On 16 Sep 2015, at 11:33, [email protected] wrote: > Hello, > > I'm trying to cut a video to get 12s sequences. It needs to be accurate. Cutting is done on begin and end of a Group Of Pictures, a GOP. Splitting always occurs the way you mention, it is ‘about 12 seconds’ What is, could be the reason, you need it absoute accurate ? One way around could be to 1st encode your source to all I-frame, key frames. This way you get a GOP-size of 1 and then you can get it accurate. > But when I ask a 12 seconds sequence (not from the begining for this example) > , I get around 12:01 seconds. > The command line is : > ffmpeg -ss 00:00:00.00 -i GOPR0151.mp4 -b:v 30150 -t 00:00:12.00 -acodec copy > -vcodec copy GOPR0151_002.mp4 > > and even, when I start from 00:02:12.00, the output lasts 12:33 seconds. > > Can anybody tell me who to get more accuracy, please ? > I noticed that the bitrate is not the same in the orginal video than in the > output. Is it important ? > Here are the informations of the original video : > ffprobe.exe GOPR0151.mp4 > ffprobe version N-74751-gb54e03c Copyright (c) 2007-2015 the FFmpeg developers > built with gcc 4.9.3 (GCC) > configuration: --enable-gpl --enable-version3 --disable-w32threads > --enable-avisynth --enable-bzlib --enable-fontconfig --enable-frei0r > --enable-gnu > tls --enable-iconv --enable-libass --enable-libbluray --enable-libbs2b > --enable-libcaca --enable-libdcadec --enable-libfreetype --enable-libgme > --enab > le-libgsm --enable-libilbc --enable-libmodplug --enable-libmp3lame > --enable-libopencore-amrnb --enable-libopencore-amrwb --enable-libopenjpeg > --enable > -libopus --enable-librtmp --enable-libschroedinger --enable-libsoxr > --enable-libspeex --enable-libtheora --enable-libtwolame --enable-libvidstab > --ena > ble-libvo-aacenc --enable-libvo-amrwbenc --enable-libvorbis --enable-libvpx > --enable-libwavpack --enable-libwebp --enable-libx264 --enable-libx265 --e > nable-libxavs --enable-libxvid --enable-lzma --enable-decklink --enable-zlib > libavutil 54. 31.100 / 54. 31.100 > libavcodec 56. 59.100 / 56. 59.100 > libavformat 56. 40.101 / 56. 40.101 > libavdevice 56. 4.100 / 56. 4.100 > libavfilter 5. 40.100 / 5. 40.100 > libswscale 3. 1.101 / 3. 1.101 > libswresample 1. 2.101 / 1. 2.101 > libpostproc 53. 3.100 / 53. 3.100 > Input #0, mov,mp4,m4a,3gp,3g2,mj2, from 'GOPR0151.mp4': > Metadata: > major_brand : avc1 > minor_version : 0 > compatible_brands: avc1isom > creation_time : 2014-10-25 09:19:36 > Duration: 00:17:24.30, start: 0.000000, bitrate: 30150 kb/s > Stream #0:0(eng): Video: h264 (High) (avc1 / 0x31637661), yuvj420p(pc, > bt709), 1280x960 [SAR 1:1 DAR 4:3], 30002 kb/s, 100 fps, 100 tbr, 180k tbn, > 200 tbc (default) > Metadata: > creation_time : 2014-10-25 09:19:36 > handler_name : GoPro AVC > encoder : GoPro AVC encoder > Stream #0:1(eng): Audio: aac (LC) (mp4a / 0x6134706D), 48000 Hz, stereo, > fltp, 128 kb/s (default) > Metadata: > creation_time : 2014-10-25 09:19:36 > handler_name : GoPro AAC > > > And the output : > ffprobe.exe GOPR0151_002.mp4 > ffprobe version N-74751-gb54e03c Copyright (c) 2007-2015 the FFmpeg developers > built with gcc 4.9.3 (GCC) > configuration: --enable-gpl --enable-version3 --disable-w32threads > --enable-avisynth --enable-bzlib --enable-fontconfig --enable-frei0r > --enable-gnu > tls --enable-iconv --enable-libass --enable-libbluray --enable-libbs2b > --enable-libcaca --enable-libdcadec --enable-libfreetype --enable-libgme > --enab > le-libgsm --enable-libilbc --enable-libmodplug --enable-libmp3lame > --enable-libopencore-amrnb --enable-libopencore-amrwb --enable-libopenjpeg > --enable > -libopus --enable-librtmp --enable-libschroedinger --enable-libsoxr > --enable-libspeex --enable-libtheora --enable-libtwolame --enable-libvidstab > --ena > ble-libvo-aacenc --enable-libvo-amrwbenc --enable-libvorbis --enable-libvpx > --enable-libwavpack --enable-libwebp --enable-libx264 --enable-libx265 --e > nable-libxavs --enable-libxvid --enable-lzma --enable-decklink --enable-zlib > libavutil 54. 31.100 / 54. 31.100 > libavcodec 56. 59.100 / 56. 59.100 > libavformat 56. 40.101 / 56. 40.101 > libavdevice 56. 4.100 / 56. 4.100 > libavfilter 5. 40.100 / 5. 40.100 > libswscale 3. 1.101 / 3. 1.101 > libswresample 1. 2.101 / 1. 2.101 > libpostproc 53. 3.100 / 53. 3.100 > Input #0, mov,mp4,m4a,3gp,3g2,mj2, from 'GOPR0151_002.mp4': > Metadata: > major_brand : isom > minor_version : 512 > compatible_brands: isomiso2avc1mp41 > encoder : Lavf56.40.101 > Duration: 00:00:12.33, start: 0.309333, bitrate: 30273 kb/s > Stream #0:0(eng): Video: h264 (High) (avc1 / 0x31637661), yuvj420p(pc, > bt709), 1280x960 [SAR 1:1 DAR 4:3], 30187 kb/s, 100 fps, 100 tbr, 180k tbn, > 200 tbc (default) > Metadata: > handler_name : VideoHandler > Stream #0:1(eng): Audio: aac (LC) (mp4a / 0x6134706D), 48000 Hz, stereo, > fltp, 128 kb/s (default) > Metadata: > handler_name : SoundHandler > > > Thanks in advance > > Fridu > _______________________________________________ > ffmpeg-user mailing list > [email protected] > http://ffmpeg.org/mailman/listinfo/ffmpeg-user
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