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• Where can I get 16-bit video sequences ? [on hold]

  9 mai 2017, par govind

  I understand that I can create 16-bit videos from 8-bit ones, but I want to work on actual 16-bit data (for a class project) and not just the bit-shifted pixel values. I just want to extract and work on the 16-bit Luma component from the video.

  https://media.xiph.org/ has 16-bit raw contents but the file size is 500GB. I would like to limit my downloads to 1-2 GB.
  The footnote at https://media.xiph.org/video/derf/ says "These were converted from 16-bit linear RGB to Y’CbCr", can I get the source from which these conversion took place.

  I could create my own content with some custom pattern but that’s not an option since I want to work on natural-looking imagery.

  I do understand that regular monitors can only display 8-bit. I also understand that it’s not a typical StackOverflow question, but I have already spent 2 hours online searching for it. Any links will be appreciated. Thanks in advance.

• How to handle queueing of video encoding during multiple video uploads ?

  6 mars 2016, par Yash Desai

  I am working on developing a video streaming site where users can upload videos to the site (multiple videos at once using the uploadify jquery plugin).

  Now, I am faced with the question of encoding the videos to FLV for streaming them online.

  When should the video encoding process take place ? Should it take place immediately after uploads have finished (i.e redirect the user to upload success page, and then start encoding in the background using exec command for ffmpeg ?) However, using this approach, how do i determine if the encoding has finished successfully ? What if users upload a corrupt video and ffmpeg fails to encode it ? How do i handle this in PHP ?

  How do i queue encoding of videos since multiple users can upload videos at the same ? Does FFMpeg has its own encoding queue ?

  I also read about gearman and message queueing options such as redis and AMQP in another related SO thread. Are these one of the potential solutions ?

  I would really appreciate if someone could give answers to my questions.

• ffmpeg : not found when running ffmpeg via php xampp (mac)

  28 août 2021, par Alex Styl

  I am trying to execute ffmpeg from php. I have installed ffmpeg locally on my mac via homebrew and I am able to run the commands I need via terminal.

  


  When I try to execute the following code :

  


  &lt;?php&#xA;    echo "Starting ffmpeg";&#xA;    $output = shell_exec("ffmpeg -i test.mp3 -codec:a libmp3lame -b:a 128k out.mp3 2>&amp;1");&#xA;    echo "<pre>$output</pre>";&#xA;?>&#xA;

  


  I am receiving the following on my browser :

  


  


  Starting ffmpeg

  


  sh : 1 : ffmpeg : not found

  


  


  I am assuming that I somehow need to install ffmpeg to my xampp server but it is not obvious how to do that. After searching online I can find linux and Windows tutorials but I couldn't figure out something out by looking at them.

  


  What I tried doing was to download the ffmpeg static build form https://ffmpeg.org/download.html#build-mac and placed it in the htdocs holder, and then tried to execute ffmpeg as if it was an executable (after changing chmod), but that gave me

  


  


  sh : 1 : ./ffmpeg : Exec format error

  


  


  How would one go and install and then run ffmpeg on their xampp server ?