getid3_mp3::RecursiveFrameScanning

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Syntax Syntax

getid3_mp3::RecursiveFrameScanning( int $offset, int $nextframetestoffset, bool $ScanAsCBR )

Parameters Parameters

$offset

(int) (Required)

$nextframetestoffset

(int) (Required)

$ScanAsCBR

(bool) (Required)

Return Return

(bool)

Source Source

File: wp-includes/ID3/module.audio.mp3.php

		//}

		return true;
	}

	/**
	 * @param int $offset
	 * @param int $nextframetestoffset
	 * @param bool $ScanAsCBR
	 *
	 * @return bool
	 */
	public function RecursiveFrameScanning(&$offset, &$nextframetestoffset, $ScanAsCBR) {
		$info = &$this->getid3->info;
		$firstframetestarray = array('error' => array(), 'warning'=> array(), 'avdataend' => $info['avdataend'], 'avdataoffset' => $info['avdataoffset']);
		$this->decodeMPEGaudioHeader($offset, $firstframetestarray, false);

		for ($i = 0; $i < GETID3_MP3_VALID_CHECK_FRAMES; $i++) {
			// check next GETID3_MP3_VALID_CHECK_FRAMES frames for validity, to make sure we haven't run across a false synch
			if (($nextframetestoffset + 4) >= $info['avdataend']) {
				// end of file
				return true;
			}

			$nextframetestarray = array('error' => array(), 'warning' => array(), 'avdataend' => $info['avdataend'], 'avdataoffset'=>$info['avdataoffset']);
			if ($this->decodeMPEGaudioHeader($nextframetestoffset, $nextframetestarray, false)) {
				if ($ScanAsCBR) {
					// force CBR mode, used for trying to pick out invalid audio streams with valid(?) VBR headers, or VBR streams with no VBR header
					if (!isset($nextframetestarray['mpeg']['audio']['bitrate']) || !isset($firstframetestarray['mpeg']['audio']['bitrate']) || ($nextframetestarray['mpeg']['audio']['bitrate'] != $firstframetestarray['mpeg']['audio']['bitrate'])) {
						return false;
					}
				}


				// next frame is OK, get ready to check the one after that
				if (isset($nextframetestarray['mpeg']['audio']['framelength']) && ($nextframetestarray['mpeg']['audio']['framelength'] > 0)) {
					$nextframetestoffset += $nextframetestarray['mpeg']['audio']['framelength'];
				} else {
					$this->error('Frame at offset ('.$offset.') is has an invalid frame length.');
					return false;
				}

			} elseif (!empty($firstframetestarray['mpeg']['audio']['framelength']) && (($nextframetestoffset + $firstframetestarray['mpeg']['audio']['framelength']) > $info['avdataend'])) {

				// it's not the end of the file, but there's not enough data left for another frame, so assume it's garbage/padding and return OK

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