public function Analyze()
{
$info =& $this->getid3->info;
$OriginalAVdataOffset = $info['avdataoffset'];
$this->fseek($info['avdataoffset']);
$VOCheader = $this->fread(26);
$magic = 'Creative Voice File';
if (substr($VOCheader, 0, 19) != $magic) {
$info['error'][] = 'Expecting "' . Utils::PrintHexBytes($magic) . '" at offset ' . $info['avdataoffset'] . ', found "' . Utils::PrintHexBytes(substr($VOCheader, 0, 19)) . '"';
return false;
}
// shortcuts
$thisfile_audio =& $info['audio'];
$info['voc'] = array();
$thisfile_voc =& $info['voc'];
$info['fileformat'] = 'voc';
$thisfile_audio['dataformat'] = 'voc';
$thisfile_audio['bitrate_mode'] = 'cbr';
$thisfile_audio['lossless'] = true;
$thisfile_audio['channels'] = 1;
// might be overriden below
$thisfile_audio['bits_per_sample'] = 8;
// might be overriden below
// byte # Description
// ------ ------------------------------------------
// 00-12 'Creative Voice File'
// 13 1A (eof to abort printing of file)
// 14-15 Offset of first datablock in .voc file (std 1A 00 in Intel Notation)
// 16-17 Version number (minor,major) (VOC-HDR puts 0A 01)
// 18-19 2's Comp of Ver. # + 1234h (VOC-HDR puts 29 11)
$thisfile_voc['header']['datablock_offset'] = Utils::LittleEndian2Int(substr($VOCheader, 20, 2));
$thisfile_voc['header']['minor_version'] = Utils::LittleEndian2Int(substr($VOCheader, 22, 1));
$thisfile_voc['header']['major_version'] = Utils::LittleEndian2Int(substr($VOCheader, 23, 1));
do {
$BlockOffset = $this->ftell();
$BlockData = $this->fread(4);
$BlockType = ord($BlockData[0]);
$BlockSize = Utils::LittleEndian2Int(substr($BlockData, 1, 3));
$ThisBlock = array();
Utils::safe_inc($thisfile_voc['blocktypes'][$BlockType], 1);
switch ($BlockType) {
case 0:
// Terminator
// do nothing, we'll break out of the loop down below
break;
case 1:
// Sound data
$BlockData .= $this->fread(2);
if ($info['avdataoffset'] <= $OriginalAVdataOffset) {
$info['avdataoffset'] = $this->ftell();
}
$this->fseek($BlockSize - 2, SEEK_CUR);
$ThisBlock['sample_rate_id'] = Utils::LittleEndian2Int(substr($BlockData, 4, 1));
$ThisBlock['compression_type'] = Utils::LittleEndian2Int(substr($BlockData, 5, 1));
$ThisBlock['compression_name'] = $this->VOCcompressionTypeLookup($ThisBlock['compression_type']);
if ($ThisBlock['compression_type'] <= 3) {
$thisfile_voc['compressed_bits_per_sample'] = Utils::CastAsInt(str_replace('-bit', '', $ThisBlock['compression_name']));
}
// Less accurate sample_rate calculation than the Extended block (#8) data (but better than nothing if Extended Block is not available)
if (empty($thisfile_audio['sample_rate'])) {
// SR byte = 256 - (1000000 / sample_rate)
$thisfile_audio['sample_rate'] = Utils::trunc(1000000 / (256 - $ThisBlock['sample_rate_id']) / $thisfile_audio['channels']);
}
break;
case 2:
// Sound continue
// Sound continue
case 3:
// Silence
// Silence
case 4:
// Marker
// Marker
case 6:
// Repeat
// Repeat
case 7:
// End repeat
// nothing useful, just skip
$this->fseek($BlockSize, SEEK_CUR);
break;
case 8:
// Extended
$BlockData .= $this->fread(4);
//00-01 Time Constant:
// Mono: 65536 - (256000000 / sample_rate)
// Stereo: 65536 - (256000000 / (sample_rate * 2))
$ThisBlock['time_constant'] = Utils::LittleEndian2Int(substr($BlockData, 4, 2));
$ThisBlock['pack_method'] = Utils::LittleEndian2Int(substr($BlockData, 6, 1));
$ThisBlock['stereo'] = (bool) Utils::LittleEndian2Int(substr($BlockData, 7, 1));
$thisfile_audio['channels'] = $ThisBlock['stereo'] ? 2 : 1;
$thisfile_audio['sample_rate'] = Utils::trunc(256000000 / (65536 - $ThisBlock['time_constant']) / $thisfile_audio['channels']);
break;
case 9:
// data block that supersedes blocks 1 and 8. Used for stereo, 16 bit
$BlockData .= $this->fread(12);
if ($info['avdataoffset'] <= $OriginalAVdataOffset) {
$info['avdataoffset'] = $this->ftell();
}
$this->fseek($BlockSize - 12, SEEK_CUR);
$ThisBlock['sample_rate'] = Utils::LittleEndian2Int(substr($BlockData, 4, 4));
$ThisBlock['bits_per_sample'] = Utils::LittleEndian2Int(substr($BlockData, 8, 1));
$ThisBlock['channels'] = Utils::LittleEndian2Int(substr($BlockData, 9, 1));
$ThisBlock['wFormat'] = Utils::LittleEndian2Int(substr($BlockData, 10, 2));
$ThisBlock['compression_name'] = $this->VOCwFormatLookup($ThisBlock['wFormat']);
if ($this->VOCwFormatActualBitsPerSampleLookup($ThisBlock['wFormat'])) {
$thisfile_voc['compressed_bits_per_sample'] = $this->VOCwFormatActualBitsPerSampleLookup($ThisBlock['wFormat']);
}
$thisfile_audio['sample_rate'] = $ThisBlock['sample_rate'];
$thisfile_audio['bits_per_sample'] = $ThisBlock['bits_per_sample'];
$thisfile_audio['channels'] = $ThisBlock['channels'];
break;
default:
$info['warning'][] = 'Unhandled block type "' . $BlockType . '" at offset ' . $BlockOffset;
$this->fseek($BlockSize, SEEK_CUR);
break;
}
if (!empty($ThisBlock)) {
$ThisBlock['block_offset'] = $BlockOffset;
$ThisBlock['block_size'] = $BlockSize;
$ThisBlock['block_type_id'] = $BlockType;
$thisfile_voc['blocks'][] = $ThisBlock;
}
} while (!feof($this->getid3->fp) && $BlockType != 0);
// Terminator block doesn't have size field, so seek back 3 spaces
$this->fseek(-3, SEEK_CUR);
ksort($thisfile_voc['blocktypes']);
if (!empty($thisfile_voc['compressed_bits_per_sample'])) {
$info['playtime_seconds'] = ($info['avdataend'] - $info['avdataoffset']) * 8 / ($thisfile_voc['compressed_bits_per_sample'] * $thisfile_audio['channels'] * $thisfile_audio['sample_rate']);
$thisfile_audio['bitrate'] = ($info['avdataend'] - $info['avdataoffset']) * 8 / $info['playtime_seconds'];
}
return true;
}
public function getAACADTSheaderFilepointer($MaxFramesToScan = 1000000, $ReturnExtendedInfo = false)
{
$info =& $this->getid3->info;
// based loosely on code from AACfile by Jurgen Faul <jfaulØgmx.de>
// http://jfaul.de/atl or http://j-faul.virtualave.net/atl/atl.html
// http://faac.sourceforge.net/wiki/index.php?page=ADTS // dead link
// http://wiki.multimedia.cx/index.php?title=ADTS
// * ADTS Fixed Header: these don't change from frame to frame
// syncword 12 always: '111111111111'
// ID 1 0: MPEG-4, 1: MPEG-2
// MPEG layer 2 If you send AAC in MPEG-TS, set to 0
// protection_absent 1 0: CRC present; 1: no CRC
// profile 2 0: AAC Main; 1: AAC LC (Low Complexity); 2: AAC SSR (Scalable Sample Rate); 3: AAC LTP (Long Term Prediction)
// sampling_frequency_index 4 15 not allowed
// private_bit 1 usually 0
// channel_configuration 3
// original/copy 1 0: original; 1: copy
// home 1 usually 0
// emphasis 2 only if ID == 0 (ie MPEG-4) // not present in some documentation?
// * ADTS Variable Header: these can change from frame to frame
// copyright_identification_bit 1
// copyright_identification_start 1
// aac_frame_length 13 length of the frame including header (in bytes)
// adts_buffer_fullness 11 0x7FF indicates VBR
// no_raw_data_blocks_in_frame 2
// * ADTS Error check
// crc_check 16 only if protection_absent == 0
$byteoffset = $info['avdataoffset'];
$framenumber = 0;
// Init bit pattern array
static $decbin = array();
// Populate $bindec
for ($i = 0; $i < 256; $i++) {
$decbin[chr($i)] = str_pad(decbin($i), 8, '0', STR_PAD_LEFT);
}
// used to calculate bitrate below
$BitrateCache = array();
while (true) {
// breaks out when end-of-file encountered, or invalid data found,
// or MaxFramesToScan frames have been scanned
if (!Utils::intValueSupported($byteoffset)) {
$info['warning'][] = 'Unable to parse AAC file beyond ' . $this->ftell() . ' (PHP does not support file operations beyond ' . round(PHP_INT_MAX / 1073741824) . 'GB)';
return false;
}
$this->fseek($byteoffset);
// First get substring
$substring = $this->fread(9);
// header is 7 bytes (or 9 if CRC is present)
$substringlength = strlen($substring);
if ($substringlength != 9) {
$info['error'][] = 'Failed to read 7 bytes at offset ' . ($this->ftell() - $substringlength) . ' (only read ' . $substringlength . ' bytes)';
return false;
}
// this would be easier with 64-bit math, but split it up to allow for 32-bit:
$header1 = Utils::BigEndian2Int(substr($substring, 0, 2));
$header2 = Utils::BigEndian2Int(substr($substring, 2, 4));
$header3 = Utils::BigEndian2Int(substr($substring, 6, 1));
$info['aac']['header']['raw']['syncword'] = ($header1 & 0xfff0) >> 4;
if ($info['aac']['header']['raw']['syncword'] != 0xfff) {
$info['error'][] = 'Synch pattern (0x0FFF) not found at offset ' . ($this->ftell() - $substringlength) . ' (found 0x0' . strtoupper(dechex($info['aac']['header']['raw']['syncword'])) . ' instead)';
//if ($info['fileformat'] == 'aac') {
// return true;
//}
unset($info['aac']);
return false;
}
// Gather info for first frame only - this takes time to do 1000 times!
if ($framenumber == 0) {
$info['aac']['header_type'] = 'ADTS';
$info['fileformat'] = 'aac';
$info['audio']['dataformat'] = 'aac';
$info['aac']['header']['raw']['mpeg_version'] = ($header1 & 0x8) >> 3;
$info['aac']['header']['raw']['mpeg_layer'] = ($header1 & 0x6) >> 1;
$info['aac']['header']['raw']['protection_absent'] = ($header1 & 0x1) >> 0;
$info['aac']['header']['raw']['profile_code'] = ($header2 & 0xc0000000) >> 30;
$info['aac']['header']['raw']['sample_rate_code'] = ($header2 & 0x3c000000) >> 26;
$info['aac']['header']['raw']['private_stream'] = ($header2 & 0x2000000) >> 25;
$info['aac']['header']['raw']['channels_code'] = ($header2 & 0x1c00000) >> 22;
$info['aac']['header']['raw']['original'] = ($header2 & 0x200000) >> 21;
$info['aac']['header']['raw']['home'] = ($header2 & 0x100000) >> 20;
$info['aac']['header']['raw']['copyright_stream'] = ($header2 & 0x80000) >> 19;
$info['aac']['header']['raw']['copyright_start'] = ($header2 & 0x40000) >> 18;
$info['aac']['header']['raw']['frame_length'] = ($header2 & 0x3ffe0) >> 5;
$info['aac']['header']['mpeg_version'] = $info['aac']['header']['raw']['mpeg_version'] ? 2 : 4;
$info['aac']['header']['crc_present'] = $info['aac']['header']['raw']['protection_absent'] ? false : true;
$info['aac']['header']['profile'] = self::AACprofileLookup($info['aac']['header']['raw']['profile_code'], $info['aac']['header']['mpeg_version']);
$info['aac']['header']['sample_frequency'] = self::AACsampleRateLookup($info['aac']['header']['raw']['sample_rate_code']);
$info['aac']['header']['private'] = (bool) $info['aac']['header']['raw']['private_stream'];
$info['aac']['header']['original'] = (bool) $info['aac']['header']['raw']['original'];
$info['aac']['header']['home'] = (bool) $info['aac']['header']['raw']['home'];
$info['aac']['header']['channels'] = $info['aac']['header']['raw']['channels_code'] == 7 ? 8 : $info['aac']['header']['raw']['channels_code'];
if ($ReturnExtendedInfo) {
$info['aac'][$framenumber]['copyright_id_bit'] = (bool) $info['aac']['header']['raw']['copyright_stream'];
$info['aac'][$framenumber]['copyright_id_start'] = (bool) $info['aac']['header']['raw']['copyright_start'];
}
if ($info['aac']['header']['raw']['mpeg_layer'] != 0) {
$info['warning'][] = 'Layer error - expected "0", found "' . $info['aac']['header']['raw']['mpeg_layer'] . '" instead';
}
if ($info['aac']['header']['sample_frequency'] == 0) {
$info['error'][] = 'Corrupt AAC file: sample_frequency == zero';
return false;
}
$info['audio']['sample_rate'] = $info['aac']['header']['sample_frequency'];
$info['audio']['channels'] = $info['aac']['header']['channels'];
}
$FrameLength = ($header2 & 0x3ffe0) >> 5;
if (!isset($BitrateCache[$FrameLength])) {
$BitrateCache[$FrameLength] = $info['aac']['header']['sample_frequency'] / 1024 * $FrameLength * 8;
}
Utils::safe_inc($info['aac']['bitrate_distribution'][$BitrateCache[$FrameLength]], 1);
$info['aac'][$framenumber]['aac_frame_length'] = $FrameLength;
$info['aac'][$framenumber]['adts_buffer_fullness'] = ($header2 & 0x1f) << 6 & ($header3 & 0xfc) >> 2;
if ($info['aac'][$framenumber]['adts_buffer_fullness'] == 0x7ff) {
$info['audio']['bitrate_mode'] = 'vbr';
} else {
$info['audio']['bitrate_mode'] = 'cbr';
}
$info['aac'][$framenumber]['num_raw_data_blocks'] = ($header3 & 0x3) >> 0;
if ($info['aac']['header']['crc_present']) {
//$info['aac'][$framenumber]['crc'] = Utils::BigEndian2Int(substr($substring, 7, 2);
}
if (!$ReturnExtendedInfo) {
unset($info['aac'][$framenumber]);
}
/*
$rounded_precision = 5000;
$info['aac']['bitrate_distribution_rounded'] = array();
foreach ($info['aac']['bitrate_distribution'] as $bitrate => $count) {
$rounded_bitrate = round($bitrate / $rounded_precision) * $rounded_precision;
Utils::safe_inc($info['aac']['bitrate_distribution_rounded'][$rounded_bitrate], $count);
}
ksort($info['aac']['bitrate_distribution_rounded']);
*/
$byteoffset += $FrameLength;
if (++$framenumber < $MaxFramesToScan && $byteoffset + 10 < $info['avdataend']) {
// keep scanning
} else {
$info['aac']['frames'] = $framenumber;
$info['playtime_seconds'] = $info['avdataend'] / $byteoffset * ($framenumber * 1024 / $info['aac']['header']['sample_frequency']);
// (1 / % of file scanned) * (samples / (samples/sec)) = seconds
if ($info['playtime_seconds'] == 0) {
$info['error'][] = 'Corrupt AAC file: playtime_seconds == zero';
return false;
}
$info['audio']['bitrate'] = ($info['avdataend'] - $info['avdataoffset']) * 8 / $info['playtime_seconds'];
ksort($info['aac']['bitrate_distribution']);
$info['audio']['encoder_options'] = $info['aac']['header_type'] . ' ' . $info['aac']['header']['profile'];
return true;
}
}
// should never get here.
}
