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• How to add a Poster Frame to an MP4 video by timecode ?

  25 mai 2020, par Crissov

  The mvhd atom or box of the original Quicktime MOV format supports a poster time variable for a timecode to use as a poster frame that can be used in preview scenarios as a thumbnail image or cover picture. As far as I can tell, the ISOBMFF-based MP4 format (.m4v) has inherited this feature, but I cannot find a way to set it using FFmpeg or MP4box or similar cross-platform CLI software. Edit : Actually, neither ISOBMFF nor MP4 imports this feature from MOV. Is there any other way to achieve this, e.g. using something like HEIFʼs derived images with a thmb (see Amendment 2) role ?

  



  

  



  The original Apple Quicktime (Pro) editor did have a menu option for doing just that. (Apple Compressor and Photos could do it, too).

  



  

  



  To be clear, I do not want to attach a separate image file, which could possibly be a screenshot grabbed from a movie still, as a separate track to the multimedia container. I know how to do that :

  



  

  • Stackoverflow #54717175

  


  • Superuser #597945

  


  



  I also know that some people used to copy the designated poster frame from its original position to the very first frame, but many automatically generated previews use a later time index, e.g. from 10 seconds, 30 seconds, 10% or 50% into the video stream.

  


• ffmpeg sometimes not working for splitted videos-moov atom not found

  19 novembre 2018, par varmashrivastava

  I am using below command to reverse video-

  {"-i", files[i].getAbsolutePath(), "-vf", "reverse", "-af", "areverse", dest.getAbsolutePath()};

  I occasionally gets below error-

  ffmpeg version n3.0.1 Copyright (c) 2000-2016 the FFmpeg developers\n
  built with gcc 4.8 (GCC)\n configuration : —target-os=linux
  —cross-prefix=/home/vagrant/SourceCode/ffmpeg-android/toolchain-android/bin/arm-linux-androideabi-
  —arch=arm —cpu=cortex-a8 —enable-runtime-cpudetect —sysroot=/home/vagrant/SourceCode/ffmpeg-android/toolchain-android/sysroot
  —enable-pic —enable-libx264 —enable-libass —enable-libfreetype —enable-libfribidi —enable-libmp3lame —enable-fontconfig —enable-pthreads —disable-debug —disable-ffserver —enable-version3 —enable-hardcoded-tables —disable-ffplay —disable-ffprobe —enable-gpl —enable-yasm —disable-doc —disable-shared —enable-static —pkg-config=/home/vagrant/SourceCode/ffmpeg-android/ffmpeg-pkg-config —prefix=/home/vagrant/SourceCode/ffmpeg-android/build/armeabi-v7a —extra-cflags=’-I/home/vagrant/SourceCode/ffmpeg-android/toolchain-android/include
  -U_FORTIFY_SOURCE -D_FORTIFY_SOURCE=2 -fno-strict-overflow -fstack-protector-all’ —extra-ldflags=’-L/home/vagrant/SourceCode/ffmpeg-android/toolchain-android/lib
  -Wl,-z,relro -Wl,-z,now -pie’ —extra-libs=’-lpng -lexpat -lm’ —extra-cxxflags=\n libavutil 55. 17.103 / 55. 17.103\n libavcodec 57. 24.102 / 57. 24.102\n libavformat 57. 25.100 /
  57. 25.100\n libavdevice 57. 0.101 / 57. 0.101\n libavfilter 6. 31.100 / 6. 31.100\n libswscale 4. 0.100 / 4. 0.100\n libswresample 2. 0.101 / 2. 0.101\n libpostproc 54. 0.100 /
  54. 0.100\n[mov,mp4,m4a,3gp,3g2,mj2 @ 0xec427000] moov atom not found\n/storage/emulated/0/Movies/.VideoSplit/split_video010.mp4 :
  Invalid data found when processing input

  By what i have researched-

  moov atom is a container for the information that describes a movie’s
  data...Generally speaking, only metadata is stored in a movie atom.
  Sample data for the movie, such as audio or video samples, are
  referenced in the movie atom, but are not contained in it.

  The videos which I am reversing are splitted videos from a main video which I have splitted using below command-

  { "-i", inputFilePath, "-c:v", "libx264", "-crf", "22", "-map", "0", "-segment_time", "6", "-g", "9", "-sc_threshold", "0", "-force_key_frames", "expr:gte(t,n_forced*6)", "-f", "segment", outputFilePath};

  How can i resolve this error ?

• pipe youtube-dl to ffmpeg within a script

  28 février 2016, par user556068

  This is an expansion to an earlier question I asked which you can find here. I have been piping youtube-dl into a script via youtube-dl -iga /path/to/myFile.txt | myscript.sh which reads a text file of urls and extracts another set of urls to the actual video content being downloaded. Everything works great but there is much room for improvement.

  Instead of piping youtube-dl into the script I would like to include the youtube-dl command within the script itself. Here is the full script I have up to this point.

  #!/bin/bash  
  
  
  
  inArgs='-i'                 
  
  outArgs='-c copy -y'        
  
  dir="$HOME/Movies/fftest/"
  
  outFile="fftest_${count}"       
  
  ext='.mp4'        
  
  
  
  #### not sure about following 2 lines
  
  
  
  youtube-dl -iga /path/to/myFile.txt > /path/to/myFile2.txt
  
  exec 0to/myFile2.txt
  
  
  
  count=0
  
  if [ ! -d "${dir}" ]; 
  
  then
  
  mkdir -p "${dir}"
  
  fi      
  
  cd || "${HOME}"
  
  
  
  while read lineIn
  
  do
  
  {
  
  (( count ++ ))
  
  echo ffmpeg $inArgs $lineIn $outArgs "$dir$outFile$count$ext" &
  
  sleep 1
  
  }  
  
  done  

  After playing around with it a little I added the following lines. Code has been edited to reflect these changes.

  youtube-dl -iga /path/to/myFile.txt > /path/to/myFile2.txt
  
  exec 0to/myFile2.txt 

  This does work but it’s also throwing up some new error from ffmpeg that I haven’t yet encountered until now. I test by placing echo before the ffmpeg command. Everything looks fine doing that so I’m not really sure what the issue is at this point.

  So there are a couple things i would like to accomplish that I haven’t been able to figure out.

  • Have I properly redirected the input and do I need to do anything later in the script to put things back as they were before the script was called or will that occur naturally on its own when exiting the script ?

  • As it currently is, the script will overwrite any files previously created every time it is called. This is fine for testing purposes but not ideal beyond that. What I am looking for is a way to start writing the next file in the number sequence based on the last file in the directory. So if one time it creates 8 files named fftest_1.mpr - fftest_8.mp4 the second time when it is called to create 14 new files, it will know to start writing a file labeled fftest_9.mp4 - fftest_22.mp4. This is however beyond my abilities at the moment. Is there a way to do this ?

  • Another issue I’ve had is when trying kill the script as it runs in the background. Ctrl C doesn’t have any effect as far as I can tell. Is there an alternative kill command or key press I can use to ensure an immediate exit if necessary. Or a way to assign such within the script itself ?

  • Also any critiques, suggestions, alternatives or additions to any part of this script are very much welcomed and appreciated. This is all very new for me and I’m trying to learn more everyday. If any part of what I said didn’t make sense I will be happy to clarify.