Opened 7 years ago
Last modified 7 years ago
#6128 new defect
Using the concat demuxer with images and specified duration directives produces wrong duration
| Reported by: | Mulvya | Owned by: | |
|---|---|---|---|
| Priority: | normal | Component: | undetermined |
| Version: | git-master | Keywords: | |
| Cc: | Blocked By: | ||
| Blocking: | Reproduced by developer: | no | |
| Analyzed by developer: | no |
Description
The FFmpeg wiki entry on Slideshow has a section at wiki:Slideshow#Concatdemuxer on using the concat demuxer to create a video from a series of images with custom duration assigned to each image. However, FFmpeg does not produce a video of the requested total duration.
How to reproduce:
- Create still images:
ffmpeg -f lavfi -i color -vframes 1 black.png ffmpeg -f lavfi -i color=white -vframes 1 white.png
- Create concat list as shown in Wiki
file black.png duration 6 file white.png duration 2
- Run the concat
ffmpeg -f concat -i list.txt result.mp4 ffmpeg version N-83410-gb1e2192007 Copyright (c) 2000-2017 the FFmpeg developers built with gcc 6.3.0 (Rev1, Built by MSYS2 project) configuration: --enable-avisynth --enable-libmp3lame --enable-libopus --enable-libvorbis --enable-libvpx --enable-libx264 --enable-libx265 --enable-cuda --enable-cuvid --enable-schannel --enable-sdl2 --enable-decklink --enable-fontconfig --enable-frei0r --enable-libass --enable-libbluray --enable-libbs2b --enable-libcaca --enable-libfreetype --enable-libfribidi --enable-libgme --enable-libgsm --enable-libilbc --enable-libmfx --enable-libmodplug --enable-libopencore-amrnb --enable-libopencore-amrwb --enable-libopenjpeg --enable-librtmp --enable-libschroedinger --enable-libsoxr --enable-libspeex --enable-libtheora --enable-libtwolame --enable-libvidstab --enable-libvo-amrwbenc --enable-libwavpack --enable-libwebp --enable-libxavs --enable-libxvid --enable-libzimg --enable-openssl --enable-libsnappy --enable-gpl --enable-opencl --enable-opengl --enable-libcdio --enable-libfdk-aac --enable-libkvazaar --enable-librubberband --enable-libssh --enable-libtesseract --enable-libzvbi --enable-chromaprint --enable-libopenh264 --enable-libopenmpt --enable-netcdf --disable-w32threads --enable-version3 --enable-nonfree --enable-filter=frei0r --disable-debug libavutil 55. 46.100 / 55. 46.100 libavcodec 57. 75.100 / 57. 75.100 libavformat 57. 66.101 / 57. 66.101 libavdevice 57. 2.100 / 57. 2.100 libavfilter 6. 72.100 / 6. 72.100 libswscale 4. 3.101 / 4. 3.101 libswresample 2. 4.100 / 2. 4.100 libpostproc 54. 2.100 / 54. 2.100 Input #0, concat, from 'list.txt': Duration: 00:00:08.00, start: 0.000000, bitrate: 0 kb/s Stream #0:0: Video: png, rgb24(pc), 320x240 [SAR 1:1 DAR 4:3], 25 tbr, 25 tbn, 25 tbc No pixel format specified, yuv444p for H.264 encoding chosen. Use -pix_fmt yuv420p for compatibility with outdated media players. [libx264 @ 000000000041c1a0] using SAR=1/1 [libx264 @ 000000000041c1a0] using cpu capabilities: MMX2 SSE2Fast SSSE3 SSE4.2 LZCNT BMI2 [libx264 @ 000000000041c1a0] profile High 4:4:4 Predictive, level 1.3, 4:4:4 8-bit [libx264 @ 000000000041c1a0] 264 - core 148 r2762 90a61ec - H.264/MPEG-4 AVC codec - Copyleft 2003-2017 - http://www.videolan.org/x264.html - options: cabac=1 ref=3 deblock=1:0:0 analyse=0x3:0x113 me=hex subme=7 psy=1 psy_rd=1.00:0.00 mixed_ref=1 me_range=16 chroma_me=1 trellis=1 8x8dct=1 cqm=0 deadzone=21,11 fast_pskip=1 chroma_qp_offset=4 threads=6 lookahead_threads=1 sliced_threads=0 nr=0 decimate=1 interlaced=0 bluray_compat=0 constrained_intra=0 bframes=3 b_pyramid=2 b_adapt=1 b_bias=0 direct=1 weightb=1 open_gop=0 weightp=2 keyint=250 keyint_min=25 scenecut=40 intra_refresh=0 rc_lookahead=40 rc=crf mbtree=1 crf=23.0 qcomp=0.60 qpmin=0 qpmax=69 qpstep=4 ip_ratio=1.40 aq=1:1.00 Output #0, mp4, to 'result.mp4': Metadata: encoder : Lavf57.66.101 Stream #0:0: Video: h264 (libx264) ([33][0][0][0] / 0x0021), yuv444p, 320x240 [SAR 1:1 DAR 4:3], q=-1--1, 25 fps, 12800 tbn, 25 tbc Metadata: encoder : Lavc57.75.100 libx264 Side data: cpb: bitrate max/min/avg: 0/0/0 buffer size: 0 vbv_delay: -1 Stream mapping: Stream #0:0 -> #0:0 (png (native) -> h264 (libx264)) Press [q] to stop, [?] for help frame= 151 fps=0.0 q=-1.0 Lsize= 6kB time=00:00:05.92 bitrate= 8.0kbits/s dup=149 drop=0 speed=82.1x video:3kB audio:0kB subtitle:0kB other streams:0kB global headers:0kB muxing overhead: 81.122292% [libx264 @ 000000000041c1a0] frame I:2 Avg QP: 9.00 size: 53 [libx264 @ 000000000041c1a0] frame P:38 Avg QP: 9.29 size: 23 [libx264 @ 000000000041c1a0] frame B:111 Avg QP:12.67 size: 15 [libx264 @ 000000000041c1a0] consecutive B-frames: 2.0% 0.0% 0.0% 98.0% [libx264 @ 000000000041c1a0] mb I I16..4: 0.3% 99.7% 0.0% [libx264 @ 000000000041c1a0] mb P I16..4: 0.0% 0.0% 0.0% P16..4: 0.0% 0.0% 0.0% 0.0% 0.0% skip:100.0% [libx264 @ 000000000041c1a0] mb B I16..4: 0.0% 0.0% 0.0% B16..8: 0.0% 0.0% 0.0% direct: 0.0% skip:100.0% [libx264 @ 000000000041c1a0] 8x8 transform intra:99.7% [libx264 @ 000000000041c1a0] coded y,u,v intra: 0.0% 0.0% 0.0% inter: 0.0% 0.0% 0.0% [libx264 @ 000000000041c1a0] i16 v,h,dc,p: 0% 0% 100% 0% [libx264 @ 000000000041c1a0] i8 v,h,dc,ddl,ddr,vr,hd,vl,hu: 0% 0% 100% 0% 0% 0% 0% 0% 0% [libx264 @ 000000000041c1a0] Weighted P-Frames: Y:0.0% UV:0.0% [libx264 @ 000000000041c1a0] kb/s:3.43
- Check output duration
ffprobe result.mp4 -show_entries format=duration -v 0 [FORMAT] duration=6.040000 [/FORMAT]
Trying to work around this, by duplicating the last image entry (with or without duration directive) also produces unexpected output.
- Updated list
file black.png duration 6 file white.png duration 2 file white.png duration 1
- Concat
ffmpeg -f concat -i list2.txt result2.mp4 ffmpeg version N-83410-gb1e2192007 Copyright (c) 2000-2017 the FFmpeg developers built with gcc 6.3.0 (Rev1, Built by MSYS2 project) configuration: --enable-avisynth --enable-libmp3lame --enable-libopus --enable-libvorbis --enable-libvpx --enable-libx264 --enable-libx265 --enable-cuda --enable-cuvid --enable-schannel --enable-sdl2 --enable-decklink --enable-fontconfig --enable-frei0r --enable-libass --enable-libbluray --enable-libbs2b --enable-libcaca --enable-libfreetype --enable-libfribidi --enable-libgme --enable-libgsm --enable-libilbc --enable-libmfx --enable-libmodplug --enable-libopencore-amrnb --enable-libopencore-amrwb --enable-libopenjpeg --enable-librtmp --enable-libschroedinger --enable-libsoxr --enable-libspeex --enable-libtheora --enable-libtwolame --enable-libvidstab --enable-libvo-amrwbenc --enable-libwavpack --enable-libwebp --enable-libxavs --enable-libxvid --enable-libzimg --enable-openssl --enable-libsnappy --enable-gpl --enable-opencl --enable-opengl --enable-libcdio --enable-libfdk-aac --enable-libkvazaar --enable-librubberband --enable-libssh --enable-libtesseract --enable-libzvbi --enable-chromaprint --enable-libopenh264 --enable-libopenmpt --enable-netcdf --disable-w32threads --enable-version3 --enable-nonfree --enable-filter=frei0r --disable-debug libavutil 55. 46.100 / 55. 46.100 libavcodec 57. 75.100 / 57. 75.100 libavformat 57. 66.101 / 57. 66.101 libavdevice 57. 2.100 / 57. 2.100 libavfilter 6. 72.100 / 6. 72.100 libswscale 4. 3.101 / 4. 3.101 libswresample 2. 4.100 / 2. 4.100 libpostproc 54. 2.100 / 54. 2.100 Input #0, concat, from 'list2.txt': Duration: 00:00:09.00, start: 0.000000, bitrate: 0 kb/s Stream #0:0: Video: png, rgb24(pc), 320x240 [SAR 1:1 DAR 4:3], 25 tbr, 25 tbn, 25 tbc No pixel format specified, yuv444p for H.264 encoding chosen. Use -pix_fmt yuv420p for compatibility with outdated media players. [libx264 @ 00000000006dc1a0] using SAR=1/1 [libx264 @ 00000000006dc1a0] using cpu capabilities: MMX2 SSE2Fast SSSE3 SSE4.2 LZCNT BMI2 [libx264 @ 00000000006dc1a0] profile High 4:4:4 Predictive, level 1.3, 4:4:4 8-bit [libx264 @ 00000000006dc1a0] 264 - core 148 r2762 90a61ec - H.264/MPEG-4 AVC codec - Copyleft 2003-2017 - http://www.videolan.org/x264.html - options: cabac=1 ref=3 deblock=1:0:0 analyse=0x3:0x113 me=hex subme=7 psy=1 psy_rd=1.00:0.00 mixed_ref=1 me_range=16 chroma_me=1 trellis=1 8x8dct=1 cqm=0 deadzone=21,11 fast_pskip=1 chroma_qp_offset=4 threads=6 lookahead_threads=1 sliced_threads=0 nr=0 decimate=1 interlaced=0 bluray_compat=0 constrained_intra=0 bframes=3 b_pyramid=2 b_adapt=1 b_bias=0 direct=1 weightb=1 open_gop=0 weightp=2 keyint=250 keyint_min=25 scenecut=40 intra_refresh=0 rc_lookahead=40 rc=crf mbtree=1 crf=23.0 qcomp=0.60 qpmin=0 qpmax=69 qpstep=4 ip_ratio=1.40 aq=1:1.00 Output #0, mp4, to 'result2.mp4': Metadata: encoder : Lavf57.66.101 Stream #0:0: Video: h264 (libx264) ([33][0][0][0] / 0x0021), yuv444p, 320x240 [SAR 1:1 DAR 4:3], q=-1--1, 25 fps, 12800 tbn, 25 tbc Metadata: encoder : Lavc57.75.100 libx264 Side data: cpb: bitrate max/min/avg: 0/0/0 buffer size: 0 vbv_delay: -1 Stream mapping: Stream #0:0 -> #0:0 (png (native) -> h264 (libx264)) Press [q] to stop, [?] for help frame= 249 fps=0.0 q=-1.0 Lsize= 9kB time=00:00:09.84 bitrate= 7.1kbits/s dup=246 drop=0 speed=88.8x video:5kB audio:0kB subtitle:0kB other streams:0kB global headers:0kB muxing overhead: 78.030922% [libx264 @ 00000000006dc1a0] frame I:2 Avg QP: 7.50 size: 54 [libx264 @ 00000000006dc1a0] frame P:62 Avg QP: 9.23 size: 23 [libx264 @ 00000000006dc1a0] frame B:185 Avg QP:12.67 size: 15 [libx264 @ 00000000006dc1a0] consecutive B-frames: 0.8% 0.0% 1.2% 98.0% [libx264 @ 00000000006dc1a0] mb I I16..4: 0.3% 99.7% 0.0% [libx264 @ 00000000006dc1a0] mb P I16..4: 0.0% 0.0% 0.0% P16..4: 0.0% 0.0% 0.0% 0.0% 0.0% skip:100.0% [libx264 @ 00000000006dc1a0] mb B I16..4: 0.0% 0.0% 0.0% B16..8: 0.0% 0.0% 0.0% direct: 0.0% skip:100.0% [libx264 @ 00000000006dc1a0] 8x8 transform intra:99.7% [libx264 @ 00000000006dc1a0] coded y,u,v intra: 0.0% 0.0% 0.0% inter: 0.0% 0.0% 0.0% [libx264 @ 00000000006dc1a0] i16 v,h,dc,p: 0% 0% 100% 0% [libx264 @ 00000000006dc1a0] i8 v,h,dc,ddl,ddr,vr,hd,vl,hu: 0% 0% 100% 0% 0% 0% 0% 0% 0% [libx264 @ 00000000006dc1a0] Weighted P-Frames: Y:0.0% UV:0.0% [libx264 @ 00000000006dc1a0] kb/s:3.40
- Check duration
ffprobe result2.mp4 -show_entries format=duration -v 0 [FORMAT] duration=9.960000 [/FORMAT]
This time, the duration is greater (9.96 sec) than it should be (9 sec)
Behaviour originally reported at http://video.stackexchange.com/q/20588/1871
Personally, I believe all the direction durative does is it alters the offset applied to the starting timestamp of successive files in the concat list and not enforce a duration per se. So, that explains to me the issue with the first concat run, but not the second.
Change History (6)
comment:1 by , 7 years ago
comment:2 by , 7 years ago
Ok, but then shouldn't the 2nd concat produce a duration of 8.04s. In any case, how should the wiki section be corrected?
comment:3 by , 7 years ago
The incorrect duration in the second case goes away with Matroska output; it seems an artifact of the MP4 format or muxer. It is unrelated to concat, as it produces the same result when converting from the correct Matroska file obtained earlier.
To get things working, you need to have the duration of the last image be a single frame for your chosen frame rate. Since you did not specify anything, that means 25 FPS, so the last segment need to be duration 0.04.
follow-up: 5 comment:4 by , 7 years ago
Does not work with MP4. Works without duration for MKV. Remuxing MKV to MP4 collapses video to n frames where n is number of entries. Producing MKV with -vsync cfr produces same result as MP4 (9.96 sec). Producing MP4 with -vsync vfr produces same result (8.04 sec) as MKV with no vsync option applied.
comment:5 by , 7 years ago
Replying to mulvya:
Producing MP4 with -vsync vfr produces same result (8.04 sec) as MKV with no vsync option applied.
But no valid output file.
comment:6 by , 7 years ago
MP4 plays fine in Potplayer and ffplay. Duration is shown as 8 and black turns to white at 6s. ffplay with autoexit exits at 8s. Does not play in VLC, though.
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ffmpegdoes not preserve the duration of the last frame, this is known issue and already reported in several tickets here.