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• ffmpeg - convert video file with 1 frame video and 4 minutes audio to HTML5 video

  4 juin 2020, par d3im

  Have this input video - it's 1 frame video (=picture) with audio :

  



      Input #0, mov,mp4,m4a,3gp,3g2,mj2, from 'input.mp4':
  Metadata:
    major_brand     : isom
    minor_version   : 512
    compatible_brands: isomiso2avc1mp41
    encoder         : Lavf57.83.100
  Duration: 00:04:34.55, start: 0.000000, bitrate: 122 kb/s
    Stream #0:0(und): Video: h264 (High) (avc1 / 0x31637661), yuvj420p(pc), 480x360 [SAR 1:1 DAR 4:3], 6375600 kb/s, 90k fps, 90k tbr, 90k tbn, 180k tbc (default)
    Metadata:
      handler_name    : VideoHandler
    Stream #0:1(und): Audio: aac (LC) (mp4a / 0x6134706D), 44100 Hz, stereo, fltp, 120 kb/s (default)
    Metadata:
      handler_name    : SoundHandler


  



  I need to convert it to mp4 with video track of length of audio for HTML5 - but ffmpeg (4.2.3) says :

  



  Stream mapping:
  Stream #0:0 -> #0:0 (h264 (native) -> h264 (libx264))
  Stream #0:1 -> #0:1 (aac (native) -> aac (libfdk_aac))
Press [q] to stop, [?] for help
[libfdk_aac @ 0x55f35bf28100] Note, the VBR setting is unsupported and only works with some parameter combinations
Too many packets buffered for output stream 0:1.
[libfdk_aac @ 0x55f35bf28100] 2 frames left in the queue on closing
Conversion failed!


  



  Converting audio or video alone is successful.

  



  Converting with -c:v copy is successful but it's not what I need.

  



  adding -max_muxing_queue_size 9999 didn't help.

  



  EDIT :

  



  full command :

  



  ffmpeg -i input.mp4 -c:a libfdk_aac -vbr 2 -c:v libx264 -crf 28 -profile:v high -level 41 -vf format=yuv420p -sn -sample_fmt s16 -ac 1 -threads 0 -map_metadata -1 low.mp4


  



  full log :

  



  ffmpeg version 4.2.3 Copyright (c) 2000-2020 the FFmpeg developers
  built with gcc 9.3.0 (Gentoo 9.3.0 p2)
  configuration: --prefix=/usr --libdir=/usr/lib64 --shlibdir=/usr/lib64 --docdir=/usr/share/doc/ffmpeg-4.2.3/html --mandir=/usr/share/man --enable-shared --cc=x86_64-pc-linux-gnu-gcc --cxx=x86_64-pc-linux-gnu-g++ --ar=x86_64-pc-linux-gnu-ar --optflags='-O2 -pipe -march=haswell -mmmx -mno-3dnow -msse -msse2 -msse3 -mssse3 -mno-sse4a -mcx16 -msahf -mmovbe -maes -mno-sha -mpclmul -mpopcnt -mabm -mno-lwp -mfma -mno-fma4 -mno-xop -mbmi -mbmi2 -mno-tbm -mavx -mavx2 -msse4.2 -msse4.1 -mlzcnt -mno-rtm -mno-hle -mrdrnd -mf16c -mfsgsbase -mno-rdseed -mno-prfchw -mno-adx -mfxsr -mxsave -mxsaveopt -mno-avx512f -mno-avx512er -mno-avx512cd -mno-avx512pf -mno-prefetchwt1 -mno-clflushopt -mno-xsavec -mno-xsaves -mno-avx512dq -mno-avx512bw -mno-avx512vl -mno-avx512ifma -mno-avx512vbmi -mno-clwb -mno-mwaitx -mno-clzero -mno-pku -mtune=haswell' --disable-static --enable-avfilter --enable-avresample --disable-stripping --disable-optimizations --disable-libcelt --enable-version3 --enable-version3 --disable-indev=oss --disable-outdev=oss --enable-version3 --enable-nonfree --enable-bzlib --disable-runtime-cpudetect --disable-debug --disable-gcrypt --enable-gnutls --disable-gmp --enable-gpl --disable-hardcoded-tables --enable-iconv --disable-libtls --disable-libxml2 --enable-lzma --enable-network --disable-opencl --disable-openssl --enable-postproc --enable-libsmbclient --enable-ffplay --enable-sdl2 --enable-vaapi --disable-vdpau --enable-xlib --enable-libxcb --enable-libxcb-shm --enable-libxcb-xfixes --enable-zlib --disable-libcdio --disable-libiec61883 --disable-libdc1394 --disable-libcaca --disable-openal --enable-opengl --disable-libv4l2 --enable-libpulse --disable-libdrm --enable-libjack --enable-libopencore-amrwb --enable-libopencore-amrnb --disable-libcodec2 --enable-libdav1d --enable-libfdk-aac --enable-libopenjpeg --enable-libbluray --disable-libgme --disable-libgsm --disable-libaribb24 --disable-mmal --disable-libmodplug --enable-libopus --disable-libilbc --enable-librtmp --disable-libssh --enable-libspeex --enable-libsrt --enable-librsvg --disable-ffnvcodec --enable-libvorbis --enable-libvpx --disable-libzvbi --disable-appkit --disable-libbs2b --disable-chromaprint --disable-cuda-llvm --disable-libflite --enable-frei0r --disable-libfribidi --disable-fontconfig --enable-ladspa --disable-libass --disable-libtesseract --enable-lv2 --enable-libfreetype --enable-libvidstab --disable-librubberband --disable-libzmq --disable-libzimg --enable-libsoxr --enable-pthreads --enable-libvo-amrwbenc --enable-libmp3lame --disable-libkvazaar --enable-libaom --disable-libopenh264 --disable-libsnappy --enable-libtheora --disable-libtwolame --enable-libwavpack --enable-libwebp --enable-libx264 --enable-libx265 --enable-libxvid --disable-armv5te --disable-armv6 --disable-armv6t2 --disable-neon --disable-vfp --disable-vfpv3 --disable-armv8 --disable-mipsdsp --disable-mipsdspr2 --disable-mipsfpu --disable-altivec --disable-amd3dnow --disable-amd3dnowext --disable-fma4 --disable-xop --cpu=haswell --disable-doc --disable-htmlpages --enable-manpages
  libavutil      56. 31.100 / 56. 31.100
  libavcodec     58. 54.100 / 58. 54.100
  libavformat    58. 29.100 / 58. 29.100
  libavdevice    58.  8.100 / 58.  8.100
  libavfilter     7. 57.100 /  7. 57.100
  libavresample   4.  0.  0 /  4.  0.  0
  libswscale      5.  5.100 /  5.  5.100
  libswresample   3.  5.100 /  3.  5.100
  libpostproc    55.  5.100 / 55.  5.100
Input #0, mov,mp4,m4a,3gp,3g2,mj2, from 'input.mp4':
  Metadata:
    major_brand     : isom
    minor_version   : 512
    compatible_brands: isomiso2avc1mp41
    encoder         : Lavf57.83.100
  Duration: 00:04:34.55, start: 0.000000, bitrate: 122 kb/s
    Stream #0:0(und): Video: h264 (High) (avc1 / 0x31637661), yuvj420p(pc), 480x360 [SAR 1:1 DAR 4:3], 6375600 kb/s, 90k fps, 90k tbr, 90k tbn, 180k tbc (default)
    Metadata:
      handler_name    : VideoHandler
    Stream #0:1(und): Audio: aac (LC) (mp4a / 0x6134706D), 44100 Hz, stereo, fltp, 120 kb/s (default)
    Metadata:
      handler_name    : SoundHandler
Stream mapping:
  Stream #0:0 -> #0:0 (h264 (native) -> h264 (libx264))
  Stream #0:1 -> #0:1 (aac (native) -> aac (libfdk_aac))
Press [q] to stop, [?] for help
[libfdk_aac @ 0x55fb6c86b080] Note, the VBR setting is unsupported and only works with some parameter combinations
Too many packets buffered for output stream 0:1.
[libfdk_aac @ 0x55fb6c86b080] 2 frames left in the queue on closing
Conversion failed!


  



  debug verbosity :

  



  ffmpeg -v debug -i input.mp4 -c:a libfdk_aac -vbr 2 -c:v libx264 -crf 28 -profile:v high -level 41 -vf format=yuv420p -sn -sample_fmt s16 -ac 1 -threads 0 -map_metadata -1 low.mp4
ffmpeg version 4.2.3 Copyright (c) 2000-2020 the FFmpeg developers
  built with gcc 9.3.0 (Gentoo 9.3.0 p2)
  configuration: --prefix=/usr --libdir=/usr/lib64 --shlibdir=/usr/lib64 --docdir=/usr/share/doc/ffmpeg-4.2.3/html --mandir=/usr/share/man --enable-shared --cc=x86_64-pc-linux-gnu-gcc --cxx=x86_64-pc-linux-gnu-g++ --ar=x86_64-pc-linux-gnu-ar --optflags='-O2 -pipe -march=haswell -mmmx -mno-3dnow -msse -msse2 -msse3 -mssse3 -mno-sse4a -mcx16 -msahf -mmovbe -maes -mno-sha -mpclmul -mpopcnt -mabm -mno-lwp -mfma -mno-fma4 -mno-xop -mbmi -mbmi2 -mno-tbm -mavx -mavx2 -msse4.2 -msse4.1 -mlzcnt -mno-rtm -mno-hle -mrdrnd -mf16c -mfsgsbase -mno-rdseed -mno-prfchw -mno-adx -mfxsr -mxsave -mxsaveopt -mno-avx512f -mno-avx512er -mno-avx512cd -mno-avx512pf -mno-prefetchwt1 -mno-clflushopt -mno-xsavec -mno-xsaves -mno-avx512dq -mno-avx512bw -mno-avx512vl -mno-avx512ifma -mno-avx512vbmi -mno-clwb -mno-mwaitx -mno-clzero -mno-pku -mtune=haswell' --disable-static --enable-avfilter --enable-avresample --disable-stripping --disable-optimizations --disable-libcelt --enable-version3 --enable-version3 --disable-indev=oss --disable-outdev=oss --enable-version3 --enable-nonfree --enable-bzlib --disable-runtime-cpudetect --disable-debug --disable-gcrypt --enable-gnutls --disable-gmp --enable-gpl --disable-hardcoded-tables --enable-iconv --disable-libtls --disable-libxml2 --enable-lzma --enable-network --disable-opencl --disable-openssl --enable-postproc --enable-libsmbclient --enable-ffplay --enable-sdl2 --enable-vaapi --disable-vdpau --enable-xlib --enable-libxcb --enable-libxcb-shm --enable-libxcb-xfixes --enable-zlib --disable-libcdio --disable-libiec61883 --disable-libdc1394 --disable-libcaca --disable-openal --enable-opengl --disable-libv4l2 --enable-libpulse --disable-libdrm --enable-libjack --enable-libopencore-amrwb --enable-libopencore-amrnb --disable-libcodec2 --enable-libdav1d --enable-libfdk-aac --enable-libopenjpeg --enable-libbluray --disable-libgme --disable-libgsm --disable-libaribb24 --disable-mmal --disable-libmodplug --enable-libopus --disable-libilbc --enable-librtmp --disable-libssh --enable-libspeex --enable-libsrt --enable-librsvg --disable-ffnvcodec --enable-libvorbis --enable-libvpx --disable-libzvbi --disable-appkit --disable-libbs2b --disable-chromaprint --disable-cuda-llvm --disable-libflite --enable-frei0r --disable-libfribidi --disable-fontconfig --enable-ladspa --disable-libass --disable-libtesseract --enable-lv2 --enable-libfreetype --enable-libvidstab --disable-librubberband --disable-libzmq --disable-libzimg --enable-libsoxr --enable-pthreads --enable-libvo-amrwbenc --enable-libmp3lame --disable-libkvazaar --enable-libaom --disable-libopenh264 --disable-libsnappy --enable-libtheora --disable-libtwolame --enable-libwavpack --enable-libwebp --enable-libx264 --enable-libx265 --enable-libxvid --disable-armv5te --disable-armv6 --disable-armv6t2 --disable-neon --disable-vfp --disable-vfpv3 --disable-armv8 --disable-mipsdsp --disable-mipsdspr2 --disable-mipsfpu --disable-altivec --disable-amd3dnow --disable-amd3dnowext --disable-fma4 --disable-xop --cpu=haswell --disable-doc --disable-htmlpages --enable-manpages
  libavutil      56. 31.100 / 56. 31.100
  libavcodec     58. 54.100 / 58. 54.100
  libavformat    58. 29.100 / 58. 29.100
  libavdevice    58.  8.100 / 58.  8.100
  libavfilter     7. 57.100 /  7. 57.100
  libavresample   4.  0.  0 /  4.  0.  0
  libswscale      5.  5.100 /  5.  5.100
  libswresample   3.  5.100 /  3.  5.100
  libpostproc    55.  5.100 / 55.  5.100
Splitting the commandline.
Reading option '-v' ... matched as option 'v' (set logging level) with argument 'debug'.
Reading option '-i' ... matched as input url with argument 'input.mp4'.
Reading option '-c:a' ... matched as option 'c' (codec name) with argument 'libfdk_aac'.
Reading option '-vbr' ... matched as AVOption 'vbr' with argument '2'.
Reading option '-c:v' ... matched as option 'c' (codec name) with argument 'libx264'.
Reading option '-crf' ... matched as AVOption 'crf' with argument '28'.
Reading option '-profile:v' ... matched as option 'profile' (set profile) with argument 'high'.
Reading option '-level' ... matched as AVOption 'level' with argument '41'.
Reading option '-vf' ... matched as option 'vf' (set video filters) with argument 'format=yuv420p'.
Reading option '-sn' ... matched as option 'sn' (disable subtitle) with argument '1'.
Reading option '-sample_fmt' ... matched as option 'sample_fmt' (set sample format) with argument 's16'.
Reading option '-ac' ... matched as option 'ac' (set number of audio channels) with argument '1'.
Reading option '-threads' ... matched as AVOption 'threads' with argument '0'.
Reading option '-map_metadata' ... matched as option 'map_metadata' (set metadata information of outfile from infile) with argument '-1'.
Reading option 'low.mp4' ... matched as output url.
Finished splitting the commandline.
Parsing a group of options: global .
Applying option v (set logging level) with argument debug.
Successfully parsed a group of options.
Parsing a group of options: input url input.mp4.
Successfully parsed a group of options.
Opening an input file: input.mp4.
[NULL @ 0x559fb7ecda40] Opening 'input.mp4' for reading
[file @ 0x559fb7ece4c0] Setting default whitelist 'file,crypto'
[mov,mp4,m4a,3gp,3g2,mj2 @ 0x559fb7ecda40] Format mov,mp4,m4a,3gp,3g2,mj2 probed with size=2048 and score=100
[mov,mp4,m4a,3gp,3g2,mj2 @ 0x559fb7ecda40] ISO: File Type Major Brand: isom
[mov,mp4,m4a,3gp,3g2,mj2 @ 0x559fb7ecda40] Unknown dref type 0x206c7275 size 12
[mov,mp4,m4a,3gp,3g2,mj2 @ 0x559fb7ecda40] Processing st: 0, edit list 0 - media time: 0, duration: 90
[mov,mp4,m4a,3gp,3g2,mj2 @ 0x559fb7ecda40] Unknown dref type 0x206c7275 size 12
[mov,mp4,m4a,3gp,3g2,mj2 @ 0x559fb7ecda40] Processing st: 1, edit list 0 - media time: 1024, duration: 12106376
[mov,mp4,m4a,3gp,3g2,mj2 @ 0x559fb7ecda40] drop a frame at curr_cts: 0 @ 0
[mov,mp4,m4a,3gp,3g2,mj2 @ 0x559fb7ecda40] Before avformat_find_stream_info() pos: 48725 bytes read:65536 seeks:0 nb_streams:2
[h264 @ 0x559fb7ecf6c0] nal_unit_type: 7(SPS), nal_ref_idc: 3
[h264 @ 0x559fb7ecf6c0] nal_unit_type: 8(PPS), nal_ref_idc: 3
[mov,mp4,m4a,3gp,3g2,mj2 @ 0x559fb7ecda40] demuxer injecting skip 1024 / discard 0
[aac @ 0x559fb7ed1180] skip 1024 / discard 0 samples due to side data
[h264 @ 0x559fb7ecf6c0] nal_unit_type: 6(SEI), nal_ref_idc: 0
[h264 @ 0x559fb7ecf6c0] nal_unit_type: 5(IDR), nal_ref_idc: 3
[h264 @ 0x559fb7ecf6c0] Format yuvj420p chosen by get_format().
[h264 @ 0x559fb7ecf6c0] Reinit context to 480x368, pix_fmt: yuvj420p
[h264 @ 0x559fb7ecf6c0] no picture 
[mov,mp4,m4a,3gp,3g2,mj2 @ 0x559fb7ecda40] All info found
[mov,mp4,m4a,3gp,3g2,mj2 @ 0x559fb7ecda40] After avformat_find_stream_info() pos: 4059034 bytes read:98304 seeks:1 frames:46
Input #0, mov,mp4,m4a,3gp,3g2,mj2, from 'input.mp4':
  Metadata:
    major_brand     : isom
    minor_version   : 512
    compatible_brands: isomiso2avc1mp41
    encoder         : Lavf57.83.100
  Duration: 00:04:34.55, start: 0.000000, bitrate: 122 kb/s
    Stream #0:0(und), 1, 1/90000: Video: h264 (High), 1 reference frame (avc1 / 0x31637661), yuvj420p(pc, left), 480x360 (480x368) [SAR 1:1 DAR 4:3], 0/1, 6375600 kb/s, 90k fps, 90k tbr, 90k tbn, 180k tbc (default)
    Metadata:
      handler_name    : VideoHandler
    Stream #0:1(und), 45, 1/44100: Audio: aac (LC) (mp4a / 0x6134706D), 44100 Hz, stereo, fltp, 120 kb/s (default)
    Metadata:
      handler_name    : SoundHandler
Successfully opened the file.
Parsing a group of options: output url low.mp4.
Applying option c:a (codec name) with argument libfdk_aac.
Applying option c:v (codec name) with argument libx264.
Applying option profile:v (set profile) with argument high.
Applying option vf (set video filters) with argument format=yuv420p.
Applying option sn (disable subtitle) with argument 1.
Applying option sample_fmt (set sample format) with argument s16.
Applying option ac (set number of audio channels) with argument 1.
Applying option map_metadata (set metadata information of outfile from infile) with argument -1.
Successfully parsed a group of options.
Opening an output file: low.mp4.
File 'low.mp4' already exists. Overwrite ? [y/N] y
[file @ 0x559fb7ef6e40] Setting default whitelist 'file,crypto'
Successfully opened the file.
detected 8 logical cores
[h264 @ 0x559fb7f2ee40] nal_unit_type: 7(SPS), nal_ref_idc: 3
[h264 @ 0x559fb7f2ee40] nal_unit_type: 8(PPS), nal_ref_idc: 3
Stream mapping:
  Stream #0:0 -> #0:0 (h264 (native) -> h264 (libx264))
  Stream #0:1 -> #0:1 (aac (native) -> aac (libfdk_aac))
Press [q] to stop, [?] for help
cur_dts is invalid st:0 (0) [init:0 i_done:0 finish:0] (this is harmless if it occurs once at the start per stream)
[aac @ 0x559fb7ed3980] skip 1024 / discard 0 samples due to side data
cur_dts is invalid st:0 (0) [init:0 i_done:0 finish:0] (this is harmless if it occurs once at the start per stream)
[graph_1_in_0_1 @ 0x559fb7f431c0] Setting 'time_base' to value '1/44100'
[graph_1_in_0_1 @ 0x559fb7f431c0] Setting 'sample_rate' to value '44100'
[graph_1_in_0_1 @ 0x559fb7f431c0] Setting 'sample_fmt' to value 'fltp'
[graph_1_in_0_1 @ 0x559fb7f431c0] Setting 'channel_layout' to value '0x3'
[graph_1_in_0_1 @ 0x559fb7f431c0] tb:1/44100 samplefmt:fltp samplerate:44100 chlayout:0x3
[format_out_0_1 @ 0x559fb8109140] Setting 'sample_fmts' to value 's16'
[format_out_0_1 @ 0x559fb8109140] Setting 'sample_rates' to value '96000|88200|64000|48000|44100|32000|24000|22050|16000|12000|11025|8000'
[format_out_0_1 @ 0x559fb8109140] Setting 'channel_layouts' to value '0x4'
[format_out_0_1 @ 0x559fb8109140] auto-inserting filter 'auto_resampler_0' between the filter 'Parsed_anull_0' and the filter 'format_out_0_1'
[AVFilterGraph @ 0x559fb7f3eb80] query_formats: 4 queried, 6 merged, 3 already done, 0 delayed
[auto_resampler_0 @ 0x559fb810a000] [SWR @ 0x559fb810a380] Using fltp internally between filters
[auto_resampler_0 @ 0x559fb810a000] [SWR @ 0x559fb810a380] Matrix coefficients:
[auto_resampler_0 @ 0x559fb810a000] [SWR @ 0x559fb810a380] FC: FL:0.500000 FR:0.500000 
[auto_resampler_0 @ 0x559fb810a000] ch:2 chl:stereo fmt:fltp r:44100Hz -> ch:1 chl:mono fmt:s16 r:44100Hz
[libfdk_aac @ 0x559fb7ef7080] Note, the VBR setting is unsupported and only works with some parameter combinations
cur_dts is invalid st:0 (0) [init:0 i_done:0 finish:0] (this is harmless if it occurs once at the start per stream)
    Last message repeated 44 times
[h264 @ 0x559fb7f2ee40] nal_unit_type: 6(SEI), nal_ref_idc: 0
[h264 @ 0x559fb7f2ee40] nal_unit_type: 5(IDR), nal_ref_idc: 3
[h264 @ 0x559fb7f2ee40] Format yuvj420p chosen by get_format().
[h264 @ 0x559fb7f2ee40] Reinit context to 480x368, pix_fmt: yuvj420p
cur_dts is invalid st:0 (0) [init:0 i_done:0 finish:0] (this is harmless if it occurs once at the start per stream)
    Last message repeated 1 times
[h264 @ 0x559fb7f2ee40] no picture 
cur_dts is invalid st:0 (0) [init:0 i_done:0 finish:0] (this is harmless if it occurs once at the start per stream)
    Last message repeated 81 times
Too many packets buffered for output stream 0:1.
[AVIOContext @ 0x559fb7ed3780] Statistics: 0 seeks, 0 writeouts
[libfdk_aac @ 0x559fb7ef7080] 2 frames left in the queue on closing
[AVIOContext @ 0x559fb7ed6880] Statistics: 131072 bytes read, 2 seeks
Conversion failed!


  



  EDIT 2 :

  



  The original file is converted by online tool which uses ffmpeg also.
The source file was .mp3 with jpeg cover inside. But I wasn't able to simulate online tool's behavior = to convert cover to one-frame video.

  


• Seek function of HTML5 video and Maximum Keyframe Interval in video encoding compression

  20 décembre 2019, par Sanxofon

  This is a very specific question about how the seek function (of an HTML5 video element) interprets a video, in this case one in WEBM format and what specific relationship it has with the Maximum Keyframe Interval in the process of coding of said video.

  I’ve made this fiddle to show what I mean :

  https://jsfiddle.net/sanxofon/hctuxo3e/

  What it does : The idea is to control the position of a paused video with the scroll wheel of the mouse ... in addition, each frame of the video is copied to a canvas element, but I think that has no relation. I mention it just in case.

  What to watch : In Chrome (v66) and slightly less in Firefox (v59) the scrolling looks pretty good when the video is encoded with a Maximum Keyframe Interval of 6 or less, but jumps are appreciated when the interval is every 24 frames or more. This is noticeable in the video and even more on the canvas.

  FFMPEG : When encoding a video with FFMPEG this is achieved with the option -g6 or -g24 of Maximum Keyframe Interval. However, the file becomes heavier as we decrease the interval. It can be seen that there is no difference between both formats when the video is in play.

  You can switch the video in the snippet with the buttons.

  • Case 1 : When we use the video encoded with -g 6 the video scrolling is acceptable but the size increases : 6.229 Mb.

  FFMPEG string used :

   ffmpeg -i INPUT.MOV -c: v libvpx -qmin 0 -deadline best -qmax 50 -crf 1 -b: v 100K -g 6 test / video_g6.webm

  • Case 2 : When we use the video encoded with -g 24 the displacement is not smooth and suffers from jumps but the size decreases : 4,477 Mb.

  FFMPEG string used :

   ffmpeg -i INPUT.MOV -c: v libvpx -qmin 0 -deadline best -qmax 50 -crf 1 -b: v 100K -g 24 test / video_g24.webm

  Why does this happen ?

  What about -keyint_min or -force_key_frames ? Do they have any positive effect ? Is it better to use something like cgop (closed gop) ?

  I would appreciate some reference of consultation on this subject or a more or less detailed explanation of this relationship for both the WEBM container and for MP4 and OGG video.

  I am not looking so much for a magical ffmpeg chain (although I would appreciate it) but rather an explanation of how this relationship between the keyframes and the seek of a javascript video works.

  Thank you very much for reading here.

  P.S. One more thing, if the seek function only stops in a keyframe, is it possible that this frame has more quality than the others so that the quality increases when the video stops ?

• Drawing text on video with avconv only at the start of the video

  21 juillet 2013, par Gael

  I want to embed the creation date of personnal videos, but only at their start (let say the 10 first seconds).

  I'm using the drawtext of avconv :

  avconv -i input.avi -vf
  "drawtext=fontcolor=white:fontsize=30:fontfile=/usr/share/fonts/truetype/ubuntu-font-family/Ubuntu-L.ttf:text='$date':x=30:y=h-text_h-30"
  test.mpg

  but I do not find any option to tell to just write the date on only a portion of the video. I could split the start of the video, or make an srt file, but there is probably an easier solution.