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/sys/plugins/id3/getid3/module.audio-video.mpeg.php

https://bitbucket.org/DESURE/dcms
PHP | 606 lines | 383 code | 66 blank | 157 comment | 37 complexity | 1482a1b328b7b0d6d88ac13d1f2ef777 MD5 | raw file
    

  1. <?php
    2. 

  2. /////////////////////////////////////////////////////////////////
    3. 

  3. /// getID3() by James Heinrich <info@getid3.org>               //
    4. 

  4. //  available at http://getid3.sourceforge.net                 //
    5. 

  5. //            or http://www.getid3.org                         //
    6. 

  6. //          also https://github.com/JamesHeinrich/getID3       //
    7. 

  7. /////////////////////////////////////////////////////////////////
    8. 

  8. // See readme.txt for more details                             //
    9. 

  9. /////////////////////////////////////////////////////////////////
    10. 

  10. //                                                             //
    11. 

  11. // module.audio-video.mpeg.php                                 //
    12. 

  12. // module for analyzing MPEG files                             //
    13. 

  13. // dependencies: module.audio.mp3.php                          //
    14. 

  14. //                                                            ///
    15. 

  15. /////////////////////////////////////////////////////////////////
    16. 

  16. 

  17. getid3_lib::IncludeDependency(GETID3_INCLUDEPATH.'module.audio.mp3.php', __FILE__, true);
    18. 

  18. 

  19. class getid3_mpeg extends getid3_handler {
    20. 

  20. 

  21. 	const START_CODE_BASE       = "\x00\x00\x01";
    22. 

  22. 	const VIDEO_PICTURE_START   = "\x00\x00\x01\x00";
    23. 

  23. 	const VIDEO_USER_DATA_START = "\x00\x00\x01\xB2";
    24. 

  24. 	const VIDEO_SEQUENCE_HEADER = "\x00\x00\x01\xB3";
    25. 

  25. 	const VIDEO_SEQUENCE_ERROR  = "\x00\x00\x01\xB4";
    26. 

  26. 	const VIDEO_EXTENSION_START = "\x00\x00\x01\xB5";
    27. 

  27. 	const VIDEO_SEQUENCE_END    = "\x00\x00\x01\xB7";
    28. 

  28. 	const VIDEO_GROUP_START     = "\x00\x00\x01\xB8";
    29. 

  29. 	const AUDIO_START           = "\x00\x00\x01\xC0";
    30. 

  30. 

  31. 

  32. 	public function Analyze() {
    33. 

  33. 		$info = &$this->getid3->info;
    34. 

  34. 

  35. 		$info['fileformat'] = 'mpeg';
    36. 

  36. 		$this->fseek($info['avdataoffset']);
    37. 

  37. 

  38. 		$MPEGstreamData = $this->fread($this->getid3->option_fread_buffer_size);
    39. 

  39. 		$MPEGstreamBaseOffset = 0; // how far are we from the beginning of the file data ($info['avdataoffset'])
    40. 

  40. 		$MPEGstreamDataOffset = 0; // how far are we from the beginning of the buffer data (~32kB)
    41. 

  41. 

  42. 		$StartCodeValue     = false;
    43. 

  43. 		$prevStartCodeValue = false;
    44. 

  44. 

  45. 		$GOPcounter = -1;
    46. 

  46. 		$FramesByGOP = array();
    47. 

  47. 		$ParsedAVchannels = array();
    48. 

  48. 

  49. 		do {
    50. 

  50. //echo $MPEGstreamDataOffset.' vs '.(strlen($MPEGstreamData) - 1024).'<Br>';
    51. 

  51. 			if ($MPEGstreamDataOffset > (strlen($MPEGstreamData) - 16384)) {
    52. 

  52. 				// buffer running low, get more data
    53. 

  53. //echo 'reading more data<br>';
    54. 

  54. 				$MPEGstreamData .= $this->fread($this->getid3->option_fread_buffer_size);
    55. 

  55. 				if (strlen($MPEGstreamData) > $this->getid3->option_fread_buffer_size) {
    56. 

  56. 					$MPEGstreamData = substr($MPEGstreamData, $MPEGstreamDataOffset);
    57. 

  57. 					$MPEGstreamBaseOffset += $MPEGstreamDataOffset;
    58. 

  58. 					$MPEGstreamDataOffset  = 0;
    59. 

  59. 				}
    60. 

  60. 			}
    61. 

  61. 			if (($StartCodeOffset = strpos($MPEGstreamData, self::START_CODE_BASE, $MPEGstreamDataOffset)) === false) {
    62. 

  62. //echo 'no more start codes found.<br>';
    63. 

  63. 				break;
    64. 

  64. 			} else {
    65. 

  65. 				$MPEGstreamDataOffset = $StartCodeOffset;
    66. 

  66. 				$prevStartCodeValue = $StartCodeValue;
    67. 

  67. 				$StartCodeValue = ord(substr($MPEGstreamData, $StartCodeOffset + 3, 1));
    68. 

  68. //echo 'Found "'.strtoupper(dechex($StartCodeValue)).'" at offset '.($MPEGstreamBaseOffset + $StartCodeOffset).' ($MPEGstreamDataOffset = '.$MPEGstreamDataOffset.')<br>';
    69. 

  69. 			}
    70. 

  70. 			$MPEGstreamDataOffset += 4;
    71. 

  71. 			switch ($StartCodeValue) {
    72. 

  72. 

  73. 				case 0x00: // picture_start_code
    74. 

  74. 					if (!empty($info['mpeg']['video']['bitrate_mode']) && ($info['mpeg']['video']['bitrate_mode'] == 'vbr')) {
    75. 

  75. 						$bitstream = getid3_lib::BigEndian2Bin(substr($MPEGstreamData, $StartCodeOffset + 4, 4));
    76. 

  76. 						$bitstreamoffset = 0;
    77. 

  77. 

  78. 						$PictureHeader = array();
    79. 

  79. 

  80. 						$PictureHeader['temporal_reference']  = self::readBitsFromStream($bitstream, $bitstreamoffset, 10); // 10-bit unsigned integer associated with each input picture. It is incremented by one, modulo 1024, for each input frame. When a frame is coded as two fields the temporal reference in the picture header of both fields is the same. Following a group start header the temporal reference of the earliest picture (in display order) shall be reset to zero.
    81. 

  81. 						$PictureHeader['picture_coding_type'] = self::readBitsFromStream($bitstream, $bitstreamoffset,  3); //  3 bits for picture_coding_type
    82. 

  82. 						$PictureHeader['vbv_delay']           = self::readBitsFromStream($bitstream, $bitstreamoffset, 16); // 16 bits for vbv_delay
    83. 

  83. 						//... etc
    84. 

  84. 

  85. 						$FramesByGOP[$GOPcounter][] = $PictureHeader;
    86. 

  86. 					}
    87. 

  87. 					break;
    88. 

  88. 

  89. 				case 0xB3: // sequence_header_code
    90. 

  90. 					/*
    91. 

  91. 					Note: purposely doing the less-pretty (and probably a bit slower) method of using string of bits rather than bitwise operations.
    92. 

  92. 					      Mostly because PHP 32-bit doesn't handle unsigned integers well for bitwise operation.
    93. 

  93. 					      Also the MPEG stream is designed as a bitstream and often doesn't align nicely with byte boundaries.
    94. 

  94. 					*/
    95. 

  95. 					$info['video']['codec'] = 'MPEG-1'; // will be updated if extension_start_code found
    96. 

  96. 

  97. 					$bitstream = getid3_lib::BigEndian2Bin(substr($MPEGstreamData, $StartCodeOffset + 4, 8));
    98. 

  98. 					$bitstreamoffset = 0;
    99. 

  99. 

  100. 					$info['mpeg']['video']['raw']['horizontal_size_value']       = self::readBitsFromStream($bitstream, $bitstreamoffset, 12); // 12 bits for horizontal frame size. Note: horizontal_size_extension, if present, will add 2 most-significant bits to this value
    101. 

  101. 					$info['mpeg']['video']['raw']['vertical_size_value']         = self::readBitsFromStream($bitstream, $bitstreamoffset, 12); // 12 bits for vertical frame size.   Note: vertical_size_extension,   if present, will add 2 most-significant bits to this value
    102. 

  102. 					$info['mpeg']['video']['raw']['aspect_ratio_information']    = self::readBitsFromStream($bitstream, $bitstreamoffset,  4); //  4 bits for aspect_ratio_information
    103. 

  103. 					$info['mpeg']['video']['raw']['frame_rate_code']             = self::readBitsFromStream($bitstream, $bitstreamoffset,  4); //  4 bits for Frame Rate id code
    104. 

  104. 					$info['mpeg']['video']['raw']['bitrate']                     = self::readBitsFromStream($bitstream, $bitstreamoffset, 18); // 18 bits for bit_rate_value (18 set bits = VBR, otherwise bitrate = this value * 400)
    105. 

  105. 					$marker_bit                                                  = self::readBitsFromStream($bitstream, $bitstreamoffset,  1); // The term "marker_bit" indicates a one bit field in which the value zero is forbidden. These marker bits are introduced at several points in the syntax to avoid start code emulation.
    106. 

  106. 					$info['mpeg']['video']['raw']['vbv_buffer_size']             = self::readBitsFromStream($bitstream, $bitstreamoffset, 10); // 10 bits vbv_buffer_size_value
    107. 

  107. 					$info['mpeg']['video']['raw']['constrained_param_flag']      = self::readBitsFromStream($bitstream, $bitstreamoffset,  1); //  1 bit flag: constrained_param_flag
    108. 

  108. 					$info['mpeg']['video']['raw']['load_intra_quantiser_matrix'] = self::readBitsFromStream($bitstream, $bitstreamoffset,  1); //  1 bit flag: load_intra_quantiser_matrix
    109. 

  109. 

  110. 					if ($info['mpeg']['video']['raw']['load_intra_quantiser_matrix']) {
    111. 

  111. 						$bitstream .= getid3_lib::BigEndian2Bin(substr($MPEGstreamData, $StartCodeOffset + 12, 64));
    112. 

  112. 						for ($i = 0; $i < 64; $i++) {
    113. 

  113. 							$info['mpeg']['video']['raw']['intra_quantiser_matrix'][$i] = self::readBitsFromStream($bitstream, $bitstreamoffset,  8);
    114. 

  114. 						}
    115. 

  115. 					}
    116. 

  116. 					$info['mpeg']['video']['raw']['load_non_intra_quantiser_matrix'] = self::readBitsFromStream($bitstream, $bitstreamoffset,  1);
    117. 

  117. 

  118. 					if ($info['mpeg']['video']['raw']['load_non_intra_quantiser_matrix']) {
    119. 

  119. 						$bitstream .= getid3_lib::BigEndian2Bin(substr($MPEGstreamData, $StartCodeOffset + 12 + ($info['mpeg']['video']['raw']['load_intra_quantiser_matrix'] ? 64 : 0), 64));
    120. 

  120. 						for ($i = 0; $i < 64; $i++) {
    121. 

  121. 							$info['mpeg']['video']['raw']['non_intra_quantiser_matrix'][$i] = self::readBitsFromStream($bitstream, $bitstreamoffset,  8);
    122. 

  122. 						}
    123. 

  123. 					}
    124. 

  124. 

  125. 					$info['mpeg']['video']['pixel_aspect_ratio']      =     self::videoAspectRatioLookup($info['mpeg']['video']['raw']['aspect_ratio_information']);
    126. 

  126. 					$info['mpeg']['video']['pixel_aspect_ratio_text'] = self::videoAspectRatioTextLookup($info['mpeg']['video']['raw']['aspect_ratio_information']);
    127. 

  127. 					$info['mpeg']['video']['frame_rate']              =       self::videoFramerateLookup($info['mpeg']['video']['raw']['frame_rate_code']);
    128. 

  128. 					if ($info['mpeg']['video']['raw']['bitrate'] == 0x3FFFF) { // 18 set bits = VBR
    129. 

  129. 						//$this->warning('This version of getID3() ['.$this->getid3->version().'] cannot determine average bitrate of VBR MPEG video files');
    130. 

  130. 						$info['mpeg']['video']['bitrate_mode'] = 'vbr';
    131. 

  131. 					} else {
    132. 

  132. 						$info['mpeg']['video']['bitrate']      = $info['mpeg']['video']['raw']['bitrate'] * 400;
    133. 

  133. 						$info['mpeg']['video']['bitrate_mode'] = 'cbr';
    134. 

  134. 						$info['video']['bitrate']              = $info['mpeg']['video']['bitrate'];
    135. 

  135. 					}
    136. 

  136. 					$info['video']['resolution_x']       = $info['mpeg']['video']['raw']['horizontal_size_value'];
    137. 

  137. 					$info['video']['resolution_y']       = $info['mpeg']['video']['raw']['vertical_size_value'];
    138. 

  138. 					$info['video']['frame_rate']         = $info['mpeg']['video']['frame_rate'];
    139. 

  139. 					$info['video']['bitrate_mode']       = $info['mpeg']['video']['bitrate_mode'];
    140. 

  140. 					$info['video']['pixel_aspect_ratio'] = $info['mpeg']['video']['pixel_aspect_ratio'];
    141. 

  141. 					$info['video']['lossless']           = false;
    142. 

  142. 					$info['video']['bits_per_sample']    = 24;
    143. 

  143. 					break;
    144. 

  144. 

  145. 				case 0xB5: // extension_start_code
    146. 

  146. 					$info['video']['codec'] = 'MPEG-2';
    147. 

  147. 

  148. 					$bitstream = getid3_lib::BigEndian2Bin(substr($MPEGstreamData, $StartCodeOffset + 4, 8)); // 48 bits for Sequence Extension ID; 61 bits for Sequence Display Extension ID; 59 bits for Sequence Scalable Extension ID
    149. 

  149. 					$bitstreamoffset = 0;
    150. 

  150. 

  151. 					$info['mpeg']['video']['raw']['extension_start_code_identifier'] = self::readBitsFromStream($bitstream, $bitstreamoffset,  4); //  4 bits for extension_start_code_identifier
    152. 

  152. //echo $info['mpeg']['video']['raw']['extension_start_code_identifier'].'<br>';
    153. 

  153. 					switch ($info['mpeg']['video']['raw']['extension_start_code_identifier']) {
    154. 

  154. 						case  1: // 0001 Sequence Extension ID
    155. 

  155. 							$info['mpeg']['video']['raw']['profile_and_level_indication']    = self::readBitsFromStream($bitstream, $bitstreamoffset,  8); //  8 bits for profile_and_level_indication
    156. 

  156. 							$info['mpeg']['video']['raw']['progressive_sequence']            = self::readBitsFromStream($bitstream, $bitstreamoffset,  1); //  1 bit flag: progressive_sequence
    157. 

  157. 							$info['mpeg']['video']['raw']['chroma_format']                   = self::readBitsFromStream($bitstream, $bitstreamoffset,  2); //  2 bits for chroma_format
    158. 

  158. 							$info['mpeg']['video']['raw']['horizontal_size_extension']       = self::readBitsFromStream($bitstream, $bitstreamoffset,  2); //  2 bits for horizontal_size_extension
    159. 

  159. 							$info['mpeg']['video']['raw']['vertical_size_extension']         = self::readBitsFromStream($bitstream, $bitstreamoffset,  2); //  2 bits for vertical_size_extension
    160. 

  160. 							$info['mpeg']['video']['raw']['bit_rate_extension']              = self::readBitsFromStream($bitstream, $bitstreamoffset, 12); // 12 bits for bit_rate_extension
    161. 

  161. 							$marker_bit                                                      = self::readBitsFromStream($bitstream, $bitstreamoffset,  1); // The term "marker_bit" indicates a one bit field in which the value zero is forbidden. These marker bits are introduced at several points in the syntax to avoid start code emulation.
    162. 

  162. 							$info['mpeg']['video']['raw']['vbv_buffer_size_extension']       = self::readBitsFromStream($bitstream, $bitstreamoffset,  8); //  8 bits for vbv_buffer_size_extension
    163. 

  163. 							$info['mpeg']['video']['raw']['low_delay']                       = self::readBitsFromStream($bitstream, $bitstreamoffset,  1); //  1 bit flag: low_delay
    164. 

  164. 							$info['mpeg']['video']['raw']['frame_rate_extension_n']          = self::readBitsFromStream($bitstream, $bitstreamoffset,  2); //  2 bits for frame_rate_extension_n
    165. 

  165. 							$info['mpeg']['video']['raw']['frame_rate_extension_d']          = self::readBitsFromStream($bitstream, $bitstreamoffset,  5); //  5 bits for frame_rate_extension_d
    166. 

  166. 

  167. 							$info['video']['resolution_x']          = ($info['mpeg']['video']['raw']['horizontal_size_extension'] << 12) | $info['mpeg']['video']['raw']['horizontal_size_value'];
    168. 

  168. 							$info['video']['resolution_y']          = ($info['mpeg']['video']['raw']['vertical_size_extension']   << 12) | $info['mpeg']['video']['raw']['vertical_size_value'];
    169. 

  169. 							$info['video']['interlaced']            = !$info['mpeg']['video']['raw']['progressive_sequence'];
    170. 

  170. 							$info['mpeg']['video']['interlaced']    = !$info['mpeg']['video']['raw']['progressive_sequence'];
    171. 

  171. 							$info['mpeg']['video']['chroma_format'] = self::chromaFormatTextLookup($info['mpeg']['video']['raw']['chroma_format']);
    172. 

  172. 							break;
    173. 

  173. 

  174. 						case  2: // 0010 Sequence Display Extension ID
    175. 

  175. 							$info['mpeg']['video']['raw']['video_format']                    = self::readBitsFromStream($bitstream, $bitstreamoffset,  3); //  3 bits for video_format
    176. 

  176. 							$info['mpeg']['video']['raw']['colour_description']              = self::readBitsFromStream($bitstream, $bitstreamoffset,  1); //  1 bit flag: colour_description
    177. 

  177. 							if ($info['mpeg']['video']['raw']['colour_description']) {
    178. 

  178. 								$info['mpeg']['video']['raw']['colour_primaries']            = self::readBitsFromStream($bitstream, $bitstreamoffset,  8); //  8 bits for colour_primaries
    179. 

  179. 								$info['mpeg']['video']['raw']['transfer_characteristics']    = self::readBitsFromStream($bitstream, $bitstreamoffset,  8); //  8 bits for transfer_characteristics
    180. 

  180. 								$info['mpeg']['video']['raw']['matrix_coefficients']         = self::readBitsFromStream($bitstream, $bitstreamoffset,  8); //  8 bits for matrix_coefficients
    181. 

  181. 							}
    182. 

  182. 							$info['mpeg']['video']['raw']['display_horizontal_size']         = self::readBitsFromStream($bitstream, $bitstreamoffset, 14); // 14 bits for display_horizontal_size
    183. 

  183. 							$marker_bit                                                      = self::readBitsFromStream($bitstream, $bitstreamoffset,  1); // The term "marker_bit" indicates a one bit field in which the value zero is forbidden. These marker bits are introduced at several points in the syntax to avoid start code emulation.
    184. 

  184. 							$info['mpeg']['video']['raw']['display_vertical_size']           = self::readBitsFromStream($bitstream, $bitstreamoffset, 14); // 14 bits for display_vertical_size
    185. 

  185. 

  186. 							$info['mpeg']['video']['video_format'] = self::videoFormatTextLookup($info['mpeg']['video']['raw']['video_format']);
    187. 

  187. 							break;
    188. 

  188. 

  189. 						case  3: // 0011 Quant Matrix Extension ID
    190. 

  190. 							break;
    191. 

  191. 

  192. 						case  5: // 0101 Sequence Scalable Extension ID
    193. 

  193. 							$info['mpeg']['video']['raw']['scalable_mode']                              = self::readBitsFromStream($bitstream, $bitstreamoffset,  2); //  2 bits for scalable_mode
    194. 

  194. 							$info['mpeg']['video']['raw']['layer_id']                                   = self::readBitsFromStream($bitstream, $bitstreamoffset,  4); //  4 bits for layer_id
    195. 

  195. 							if ($info['mpeg']['video']['raw']['scalable_mode'] == 1) { // "spatial scalability"
    196. 

  196. 								$info['mpeg']['video']['raw']['lower_layer_prediction_horizontal_size'] = self::readBitsFromStream($bitstream, $bitstreamoffset, 14); // 14 bits for lower_layer_prediction_horizontal_size
    197. 

  197. 								$marker_bit                                                             = self::readBitsFromStream($bitstream, $bitstreamoffset,  1); // The term "marker_bit" indicates a one bit field in which the value zero is forbidden. These marker bits are introduced at several points in the syntax to avoid start code emulation.
    198. 

  198. 								$info['mpeg']['video']['raw']['lower_layer_prediction_vertical_size']   = self::readBitsFromStream($bitstream, $bitstreamoffset, 14); // 14 bits for lower_layer_prediction_vertical_size
    199. 

  199. 								$info['mpeg']['video']['raw']['horizontal_subsampling_factor_m']        = self::readBitsFromStream($bitstream, $bitstreamoffset,  5); //  5 bits for horizontal_subsampling_factor_m
    200. 

  200. 								$info['mpeg']['video']['raw']['horizontal_subsampling_factor_n']        = self::readBitsFromStream($bitstream, $bitstreamoffset,  5); //  5 bits for horizontal_subsampling_factor_n
    201. 

  201. 								$info['mpeg']['video']['raw']['vertical_subsampling_factor_m']          = self::readBitsFromStream($bitstream, $bitstreamoffset,  5); //  5 bits for vertical_subsampling_factor_m
    202. 

  202. 								$info['mpeg']['video']['raw']['vertical_subsampling_factor_n']          = self::readBitsFromStream($bitstream, $bitstreamoffset,  5); //  5 bits for vertical_subsampling_factor_n
    203. 

  203. 							} elseif ($info['mpeg']['video']['raw']['scalable_mode'] == 3) { // "temporal scalability"
    204. 

  204. 								$info['mpeg']['video']['raw']['picture_mux_enable']                     = self::readBitsFromStream($bitstream, $bitstreamoffset,  1); //  1 bit flag: picture_mux_enable
    205. 

  205. 								if ($info['mpeg']['video']['raw']['picture_mux_enable']) {
    206. 

  206. 									$info['mpeg']['video']['raw']['mux_to_progressive_sequence']        = self::readBitsFromStream($bitstream, $bitstreamoffset,  1); //  1 bit flag: mux_to_progressive_sequence
    207. 

  207. 								}
    208. 

  208. 								$info['mpeg']['video']['raw']['picture_mux_order']                      = self::readBitsFromStream($bitstream, $bitstreamoffset,  3); //  3 bits for picture_mux_order
    209. 

  209. 								$info['mpeg']['video']['raw']['picture_mux_factor']                     = self::readBitsFromStream($bitstream, $bitstreamoffset,  3); //  3 bits for picture_mux_factor
    210. 

  210. 							}
    211. 

  211. 

  212. 							$info['mpeg']['video']['scalable_mode'] = self::scalableModeTextLookup($info['mpeg']['video']['raw']['scalable_mode']);
    213. 

  213. 							break;
    214. 

  214. 

  215. 						case  7: // 0111 Picture Display Extension ID
    216. 

  216. 							break;
    217. 

  217. 

  218. 						case  8: // 1000 Picture Coding Extension ID
    219. 

  219. 							$info['mpeg']['video']['raw']['f_code_00']                       = self::readBitsFromStream($bitstream, $bitstreamoffset,  4); // 4 bits for f_code[0][0] (forward horizontal)
    220. 

  220. 							$info['mpeg']['video']['raw']['f_code_01']                       = self::readBitsFromStream($bitstream, $bitstreamoffset,  4); // 4 bits for f_code[0][1] (forward vertical)
    221. 

  221. 							$info['mpeg']['video']['raw']['f_code_10']                       = self::readBitsFromStream($bitstream, $bitstreamoffset,  4); // 4 bits for f_code[1][0] (backward horizontal)
    222. 

  222. 							$info['mpeg']['video']['raw']['f_code_11']                       = self::readBitsFromStream($bitstream, $bitstreamoffset,  4); // 4 bits for f_code[1][1] (backward vertical)
    223. 

  223. 							$info['mpeg']['video']['raw']['intra_dc_precision']              = self::readBitsFromStream($bitstream, $bitstreamoffset,  2); // 2 bits for intra_dc_precision
    224. 

  224. 							$info['mpeg']['video']['raw']['picture_structure']               = self::readBitsFromStream($bitstream, $bitstreamoffset,  2); // 2 bits for picture_structure
    225. 

  225. 							$info['mpeg']['video']['raw']['top_field_first']                 = self::readBitsFromStream($bitstream, $bitstreamoffset,  1); // 1 bit flag: top_field_first
    226. 

  226. 							$info['mpeg']['video']['raw']['frame_pred_frame_dct']            = self::readBitsFromStream($bitstream, $bitstreamoffset,  1); // 1 bit flag: frame_pred_frame_dct
    227. 

  227. 							$info['mpeg']['video']['raw']['concealment_motion_vectors']      = self::readBitsFromStream($bitstream, $bitstreamoffset,  1); // 1 bit flag: concealment_motion_vectors
    228. 

  228. 							$info['mpeg']['video']['raw']['q_scale_type']                    = self::readBitsFromStream($bitstream, $bitstreamoffset,  1); // 1 bit flag: q_scale_type
    229. 

  229. 							$info['mpeg']['video']['raw']['intra_vlc_format']                = self::readBitsFromStream($bitstream, $bitstreamoffset,  1); // 1 bit flag: intra_vlc_format
    230. 

  230. 							$info['mpeg']['video']['raw']['alternate_scan']                  = self::readBitsFromStream($bitstream, $bitstreamoffset,  1); // 1 bit flag: alternate_scan
    231. 

  231. 							$info['mpeg']['video']['raw']['repeat_first_field']              = self::readBitsFromStream($bitstream, $bitstreamoffset,  1); // 1 bit flag: repeat_first_field
    232. 

  232. 							$info['mpeg']['video']['raw']['chroma_420_type']                 = self::readBitsFromStream($bitstream, $bitstreamoffset,  1); // 1 bit flag: chroma_420_type
    233. 

  233. 							$info['mpeg']['video']['raw']['progressive_frame']               = self::readBitsFromStream($bitstream, $bitstreamoffset,  1); // 1 bit flag: progressive_frame
    234. 

  234. 							$info['mpeg']['video']['raw']['composite_display_flag']          = self::readBitsFromStream($bitstream, $bitstreamoffset,  1); // 1 bit flag: composite_display_flag
    235. 

  235. 							if ($info['mpeg']['video']['raw']['composite_display_flag']) {
    236. 

  236. 								$info['mpeg']['video']['raw']['v_axis']                      = self::readBitsFromStream($bitstream, $bitstreamoffset,  1); // 1 bit flag: v_axis
    237. 

  237. 								$info['mpeg']['video']['raw']['field_sequence']              = self::readBitsFromStream($bitstream, $bitstreamoffset,  3); // 3 bits for field_sequence
    238. 

  238. 								$info['mpeg']['video']['raw']['sub_carrier']                 = self::readBitsFromStream($bitstream, $bitstreamoffset,  1); // 1 bit flag: sub_carrier
    239. 

  239. 								$info['mpeg']['video']['raw']['burst_amplitude']             = self::readBitsFromStream($bitstream, $bitstreamoffset,  7); // 7 bits for burst_amplitude
    240. 

  240. 								$info['mpeg']['video']['raw']['sub_carrier_phase']           = self::readBitsFromStream($bitstream, $bitstreamoffset,  8); // 8 bits for sub_carrier_phase
    241. 

  241. 							}
    242. 

  242. 

  243. 							$info['mpeg']['video']['intra_dc_precision_bits'] = $info['mpeg']['video']['raw']['intra_dc_precision'] + 8;
    244. 

  244. 							$info['mpeg']['video']['picture_structure'] = self::pictureStructureTextLookup($info['mpeg']['video']['raw']['picture_structure']);
    245. 

  245. 							break;
    246. 

  246. 

  247. 						case  9: // 1001 Picture Spatial Scalable Extension ID
    248. 

  248. 							break;
    249. 

  249. 						case 10: // 1010 Picture Temporal Scalable Extension ID
    250. 

  250. 							break;
    251. 

  251. 

  252. 						default:
    253. 

  253. 							$this->warning('Unexpected $info[mpeg][video][raw][extension_start_code_identifier] value of '.$info['mpeg']['video']['raw']['extension_start_code_identifier']);
    254. 

  254. 							break;
    255. 

  255. 					}
    256. 

  256. 					break;
    257. 

  257. 

  258. 

  259. 				case 0xB8: // group_of_pictures_header
    260. 

  260. 					$GOPcounter++;
    261. 

  261. 					if ($info['mpeg']['video']['bitrate_mode'] == 'vbr') {
    262. 

  262. 						$bitstream = getid3_lib::BigEndian2Bin(substr($MPEGstreamData, $StartCodeOffset + 4, 4)); // 27 bits needed for group_of_pictures_header
    263. 

  263. 						$bitstreamoffset = 0;
    264. 

  264. 

  265. 						$GOPheader = array();
    266. 

  266. 

  267. 						$GOPheader['byte_offset'] = $MPEGstreamBaseOffset + $StartCodeOffset;
    268. 

  268. 						$GOPheader['drop_frame_flag']    = self::readBitsFromStream($bitstream, $bitstreamoffset,  1); //  1 bit flag: drop_frame_flag
    269. 

  269. 						$GOPheader['time_code_hours']    = self::readBitsFromStream($bitstream, $bitstreamoffset,  5); //  5 bits for time_code_hours
    270. 

  270. 						$GOPheader['time_code_minutes']  = self::readBitsFromStream($bitstream, $bitstreamoffset,  6); //  6 bits for time_code_minutes
    271. 

  271. 						$marker_bit                      = self::readBitsFromStream($bitstream, $bitstreamoffset,  1); // The term "marker_bit" indicates a one bit field in which the value zero is forbidden. These marker bits are introduced at several points in the syntax to avoid start code emulation.
    272. 

  272. 						$GOPheader['time_code_seconds']  = self::readBitsFromStream($bitstream, $bitstreamoffset,  6); //  6 bits for time_code_seconds
    273. 

  273. 						$GOPheader['time_code_pictures'] = self::readBitsFromStream($bitstream, $bitstreamoffset,  6); //  6 bits for time_code_pictures
    274. 

  274. 						$GOPheader['closed_gop']         = self::readBitsFromStream($bitstream, $bitstreamoffset,  1); //  1 bit flag: closed_gop
    275. 

  275. 						$GOPheader['broken_link']        = self::readBitsFromStream($bitstream, $bitstreamoffset,  1); //  1 bit flag: broken_link
    276. 

  276. 

  277. 						$time_code_separator = ($GOPheader['drop_frame_flag'] ? ';' : ':'); // While non-drop time code is displayed with colons separating the digit pairs—"HH:MM:SS:FF"—drop frame is usually represented with a semi-colon (;) or period (.) as the divider between all the digit pairs—"HH;MM;SS;FF", "HH.MM.SS.FF"
    278. 

  278. 						$GOPheader['time_code'] = sprintf('%02d'.$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']);
    279. 

  279. 

  280. 						$info['mpeg']['group_of_pictures'][] = $GOPheader;
    281. 

  281. 					}
    282. 

  282. 					break;
    283. 

  283. 

  284. 				case 0xC0: // audio stream
    285. 

  285. 				case 0xC1: // audio stream
    286. 

  286. 				case 0xC2: // audio stream
    287. 

  287. 				case 0xC3: // audio stream
    288. 

  288. 				case 0xC4: // audio stream
    289. 

  289. 				case 0xC5: // audio stream
    290. 

  290. 				case 0xC6: // audio stream
    291. 

  291. 				case 0xC7: // audio stream
    292. 

  292. 				case 0xC8: // audio stream
    293. 

  293. 				case 0xC9: // audio stream
    294. 

  294. 				case 0xCA: // audio stream
    295. 

  295. 				case 0xCB: // audio stream
    296. 

  296. 				case 0xCC: // audio stream
    297. 

  297. 				case 0xCD: // audio stream
    298. 

  298. 				case 0xCE: // audio stream
    299. 

  299. 				case 0xCF: // audio stream
    300. 

  300. 				case 0xD0: // audio stream
    301. 

  301. 				case 0xD1: // audio stream
    302. 

  302. 				case 0xD2: // audio stream
    303. 

  303. 				case 0xD3: // audio stream
    304. 

  304. 				case 0xD4: // audio stream
    305. 

  305. 				case 0xD5: // audio stream
    306. 

  306. 				case 0xD6: // audio stream
    307. 

  307. 				case 0xD7: // audio stream
    308. 

  308. 				case 0xD8: // audio stream
    309. 

  309. 				case 0xD9: // audio stream
    310. 

  310. 				case 0xDA: // audio stream
    311. 

  311. 				case 0xDB: // audio stream
    312. 

  312. 				case 0xDC: // audio stream
    313. 

  313. 				case 0xDD: // audio stream
    314. 

  314. 				case 0xDE: // audio stream
    315. 

  315. 				case 0xDF: // audio stream
    316. 

  316. 				//case 0xE0: // video stream
    317. 

  317. 				//case 0xE1: // video stream
    318. 

  318. 				//case 0xE2: // video stream
    319. 

  319. 				//case 0xE3: // video stream
    320. 

  320. 				//case 0xE4: // video stream
    321. 

  321. 				//case 0xE5: // video stream
    322. 

  322. 				//case 0xE6: // video stream
    323. 

  323. 				//case 0xE7: // video stream
    324. 

  324. 				//case 0xE8: // video stream
    325. 

  325. 				//case 0xE9: // video stream
    326. 

  326. 				//case 0xEA: // video stream
    327. 

  327. 				//case 0xEB: // video stream
    328. 

  328. 				//case 0xEC: // video stream
    329. 

  329. 				//case 0xED: // video stream
    330. 

  330. 				//case 0xEE: // video stream
    331. 

  331. 				//case 0xEF: // video stream
    332. 

  332. 					if (isset($ParsedAVchannels[$StartCodeValue])) {
    333. 

  333. 						break;
    334. 

  334. 					}
    335. 

  335. 					$ParsedAVchannels[$StartCodeValue] = $StartCodeValue;
    336. 

  336. 					// http://en.wikipedia.org/wiki/Packetized_elementary_stream
    337. 

  337. 					// http://dvd.sourceforge.net/dvdinfo/pes-hdr.html
    338. 

  338. /*
    339. 

  339. 					$PackedElementaryStream = array();
    340. 

  340. 					if ($StartCodeValue >= 0xE0) {
    341. 

  341. 						$PackedElementaryStream['stream_type'] = 'video';
    342. 

  342. 						$PackedElementaryStream['stream_id']   = $StartCodeValue - 0xE0;
    343. 

  343. 					} else {
    344. 

  344. 						$PackedElementaryStream['stream_type'] = 'audio';
    345. 

  345. 						$PackedElementaryStream['stream_id']   = $StartCodeValue - 0xC0;
    346. 

  346. 					}
    347. 

  347. 					$PackedElementaryStream['packet_length'] = getid3_lib::BigEndian2Int(substr($MPEGstreamData, $StartCodeOffset + 4, 2));
    348. 

    349. 

  349. 					$bitstream = getid3_lib::BigEndian2Bin(substr($MPEGstreamData, $StartCodeOffset + 6, 3)); // more may be needed below
    350. 

  350. 					$bitstreamoffset = 0;
    351. 

    352. 

  352. 					$PackedElementaryStream['marker_bits']               = self::readBitsFromStream($bitstream, $bitstreamoffset,  2); //  2 bits for marker_bits -- should be "10" = 2
    353. 

  353. echo 'marker_bits = '.$PackedElementaryStream['marker_bits'].'<br>';
    354. 

  354. 					$PackedElementaryStream['scrambling_control']        = self::readBitsFromStream($bitstream, $bitstreamoffset,  2); //  2 bits for scrambling_control -- 00 implies not scrambled
    355. 

  355. 					$PackedElementaryStream['priority']                  = self::readBitsFromStream($bitstream, $bitstreamoffset,  1); //  1 bit flag: priority
    356. 

  356. 					$PackedElementaryStream['data_alignment_indicator']  = self::readBitsFromStream($bitstream, $bitstreamoffset,  1); //  1 bit flag: data_alignment_indicator -- 1 indicates that the PES packet header is immediately followed by the video start code or audio syncword
    357. 

  357. 					$PackedElementaryStream['copyright']                 = self::readBitsFromStream($bitstream, $bitstreamoffset,  1); //  1 bit flag: copyright -- 1 implies copyrighted
    358. 

  358. 					$PackedElementaryStream['original_or_copy']          = self::readBitsFromStream($bitstream, $bitstreamoffset,  1); //  1 bit flag: original_or_copy -- 1 implies original
    359. 

  359. 					$PackedElementaryStream['pts_flag']                  = self::readBitsFromStream($bitstream, $bitstreamoffset,  1); //  1 bit flag: pts_flag -- Presentation Time Stamp
    360. 

  360. 					$PackedElementaryStream['dts_flag']                  = self::readBitsFromStream($bitstream, $bitstreamoffset,  1); //  1 bit flag: dts_flag -- Decode Time Stamp
    361. 

  361. 					$PackedElementaryStream['escr_flag']                 = self::readBitsFromStream($bitstream, $bitstreamoffset,  1); //  1 bit flag: escr_flag -- Elementary Stream Clock Reference
    362. 

  362. 					$PackedElementaryStream['es_rate_flag']              = self::readBitsFromStream($bitstream, $bitstreamoffset,  1); //  1 bit flag: es_rate_flag -- Elementary Stream [data] Rate
    363. 

  363. 					$PackedElementaryStream['dsm_trick_mode_flag']       = self::readBitsFromStream($bitstream, $bitstreamoffset,  1); //  1 bit flag: dsm_trick_mode_flag -- DSM trick mode - not used by DVD
    364. 

  364. 					$PackedElementaryStream['additional_copy_info_flag'] = self::readBitsFromStream($bitstream, $bitstreamoffset,  1); //  1 bit flag: additional_copy_info_flag
    365. 

  365. 					$PackedElementaryStream['crc_flag']                  = self::readBitsFromStream($bitstream, $bitstreamoffset,  1); //  1 bit flag: crc_flag
    366. 

  366. 					$PackedElementaryStream['extension_flag']            = self::readBitsFromStream($bitstream, $bitstreamoffset,  1); //  1 bit flag: extension_flag
    367. 

  367. 					$PackedElementaryStream['pes_remain_header_length']  = self::readBitsFromStream($bitstream, $bitstreamoffset,  8); //  1 bit flag: priority
    368. 

    369. 

  369. 					$additional_header_bytes = 0;
    370. 

  370. 					$additional_header_bytes += ($PackedElementaryStream['pts_flag']                  ? 5 : 0);
    371. 

  371. 					$additional_header_bytes += ($PackedElementaryStream['dts_flag']                  ? 5 : 0);
    372. 

  372. 					$additional_header_bytes += ($PackedElementaryStream['escr_flag']                 ? 6 : 0);
    373. 

  373. 					$additional_header_bytes += ($PackedElementaryStream['es_rate_flag']              ? 3 : 0);
    374. 

  374. 					$additional_header_bytes += ($PackedElementaryStream['additional_copy_info_flag'] ? 1 : 0);
    375. 

  375. 					$additional_header_bytes += ($PackedElementaryStream['crc_flag']                  ? 2 : 0);
    376. 

  376. 					$additional_header_bytes += ($PackedElementaryStream['extension_flag']            ? 1 : 0);
    377. 

  377. $PackedElementaryStream['additional_header_bytes'] = $additional_header_bytes;
    378. 

  378. 					$bitstream .= getid3_lib::BigEndian2Bin(substr($MPEGstreamData, $StartCodeOffset + 9, $additional_header_bytes));
    379. 

    380. 

  380. 					$info['mpeg']['packed_elementary_streams'][$PackedElementaryStream['stream_type']][$PackedElementaryStream['stream_id']][] = $PackedElementaryStream;
    381. 

  381. */
    382. 

  382. 					$getid3_temp = new getID3();
    383. 

  383. 					$getid3_temp->openfile($this->getid3->filename);
    384. 

  384. 					$getid3_temp->info = $info;
    385. 

  385. 					$getid3_mp3 = new getid3_mp3($getid3_temp);
    386. 

  386. 					for ($i = 0; $i <= 7; $i++) {
    387. 

  387. 						// some files have the MPEG-audio header 8 bytes after the end of the $00 $00 $01 $C0 signature, some have it up to 13 bytes (or more?) after
    388. 

  388. 						// I have no idea why or what the difference is, so this is a stupid hack.
    389. 

  389. 						// If anybody has any better idea of what's going on, please let me know - info@getid3.org
    390. 

  390. 						$getid3_temp->info = $info; // only overwrite real data if valid header found
    391. 

  391. //echo 'audio at? '.($MPEGstreamBaseOffset + $StartCodeOffset + 4 + 8 + $i).'<br>';
    392. 

  392. 						if ($getid3_mp3->decodeMPEGaudioHeader($MPEGstreamBaseOffset + $StartCodeOffset + 4 + 8 + $i, $getid3_temp->info, false)) {
    393. 

  393. //echo 'yes!<br>';
    394. 

  394. 							$info = $getid3_temp->info;
    395. 

  395. 							$info['audio']['bitrate_mode'] = 'cbr';
    396. 

  396. 							$info['audio']['lossless']     = false;
    397. 

  397. 							break;
    398. 

  398. 						}
    399. 

  399. 					}
    400. 

  400. 					unset($getid3_temp, $getid3_mp3);
    401. 

  401. 					break;
    402. 

  402. 

  403. 				case 0xBC: // Program Stream Map
    404. 

  404. 				case 0xBD: // Private stream 1 (non MPEG audio, subpictures)
    405. 

  405. 				case 0xBE: // Padding stream
    406. 

  406. 				case 0xBF: // Private stream 2 (navigation data)
    407. 

  407. 				case 0xF0: // ECM stream
    408. 

  408. 				case 0xF1: // EMM stream
    409. 

  409. 				case 0xF2: // DSM-CC stream
    410. 

  410. 				case 0xF3: // ISO/IEC_13522_stream
    411. 

  411. 				case 0xF4: // ITU-I Rec. H.222.1 type A
    412. 

  412. 				case 0xF5: // ITU-I Rec. H.222.1 type B
    413. 

  413. 				case 0xF6: // ITU-I Rec. H.222.1 type C
    414. 

  414. 				case 0xF7: // ITU-I Rec. H.222.1 type D
    415. 

  415. 				case 0xF8: // ITU-I Rec. H.222.1 type E
    416. 

  416. 				case 0xF9: // ancilliary stream
    417. 

  417. 				case 0xFA: // ISO/IEC 14496-1 SL-packtized stream
    418. 

  418. 				case 0xFB: // ISO/IEC 14496-1 FlexMux stream
    419. 

  419. 				case 0xFC: // metadata stream
    420. 

  420. 				case 0xFD: // extended stream ID
    421. 

  421. 				case 0xFE: // reserved data stream
    422. 

  422. 				case 0xFF: // program stream directory
    423. 

  423. 					// ignore
    424. 

  424. 					break;
    425. 

  425. 

  426. 				default:
    427. 

  427. 					// ignore
    428. 

  428. 					break;
    429. 

  429. 			}
    430. 

  430. 		} while (true);
    431. 

  431. 

  432. 

  433. 

  434. //		// Temporary hack to account for interleaving overhead:
    435. 

  435. //		if (!empty($info['video']['bitrate']) && !empty($info['audio']['bitrate'])) {
    436. 

  436. //			$info['playtime_seconds'] = (($info['avdataend'] - $info['avdataoffset']) * 8) / ($info['video']['bitrate'] + $info['audio']['bitrate']);
    437. 

  437. //
    438. 

  438. //			// Interleaved MPEG audio/video files have a certain amount of overhead that varies
    439. 

  439. //			// by both video and audio bitrates, and not in any sensible, linear/logarithmic pattern
    440. 

  440. //			// Use interpolated lookup tables to approximately guess how much is overhead, because
    441. 

  441. //			// playtime is calculated as filesize / total-bitrate
    442. 

  442. //			$info['playtime_seconds'] *= self::systemNonOverheadPercentage($info['video']['bitrate'], $info['audio']['bitrate']);
    443. 

  443. //
    444. 

  444. //			//switch ($info['video']['bitrate']) {
    445. 

  445. //			//	case('5000000'):
    446. 

  446. //			//		$multiplier = 0.93292642112380355828048824319889;
    447. 

  447. //			//		break;
    448. 

  448. //			//	case('5500000'):
    449. 

  449. //			//		$multiplier = 0.93582895375200989965359777343219;
    450. 

  450. //			//		break;
    451. 

  451. //			//	case('6000000'):
    452. 

  452. //			//		$multiplier = 0.93796247714820932532911373859139;
    453. 

  453. //			//		break;
    454. 

  454. //			//	case('7000000'):
    455. 

  455. //			//		$multiplier = 0.9413264083635103463010117778776;
    456. 

  456. //			//		break;
    457. 

  457. //			//	default:
    458. 

  458. //			//		$multiplier = 1;
    459. 

  459. //			//		break;
    460. 

  460. //			//}
    461. 

  461. //			//$info['playtime_seconds'] *= $multiplier;
    462. 

  462. //			//$info['warning'][] = 'Interleaved MPEG audio/video playtime may be inaccurate. With current hack should be within a few seconds of accurate. Report to info@getid3.org if off by more than 10 seconds.';
    463. 

  463. //			if ($info['video']['bitrate'] < 50000) {
    464. 

  464. //				$this->warning('Interleaved MPEG audio/video playtime may be slightly inaccurate for video bitrates below 100kbps. Except in extreme low-bitrate situations, error should be less than 1%. Report to info@getid3.org if greater than this.');
    465. 

  465. //			}
    466. 

  466. //		}
    467. 

  467. //
    468. 

  468. /*
    469. 

  469. $time_prev = 0;
    470. 

  470. $byte_prev = 0;
    471. 

  471. $vbr_bitrates = array();
    472. 

  472. foreach ($info['mpeg']['group_of_pictures'] as $gopkey => $gopdata) {
    473. 

  473. 	$time_this = ($gopdata['time_code_hours'] * 3600) + ($gopdata['time_code_minutes'] * 60) + $gopdata['time_code_seconds'] + ($gopdata['time_code_seconds'] / 30);
    474. 

  474. 	$byte_this = $gopdata['byte_offset'];
    475. 

  475. 	if ($gopkey > 0) {
    476. 

  476. 		if ($time_this > $time_prev) {
    477. 

  477. 			$bytedelta = $byte_this - $byte_prev;
    478. 

  478. 			$timedelta = $time_this - $time_prev;
    479. 

  479. 			$this_bitrate = ($bytedelta * 8) / $timedelta;
    480. 

  480. echo $gopkey.': ('.number_format($time_prev, 2).'-'.number_format($time_this, 2).') '.number_format($bytedelta).' bytes over '.number_format($timedelta, 3).' seconds = '.number_format($this_bitrate / 1000, 2).'kbps<br>';
    481. 

  481. 			$time_prev = $time_this;
    482. 

  482. 			$byte_prev = $byte_this;
    483. 

  483. 			$vbr_bitrates[] = $this_bitrate;
    484. 

  484. 		}
    485. 

  485. 	}
    486. 

  486. }
    487. 

  487. echo 'average_File_bitrate = '.number_format(array_sum($vbr_bitrates) / count($vbr_bitrates), 1).'<br>';
    488. 

  488. */
    489. 

  489. //echo '<pre>'.print_r($FramesByGOP, true).'</pre>';
    490. 

  490. 		if (!empty($info['mpeg']['video']['bitrate_mode']) && ($info['mpeg']['video']['bitrate_mode'] == 'vbr')) {
    491. 

  491. 			$last_GOP_id = max(array_keys($FramesByGOP));
    492. 

  492. 			$frames_in_last_GOP = count($FramesByGOP[$last_GOP_id]);
    493. 

  493. 			$gopdata = &$info['mpeg']['group_of_pictures'][$last_GOP_id];
    494. 

  494. 			$info['playtime_seconds'] = ($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']);
    495. 

  495. 			if (!isset($info['video']['bitrate'])) {
    496. 

  496. 				$overall_bitrate = ($info['avdataend'] - $info['avdataoffset']) * 8 / $info['playtime_seconds'];
    497. 

  497. 				$info['video']['bitrate'] = $overall_bitrate - (isset($info['audio']['bitrate']) ? $info['audio']['bitrate'] : 0);
    498. 

  498. 			}
    499. 

  499. 			unset($info['mpeg']['group_of_pictures']);
    500. 

  500. 		}
    501. 

  501. 

  502. 		return true;
    503. 

  503. 	}
    504. 

  504. 

  505. 	private function readBitsFromStream(&$bitstream, &$bitstreamoffset, $bits_to_read, $return_singlebit_as_boolean=true) {
    506. 

  506. 		$return = bindec(substr($bitstream, $bitstreamoffset, $bits_to_read));
    507. 

  507. 		$bitstreamoffset += $bits_to_read;
    508. 

  508. 		if (($bits_to_read == 1) && $return_singlebit_as_boolean) {
    509. 

  509. 			$return = (bool) $return;
    510. 

  510. 		}
    511. 

  511. 		return $return;
    512. 

  512. 	}
    513. 

  513. 

  514. 

  515. 	public static function systemNonOverheadPercentage($VideoBitrate, $AudioBitrate) {
    516. 

  516. 		$OverheadPercentage = 0;
    517. 

  517. 

  518. 		$AudioBitrate = max(min($AudioBitrate / 1000,   384), 32); // limit to range of 32kbps - 384kbps (should be only legal bitrates, but maybe VBR?)
    519. 

  519. 		$VideoBitrate = max(min($VideoBitrate / 1000, 10000), 10); // limit to range of 10kbps -  10Mbps (beyond that curves flatten anyways, no big loss)
    520. 

  520. 

  521. 

  522. 		//OMBB[audiobitrate]              = array(video-10kbps,       video-100kbps,      video-1000kbps,     video-10000kbps)
    523. 

  523. 		$OverheadMultiplierByBitrate[32]  = array(0, 0.9676287944368530, 0.9802276264360310, 0.9844916183244460, 0.9852821845179940);
    524. 

  524. 		$OverheadMultiplierByBitrate[48]  = array(0, 0.9779100089209830, 0.9787770035359320, 0.9846738664076130, 0.9852683013799960);
    525. 

  525. 		$OverheadMultiplierByBitrate[56]  = array(0, 0.9731249855367600, 0.9776624308938040, 0.9832606361852130, 0.9843922606633340);
    526. 

  526. 		$OverheadMultiplierByBitrate[64]  = array(0, 0.9755642683275760, 0.9795256705493390, 0.9836573009193170, 0.9851122539404470);
    527. 

  527. 		$OverheadMultiplierByBitrate[96]  = array(0, 0.9788025247497290, 0.9798553314148700, 0.9822956869792560, 0.9834815119124690);
    528. 

  528. 		$OverheadMultiplierByBitrate[128] = array(0, 0.9816940050925480, 0.9821675936072120, 0.9829756927470870, 0.9839763420152050);
    529. 

  529. 		$OverheadMultiplierByBitrate[160] = array(0, 0.9825894094561180, 0.9820913399073960, 0.9823907143253970, 0.9832821783651570);
    530. 

  530. 		$OverheadMultiplierByBitrate[192] = array(0, 0.9832038474336260, 0.9825731694317960, 0.9821028622712400, 0.9828262076447620);
    531. 

  531. 		$OverheadMultiplierByBitrate[224] = array(0, 0.9836516298538770, 0.9824718601823890, 0.9818302180625380, 0.9823735101626480);
    532. 

  532. 		$OverheadMultiplierByBitrate[256] = array(0, 0.9845863022094920, 0.9837229411967540, 0.9824521662210830, 0.9828645172100790);
    533. 

  533. 		$OverheadMultiplierByBitrate[320] = array(0, 0.9849565280263180, 0.9837683142805110, 0.9822885275960400, 0.9824424382727190);
    534. 

  534. 		$OverheadMultiplierByBitrate[384] = array(0, 0.9856094774357600, 0.9844573394432720, 0.9825970399837330, 0.9824673808303890);
    535. 

  535. 

  536. 		$BitrateToUseMin = 32;
    537. 

  537. 		$BitrateToUseMax = 32;
    538. 

  538. 		$previousBitrate = 32;
    539. 

  539. 		foreach ($OverheadMultiplierByBitrate as $key => $value) {
    540. 

  540. 			if ($AudioBitrate >= $previousBitrate) {
    541. 

  541. 				$BitrateToUseMin = $previousBitrate;
    542. 

  542. 			}
    543. 

  543. 			if ($AudioBitrate < $key) {
    544. 

  544. 				$BitrateToUseMax = $key;
    545. 

  545. 				break;
    546. 

  546. 			}
    547. 

  547. 			$previousBitrate = $key;
    548. 

  548. 		}
    549. 

  549. 		$FactorA = ($BitrateToUseMax - $AudioBitrate) / ($BitrateToUseMax - $BitrateToUseMin);
    550. 

  550. 

  551. 		$VideoBitrateLog10 = log10($VideoBitrate);
    552. 

  552. 		$VideoFactorMin1 = $OverheadMultiplierByBitrate[$BitrateToUseMin][floor($VideoBitrateLog10)];
    553. 

  553. 		$VideoFactorMin2 = $OverheadMultiplierByBitrate[$BitrateToUseMax][floor($VideoBitrateLog10)];
    554. 

  554. 		$VideoFactorMax1 = $OverheadMultiplierByBitrate[$BitrateToUseMin][ceil($VideoBitrateLog10)];
    555. 

  555. 		$VideoFactorMax2 = $OverheadMultiplierByBitrate[$BitrateToUseMax][ceil($VideoBitrateLog10)];
    556. 

  556. 		$FactorV = $VideoBitrateLog10 - floor($VideoBitrateLog10);
    557. 

  557. 

  558. 		$OverheadPercentage  = $VideoFactorMin1 *      $FactorA  *      $FactorV;
    559. 

  559. 		$OverheadPercentage += $VideoFactorMin2 * (1 - $FactorA) *      $FactorV;
    560. 

  560. 		$OverheadPercentage += $VideoFactorMax1 *      $FactorA  * (1 - $FactorV);
    561. 

  561. 		$OverheadPercentage += $VideoFactorMax2 * (1 - $FactorA) * (1 - $FactorV);
    562. 

  562. 

  563. 		return $OverheadPercentage;
    564. 

  564. 	}
    565. 

  565. 

  566. 

  567. 	public static function videoFramerateLookup($rawframerate) {
    568. 

  568. 		$lookup = array(0, 23.976, 24, 25, 29.97, 30, 50, 59.94, 60);
    569. 

  569. 		return (isset($lookup[$rawframerate]) ? (float) $lookup[$rawframerate] : (float) 0);
    570. 

  570. 	}
    571. 

  571. 

  572. 	public static function videoAspectRatioLookup($rawaspectratio) {
    573. 

  573. 		$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);
    574. 

  574. 		return (isset($lookup[$rawaspectratio]) ? (float) $lookup[$rawaspectratio] : (float) 0);
    575. 

  575. 	}
    576. 

  576. 

  577. 	public static function videoAspectRatioTextLookup($rawaspectratio) {
    578. 

  578. 		$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');
    579. 

  579. 		return (isset($lookup[$rawaspectratio]) ? $lookup[$rawaspectratio] : '');
    580. 

  580. 	}
    581. 

  581. 

  582. 	public static function videoFormatTextLookup($video_format) {
    583. 

  583. 		// ISO/IEC 13818-2, section 6.3.6, Table 6-6. Meaning of video_format
    584. 

  584. 		$lookup = array('component', 'PAL', 'NTSC', 'SECAM', 'MAC', 'Unspecified video format', 'reserved(6)', 'reserved(7)');
    585. 

  585. 		return (isset($lookup[$video_format]) ? $lookup[$video_format] : '');
    586. 

  586. 	}
    587. 

  587. 

  588. 	public static function scalableModeTextLookup($scalable_mode) {
    589. 

  589. 		// ISO/IEC 13818-2, section 6.3.8, Table 6-10. Definition of scalable_mode
    590. 

  590. 		$lookup = array('data partitioning', 'spatial scalability', 'SNR scalability', 'temporal scalability');
    591. 

  591. 		return (isset($lookup[$scalable_mode]) ? $lookup[$scalable_mode] : '');
    592. 

  592. 	}
    593. 

  593. 

  594. 	public static function pictureStructureTextLookup($picture_structure) {
    595. 

  595. 		// ISO/IEC 13818-2, section 6.3.11, Table 6-14 Meaning of picture_structure
    596. 

  596. 		$lookup = array('reserved', 'Top Field', 'Bottom Field', 'Frame picture');
    597. 

  597. 		return (isset($lookup[$picture_structure]) ? $lookup[$picture_structure] : '');
    598. 

  598. 	}
    599. 

  599. 

  600. 	public static function chromaFormatTextLookup($chroma_format) {
    601. 

  601. 		// ISO/IEC 13818-2, section 6.3.11, Table 6-14 Meaning of picture_structure
    602. 

  602. 		$lookup = array('reserved', '4:2:0', '4:2:2', '4:4:4');
    603. 

  603. 		return (isset($lookup[$chroma_format]) ? $lookup[$chroma_format] : '');
    604. 

  604. 	}
    605. 

  605. 

  606. }
    607.