I did one step backward and tried to construct a vfr video from the scratch using slides a an input:
ffmpeg -y -f concat -i input.txt colors.mkv with input.txt as: ffconcat version 1.0 file 'red.png' duration 250ms file 'yellow.png' duration 500ms file 'green.png' duration 500ms file 'cyan.png' duration 250ms file 'blue.png' duration 500ms file 'black.png' duration 500ms This resulted in cfr for mp4 an vfr for mkv or webm (according to MediaInfo, a Windows application). However, there seems to be something wrong with the result colors.mkv, as no player, including ffplay uses the specified durations. This is the output: ffmpeg version 2021-01-24-git-1775688292-full_build-www.gyan.dev Copyright (c) 2000-2021 the FFmpeg developers built with gcc 10.2.0 (Rev6, Built by MSYS2 project) configuration: --enable-gpl --enable-version3 --enable-static --disable-w32threads --disable-autodetect --enable-fontconfig --enable-iconv --enable-gnutls --enable-libxml2 --enable-gmp --enable-lzma --enable-libsnappy --enable-zlib --enable-libsrt --enable-libssh --enable-libzmq --enable-avisynth --enable-libbluray --enable-libcaca --enable-sdl2 --enable-libdav1d --enable-libzvbi --enable-librav1e --enable-libsvtav1 --enable-libwebp --enable-libx264 --enable-libx265 --enable-libxvid --enable-libaom --enable-libopenjpeg --enable-libvpx --enable-libass --enable-frei0r --enable-libfreetype --enable-libfribidi --enable-libvidstab --enable-libvmaf --enable-libzimg --enable-amf --enable-cuda-llvm --enable-cuvid --enable-ffnvcodec --enable-nvdec --enable-nvenc --enable-d3d11va --enable-dxva2 --enable-libmfx --enable-libglslang --enable-vulkan --enable-opencl --enable-libcdio --enable-libgme --enable-libmodplug --enable-libopenmpt --enable-libopencore-amrwb --enable-libmp3lame --enable-libshine --enable-libtheora --enable-libtwolame --enable-libvo-amrwbenc --enable-libilbc --enable-libgsm --enable-libopencore-amrnb --enable-libopus --enable-libspeex --enable-libvorbis --enable-ladspa --enable-libbs2b --enable-libflite --enable-libmysofa --enable-librubberband --enable-libsoxr --enable-chromaprint libavutil 56. 63.101 / 56. 63.101 libavcodec 58.117.101 / 58.117.101 libavformat 58. 65.101 / 58. 65.101 libavdevice 58. 11.103 / 58. 11.103 libavfilter 7. 96.100 / 7. 96.100 libswscale 5. 8.100 / 5. 8.100 libswresample 3. 8.100 / 3. 8.100 libpostproc 55. 8.100 / 55. 8.100 Input #0, concat, from 'input.txt': Duration: 00:00:05.00, start: 0.000000, bitrate: 0 kb/s Stream #0:0: Video: png, pal8(pc), 800x600, 25 fps, 25 tbr, 25 tbn, 25 tbc Stream mapping: Stream #0:0 -> #0:0 (png (native) -> h264 (libx264)) Press [q] to stop, [?] for help [libx264 @ 000002159ed90c00] using cpu capabilities: MMX2 SSE2Fast SSSE3 SSE4.2 AVX [libx264 @ 000002159ed90c00] profile High 4:4:4 Predictive, level 3.1, 4:4:4, 8-bit [libx264 @ 000002159ed90c00] 264 - core 161 r3033 0d754ec - H.264/MPEG-4 AVC codec - Copyleft 2003-2020 - 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, matroska, to 'colors.mkv': Metadata: encoder : Lavf58.65.101 Stream #0:0: Video: h264 (H264 / 0x34363248), yuv444p(tv, progressive), 800x600, q=2-31, 25 fps, 1k tbn Metadata: encoder : Lavc58.117.101 libx264 Side data: cpb: bitrate max/min/avg: 0/0/0 buffer size: 0 vbv_delay: N/A frame= 1 fps=0.0 q=0.0 size= 1kB time=00:00:00.00 bitrate=N/A speed= 0x frame= 12 fps=0.0 q=-1.0 Lsize= 4kB time=00:00:03.76 bitrate= 9.2kbits/s speed=12.1x video:3kB audio:0kB subtitle:0kB other streams:0kB global headers:0kB muxing overhead: 20.582470% [libx264 @ 000002159ed90c00] frame I:1 Avg QP: 4.00 size: 194 [libx264 @ 000002159ed90c00] frame P:9 Avg QP: 4.89 size: 86 [libx264 @ 000002159ed90c00] frame B:2 Avg QP: 5.50 size: 960 [libx264 @ 000002159ed90c00] consecutive B-frames: 66.7% 33.3% 0.0% 0.0% [libx264 @ 000002159ed90c00] mb I I16..4: 100.0% 0.0% 0.0% [libx264 @ 000002159ed90c00] mb P I16..4: 22.2% 0.0% 0.0% P16..4: 0.0% 0.0% 0.0% 0.0% 0.0% skip:77.8% [libx264 @ 000002159ed90c00] mb B I16..4: 99.9% 0.1% 0.0% B16..8: 0.0% 0.0% 0.0% direct: 0.0% skip: 0.0% [libx264 @ 000002159ed90c00] 8x8 transform intra:0.0% inter:100.0% [libx264 @ 000002159ed90c00] coded y,u,v intra: 0.0% 0.0% 0.0% inter: 0.0% 0.0% 0.0% [libx264 @ 000002159ed90c00] i16 v,h,dc,p: 97% 0% 3% 0% [libx264 @ 000002159ed90c00] i8 v,h,dc,ddl,ddr,vr,hd,vl,hu: 0% 0% 100% 0% 0% 0% 0% 0% 0% [libx264 @ 000002159ed90c00] Weighted P-Frames: Y:77.8% UV:77.8% [libx264 @ 000002159ed90c00] kb/s:4.58 _______________________________________________ ffmpeg-user mailing list ffmpeg-user@ffmpeg.org https://ffmpeg.org/mailman/listinfo/ffmpeg-user To unsubscribe, visit link above, or email ffmpeg-user-requ...@ffmpeg.org with subject "unsubscribe".