public function PHPVideoToolkit::extractFrames in Video 7.2

Same name and namespace in other branches

1. 7 libraries/phpvideotoolkit/phpvideotoolkit.php5.php \PHPVideoToolkit::extractFrames()

Extracts frames from a video. (Note; If set to 1 and the duration set by $extract_begin_timecode and $extract_end_timecode is equal to 1 you get more than one frame. For example if you set $extract_begin_timecode='00:00:00' and $extract_end_timecode='00:00:01' you might expect because the time span is 1 second only to get one frame if you set $frames_per_second=1. However this is not correct. The timecode you set in $extract_begin_timecode acts as the beginning frame. Thus in this example the first frame exported will be from the very beginning of the video, the video will then move onto the next frame and export a frame there. Therefore if you wish to export just one frame from one position in the video, say 1 second in you should set $extract_begin_timecode='00:00:01' and set $extract_end_timecode='00:00:01'.)

@access public

Parameters

string $extract_begin_timecode A timecode (hh:mm:ss.fn - you can change the timecode format by changing the $timecode_format param: it obeys the formatting of PHPVideoToolkit::formatTimecode(), see below for more info)

string|integer|boolean $extract_end_timecode A timecode (hh:mm:ss.fn - you can change the timecode format by changing the $timecode_format param: it obeys the formatting of PHPVideoToolkit::formatTimecode(), see below for more info), or FALSE if all frames from the begin timecode are to be exported. (Boolean added by Matthias. Thanks. 12th March 2007)

boolean|integer $frames_per_second The number of frames per second to extract. If left as default FALSE, then the number of frames per second: will be automagically gained from PHPVideoToolkit::fileGetInfo();

boolean|integer $frame_limit Frame limiter. If set to FALSE then all the frames will be exported from the given time codes, however: if you wish to set a export limit to the number of frames that are exported you can set an integer. For example; if you set $extract_begin_timecode='00:00:11.01', $extract_end_timecode='00:01:10.01', $frames_per_second=1, you will get one frame for every second in the video between 00:00:11 and 00:01:10 (ie 60 frames), however if you ant to artificially limit this to exporting only ten frames then you set $frame_limit=10. You could of course alter the timecode to reflect you desired frame number, however there are situations when a shortcut such as this is useful and necessary.

integer $timecode_format The format of the $extract_begin_timecode and $extract_end_timecode timecodes are being given in.: default '%hh:%mm:%ss' - %hh (hours) representative of hours - %mm (minutes) representative of minutes - %ss (seconds) representative of seconds - %fn (frame number) representative of frames (of the current second, not total frames) - %ms (milliseconds) representative of milliseconds (of the current second, not total milliseconds) (rounded to 3 decimal places) - %ft (frames total) representative of total frames (ie frame number) - %st (seconds total) representative of total seconds (rounded). - %sf (seconds floored) representative of total seconds (floored). - %mt (milliseconds total) representative of total milliseconds. (rounded to 3 decimal places) Thus you could use an alternative, '%hh:%mm:%ss:%ms', or '%hh:%mm:%ss' dependent on your usage.

boolean $check_frames_exist Determines if a frame exists check should be made to ensure the timecode given by $extract_end_timecode: actually exists.

1 call to PHPVideoToolkit::extractFrames()

PHPVideoToolkit::extractFrame in libraries/phpvideotoolkit/phpvideotoolkit.php5.php

Extracts exactly one frame

File

libraries/phpvideotoolkit/phpvideotoolkit.php5.php, line 1865

Libary to access FFmpeg

Class

PHPVideoToolkit

Code

public function extractFrames($extract_begin_timecode, $extract_end_timecode, $frames_per_second = FALSE, $frame_limit = FALSE, $timecode_format = '%hh:%mm:%ss.%fn', $check_frames_exist = TRUE) {

  // 			are we autoguessing the frame rate?
  if ($frames_per_second === FALSE || $check_frames_exist) {

    // 				get the file info, will exit if no input has been set
    $info = $this
      ->getFileInfo();
    if ($info === FALSE || isset($info['video']) === FALSE) {

      // 					the input has not returned any video data so the frame rate can not be guessed
      return $this
        ->_raiseError('extractFrame_video_frame_rate_404');
    }
    $frames_per_second = $info['video']['frame_rate'];
  }

  // 			check if frame exists
  if ($check_frames_exist) {
    if ($info['video']['frame_count'] < $this
      ->formatTimecode($extract_end_timecode, $timecode_format, '%ft', $frames_per_second)) {

      // 					the input has not returned any video data so the frame rate can not be guessed
      return $this
        ->_raiseError('extractFrames_video_end_frame_count');
    }
    elseif ($extract_end_timecode !== FALSE && $info['video']['frame_count'] < $this
      ->formatTimecode($extract_begin_timecode, $timecode_format, '%ft', $frames_per_second)) {

      // 					the input has not returned any video data so the frame rate can not be guessed
      return $this
        ->_raiseError('extractFrames_video_begin_frame_count');
    }
  }

  // 			disable audio output
  $this
    ->disableAudio();

  // 			format the begin timecode if the timecode format is not already ok.

  /*
   if($timecode_format !== '%hh:%mm:%ss.%ms')
   {
   $extract_begin_timecode = $this->formatTimecode($extract_begin_timecode, $timecode_format, '%hh:%mm:%ss.%ms', $frames_per_second);
   }
  */

  // Use seek before the input tag to quickly move to the approximate location,
  // then use the seek after the input tag to locate the exact frames.
  // See http://ffmpeg.org/trac/ffmpeg/wiki/Seeking%20with%20FFmpeg
  $seconds = $this
    ->formatTimecode($extract_begin_timecode, $timecode_format, '%st', $frames_per_second);
  if ($seconds > 5) {
    $this
      ->addCommand('-ss', $this
      ->formatTimecode($seconds - 5, $timecode_format, '%hh:%mm:%ss.%ms', $frames_per_second), TRUE);
    $this
      ->addCommand('-ss', $this
      ->formatTimecode(5, $timecode_format, '%hh:%mm:%ss.%ms', $frames_per_second), FALSE);
  }
  else {
    $this
      ->addCommand('-ss', $extract_begin_timecode);
  }

  //			added by Matthias on 12th March 2007
  //			allows for exporting the entire timeline
  if ($extract_end_timecode !== FALSE) {

    // 				format the end timecode if the timecode format is not already ok.
    if ($timecode_format !== '%hh:%mm:%ss.%ms') {
      $extract_end_timecode = $this
        ->formatTimecode($extract_end_timecode, $timecode_format, '%hh:%mm:%ss.%ms', $frames_per_second);
    }
    $this
      ->addCommand('-t', $extract_end_timecode);
  }

  // 			set the output frame rate
  $this
    ->setVideoFrameRate($frames_per_second);

  // 			do we need to limit the number of frames outputted?
  if ($frame_limit !== FALSE) {
    $this
      ->addCommand('-vframes', $frame_limit);
  }
  $this->_image_output_timecode_start = $extract_begin_timecode;
  $this->_image_output_timecode_fps = $frames_per_second;
}