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• How to determine the specific H264 encoder in use from FFmpeg library ?

  11 mai 2017, par Peter

  Looking at h264 encoders supported by FFmpeg library, I see quite a few encoders :

  libx264
  
  nvenc_h264
  
  h264_nvenc
  
  h264_vaapi
  
  h264_cuvid
  
  h264_vdpau

  To obtain an H264 encoder, we make a generic call :

  encoder = avcodec_find_encoder(AV_CODEC_ID_H264);

  How do we know which encoder was actually picked up ? Regards.

• how to determine if video file is 'high quality' using bitrate and dimensions ?

  22 août 2016, par Flo Woo

  Assuming a directory full of videos, if you extracted the video metadata to get video bitrate and dimensions. Is there a recommend way to plug in these values and get a LOW/HI quality answer.

  I would like to sort videos into a LOW/HI quality directory layout but after using ffmpeg to get the meta data, it isn’t obvious how to programmatically ascertain the videos quality.

  Is this possible ?

  Thank you.

• How can I determine video rotation/orientation in PHP/FFMPEG/PhoneGap ?

  14 juin 2014, par SomethingOn

  Once I upload videos to my server I’m creating a screencap using FFMPEG. Problem is, if the user takes a video in portrait mode the screencap is rotated 90º. The ridiculous things is that PhoneGap and FFMEG-php and FFMPEG don’t seem to offer a mechanism for reading the video rotation/orientation value.

  I found another library called mediainfo that will provide the info, but not in an easy to read/digest manner and I’m trying to avoid having to use another library.

  Am I wrong about PhoneGap/FFMPEG ? Is there a direct way to determine video orienation ?

  ---

  Here’s my solution as a PHP function :

  function get_video_orientation($video_path) {
  
      $cmd = FFMPEG_PATH . "ffprobe " . $video_path . " -show_streams 2>/dev/null";
  
      $result = shell_exec($cmd);
  
  
  
      $orientation = 0;
  
      if(strpos($result, 'TAG:rotate') !== FALSE) {
  
          $result = explode("\n", $result);
  
          foreach($result as $line) {
  
              if(strpos($line, 'TAG:rotate') !== FALSE) {
  
                  $stream_info = explode("=", $line);
  
                  $orientation = $stream_info[1];
  
              }
  
          }
  
      }
  
  
  
      return $orientation;
  
  }