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• ffmpeg "Automatic encoder selection failed for output stream"

  6 octobre 2018, par polmonroig

  I am trying to convert a video file from mp4 to exr but I am getting this error with this command in ffmpeg.

  Command

  ffmpeg -i 'video.MP4' 'video.%04d.exr'

  Error

  Automatic encoder selection failed for output stream #0:0. Default encoder for format image2 (codec exr) is probably disabled. Please choose an encoder manually.
  
      Error selecting an encoder for stream 0:0

  I hope someone can help me, I am really lost.

  Thank you !

• How to install ffmpeg and convert videos to mp4 in PHP ?

  21 octobre 2018, par loot verge

  I downloaded the latest version of ffmpeg.exe. How can I use it in order to convert videos to mp4 using PHP script and Do I need to install the ffmpeg.exe in order for me to use it if so, how can I install it properly ? I am using the latest version XAMPP. I have seen many sites with tutorial but none of the have the proper information to install and use ffmpeg. I hope you guys can help me. I tried to copy the ffmpeg.exe in the folder of my site and tried the code below I am getting an error

  if(exec("ffmpeg.exe")){
  
      echo "ok";
  
  }
  
  else {
  
      echo "error";
  
  }

• Scenecut detection and consistent GOP size - adaptive streaming

  24 mars 2014, par Tarun

  Sample Command :

  -map 0:0 -f mp4 -vcodec libx264 -preset slow -profile:v main -vf scale="640:trunc(ow/a/2)*2" -vb 700k -minrate 650k -maxrate 750k -bufsize 10000k -an -g 48 -x264opts keyint=48:min-keyint=10:scenecut=40 -flags +cgop -sc_threshold 40 -pix_fmt yuv420p -threads 0 -y

  There is as such no error in encoding, But I wanted to understand following points-

  1) the above command will ensure that range of GOP size is 10,48, and if any scene change value (frame1 to fame2) is >40%, then a keyframe is introduced there ?

  2) So that means in a 3 hours of source video, there is no guarantee that GOP size will remain same

  3) No consider, I am creating 7 MP4 files each with different bitrate and resolution. (These Mp4s will be encoded to smooth in later stage). Hence i am targeting adaptive streaming. But when I did that, I found that if GOP sizes were not consistent across each bitrates. What I mean by this is, for ex : if in Bitrate1 - GOP size is like 10, 20, 48 and so on, in other bitrates it wasnt in the same sequence. I hope my question makes sense.

  So is there a way to ensure that GOP size may vary across one single output. But it should be consistent across each bitrate provided that the source is same ?

  Also for adaptive streaming Is scenecut detection advisable ?