAJOR_BRAND : qt MINOR_VERSION : 537199360 COMPATIBLE_BRANDS: qt TIMECODE : 00:00:00:00 encoder : Lavf54.61.104 Stream #0:0(eng): Video: mjpeg, yuvj420p, 1920x1080 [SAR 1:1 DAR 16:9], q=2-31, 200 kb/s, 90k tbn, 24 tbc (default) Metadata: CREATION_TIME : 2008-05-27 18:40:35 LANGUAGE : eng HANDLER_NAME : Apple Alias Data Handler Stream mapping: Stream #0:0 -> #0:0 (h264 -> mjpeg) Press [q] to stop, [?] for help frame= 1 fps=0.0 q=0.0 Lsize=N/A time=00:00:00.04 bitrate=N/A dup=0 drop=21 video:205kB audio:0kB subtitle:0 global headers:0kB muxing overhead -100.010488% 0.42 real 0.70 user 0.07 sys }}} I’ll upload the sample files to the FTP server." enhancement closed wish avformat git-master fixed h264 mkv 0 0