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• Accurate FFmpeg capture start time

  28 juillet 2016, par Adam

  I’m using ffmpeg from the command line to capture from a webcam to a file using the following :

  ffmpeg -y -rtbufsize 702000k -f dshow -s 320x240 -r 25 -i video="<device>" -t 10 -vcodec mjpeg -q:v 2 out.mp4
  
  </device>

  There is a slight delay between executing the command and the start of the capture ( 0.5 sec).
  I’m trying to find a way to accurately determine the start time (UTC/GMT) of the capture.

  My initial thought was to use the file-creation time as this might accurately reflect when the first frame was encoded (as opposed to when the command was executed). Unfortunately the file creation time is only accurate to the second which is not precise enough (and I’m not sure this would have given an accurate result anyway).

  My next thought was to use ffmpegs timestamp option. According to the documentation (http://www.ffmpeg.org/ffmpeg.html) :

  ‘-timestamp time (output)’

  Set the recording timestamp in the container. The syntax for time is:
  
  
  
  now|([(YYYY-MM-DD|YYYYMMDD)[T|t| ]]((HH:MM:SS[.m...])|(HHMMSS[.m...]))[Z|z])

  If the value is "now" it takes the current time. Time is local time unless ’Z’ or
  ’z’ is appended, in which case it is interpreted as UTC. If the year-month-day part
  is not specified it takes the current year-month-day.

  So I added the option :

  ffmpeg -y -rtbufsize 702000k -f dshow -s 320x240 -r 25 -i video="<device>" -t 10 -vcodec mjpeg -q:v 2 -timestamp now out.mp4
  
  </device>

  Unfortunately ffmpeg doesn’t seem to like this :

  Option timestamp (set the recording timestamp (’now’ to set the
  current time)) cannot be applied to output file out.mp4 — you are
  trying to apply an input option to an output file or vice versa. Move
  this option before the file it belongs to.

  Error parsing options for output file out.mp4.

  Error opening output files : Error number -22 occurred

  The documentation says -timestamp is an output option and it appears to be applied to the output file so I’m confused by this error.

  Can anyone suggest a way to accurately determine the capture start time ?

  Does anyone know why the -timestamp option gives an error ?

• Unplayable video after running FFmpeg command

  25 mai 2020, par HB.

  I asked this question last year. I resolved the issue I had and I implemented the same logic for merging an image with a video, instead of two images. This is running on Android.

  



  Here is the command I'm using currently :

  



  "-i", mFilePath, "-i", drawingPath, "-filter_complex", "[0:v]scale=iw*sar:ih,setsar=1,pad='max(iw\\,2*trunc(ih*47/80/2))':'max(ih\\,2*trunc(ow*80/47/2))':(ow-iw)/2:(oh-ih)/2[v0];[1:v][v0]scale2ref[v1][v0];[v0][v1]overlay=x=(W-w)/2:y=(H-h)/2[v]", "-map", "[v]", "-map", "0:a", "-c:v", "libx264", "-preset", "ultrafast", "-r", outputFPS, outputPath}


  



  47/80/2 is calculated by getting a device's screen dimensions - 1128 x 1920.

  



  When running this on certain devices, it results in an unplayable video.

  



  But running the following command works perfectly fine :

  



  "-i", mFilePath, "-crf", "18", "-c:v", "libx264", "-preset", "ultrafast", outputPath};


  



  I think the issue is with the filter being applied ?

  



  ---

  



  I compared running the first command on two different devices.

  



  

  • On the first device (Samsung J7 Pro), I was able to run the command successfully and play the video afterward. I tested the output on both devices and it is working.

  


  • On the second device (Sony Xperia Tablet Z), I was able to run the command successfully but could not play the video. I tested the output on both devices and it doesn't play on either. It does play on my computer.

  


  



  I compared the original video with the one not working and the one without a filter and the only difference I could find is that the one that is not working profile is Baseline@L4.2 and the one without a filter profile is Baseline@L4.0. The original video profile is High@L4.0.

  



  Here are all the videos. The original, the one without a filter (working) and the one with the filter(no working).

  



  I have no idea why this is happening ? Any help would be appreciated.

  



  ---

  



  Edit 1 :

  



  Here is the actual log as requested :

  



  "-i", "/storage/emulated/0/Android/data/com.my.package/files/CameraTemp/2020_05_24_09_17_53.mp4", "-i", "/storage/emulated/0/Android/data/com.my.package/files/MyVideos/tempShapes.png", "-filter_complex", "[0:v]scale=iw*sar:ih,setsar=1,pad='max(iw\\,2*trunc(ih*47/80/2))':'max(ih\\,2*trunc(ow*80/47/2))':(ow-iw)/2:(oh-ih)/2[v0];[1:v][v0]scale2ref[v1][v0];[v0][v1]overlay=x=(W-w)/2:y=(H-h)/2[v]", "-map", "[v]", "-map", "0:a", "-c:v", "libx264", "-preset", "ultrafast", "-r", "30", "/storage/emulated/0/Android/data/com.my.package/files/MyVideos/video with line.mp4"


  



  and here is the complete log :

  



  ffmpeg version n4.0-39-gda39990 Copyright (c) 2000-2018 the FFmpeg developers
  built with gcc 4.9.x (GCC) 20150123 (prerelease)
  configuration: --target-os=linux --cross-prefix=/root/bravobit/ffmpeg-android/toolchain-android/bin/arm-linux-androideabi- --arch=arm --cpu=cortex-a8 --enable-runtime-cpudetect --sysroot=/root/bravobit/ffmpeg-android/toolchain-android/sysroot --enable-pic --enable-libx264 --enable-ffprobe --enable-libopus --enable-libvorbis --enable-libfdk-aac --enable-libfreetype --enable-libfribidi --enable-libmp3lame --enable-fontconfig --enable-libvpx --enable-libass --enable-yasm --enable-pthreads --disable-debug --enable-version3 --enable-hardcoded-tables --disable-ffplay --disable-linux-perf --disable-doc --disable-shared --enable-static --enable-runtime-cpudetect --enable-nonfree --enable-network --enable-avresample --enable-avformat --enable-avcodec --enable-indev=lavfi --enable-hwaccels --enable-ffmpeg --enable-zlib --enable-gpl --enable-small --enable-nonfree --pkg-config=pkg-config --pkg-config-flags=--static --prefix=/root/bravobit/ffmpeg-android/build/armeabi-v7a --extra-cflags='-I/root/bravobit/ffmpeg-android/toolchain-android/include -U_FORTIFY_SOURCE -D_FORTIFY_SOURCE=2 -fno-strict-overflow -fstack-protector-all' --extra-ldflags='-L/root/bravobit/ffmpeg-android/toolchain-android/lib -Wl,-z,relro -Wl,-z,now -pie' --extra-cxxflags=
  libavutil      56. 14.100 / 56. 14.100
  libavcodec     58. 18.100 / 58. 18.100
  libavformat    58. 12.100 / 58. 12.100
  libavdevice    58.  3.100 / 58.  3.100
  libavfilter     7. 16.100 /  7. 16.100
  libavresample   4.  0.  0 /  4.  0.  0
  libswscale      5.  1.100 /  5.  1.100
  libswresample   3.  1.100 /  3.  1.100
  libpostproc    55.  1.100 / 55.  1.100
Input #0, mov,mp4,m4a,3gp,3g2,mj2, from '/storage/emulated/0/Android/data/com.my.package/files/CameraTemp/2020_05_24_09_17_53.mp4':
  Metadata:
    major_brand     : mp42
    minor_version   : 0
    compatible_brands: isommp42
    creation_time   : 2020-05-24T08:18:02.000000Z
  Duration: 00:00:01.64, start: 0.000000, bitrate: 20750 kb/s
    Stream #0:0(eng): Video: h264 (avc1 / 0x31637661), yuv420p, 1920x1080, 18056 kb/s, SAR 1:1 DAR 16:9, 29.70 fps, 29.67 tbr, 90k tbn, 180k tbc (default)
    Metadata:
      creation_time   : 2020-05-24T08:18:02.000000Z
      handler_name    : VideoHandle
    Stream #0:1(eng): Audio: aac (mp4a / 0x6134706D), 48000 Hz, stereo, fltp, 155 kb/s (default)
    Metadata:
      creation_time   : 2020-05-24T08:18:02.000000Z
      handler_name    : SoundHandle
Input #1, png_pipe, from '/storage/emulated/0/Android/data/com.my.package/files/MyVideos/tempShapes.png':
  Duration: N/A, bitrate: N/A
    Stream #1:0: Video: png, rgba(pc), 1920x1128, 25 tbr, 25 tbn, 25 tbc
Stream mapping:
  Stream #0:0 (h264) -> scale (graph 0)
  Stream #1:0 (png) -> scale2ref:default (graph 0)
  overlay (graph 0) -> Stream #0:0 (libx264)
  Stream #0:1 -> #0:1 (aac (native) -> aac (native))
Press [q] to stop, [?] for help
frame=    0 fps=0.0 q=0.0 size=       0kB time=-577014:32:22.77 bitrate=  -0.0kbits/s speed=N/A    
frame=    0 fps=0.0 q=0.0 size=       0kB time=-577014:32:22.77 bitrate=  -0.0kbits/s speed=N/A    
[libx264 @ 0xb83fc8a0] using SAR=1/1
[libx264 @ 0xb83fc8a0] using cpu capabilities: ARMv6 NEON
[libx264 @ 0xb83fc8a0] profile Constrained Baseline, level 4.2
[libx264 @ 0xb83fc8a0] 264 - core 152 r2851M ba24899 - H.264/MPEG-4 AVC codec - Copyleft 2003-2017 - http://www.videolan.org/x264.html - options: cabac=0 ref=1 deblock=0:0:0 analyse=0:0 me=dia subme=0 psy=1 psy_rd=1.00:0.00 mixed_ref=0 me_range=16 chroma_me=1 trellis=0 8x8dct=0 cqm=0 deadzone=21,11 fast_pskip=1 chroma_qp_offset=0 threads=6 lookahead_threads=1 sliced_threads=0 nr=0 decimate=1 interlaced=0 bluray_compat=0 constrained_intra=0 bframes=0 weightp=0 keyint=2 keyint_min=1 scenecut=0 intra_refresh=0 rc=crf mbtree=0 crf=23.0 qcomp=0.60 qpmin=0 qpmax=69 qpstep=4 ip_ratio=1.40 aq=0
Output #0, mp4, to '/storage/emulated/0/Android/data/com.my.package/files/MyVideos/video with line.mp4':
  Metadata:
    major_brand     : mp42
    minor_version   : 0
    compatible_brands: isommp42
    encoder         : Lavf58.12.100
    Stream #0:0: Video: h264 (libx264) (avc1 / 0x31637661), yuv420p, 1920x1128 [SAR 1:1 DAR 80:47], q=-1--1, 29 fps, 14848 tbn, 29 tbc (default)
    Metadata:
      encoder         : Lavc58.18.100 libx264
    Side data:
      cpb: bitrate max/min/avg: 0/0/0 buffer size: 0 vbv_delay: -1
    Stream #0:1(eng): Audio: aac (mp4a / 0x6134706D), 48000 Hz, stereo, fltp, 128 kb/s (default)
    Metadata:
      creation_time   : 2020-05-24T08:18:02.000000Z
      handler_name    : SoundHandle
      encoder         : Lavc58.18.100 aac
frame=    1 fps=0.4 q=0.0 size=       0kB time=00:00:01.01 bitrate=   0.4kbits/s speed=0.397x    
frame=    5 fps=1.6 q=0.0 size=       0kB time=00:00:01.01 bitrate=   0.4kbits/s speed=0.33x    
frame=    9 fps=2.5 q=24.0 size=     256kB time=00:00:01.01 bitrate=2075.0kbits/s speed=0.28x    
frame=   13 fps=3.1 q=25.0 size=    1024kB time=00:00:01.01 bitrate=8298.9kbits/s speed=0.243x    
frame=   18 fps=3.8 q=29.0 size=    2048kB time=00:00:01.01 bitrate=16597.5kbits/s speed=0.214x    
frame=   21 fps=3.9 q=25.0 size=    2560kB time=00:00:01.01 bitrate=20746.7kbits/s speed=0.19x    
frame=   23 fps=3.9 q=25.0 size=    2816kB time=00:00:01.01 bitrate=22821.4kbits/s speed=0.173x    
frame=   26 fps=4.0 q=29.0 size=    3584kB time=00:00:01.01 bitrate=29045.3kbits/s speed=0.156x    
Past duration 0.617577 too large
Past duration 0.639641 too large
frame=   28 fps=3.9 q=29.0 size=    3840kB time=00:00:01.01 bitrate=31119.9kbits/s speed=0.142x    
Past duration 0.665230 too large
frame=   29 fps=3.8 q=25.0 size=    3840kB time=00:00:01.01 bitrate=31119.9kbits/s speed=0.132x    
Past duration 0.690834 too large
Past duration 0.711281 too large
Past duration 0.736885 too large
frame=   32 fps=3.9 q=29.0 size=    4608kB time=00:00:01.01 bitrate=37343.8kbits/s speed=0.123x    
Past duration 0.762474 too large
Past duration 0.783577 too large
Past duration 0.807564 too large
frame=   35 fps=3.9 q=25.0 size=    4864kB time=00:00:01.01 bitrate=39418.4kbits/s speed=0.112x    
Past duration 0.831551 too large
Past duration 0.855537 too large
frame=   37 fps=3.5 q=25.0 size=    5376kB time=00:00:01.01 bitrate=43567.7kbits/s speed=0.0968x    
Past duration 0.879524 too large
Past duration 0.903511 too large
frame=   39 fps=3.4 q=25.0 size=    5376kB time=00:00:01.06 bitrate=41196.6kbits/s speed=0.0927x    
Past duration 0.927498 too large
Past duration 0.951500 too large
frame=   41 fps=3.4 q=25.0 size=    5376kB time=00:00:01.13 bitrate=38700.0kbits/s speed=0.0931x    
frame=   41 fps=3.2 q=25.0 size=    5376kB time=00:00:01.13 bitrate=38700.0kbits/s speed=0.0886x    
frame=   41 fps=3.1 q=25.0 size=    5888kB time=00:00:01.43 bitrate=33554.2kbits/s speed=0.108x    
Past duration 0.975487 too large
frame=   45 fps=3.2 q=26.0 size=    6656kB time=00:00:01.60 bitrate=33905.4kbits/s speed=0.114x    
frame=   45 fps=3.0 q=-1.0 Lsize=    8158kB time=00:00:01.65 bitrate=40480.7kbits/s speed=0.11x    
video:8127kB audio:28kB subtitle:0kB other streams:0kB global headers:0kB muxing overhead: 0.032895%
[libx264 @ 0xb83fc8a0] frame I:23    Avg QP:24.70  size:337646
[libx264 @ 0xb83fc8a0] frame P:22    Avg QP:29.00  size: 25250
[libx264 @ 0xb83fc8a0] mb I  I16..4: 100.0%  0.0%  0.0%
[libx264 @ 0xb83fc8a0] mb P  I16..4:  0.4%  0.0%  0.0%  P16..4: 43.6%  0.0%  0.0%  0.0%  0.0%    skip:56.0%
[libx264 @ 0xb83fc8a0] coded y,uvDC,uvAC intra: 90.0% 84.7% 58.1% inter: 20.1% 6.2% 0.1%
[libx264 @ 0xb83fc8a0] i16 v,h,dc,p: 25% 28% 28% 20%
[libx264 @ 0xb83fc8a0] i8c dc,h,v,p: 39% 25% 20% 16%
[libx264 @ 0xb83fc8a0] kb/s:42901.20
[aac @ 0xb83d7d10] Qavg: 3517.779


  


• How do I use ffmpeg to put HTML text overlay in a video ? [closed]

  29 septembre 2020, par Tom

  How do I use ffmpeg to put HTML text overlay in a video ?

  


  I have a web page where a user can write html text with online editor tool. I want to overlay the html text to a video. What can I do ?
Here is a sample HTML text.

  


  <p style="color:#000;"><span style="color:#FFFFFF;"><span style="font-size:48px;"><span style="font-family:philosopher;">Best Wishes for </span></span></span></p><p style="color:#000;"><span style="color:#FFFFFF;"><span style="font-size:48px;"><span style="font-family:philosopher;">a joyful and prosperous<br />New Year!</span></span></span></p>&#xA;