id summary reporter owner description type status priority component version resolution keywords cc blockedby blocking reproduced analyzed 2300 segment muxer produces files with wrong duration Cigaes "The duration stored in the headers of the segments produced by the segment demuxer is not consistent with the timestamps of the frames it contains. Example: {{{ ./ffmpeg_g -f lavfi -i testsrc=d=20 -f segment -c mpeg4 -map 0 -segment_time 10 -y /tmp/segment%03d.mp4 ./ffprobe_g -show_packets -show_format -of compact -show_entries packet=pts_time -show_entries format=duration /tmp/segment000.mp4 ./ffprobe_g -show_packets -show_format -of compact -show_entries packet=pts_time -show_entries format=duration /tmp/segment001.mp4 }}} {{{ packet|pts_time=9.960000 packet|pts_time=10.000000 packet|pts_time=10.040000 format|duration=10.322000|tag:major_brand= }}} {{{ packet|pts_time=10.080000 packet|pts_time=10.120000 packet|pts_time=10.160000 }}} As you can see, the timestamps of the segments are consistent, but the duration of the first fragment should be 10.08, that makes a 0.242 error. The result is correct without the segment muxer: {{{ ./ffmpeg_g -f lavfi -i testsrc=d=10.08 -c mpeg4 -map 0 -y /tmp/segment.mp4 ./ffprobe_g -show_packets -show_format -of compact -show_entries packet=pts_time -show_entries format=duration /tmp/segment.mp4 }}} {{{ packet|pts_time=10.000000 packet|pts_time=10.040000 format|duration=10.080000|tag:major_brand= }}} The same problem seems to happen with other formats than MP4, for example Matroska: {{{ packet|pts_time=10.000000 packet|pts_time=10.040000 format|duration=13.640000|tag:ENCODER=Lavf54.63.100 }}} Full (almost) console output of the previous commands (probably not helpful): {{{ ./ffmpeg_g -f lavfi -i testsrc=d=20 -f segment -c mpeg4 -map 0 -segment_time 10 -y /tmp/segment%03d.mp4 ffmpeg version N-50194-g0ac71f9 Copyright (c) 2000-2013 the FFmpeg developers built on Feb 23 2013 11:34:47 with gcc 4.7 (Debian 4.7.2-5) configuration: --enable-shared --disable-static --enable-gpl --enable-libx264 --enable-libass --enable-libfreetype --enable-libopus --assert-level=2 libavutil 52. 17.103 / 52. 17.103 libavcodec 54. 92.100 / 54. 92.100 libavformat 54. 63.100 / 54. 63.100 libavdevice 54. 3.103 / 54. 3.103 libavfilter 3. 39.101 / 3. 39.101 libswscale 2. 2.100 / 2. 2.100 libswresample 0. 17.102 / 0. 17.102 libpostproc 52. 2.100 / 52. 2.100 [lavfi @ 0x101c0c0] Estimating duration from bitrate, this may be inaccurate Input #0, lavfi, from 'testsrc=d=20': Duration: N/A, start: 0.000000, bitrate: N/A Stream #0:0: Video: rawvideo (RGB[24] / 0x18424752), rgb24, 320x240 [SAR 1:1 DAR 4:3], 25 tbr, 25 tbn, 25 tbc Output #0, segment, to '/tmp/segment%03d.mp4': Metadata: encoder : Lavf54.63.100 Stream #0:0: Video: mpeg4, yuv420p, 320x240 [SAR 1:1 DAR 4:3], q=2-31, 200 kb/s, 90k tbn, 25 tbc Stream mapping: Stream #0:0 -> #0:0 (rawvideo -> mpeg4) Press [q] to stop, [?] for help frame= 500 fps=0.0 q=3.6 Lsize=N/A time=00:00:20.00 bitrate=N/A video:742kB audio:0kB subtitle:0 global headers:0kB muxing overhead -100.002896% }}} {{{ ./ffprobe_g -show_packets -show_format -of compact -show_entries packet=pts_time -show_entries format=duration /tmp/segment000.mp4 ffprobe version N-50194-g0ac71f9 Copyright (c) 2007-2013 the FFmpeg developers built on Feb 23 2013 11:34:47 with gcc 4.7 (Debian 4.7.2-5) configuration: --enable-shared --disable-static --enable-gpl --enable-libx264 --enable-libass --enable-libfreetype --enable-libopus --assert-level=2 libavutil 52. 17.103 / 52. 17.103 libavcodec 54. 92.100 / 54. 92.100 libavformat 54. 63.100 / 54. 63.100 libavdevice 54. 3.103 / 54. 3.103 libavfilter 3. 39.101 / 3. 39.101 libswscale 2. 2.100 / 2. 2.100 libswresample 0. 17.102 / 0. 17.102 libpostproc 52. 2.100 / 52. 2.100 Input #0, mov,mp4,m4a,3gp,3g2,mj2, from '/tmp/segment000.mp4': Metadata: major_brand : isom minor_version : 512 compatible_brands: isomiso2mp41 encoder : Lavf54.63.100 Duration: 00:00:10.32, start: 0.000000, bitrate: 313 kb/s Stream #0:0(und): Video: mpeg4 (Simple Profile) (mp4v / 0x7634706D), yuv420p, 320x240 [SAR 1:1 DAR 4:3], 312 kb/s, 24.42 fps, 25 tbr, 12800 tbn, 25 tbc Metadata: handler_name : VideoHandler packet|pts_time=0.000000 packet|pts_time=0.040000 packet|pts_time=0.080000 packet|pts_time=0.120000 ... packet|pts_time=9.880000 packet|pts_time=9.920000 packet|pts_time=9.960000 packet|pts_time=10.000000 packet|pts_time=10.040000 format|duration=10.322000|tag:major_brand=isom|tag:minor_version=512|tag:compatible_brands=isomiso2mp41|tag:encoder=Lavf54.63.100 }}} {{{ ./ffmpeg_g -f lavfi -i testsrc=d=10.08 -c mpeg4 -map 0 -y /tmp/segment.mp4 ffmpeg version N-50194-g0ac71f9 Copyright (c) 2000-2013 the FFmpeg developers built on Feb 23 2013 11:34:47 with gcc 4.7 (Debian 4.7.2-5) configuration: --enable-shared --disable-static --enable-gpl --enable-libx264 --enable-libass --enable-libfreetype --enable-libopus --assert-level=2 libavutil 52. 17.103 / 52. 17.103 libavcodec 54. 92.100 / 54. 92.100 libavformat 54. 63.100 / 54. 63.100 libavdevice 54. 3.103 / 54. 3.103 libavfilter 3. 39.101 / 3. 39.101 libswscale 2. 2.100 / 2. 2.100 libswresample 0. 17.102 / 0. 17.102 libpostproc 52. 2.100 / 52. 2.100 [lavfi @ 0x10b8000] Estimating duration from bitrate, this may be inaccurate Input #0, lavfi, from 'testsrc=d=10.08': Duration: N/A, start: 0.000000, bitrate: N/A Stream #0:0: Video: rawvideo (RGB[24] / 0x18424752), rgb24, 320x240 [SAR 1:1 DAR 4:3], 25 tbr, 25 tbn, 25 tbc Output #0, mp4, to '/tmp/segment.mp4': Metadata: encoder : Lavf54.63.100 Stream #0:0: Video: mpeg4 ( [0][0][0] / 0x0020), yuv420p, 320x240 [SAR 1:1 DAR 4:3], q=2-31, 200 kb/s, 12800 tbn, 25 tbc Stream mapping: Stream #0:0 -> #0:0 (rawvideo -> mpeg4) Press [q] to stop, [?] for help frame= 252 fps=0.0 q=2.7 Lsize= 396kB time=00:00:10.08 bitrate= 321.5kbits/s video:394kB audio:0kB subtitle:0 global headers:0kB muxing overhead 0.471736% }}} {{{ ./ffprobe_g -show_packets -show_format -of compact -show_entries packet=pts_time -show_entries format=duration /tmp/segment.mp4 ffprobe version N-50194-g0ac71f9 Copyright (c) 2007-2013 the FFmpeg developers built on Feb 23 2013 11:34:47 with gcc 4.7 (Debian 4.7.2-5) configuration: --enable-shared --disable-static --enable-gpl --enable-libx264 --enable-libass --enable-libfreetype --enable-libopus --assert-level=2 libavutil 52. 17.103 / 52. 17.103 libavcodec 54. 92.100 / 54. 92.100 libavformat 54. 63.100 / 54. 63.100 libavdevice 54. 3.103 / 54. 3.103 libavfilter 3. 39.101 / 3. 39.101 libswscale 2. 2.100 / 2. 2.100 libswresample 0. 17.102 / 0. 17.102 libpostproc 52. 2.100 / 52. 2.100 Input #0, mov,mp4,m4a,3gp,3g2,mj2, from '/tmp/segment.mp4': Metadata: major_brand : isom minor_version : 512 compatible_brands: isomiso2mp41 encoder : Lavf54.63.100 Duration: 00:00:10.08, start: 0.000000, bitrate: 321 kb/s Stream #0:0(und): Video: mpeg4 (Simple Profile) (mp4v / 0x7634706D), yuv420p, 320x240 [SAR 1:1 DAR 4:3], 319 kb/s, 25 fps, 25 tbr, 12800 tbn, 25 tbc Metadata: handler_name : VideoHandler packet|pts_time=0.000000 packet|pts_time=0.040000 packet|pts_time=0.080000 ... packet|pts_time=9.960000 packet|pts_time=10.000000 packet|pts_time=10.040000 format|duration=10.080000|tag:major_brand=isom|tag:minor_version=512|tag:compatible_brands=isomiso2mp41|tag:encoder=Lavf54.63.100 }}} " defect closed normal avformat git-master fixed segment 1 0