diff options
Diffstat (limited to 'modules/getid3/module.audio.aac_adts.php')
| -rw-r--r-- | modules/getid3/module.audio.aac_adts.php | 66 |
1 files changed, 33 insertions, 33 deletions
diff --git a/modules/getid3/module.audio.aac_adts.php b/modules/getid3/module.audio.aac_adts.php index 1b98c4c6..bf252997 100644 --- a/modules/getid3/module.audio.aac_adts.php +++ b/modules/getid3/module.audio.aac_adts.php @@ -22,43 +22,43 @@ // // $Id: module.audio.aac_adts.php,v 1.4 2006/11/02 10:48:01 ah Exp $ - - + + class getid3_aac_adts extends getid3_handler { public $option_max_frames_to_scan = 1000000; public $option_return_extended_info = false; - + private $decbin_cache; private $bitrate_cache; - + public function __construct(getID3 $getid3) { - + parent::__construct($getid3); - + // Populate bindec_cache for ($i = 0; $i < 256; $i++) { $this->decbin_cache[chr($i)] = str_pad(decbin($i), 8, '0', STR_PAD_LEFT); } - + // Init cache $this->bitrate_cache = array (); - + // Fast scanning? if (!$getid3->option_accurate_results) { $this->option_max_frames_to_scan = 200; $getid3->warning('option_accurate_results set to false - bitrate and playing time are not accurate.'); } } - - + + public function Analyze() { - + $getid3 = $this->getid3; // based loosely on code from AACfile by Jurgen Faul <jfaulØgmx.de> @@ -97,7 +97,7 @@ class getid3_aac_adts extends getid3_handler $byte_offset = $frame_number = 0; while (true) { - + // Breaks out when end-of-file encountered, or invalid data found, // or MaxFramesToScan frames have been scanned @@ -117,10 +117,10 @@ class getid3_aac_adts extends getid3_handler for ($i = 0; $i < 10; $i++) { $aac_header_bitstream .= $this->decbin_cache[$sub_string[$i]]; } - + $sync_test = bindec(substr($aac_header_bitstream, 0, 12)); $bit_offset = 12; - + if ($sync_test != 0x0FFF) { throw new getid3_exception('Synch pattern (0x0FFF) not found at offset '.(ftell($getid3->fp) - 10).' (found 0x0'.strtoupper(dechex($sync_test)).' instead)'); } @@ -130,8 +130,8 @@ class getid3_aac_adts extends getid3_handler // MPEG-4: 20, // MPEG-2: 18 $bit_offset += $aac_header_bitstream[$bit_offset] ? 18 : 20; - } - + } + // Gather info for first frame only - this takes time to do 1000 times! else { @@ -143,30 +143,30 @@ class getid3_aac_adts extends getid3_handler $info_aac_header['mpeg_version'] = $aac_header_bitstream{$bit_offset++} == '0' ? 4 : 2; $info_aac_header['layer'] = bindec(substr($aac_header_bitstream, $bit_offset, 2)); $bit_offset += 2; - + if ($info_aac_header['layer'] != 0) { throw new getid3_exception('Layer error - expected 0x00, found 0x'.dechex($info_aac_header['layer']).' instead'); } - + $info_aac_header['crc_present'] = $aac_header_bitstream{$bit_offset++} == '0' ? true : false; - + $info_aac_header['profile_id'] = bindec(substr($aac_header_bitstream, $bit_offset, 2)); $bit_offset += 2; - + $info_aac_header['profile_text'] = getid3_aac_adts::AACprofileLookup($info_aac_header['profile_id'], $info_aac_header['mpeg_version']); $info_aac_header['sample_frequency_index'] = bindec(substr($aac_header_bitstream, $bit_offset, 4)); $bit_offset += 4; - + $info_aac_header['sample_frequency'] = getid3_aac_adts::AACsampleRateLookup($info_aac_header['sample_frequency_index']); - + $getid3->info['audio']['sample_rate'] = $info_aac_header['sample_frequency']; $info_aac_header['private'] = $aac_header_bitstream{$bit_offset++} == 1; - + $info_aac_header['channel_configuration'] = $getid3->info['audio']['channels'] = bindec(substr($aac_header_bitstream, $bit_offset, 3)); $bit_offset += 3; - + $info_aac_header['original'] = $aac_header_bitstream{$bit_offset++} == 1; $info_aac_header['home'] = $aac_header_bitstream{$bit_offset++} == 1; @@ -194,12 +194,12 @@ class getid3_aac_adts extends getid3_handler $info_aac[$frame_number]['aac_frame_length'] = $frame_length; $bit_offset += 13; - + $info_aac[$frame_number]['adts_buffer_fullness'] = bindec(substr($aac_header_bitstream, $bit_offset, 11)); $bit_offset += 11; - + $getid3->info['audio']['bitrate_mode'] = ($info_aac[$frame_number]['adts_buffer_fullness'] == 0x07FF) ? 'vbr' : 'cbr'; - + $info_aac[$frame_number]['num_raw_data_blocks'] = bindec(substr($aac_header_bitstream, $bit_offset, 2)); $bit_offset += 2; @@ -230,10 +230,10 @@ class getid3_aac_adts extends getid3_handler } } - - + + public static function AACsampleRateLookup($samplerate_id) { - + static $lookup = array ( 0 => 96000, 1 => 88200, @@ -258,14 +258,14 @@ class getid3_aac_adts extends getid3_handler public static function AACprofileLookup($profile_id, $mpeg_version) { - + static $lookup = array ( - 2 => array ( + 2 => array ( 0 => 'Main profile', 1 => 'Low Complexity profile (LC)', 2 => 'Scalable Sample Rate profile (SSR)', 3 => '(reserved)' - ), + ), 4 => array ( 0 => 'AAC_MAIN', 1 => 'AAC_LC', |