| <Website> | getID3 |  |
|
| Size: | 22420 |
| Storage flags: | strip |
<?php
getid3_lib::IncludeDependency(GETID3_INCLUDEPATH.'module.audio.mp3.php', __FILE__, true);
class getid3_mpeg extends getid3_handler {
const START_CODE_BASE = "\x00\x00\x01";
const VIDEO_PICTURE_START = "\x00\x00\x01\x00";
const VIDEO_USER_DATA_START = "\x00\x00\x01\xB2";
const VIDEO_SEQUENCE_HEADER = "\x00\x00\x01\xB3";
const VIDEO_SEQUENCE_ERROR = "\x00\x00\x01\xB4";
const VIDEO_EXTENSION_START = "\x00\x00\x01\xB5";
const VIDEO_SEQUENCE_END = "\x00\x00\x01\xB7";
const VIDEO_GROUP_START = "\x00\x00\x01\xB8";
const AUDIO_START = "\x00\x00\x01\xC0";
public function Analyze() {
$info = &$this->getid3->info;
$info['fileformat'] = 'mpeg';
$this->fseek($info['avdataoffset']);
$MPEGstreamData = $this->fread($this->getid3->option_fread_buffer_size);
$MPEGstreamBaseOffset = 0;
$MPEGstreamDataOffset = 0;
$StartCodeValue = false;
$prevStartCodeValue = false;
$GOPcounter = -1;
$FramesByGOP = array();
$ParsedAVchannels = array();
do {
if ($MPEGstreamDataOffset > (strlen($MPEGstreamData) - 16384)) {
$MPEGstreamData .= $this->fread($this->getid3->option_fread_buffer_size);
if (strlen($MPEGstreamData) > $this->getid3->option_fread_buffer_size) {
$MPEGstreamData = substr($MPEGstreamData, $MPEGstreamDataOffset);
$MPEGstreamBaseOffset += $MPEGstreamDataOffset;
$MPEGstreamDataOffset = 0;
}
}
if (($StartCodeOffset = strpos($MPEGstreamData, self::START_CODE_BASE, $MPEGstreamDataOffset)) === false) {
break;
} else {
$MPEGstreamDataOffset = $StartCodeOffset;
$prevStartCodeValue = $StartCodeValue;
$StartCodeValue = ord(substr($MPEGstreamData, $StartCodeOffset + 3, 1));
}
$MPEGstreamDataOffset += 4;
switch ($StartCodeValue) {
case 0x00:
if (!empty($info['mpeg']['video']['bitrate_mode']) && ($info['mpeg']['video']['bitrate_mode'] == 'vbr')) {
$bitstream = getid3_lib::BigEndian2Bin(substr($MPEGstreamData, $StartCodeOffset + 4, 4));
$bitstreamoffset = 0;
$PictureHeader = array();
$PictureHeader['temporal_reference'] = self::readBitsFromStream($bitstream, $bitstreamoffset, 10);
$PictureHeader['picture_coding_type'] = self::readBitsFromStream($bitstream, $bitstreamoffset, 3);
$PictureHeader['vbv_delay'] = self::readBitsFromStream($bitstream, $bitstreamoffset, 16);
$FramesByGOP[$GOPcounter][] = $PictureHeader;
}
break;
case 0xB3:
$info['video']['codec'] = 'MPEG-1';
$bitstream = getid3_lib::BigEndian2Bin(substr($MPEGstreamData, $StartCodeOffset + 4, 8));
$bitstreamoffset = 0;
$info['mpeg']['video']['raw']['horizontal_size_value'] = self::readBitsFromStream($bitstream, $bitstreamoffset, 12);
$info['mpeg']['video']['raw']['vertical_size_value'] = self::readBitsFromStream($bitstream, $bitstreamoffset, 12);
$info['mpeg']['video']['raw']['aspect_ratio_information'] = self::readBitsFromStream($bitstream, $bitstreamoffset, 4);
$info['mpeg']['video']['raw']['frame_rate_code'] = self::readBitsFromStream($bitstream, $bitstreamoffset, 4);
$info['mpeg']['video']['raw']['bitrate'] = self::readBitsFromStream($bitstream, $bitstreamoffset, 18);
$marker_bit = self::readBitsFromStream($bitstream, $bitstreamoffset, 1);
$info['mpeg']['video']['raw']['vbv_buffer_size'] = self::readBitsFromStream($bitstream, $bitstreamoffset, 10);
$info['mpeg']['video']['raw']['constrained_param_flag'] = self::readBitsFromStream($bitstream, $bitstreamoffset, 1);
$info['mpeg']['video']['raw']['load_intra_quantiser_matrix'] = self::readBitsFromStream($bitstream, $bitstreamoffset, 1);
if ($info['mpeg']['video']['raw']['load_intra_quantiser_matrix']) {
$bitstream .= getid3_lib::BigEndian2Bin(substr($MPEGstreamData, $StartCodeOffset + 12, 64));
for ($i = 0; $i < 64; $i++) {
$info['mpeg']['video']['raw']['intra_quantiser_matrix'][$i] = self::readBitsFromStream($bitstream, $bitstreamoffset, 8);
}
}
$info['mpeg']['video']['raw']['load_non_intra_quantiser_matrix'] = self::readBitsFromStream($bitstream, $bitstreamoffset, 1);
if ($info['mpeg']['video']['raw']['load_non_intra_quantiser_matrix']) {
$bitstream .= getid3_lib::BigEndian2Bin(substr($MPEGstreamData, $StartCodeOffset + 12 + ($info['mpeg']['video']['raw']['load_intra_quantiser_matrix'] ? 64 : 0), 64));
for ($i = 0; $i < 64; $i++) {
$info['mpeg']['video']['raw']['non_intra_quantiser_matrix'][$i] = self::readBitsFromStream($bitstream, $bitstreamoffset, 8);
}
}
$info['mpeg']['video']['pixel_aspect_ratio'] = self::videoAspectRatioLookup($info['mpeg']['video']['raw']['aspect_ratio_information']);
$info['mpeg']['video']['pixel_aspect_ratio_text'] = self::videoAspectRatioTextLookup($info['mpeg']['video']['raw']['aspect_ratio_information']);
$info['mpeg']['video']['frame_rate'] = self::videoFramerateLookup($info['mpeg']['video']['raw']['frame_rate_code']);
if ($info['mpeg']['video']['raw']['bitrate'] == 0x3FFFF) {
$info['mpeg']['video']['bitrate_mode'] = 'vbr';
} else {
$info['mpeg']['video']['bitrate'] = $info['mpeg']['video']['raw']['bitrate'] * 400;
$info['mpeg']['video']['bitrate_mode'] = 'cbr';
$info['video']['bitrate'] = $info['mpeg']['video']['bitrate'];
}
$info['video']['resolution_x'] = $info['mpeg']['video']['raw']['horizontal_size_value'];
$info['video']['resolution_y'] = $info['mpeg']['video']['raw']['vertical_size_value'];
$info['video']['frame_rate'] = $info['mpeg']['video']['frame_rate'];
$info['video']['bitrate_mode'] = $info['mpeg']['video']['bitrate_mode'];
$info['video']['pixel_aspect_ratio'] = $info['mpeg']['video']['pixel_aspect_ratio'];
$info['video']['lossless'] = false;
$info['video']['bits_per_sample'] = 24;
break;
case 0xB5:
$info['video']['codec'] = 'MPEG-2';
$bitstream = getid3_lib::BigEndian2Bin(substr($MPEGstreamData, $StartCodeOffset + 4, 8));
$bitstreamoffset = 0;
$info['mpeg']['video']['raw']['extension_start_code_identifier'] = self::readBitsFromStream($bitstream, $bitstreamoffset, 4);
switch ($info['mpeg']['video']['raw']['extension_start_code_identifier']) {
case 1:
$info['mpeg']['video']['raw']['profile_and_level_indication'] = self::readBitsFromStream($bitstream, $bitstreamoffset, 8);
$info['mpeg']['video']['raw']['progressive_sequence'] = self::readBitsFromStream($bitstream, $bitstreamoffset, 1);
$info['mpeg']['video']['raw']['chroma_format'] = self::readBitsFromStream($bitstream, $bitstreamoffset, 2);
$info['mpeg']['video']['raw']['horizontal_size_extension'] = self::readBitsFromStream($bitstream, $bitstreamoffset, 2);
$info['mpeg']['video']['raw']['vertical_size_extension'] = self::readBitsFromStream($bitstream, $bitstreamoffset, 2);
$info['mpeg']['video']['raw']['bit_rate_extension'] = self::readBitsFromStream($bitstream, $bitstreamoffset, 12);
$marker_bit = self::readBitsFromStream($bitstream, $bitstreamoffset, 1);
$info['mpeg']['video']['raw']['vbv_buffer_size_extension'] = self::readBitsFromStream($bitstream, $bitstreamoffset, 8);
$info['mpeg']['video']['raw']['low_delay'] = self::readBitsFromStream($bitstream, $bitstreamoffset, 1);
$info['mpeg']['video']['raw']['frame_rate_extension_n'] = self::readBitsFromStream($bitstream, $bitstreamoffset, 2);
$info['mpeg']['video']['raw']['frame_rate_extension_d'] = self::readBitsFromStream($bitstream, $bitstreamoffset, 5);
$info['video']['resolution_x'] = ($info['mpeg']['video']['raw']['horizontal_size_extension'] << 12) | $info['mpeg']['video']['raw']['horizontal_size_value'];
$info['video']['resolution_y'] = ($info['mpeg']['video']['raw']['vertical_size_extension'] << 12) | $info['mpeg']['video']['raw']['vertical_size_value'];
$info['video']['interlaced'] = !$info['mpeg']['video']['raw']['progressive_sequence'];
$info['mpeg']['video']['interlaced'] = !$info['mpeg']['video']['raw']['progressive_sequence'];
$info['mpeg']['video']['chroma_format'] = self::chromaFormatTextLookup($info['mpeg']['video']['raw']['chroma_format']);
break;
case 2:
$info['mpeg']['video']['raw']['video_format'] = self::readBitsFromStream($bitstream, $bitstreamoffset, 3);
$info['mpeg']['video']['raw']['colour_description'] = self::readBitsFromStream($bitstream, $bitstreamoffset, 1);
if ($info['mpeg']['video']['raw']['colour_description']) {
$info['mpeg']['video']['raw']['colour_primaries'] = self::readBitsFromStream($bitstream, $bitstreamoffset, 8);
$info['mpeg']['video']['raw']['transfer_characteristics'] = self::readBitsFromStream($bitstream, $bitstreamoffset, 8);
$info['mpeg']['video']['raw']['matrix_coefficients'] = self::readBitsFromStream($bitstream, $bitstreamoffset, 8);
}
$info['mpeg']['video']['raw']['display_horizontal_size'] = self::readBitsFromStream($bitstream, $bitstreamoffset, 14);
$marker_bit = self::readBitsFromStream($bitstream, $bitstreamoffset, 1);
$info['mpeg']['video']['raw']['display_vertical_size'] = self::readBitsFromStream($bitstream, $bitstreamoffset, 14);
$info['mpeg']['video']['video_format'] = self::videoFormatTextLookup($info['mpeg']['video']['raw']['video_format']);
break;
case 3:
break;
case 5:
$info['mpeg']['video']['raw']['scalable_mode'] = self::readBitsFromStream($bitstream, $bitstreamoffset, 2);
$info['mpeg']['video']['raw']['layer_id'] = self::readBitsFromStream($bitstream, $bitstreamoffset, 4);
if ($info['mpeg']['video']['raw']['scalable_mode'] == 1) {
$info['mpeg']['video']['raw']['lower_layer_prediction_horizontal_size'] = self::readBitsFromStream($bitstream, $bitstreamoffset, 14);
$marker_bit = self::readBitsFromStream($bitstream, $bitstreamoffset, 1);
$info['mpeg']['video']['raw']['lower_layer_prediction_vertical_size'] = self::readBitsFromStream($bitstream, $bitstreamoffset, 14);
$info['mpeg']['video']['raw']['horizontal_subsampling_factor_m'] = self::readBitsFromStream($bitstream, $bitstreamoffset, 5);
$info['mpeg']['video']['raw']['horizontal_subsampling_factor_n'] = self::readBitsFromStream($bitstream, $bitstreamoffset, 5);
$info['mpeg']['video']['raw']['vertical_subsampling_factor_m'] = self::readBitsFromStream($bitstream, $bitstreamoffset, 5);
$info['mpeg']['video']['raw']['vertical_subsampling_factor_n'] = self::readBitsFromStream($bitstream, $bitstreamoffset, 5);
} elseif ($info['mpeg']['video']['raw']['scalable_mode'] == 3) {
$info['mpeg']['video']['raw']['picture_mux_enable'] = self::readBitsFromStream($bitstream, $bitstreamoffset, 1);
if ($info['mpeg']['video']['raw']['picture_mux_enable']) {
$info['mpeg']['video']['raw']['mux_to_progressive_sequence'] = self::readBitsFromStream($bitstream, $bitstreamoffset, 1);
}
$info['mpeg']['video']['raw']['picture_mux_order'] = self::readBitsFromStream($bitstream, $bitstreamoffset, 3);
$info['mpeg']['video']['raw']['picture_mux_factor'] = self::readBitsFromStream($bitstream, $bitstreamoffset, 3);
}
$info['mpeg']['video']['scalable_mode'] = self::scalableModeTextLookup($info['mpeg']['video']['raw']['scalable_mode']);
break;
case 7:
break;
case 8:
$info['mpeg']['video']['raw']['f_code_00'] = self::readBitsFromStream($bitstream, $bitstreamoffset, 4);
$info['mpeg']['video']['raw']['f_code_01'] = self::readBitsFromStream($bitstream, $bitstreamoffset, 4);
$info['mpeg']['video']['raw']['f_code_10'] = self::readBitsFromStream($bitstream, $bitstreamoffset, 4);
$info['mpeg']['video']['raw']['f_code_11'] = self::readBitsFromStream($bitstream, $bitstreamoffset, 4);
$info['mpeg']['video']['raw']['intra_dc_precision'] = self::readBitsFromStream($bitstream, $bitstreamoffset, 2);
$info['mpeg']['video']['raw']['picture_structure'] = self::readBitsFromStream($bitstream, $bitstreamoffset, 2);
$info['mpeg']['video']['raw']['top_field_first'] = self::readBitsFromStream($bitstream, $bitstreamoffset, 1);
$info['mpeg']['video']['raw']['frame_pred_frame_dct'] = self::readBitsFromStream($bitstream, $bitstreamoffset, 1);
$info['mpeg']['video']['raw']['concealment_motion_vectors'] = self::readBitsFromStream($bitstream, $bitstreamoffset, 1);
$info['mpeg']['video']['raw']['q_scale_type'] = self::readBitsFromStream($bitstream, $bitstreamoffset, 1);
$info['mpeg']['video']['raw']['intra_vlc_format'] = self::readBitsFromStream($bitstream, $bitstreamoffset, 1);
$info['mpeg']['video']['raw']['alternate_scan'] = self::readBitsFromStream($bitstream, $bitstreamoffset, 1);
$info['mpeg']['video']['raw']['repeat_first_field'] = self::readBitsFromStream($bitstream, $bitstreamoffset, 1);
$info['mpeg']['video']['raw']['chroma_420_type'] = self::readBitsFromStream($bitstream, $bitstreamoffset, 1);
$info['mpeg']['video']['raw']['progressive_frame'] = self::readBitsFromStream($bitstream, $bitstreamoffset, 1);
$info['mpeg']['video']['raw']['composite_display_flag'] = self::readBitsFromStream($bitstream, $bitstreamoffset, 1);
if ($info['mpeg']['video']['raw']['composite_display_flag']) {
$info['mpeg']['video']['raw']['v_axis'] = self::readBitsFromStream($bitstream, $bitstreamoffset, 1);
$info['mpeg']['video']['raw']['field_sequence'] = self::readBitsFromStream($bitstream, $bitstreamoffset, 3);
$info['mpeg']['video']['raw']['sub_carrier'] = self::readBitsFromStream($bitstream, $bitstreamoffset, 1);
$info['mpeg']['video']['raw']['burst_amplitude'] = self::readBitsFromStream($bitstream, $bitstreamoffset, 7);
$info['mpeg']['video']['raw']['sub_carrier_phase'] = self::readBitsFromStream($bitstream, $bitstreamoffset, 8);
}
$info['mpeg']['video']['intra_dc_precision_bits'] = $info['mpeg']['video']['raw']['intra_dc_precision'] + 8;
$info['mpeg']['video']['picture_structure'] = self::pictureStructureTextLookup($info['mpeg']['video']['raw']['picture_structure']);
break;
case 9:
break;
case 10:
break;
default:
$this->warning('Unexpected $info[mpeg][video][raw][extension_start_code_identifier] value of '.$info['mpeg']['video']['raw']['extension_start_code_identifier']);
break;
}
break;
case 0xB8:
$GOPcounter++;
if ($info['mpeg']['video']['bitrate_mode'] == 'vbr') {
$bitstream = getid3_lib::BigEndian2Bin(substr($MPEGstreamData, $StartCodeOffset + 4, 4));
$bitstreamoffset = 0;
$GOPheader = array();
$GOPheader['byte_offset'] = $MPEGstreamBaseOffset + $StartCodeOffset;
$GOPheader['drop_frame_flag'] = self::readBitsFromStream($bitstream, $bitstreamoffset, 1);
$GOPheader['time_code_hours'] = self::readBitsFromStream($bitstream, $bitstreamoffset, 5);
$GOPheader['time_code_minutes'] = self::readBitsFromStream($bitstream, $bitstreamoffset, 6);
$marker_bit = self::readBitsFromStream($bitstream, $bitstreamoffset, 1);
$GOPheader['time_code_seconds'] = self::readBitsFromStream($bitstream, $bitstreamoffset, 6);
$GOPheader['time_code_pictures'] = self::readBitsFromStream($bitstream, $bitstreamoffset, 6);
$GOPheader['closed_gop'] = self::readBitsFromStream($bitstream, $bitstreamoffset, 1);
$GOPheader['broken_link'] = self::readBitsFromStream($bitstream, $bitstreamoffset, 1);
$time_code_separator = ($GOPheader['drop_frame_flag'] ? ';' : ':');
$GOPheader['time_code'] = sprintf('%02d'.$time_code_separator.'%02d'.$time_code_separator.'%02d'.$time_code_separator.'%02d', $GOPheader['time_code_hours'], $GOPheader['time_code_minutes'], $GOPheader['time_code_seconds'], $GOPheader['time_code_pictures']);
$info['mpeg']['group_of_pictures'][] = $GOPheader;
}
break;
case 0xC0:
case 0xC1:
case 0xC2:
case 0xC3:
case 0xC4:
case 0xC5:
case 0xC6:
case 0xC7:
case 0xC8:
case 0xC9:
case 0xCA:
case 0xCB:
case 0xCC:
case 0xCD:
case 0xCE:
case 0xCF:
case 0xD0:
case 0xD1:
case 0xD2:
case 0xD3:
case 0xD4:
case 0xD5:
case 0xD6:
case 0xD7:
case 0xD8:
case 0xD9:
case 0xDA:
case 0xDB:
case 0xDC:
case 0xDD:
case 0xDE:
case 0xDF:
if (isset($ParsedAVchannels[$StartCodeValue])) {
break;
}
$ParsedAVchannels[$StartCodeValue] = $StartCodeValue;
$getid3_temp = new getID3();
$getid3_temp->openfile($this->getid3->filename);
$getid3_temp->info = $info;
$getid3_mp3 = new getid3_mp3($getid3_temp);
for ($i = 0; $i <= 7; $i++) {
$getid3_temp->info = $info;
if ($getid3_mp3->decodeMPEGaudioHeader($MPEGstreamBaseOffset + $StartCodeOffset + 4 + 8 + $i, $getid3_temp->info, false)) {
$info = $getid3_temp->info;
$info['audio']['bitrate_mode'] = 'cbr';
$info['audio']['lossless'] = false;
break;
}
}
unset($getid3_temp, $getid3_mp3);
break;
case 0xBC:
case 0xBD:
case 0xBE:
case 0xBF:
case 0xF0:
case 0xF1:
case 0xF2:
case 0xF3:
case 0xF4:
case 0xF5:
case 0xF6:
case 0xF7:
case 0xF8:
case 0xF9:
case 0xFA:
case 0xFB:
case 0xFC:
case 0xFD:
case 0xFE:
case 0xFF:
break;
default:
break;
}
} while (true);
if (!empty($info['mpeg']['video']['bitrate_mode']) && ($info['mpeg']['video']['bitrate_mode'] == 'vbr')) {
$last_GOP_id = max(array_keys($FramesByGOP));
$frames_in_last_GOP = count($FramesByGOP[$last_GOP_id]);
$gopdata = &$info['mpeg']['group_of_pictures'][$last_GOP_id];
$info['playtime_seconds'] = ($gopdata['time_code_hours'] * 3600) + ($gopdata['time_code_minutes'] * 60) + $gopdata['time_code_seconds'] + (($gopdata['time_code_pictures'] + $frames_in_last_GOP + 1) / $info['mpeg']['video']['frame_rate']);
if (!isset($info['video']['bitrate'])) {
$overall_bitrate = ($info['avdataend'] - $info['avdataoffset']) * 8 / $info['playtime_seconds'];
$info['video']['bitrate'] = $overall_bitrate - (isset($info['audio']['bitrate']) ? $info['audio']['bitrate'] : 0);
}
unset($info['mpeg']['group_of_pictures']);
}
return true;
}
private function readBitsFromStream(&$bitstream, &$bitstreamoffset, $bits_to_read, $return_singlebit_as_boolean=true) {
$return = bindec(substr($bitstream, $bitstreamoffset, $bits_to_read));
$bitstreamoffset += $bits_to_read;
if (($bits_to_read == 1) && $return_singlebit_as_boolean) {
$return = (bool) $return;
}
return $return;
}
public static function systemNonOverheadPercentage($VideoBitrate, $AudioBitrate) {
$OverheadPercentage = 0;
$AudioBitrate = max(min($AudioBitrate / 1000, 384), 32);
$VideoBitrate = max(min($VideoBitrate / 1000, 10000), 10);
$OverheadMultiplierByBitrate[32] = array(0, 0.9676287944368530, 0.9802276264360310, 0.9844916183244460, 0.9852821845179940);
$OverheadMultiplierByBitrate[48] = array(0, 0.9779100089209830, 0.9787770035359320, 0.9846738664076130, 0.9852683013799960);
$OverheadMultiplierByBitrate[56] = array(0, 0.9731249855367600, 0.9776624308938040, 0.9832606361852130, 0.9843922606633340);
$OverheadMultiplierByBitrate[64] = array(0, 0.9755642683275760, 0.9795256705493390, 0.9836573009193170, 0.9851122539404470);
$OverheadMultiplierByBitrate[96] = array(0, 0.9788025247497290, 0.9798553314148700, 0.9822956869792560, 0.9834815119124690);
$OverheadMultiplierByBitrate[128] = array(0, 0.9816940050925480, 0.9821675936072120, 0.9829756927470870, 0.9839763420152050);
$OverheadMultiplierByBitrate[160] = array(0, 0.9825894094561180, 0.9820913399073960, 0.9823907143253970, 0.9832821783651570);
$OverheadMultiplierByBitrate[192] = array(0, 0.9832038474336260, 0.9825731694317960, 0.9821028622712400, 0.9828262076447620);
$OverheadMultiplierByBitrate[224] = array(0, 0.9836516298538770, 0.9824718601823890, 0.9818302180625380, 0.9823735101626480);
$OverheadMultiplierByBitrate[256] = array(0, 0.9845863022094920, 0.9837229411967540, 0.9824521662210830, 0.9828645172100790);
$OverheadMultiplierByBitrate[320] = array(0, 0.9849565280263180, 0.9837683142805110, 0.9822885275960400, 0.9824424382727190);
$OverheadMultiplierByBitrate[384] = array(0, 0.9856094774357600, 0.9844573394432720, 0.9825970399837330, 0.9824673808303890);
$BitrateToUseMin = 32;
$BitrateToUseMax = 32;
$previousBitrate = 32;
foreach ($OverheadMultiplierByBitrate as $key => $value) {
if ($AudioBitrate >= $previousBitrate) {
$BitrateToUseMin = $previousBitrate;
}
if ($AudioBitrate < $key) {
$BitrateToUseMax = $key;
break;
}
$previousBitrate = $key;
}
$FactorA = ($BitrateToUseMax - $AudioBitrate) / ($BitrateToUseMax - $BitrateToUseMin);
$VideoBitrateLog10 = log10($VideoBitrate);
$VideoFactorMin1 = $OverheadMultiplierByBitrate[$BitrateToUseMin][floor($VideoBitrateLog10)];
$VideoFactorMin2 = $OverheadMultiplierByBitrate[$BitrateToUseMax][floor($VideoBitrateLog10)];
$VideoFactorMax1 = $OverheadMultiplierByBitrate[$BitrateToUseMin][ceil($VideoBitrateLog10)];
$VideoFactorMax2 = $OverheadMultiplierByBitrate[$BitrateToUseMax][ceil($VideoBitrateLog10)];
$FactorV = $VideoBitrateLog10 - floor($VideoBitrateLog10);
$OverheadPercentage = $VideoFactorMin1 * $FactorA * $FactorV;
$OverheadPercentage += $VideoFactorMin2 * (1 - $FactorA) * $FactorV;
$OverheadPercentage += $VideoFactorMax1 * $FactorA * (1 - $FactorV);
$OverheadPercentage += $VideoFactorMax2 * (1 - $FactorA) * (1 - $FactorV);
return $OverheadPercentage;
}
public static function videoFramerateLookup($rawframerate) {
$lookup = array(0, 23.976, 24, 25, 29.97, 30, 50, 59.94, 60);
return (isset($lookup[$rawframerate]) ? (float) $lookup[$rawframerate] : (float) 0);
}
public static function videoAspectRatioLookup($rawaspectratio) {
$lookup = array(0, 1, 0.6735, 0.7031, 0.7615, 0.8055, 0.8437, 0.8935, 0.9157, 0.9815, 1.0255, 1.0695, 1.0950, 1.1575, 1.2015, 0);
return (isset($lookup[$rawaspectratio]) ? (float) $lookup[$rawaspectratio] : (float) 0);
}
public static function videoAspectRatioTextLookup($rawaspectratio) {
$lookup = array('forbidden', 'square pixels', '0.6735', '16:9, 625 line, PAL', '0.7615', '0.8055', '16:9, 525 line, NTSC', '0.8935', '4:3, 625 line, PAL, CCIR601', '0.9815', '1.0255', '1.0695', '4:3, 525 line, NTSC, CCIR601', '1.1575', '1.2015', 'reserved');
return (isset($lookup[$rawaspectratio]) ? $lookup[$rawaspectratio] : '');
}
public static function videoFormatTextLookup($video_format) {
$lookup = array('component', 'PAL', 'NTSC', 'SECAM', 'MAC', 'Unspecified video format', 'reserved(6)', 'reserved(7)');
return (isset($lookup[$video_format]) ? $lookup[$video_format] : '');
}
public static function scalableModeTextLookup($scalable_mode) {
$lookup = array('data partitioning', 'spatial scalability', 'SNR scalability', 'temporal scalability');
return (isset($lookup[$scalable_mode]) ? $lookup[$scalable_mode] : '');
}
public static function pictureStructureTextLookup($picture_structure) {
$lookup = array('reserved', 'Top Field', 'Bottom Field', 'Frame picture');
return (isset($lookup[$picture_structure]) ? $lookup[$picture_structure] : '');
}
public static function chromaFormatTextLookup($chroma_format) {
$lookup = array('reserved', '4:2:0', '4:2:2', '4:4:4');
return (isset($lookup[$chroma_format]) ? $lookup[$chroma_format] : '');
}
}