return $i_min;
}
+/**
+ * "Private" function used by get_av_info which returns the value from a
+ * "key=value" formatted string.
+ *
+ * @param string $str_key_value a string formatted as key=value
+ * @return string
+ */
+function _parse_value($str_key_value)
+{
+ return trim(substr(
+ $str_key_value,
+ strpos($str_key_value, '=') + 1,
+ strlen($str_key_value)
+ ));
+}
+
+/**
+ * Formats the floating number of seconds to a string with format [HH:]mm:ss .
+ *
+ * @param float $secs
+ * @return string
+ */
+function format_duration($secs)
+{
+ $secs = intval(round($secs));
+
+ $h = intval(floor($secs / 3600));
+ $m = intval(floor(($secs % 3600) / 60));
+ $s = $secs % 3600 % 60;
+
+ $duration = sprintf('%02d', $m) . ':' . sprintf('%02d', $s);
+
+ if ($h > 0)
+ return sprintf('%02d', $h) . ':' . $duration;
+
+ return $duration;
+}
+
/**
* Returns information about an Audio/Video file.
*
* @param string $file_name Audio/Video file
- * @return dictionary a dictionary of audio/video properties with keys:
+ * @return dictionary FALSE on error or a dictionary of audio/video properties
+ * with the following keys otherwise:
* <ul>
* <li>width</li>
* <li>height</li>
*/
function get_av_info($file_name)
{
- // TODO use ffprobe to return width, height, DAR, duration and size of a video
+ $h = popen('ffprobe -show_streams -show_format "'
+ . $file_name . '" 2> /dev/null', 'r');
+
+ $tag = NULL;
+
+ while ( ($r = fgets($h, 512)) !== FALSE)
+ {
+ // Match tags.
+ if (preg_match('/^\[FORMAT\]/', $r))
+ {
+ $tag = 'FORMAT';
+ continue;
+ }
+ if (preg_match('/^\[STREAM\]/', $r))
+ {
+ $tag = 'STREAM';
+ continue;
+ }
+
+ if ($tag == 'FORMAT')
+ {
+ // Duration
+ if (preg_match('/^duration=/', $r))
+ $duration = format_duration(floatval(_parse_value($r)));
+
+ // Size
+ if (preg_match('/^size=/', $r))
+ $size = intval(_parse_value ($r));
+ }
+
+ if ($tag == 'STREAM')
+ {
+ // Width
+ if (preg_match('/^width=/', $r))
+ $width = intval(_parse_value($r));
+
+ // Height
+ if (preg_match('/^height=/', $r))
+ $height = intval(_parse_value($r));
+
+ // DAR
+ if (preg_match('/^display_aspect_ratio=/', $r))
+ $dar = _parse_value($r);
+ }
+ }
+
+ if (pclose($h) > 0)
+ return FALSE;
+
+ return array('width'=>$width, 'height'=>$height, 'dar'=>$dar,
+ 'duration'=>$duration, 'size'=>$size);
+
+// return array('width'=> 1440, 'height'=> 1080, 'dar'=> '16:9',
+// 'duration'=> '00:10', 'size'=> 5568748);
+}
+
+/**
+ * Return a dictionary with formats compliant for DB and CIS and computes
+ * resolutions such that an uploaded video will not be converted to a higher
+ * resolution.
+ *
+ * @param type $formats formats as in content_ingestion config file
+ * @param type $av_info structure as returned by get_av_info function from this
+ * helper
+ * @param type $elim_dupl_res eliminate consecutive formats with the same
+ * resolution
+ * @return array a dictionary with DB format at key 'db_formats' and CIS format
+ * at key 'transcode_configs'
+ */
+function prepare_formats($formats, $av_info, $elim_dupl_res=FALSE)
+{
+ $transcode_configs = array();
+ $db_formats = array();
+
+ for ($i = 0; $i < count($formats); $i++)
+ {
+ $transcode_configs[$i]['container'] = $formats[$i]['container'];
+ $transcode_configs[$i]['extension'] = $formats[$i]['extension'];
+ $db_formats[$i]['ext'] = $formats[$i]['extension'];
+ $transcode_configs[$i]['a_codec'] = $formats[$i]['audio_codec'];
+ $transcode_configs[$i]['a_bitrate'] = $formats[$i]['audio_bit_rate'];
+ $transcode_configs[$i]['a_samplingrate'] = $formats[$i]['audio_sampling_rate'];
+ $transcode_configs[$i]['a_channels'] = $formats[$i]['audio_channels'];
+ $transcode_configs[$i]['v_codec'] = $formats[$i]['video_codec'];
+ $transcode_configs[$i]['v_bitrate'] = $formats[$i]['video_bit_rate'];
+ $transcode_configs[$i]['v_framerate'] = $formats[$i]['video_frame_rate'];
+ $transcode_configs[$i]['v_dar'] = $av_info['dar'];
+ $db_formats[$i]['dar'] = $av_info['dar'];
+
+ $sar = $av_info['width'] / $av_info['height'];
+
+ if ($av_info['height'] < $formats[$i]['video_height'])
+ {
+ $width = $av_info['width'];
+ $height = $av_info['height'];
+ }
+ else
+ {
+ $height = $formats[$i]['video_height'];
+ $width = round($sar * $height);
+ }
+
+ $transcode_configs[$i]['v_resolution'] = "${width}x${height}";
+ $db_formats[$i]['res'] = "${width}x${height}";
+ }
+
+ // Eliminate formats with duplicate resolutions.
+ if ($elim_dupl_res)
+ {
+ for ($i = 1; $i < count($transcode_configs); $i++)
+ {
+ if ($transcode_configs[$i]['v_resolution']
+ === $transcode_configs[$i - 1]['v_resolution'])
+ {
+ unset($transcode_configs[$i - 1]);
+ unset($db_formats[$i - 1]);
+ $i--;
+ }
+ }
+ }
- return array('width'=> 800, 'height'=> 600, 'dar'=> '16:9',
- 'duration'=> '00:10', 'size'=> 1101693);
+ return array('transcode_configs'=>$transcode_configs,
+ 'db_formats'=>$db_formats);
}
/* End of file video_helper.php */
projects / living-lab-site.git / blobdiff