ILIAS  release_5-4 Revision v5.4.26-12-gabc799a52e6
Public Member Functions | Static Public Member Functions | Data Fields | Private Member Functions
getid3_mpeg Class Reference
+ Inheritance diagram for getid3_mpeg:
+ Collaboration diagram for getid3_mpeg:

Public Member Functions

 Analyze ()
 
- Public Member Functions inherited from getid3_handler
 __construct (getID3 $getid3, $call_module=null)
 
 Analyze ()
 
 AnalyzeString ($string)
 
 setStringMode ($string)
 
 saveAttachment ($name, $offset, $length, $image_mime=null)
 

Static Public Member Functions

static systemNonOverheadPercentage ($VideoBitrate, $AudioBitrate)
 
static videoFramerateLookup ($rawframerate)
 
static videoAspectRatioLookup ($rawaspectratio)
 
static videoAspectRatioTextLookup ($rawaspectratio)
 
static videoFormatTextLookup ($video_format)
 
static scalableModeTextLookup ($scalable_mode)
 
static pictureStructureTextLookup ($picture_structure)
 
static chromaFormatTextLookup ($chroma_format)
 

Data Fields

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"
 

Private Member Functions

 readBitsFromStream (&$bitstream, &$bitstreamoffset, $bits_to_read, $return_singlebit_as_boolean=true)
 

Additional Inherited Members

- Protected Member Functions inherited from getid3_handler
 ftell ()
 
 fread ($bytes)
 
 fseek ($bytes, $whence=SEEK_SET)
 
 feof ()
 
 isDependencyFor ($module)
 
 error ($text)
 
 warning ($text)
 
 notice ($text)
 
- Protected Attributes inherited from getid3_handler
 $getid3
 
 $data_string_flag = false
 
 $data_string = ''
 
 $data_string_position = 0
 
 $data_string_length = 0
 

Detailed Description

Definition at line 19 of file module.audio-video.mpeg.php.

Member Function Documentation

◆ Analyze()

getid3_mpeg::Analyze ( )

Definition at line 32 of file module.audio-video.mpeg.php.

References $i, $info, getid3_lib\BigEndian2Bin(), getid3_handler\fread(), getid3_handler\fseek(), and getid3_handler\warning().

32  {
33  $info = &$this->getid3->info;
34 
35  $info['fileformat'] = 'mpeg';
36  $this->fseek($info['avdataoffset']);
37 
38  $MPEGstreamData = $this->fread($this->getid3->option_fread_buffer_size);
39  $MPEGstreamBaseOffset = 0; // how far are we from the beginning of the file data ($info['avdataoffset'])
40  $MPEGstreamDataOffset = 0; // how far are we from the beginning of the buffer data (~32kB)
41 
42  $StartCodeValue = false;
43  $prevStartCodeValue = false;
44 
45  $GOPcounter = -1;
46  $FramesByGOP = array();
47  $ParsedAVchannels = array();
48 
49  do {
50 //echo $MPEGstreamDataOffset.' vs '.(strlen($MPEGstreamData) - 1024).'<Br>';
51  if ($MPEGstreamDataOffset > (strlen($MPEGstreamData) - 16384)) {
52  // buffer running low, get more data
53 //echo 'reading more data<br>';
54  $MPEGstreamData .= $this->fread($this->getid3->option_fread_buffer_size);
55  if (strlen($MPEGstreamData) > $this->getid3->option_fread_buffer_size) {
56  $MPEGstreamData = substr($MPEGstreamData, $MPEGstreamDataOffset);
57  $MPEGstreamBaseOffset += $MPEGstreamDataOffset;
58  $MPEGstreamDataOffset = 0;
59  }
60  }
61  if (($StartCodeOffset = strpos($MPEGstreamData, self::START_CODE_BASE, $MPEGstreamDataOffset)) === false) {
62 //echo 'no more start codes found.<br>';
63  break;
64  } else {
65  $MPEGstreamDataOffset = $StartCodeOffset;
66  $prevStartCodeValue = $StartCodeValue;
67  $StartCodeValue = ord(substr($MPEGstreamData, $StartCodeOffset + 3, 1));
68 //echo 'Found "'.strtoupper(dechex($StartCodeValue)).'" at offset '.($MPEGstreamBaseOffset + $StartCodeOffset).' ($MPEGstreamDataOffset = '.$MPEGstreamDataOffset.')<br>';
69  }
70  $MPEGstreamDataOffset += 4;
71  switch ($StartCodeValue) {
72 
73  case 0x00: // picture_start_code
74  if (!empty($info['mpeg']['video']['bitrate_mode']) && ($info['mpeg']['video']['bitrate_mode'] == 'vbr')) {
75  $bitstream = getid3_lib::BigEndian2Bin(substr($MPEGstreamData, $StartCodeOffset + 4, 4));
76  $bitstreamoffset = 0;
77 
78  $PictureHeader = array();
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  $PictureHeader['picture_coding_type'] = self::readBitsFromStream($bitstream, $bitstreamoffset, 3); // 3 bits for picture_coding_type
82  $PictureHeader['vbv_delay'] = self::readBitsFromStream($bitstream, $bitstreamoffset, 16); // 16 bits for vbv_delay
83  //... etc
84 
85  $FramesByGOP[$GOPcounter][] = $PictureHeader;
86  }
87  break;
88 
89  case 0xB3: // sequence_header_code
90  /*
91  Note: purposely doing the less-pretty (and probably a bit slower) method of using string of bits rather than bitwise operations.
92  Mostly because PHP 32-bit doesn't handle unsigned integers well for bitwise operation.
93  Also the MPEG stream is designed as a bitstream and often doesn't align nicely with byte boundaries.
94  */
95  $info['video']['codec'] = 'MPEG-1'; // will be updated if extension_start_code found
96 
97  $bitstream = getid3_lib::BigEndian2Bin(substr($MPEGstreamData, $StartCodeOffset + 4, 8));
98  $bitstreamoffset = 0;
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  $info['mpeg']['video']['raw']['vertical_size_value'] = self::readBitsFromStream($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  $info['mpeg']['video']['raw']['aspect_ratio_information'] = self::readBitsFromStream($bitstream, $bitstreamoffset, 4); // 4 bits for aspect_ratio_information
103  $info['mpeg']['video']['raw']['frame_rate_code'] = self::readBitsFromStream($bitstream, $bitstreamoffset, 4); // 4 bits for Frame Rate id code
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  $marker_bit = self::readBitsFromStream($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  $info['mpeg']['video']['raw']['vbv_buffer_size'] = self::readBitsFromStream($bitstream, $bitstreamoffset, 10); // 10 bits vbv_buffer_size_value
107  $info['mpeg']['video']['raw']['constrained_param_flag'] = self::readBitsFromStream($bitstream, $bitstreamoffset, 1); // 1 bit flag: constrained_param_flag
108  $info['mpeg']['video']['raw']['load_intra_quantiser_matrix'] = self::readBitsFromStream($bitstream, $bitstreamoffset, 1); // 1 bit flag: load_intra_quantiser_matrix
109 
110  if ($info['mpeg']['video']['raw']['load_intra_quantiser_matrix']) {
111  $bitstream .= getid3_lib::BigEndian2Bin(substr($MPEGstreamData, $StartCodeOffset + 12, 64));
112  for ($i = 0; $i < 64; $i++) {
113  $info['mpeg']['video']['raw']['intra_quantiser_matrix'][$i] = self::readBitsFromStream($bitstream, $bitstreamoffset, 8);
114  }
115  }
116  $info['mpeg']['video']['raw']['load_non_intra_quantiser_matrix'] = self::readBitsFromStream($bitstream, $bitstreamoffset, 1);
117 
118  if ($info['mpeg']['video']['raw']['load_non_intra_quantiser_matrix']) {
119  $bitstream .= getid3_lib::BigEndian2Bin(substr($MPEGstreamData, $StartCodeOffset + 12 + ($info['mpeg']['video']['raw']['load_intra_quantiser_matrix'] ? 64 : 0), 64));
120  for ($i = 0; $i < 64; $i++) {
121  $info['mpeg']['video']['raw']['non_intra_quantiser_matrix'][$i] = self::readBitsFromStream($bitstream, $bitstreamoffset, 8);
122  }
123  }
124 
125  $info['mpeg']['video']['pixel_aspect_ratio'] = self::videoAspectRatioLookup($info['mpeg']['video']['raw']['aspect_ratio_information']);
126  $info['mpeg']['video']['pixel_aspect_ratio_text'] = self::videoAspectRatioTextLookup($info['mpeg']['video']['raw']['aspect_ratio_information']);
127  $info['mpeg']['video']['frame_rate'] = self::videoFramerateLookup($info['mpeg']['video']['raw']['frame_rate_code']);
128  if ($info['mpeg']['video']['raw']['bitrate'] == 0x3FFFF) { // 18 set bits = VBR
129  //$this->warning('This version of getID3() ['.$this->getid3->version().'] cannot determine average bitrate of VBR MPEG video files');
130  $info['mpeg']['video']['bitrate_mode'] = 'vbr';
131  } else {
132  $info['mpeg']['video']['bitrate'] = $info['mpeg']['video']['raw']['bitrate'] * 400;
133  $info['mpeg']['video']['bitrate_mode'] = 'cbr';
134  $info['video']['bitrate'] = $info['mpeg']['video']['bitrate'];
135  }
136  $info['video']['resolution_x'] = $info['mpeg']['video']['raw']['horizontal_size_value'];
137  $info['video']['resolution_y'] = $info['mpeg']['video']['raw']['vertical_size_value'];
138  $info['video']['frame_rate'] = $info['mpeg']['video']['frame_rate'];
139  $info['video']['bitrate_mode'] = $info['mpeg']['video']['bitrate_mode'];
140  $info['video']['pixel_aspect_ratio'] = $info['mpeg']['video']['pixel_aspect_ratio'];
141  $info['video']['lossless'] = false;
142  $info['video']['bits_per_sample'] = 24;
143  break;
144 
145  case 0xB5: // extension_start_code
146  $info['video']['codec'] = 'MPEG-2';
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  $bitstreamoffset = 0;
150 
151  $info['mpeg']['video']['raw']['extension_start_code_identifier'] = self::readBitsFromStream($bitstream, $bitstreamoffset, 4); // 4 bits for extension_start_code_identifier
152 //echo $info['mpeg']['video']['raw']['extension_start_code_identifier'].'<br>';
153  switch ($info['mpeg']['video']['raw']['extension_start_code_identifier']) {
154  case 1: // 0001 Sequence Extension ID
155  $info['mpeg']['video']['raw']['profile_and_level_indication'] = self::readBitsFromStream($bitstream, $bitstreamoffset, 8); // 8 bits for profile_and_level_indication
156  $info['mpeg']['video']['raw']['progressive_sequence'] = self::readBitsFromStream($bitstream, $bitstreamoffset, 1); // 1 bit flag: progressive_sequence
157  $info['mpeg']['video']['raw']['chroma_format'] = self::readBitsFromStream($bitstream, $bitstreamoffset, 2); // 2 bits for chroma_format
158  $info['mpeg']['video']['raw']['horizontal_size_extension'] = self::readBitsFromStream($bitstream, $bitstreamoffset, 2); // 2 bits for horizontal_size_extension
159  $info['mpeg']['video']['raw']['vertical_size_extension'] = self::readBitsFromStream($bitstream, $bitstreamoffset, 2); // 2 bits for vertical_size_extension
160  $info['mpeg']['video']['raw']['bit_rate_extension'] = self::readBitsFromStream($bitstream, $bitstreamoffset, 12); // 12 bits for bit_rate_extension
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  $info['mpeg']['video']['raw']['vbv_buffer_size_extension'] = self::readBitsFromStream($bitstream, $bitstreamoffset, 8); // 8 bits for vbv_buffer_size_extension
163  $info['mpeg']['video']['raw']['low_delay'] = self::readBitsFromStream($bitstream, $bitstreamoffset, 1); // 1 bit flag: low_delay
164  $info['mpeg']['video']['raw']['frame_rate_extension_n'] = self::readBitsFromStream($bitstream, $bitstreamoffset, 2); // 2 bits for frame_rate_extension_n
165  $info['mpeg']['video']['raw']['frame_rate_extension_d'] = self::readBitsFromStream($bitstream, $bitstreamoffset, 5); // 5 bits for frame_rate_extension_d
166 
167  $info['video']['resolution_x'] = ($info['mpeg']['video']['raw']['horizontal_size_extension'] << 12) | $info['mpeg']['video']['raw']['horizontal_size_value'];
168  $info['video']['resolution_y'] = ($info['mpeg']['video']['raw']['vertical_size_extension'] << 12) | $info['mpeg']['video']['raw']['vertical_size_value'];
169  $info['video']['interlaced'] = !$info['mpeg']['video']['raw']['progressive_sequence'];
170  $info['mpeg']['video']['interlaced'] = !$info['mpeg']['video']['raw']['progressive_sequence'];
171  $info['mpeg']['video']['chroma_format'] = self::chromaFormatTextLookup($info['mpeg']['video']['raw']['chroma_format']);
172  break;
173 
174  case 2: // 0010 Sequence Display Extension ID
175  $info['mpeg']['video']['raw']['video_format'] = self::readBitsFromStream($bitstream, $bitstreamoffset, 3); // 3 bits for video_format
176  $info['mpeg']['video']['raw']['colour_description'] = self::readBitsFromStream($bitstream, $bitstreamoffset, 1); // 1 bit flag: colour_description
177  if ($info['mpeg']['video']['raw']['colour_description']) {
178  $info['mpeg']['video']['raw']['colour_primaries'] = self::readBitsFromStream($bitstream, $bitstreamoffset, 8); // 8 bits for colour_primaries
179  $info['mpeg']['video']['raw']['transfer_characteristics'] = self::readBitsFromStream($bitstream, $bitstreamoffset, 8); // 8 bits for transfer_characteristics
180  $info['mpeg']['video']['raw']['matrix_coefficients'] = self::readBitsFromStream($bitstream, $bitstreamoffset, 8); // 8 bits for matrix_coefficients
181  }
182  $info['mpeg']['video']['raw']['display_horizontal_size'] = self::readBitsFromStream($bitstream, $bitstreamoffset, 14); // 14 bits for display_horizontal_size
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  $info['mpeg']['video']['raw']['display_vertical_size'] = self::readBitsFromStream($bitstream, $bitstreamoffset, 14); // 14 bits for display_vertical_size
185 
186  $info['mpeg']['video']['video_format'] = self::videoFormatTextLookup($info['mpeg']['video']['raw']['video_format']);
187  break;
188 
189  case 3: // 0011 Quant Matrix Extension ID
190  break;
191 
192  case 5: // 0101 Sequence Scalable Extension ID
193  $info['mpeg']['video']['raw']['scalable_mode'] = self::readBitsFromStream($bitstream, $bitstreamoffset, 2); // 2 bits for scalable_mode
194  $info['mpeg']['video']['raw']['layer_id'] = self::readBitsFromStream($bitstream, $bitstreamoffset, 4); // 4 bits for layer_id
195  if ($info['mpeg']['video']['raw']['scalable_mode'] == 1) { // "spatial scalability"
196  $info['mpeg']['video']['raw']['lower_layer_prediction_horizontal_size'] = self::readBitsFromStream($bitstream, $bitstreamoffset, 14); // 14 bits for lower_layer_prediction_horizontal_size
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  $info['mpeg']['video']['raw']['lower_layer_prediction_vertical_size'] = self::readBitsFromStream($bitstream, $bitstreamoffset, 14); // 14 bits for lower_layer_prediction_vertical_size
199  $info['mpeg']['video']['raw']['horizontal_subsampling_factor_m'] = self::readBitsFromStream($bitstream, $bitstreamoffset, 5); // 5 bits for horizontal_subsampling_factor_m
200  $info['mpeg']['video']['raw']['horizontal_subsampling_factor_n'] = self::readBitsFromStream($bitstream, $bitstreamoffset, 5); // 5 bits for horizontal_subsampling_factor_n
201  $info['mpeg']['video']['raw']['vertical_subsampling_factor_m'] = self::readBitsFromStream($bitstream, $bitstreamoffset, 5); // 5 bits for vertical_subsampling_factor_m
202  $info['mpeg']['video']['raw']['vertical_subsampling_factor_n'] = self::readBitsFromStream($bitstream, $bitstreamoffset, 5); // 5 bits for vertical_subsampling_factor_n
203  } elseif ($info['mpeg']['video']['raw']['scalable_mode'] == 3) { // "temporal scalability"
204  $info['mpeg']['video']['raw']['picture_mux_enable'] = self::readBitsFromStream($bitstream, $bitstreamoffset, 1); // 1 bit flag: picture_mux_enable
205  if ($info['mpeg']['video']['raw']['picture_mux_enable']) {
206  $info['mpeg']['video']['raw']['mux_to_progressive_sequence'] = self::readBitsFromStream($bitstream, $bitstreamoffset, 1); // 1 bit flag: mux_to_progressive_sequence
207  }
208  $info['mpeg']['video']['raw']['picture_mux_order'] = self::readBitsFromStream($bitstream, $bitstreamoffset, 3); // 3 bits for picture_mux_order
209  $info['mpeg']['video']['raw']['picture_mux_factor'] = self::readBitsFromStream($bitstream, $bitstreamoffset, 3); // 3 bits for picture_mux_factor
210  }
211 
212  $info['mpeg']['video']['scalable_mode'] = self::scalableModeTextLookup($info['mpeg']['video']['raw']['scalable_mode']);
213  break;
214 
215  case 7: // 0111 Picture Display Extension ID
216  break;
217 
218  case 8: // 1000 Picture Coding Extension ID
219  $info['mpeg']['video']['raw']['f_code_00'] = self::readBitsFromStream($bitstream, $bitstreamoffset, 4); // 4 bits for f_code[0][0] (forward horizontal)
220  $info['mpeg']['video']['raw']['f_code_01'] = self::readBitsFromStream($bitstream, $bitstreamoffset, 4); // 4 bits for f_code[0][1] (forward vertical)
221  $info['mpeg']['video']['raw']['f_code_10'] = self::readBitsFromStream($bitstream, $bitstreamoffset, 4); // 4 bits for f_code[1][0] (backward horizontal)
222  $info['mpeg']['video']['raw']['f_code_11'] = self::readBitsFromStream($bitstream, $bitstreamoffset, 4); // 4 bits for f_code[1][1] (backward vertical)
223  $info['mpeg']['video']['raw']['intra_dc_precision'] = self::readBitsFromStream($bitstream, $bitstreamoffset, 2); // 2 bits for intra_dc_precision
224  $info['mpeg']['video']['raw']['picture_structure'] = self::readBitsFromStream($bitstream, $bitstreamoffset, 2); // 2 bits for picture_structure
225  $info['mpeg']['video']['raw']['top_field_first'] = self::readBitsFromStream($bitstream, $bitstreamoffset, 1); // 1 bit flag: top_field_first
226  $info['mpeg']['video']['raw']['frame_pred_frame_dct'] = self::readBitsFromStream($bitstream, $bitstreamoffset, 1); // 1 bit flag: frame_pred_frame_dct
227  $info['mpeg']['video']['raw']['concealment_motion_vectors'] = self::readBitsFromStream($bitstream, $bitstreamoffset, 1); // 1 bit flag: concealment_motion_vectors
228  $info['mpeg']['video']['raw']['q_scale_type'] = self::readBitsFromStream($bitstream, $bitstreamoffset, 1); // 1 bit flag: q_scale_type
229  $info['mpeg']['video']['raw']['intra_vlc_format'] = self::readBitsFromStream($bitstream, $bitstreamoffset, 1); // 1 bit flag: intra_vlc_format
230  $info['mpeg']['video']['raw']['alternate_scan'] = self::readBitsFromStream($bitstream, $bitstreamoffset, 1); // 1 bit flag: alternate_scan
231  $info['mpeg']['video']['raw']['repeat_first_field'] = self::readBitsFromStream($bitstream, $bitstreamoffset, 1); // 1 bit flag: repeat_first_field
232  $info['mpeg']['video']['raw']['chroma_420_type'] = self::readBitsFromStream($bitstream, $bitstreamoffset, 1); // 1 bit flag: chroma_420_type
233  $info['mpeg']['video']['raw']['progressive_frame'] = self::readBitsFromStream($bitstream, $bitstreamoffset, 1); // 1 bit flag: progressive_frame
234  $info['mpeg']['video']['raw']['composite_display_flag'] = self::readBitsFromStream($bitstream, $bitstreamoffset, 1); // 1 bit flag: composite_display_flag
235  if ($info['mpeg']['video']['raw']['composite_display_flag']) {
236  $info['mpeg']['video']['raw']['v_axis'] = self::readBitsFromStream($bitstream, $bitstreamoffset, 1); // 1 bit flag: v_axis
237  $info['mpeg']['video']['raw']['field_sequence'] = self::readBitsFromStream($bitstream, $bitstreamoffset, 3); // 3 bits for field_sequence
238  $info['mpeg']['video']['raw']['sub_carrier'] = self::readBitsFromStream($bitstream, $bitstreamoffset, 1); // 1 bit flag: sub_carrier
239  $info['mpeg']['video']['raw']['burst_amplitude'] = self::readBitsFromStream($bitstream, $bitstreamoffset, 7); // 7 bits for burst_amplitude
240  $info['mpeg']['video']['raw']['sub_carrier_phase'] = self::readBitsFromStream($bitstream, $bitstreamoffset, 8); // 8 bits for sub_carrier_phase
241  }
242 
243  $info['mpeg']['video']['intra_dc_precision_bits'] = $info['mpeg']['video']['raw']['intra_dc_precision'] + 8;
244  $info['mpeg']['video']['picture_structure'] = self::pictureStructureTextLookup($info['mpeg']['video']['raw']['picture_structure']);
245  break;
246 
247  case 9: // 1001 Picture Spatial Scalable Extension ID
248  break;
249  case 10: // 1010 Picture Temporal Scalable Extension ID
250  break;
251 
252  default:
253  $this->warning('Unexpected $info[mpeg][video][raw][extension_start_code_identifier] value of '.$info['mpeg']['video']['raw']['extension_start_code_identifier']);
254  break;
255  }
256  break;
257 
258 
259  case 0xB8: // group_of_pictures_header
260  $GOPcounter++;
261  if ($info['mpeg']['video']['bitrate_mode'] == 'vbr') {
262  $bitstream = getid3_lib::BigEndian2Bin(substr($MPEGstreamData, $StartCodeOffset + 4, 4)); // 27 bits needed for group_of_pictures_header
263  $bitstreamoffset = 0;
264 
265  $GOPheader = array();
266 
267  $GOPheader['byte_offset'] = $MPEGstreamBaseOffset + $StartCodeOffset;
268  $GOPheader['drop_frame_flag'] = self::readBitsFromStream($bitstream, $bitstreamoffset, 1); // 1 bit flag: drop_frame_flag
269  $GOPheader['time_code_hours'] = self::readBitsFromStream($bitstream, $bitstreamoffset, 5); // 5 bits for time_code_hours
270  $GOPheader['time_code_minutes'] = self::readBitsFromStream($bitstream, $bitstreamoffset, 6); // 6 bits for time_code_minutes
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  $GOPheader['time_code_seconds'] = self::readBitsFromStream($bitstream, $bitstreamoffset, 6); // 6 bits for time_code_seconds
273  $GOPheader['time_code_pictures'] = self::readBitsFromStream($bitstream, $bitstreamoffset, 6); // 6 bits for time_code_pictures
274  $GOPheader['closed_gop'] = self::readBitsFromStream($bitstream, $bitstreamoffset, 1); // 1 bit flag: closed_gop
275  $GOPheader['broken_link'] = self::readBitsFromStream($bitstream, $bitstreamoffset, 1); // 1 bit flag: broken_link
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  $GOPheader['time_code'] = sprintf('%02d'.$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 
280  $info['mpeg']['group_of_pictures'][] = $GOPheader;
281  }
282  break;
283 
284  case 0xC0: // audio stream
285  case 0xC1: // audio stream
286  case 0xC2: // audio stream
287  case 0xC3: // audio stream
288  case 0xC4: // audio stream
289  case 0xC5: // audio stream
290  case 0xC6: // audio stream
291  case 0xC7: // audio stream
292  case 0xC8: // audio stream
293  case 0xC9: // audio stream
294  case 0xCA: // audio stream
295  case 0xCB: // audio stream
296  case 0xCC: // audio stream
297  case 0xCD: // audio stream
298  case 0xCE: // audio stream
299  case 0xCF: // audio stream
300  case 0xD0: // audio stream
301  case 0xD1: // audio stream
302  case 0xD2: // audio stream
303  case 0xD3: // audio stream
304  case 0xD4: // audio stream
305  case 0xD5: // audio stream
306  case 0xD6: // audio stream
307  case 0xD7: // audio stream
308  case 0xD8: // audio stream
309  case 0xD9: // audio stream
310  case 0xDA: // audio stream
311  case 0xDB: // audio stream
312  case 0xDC: // audio stream
313  case 0xDD: // audio stream
314  case 0xDE: // audio stream
315  case 0xDF: // audio stream
316  //case 0xE0: // video stream
317  //case 0xE1: // video stream
318  //case 0xE2: // video stream
319  //case 0xE3: // video stream
320  //case 0xE4: // video stream
321  //case 0xE5: // video stream
322  //case 0xE6: // video stream
323  //case 0xE7: // video stream
324  //case 0xE8: // video stream
325  //case 0xE9: // video stream
326  //case 0xEA: // video stream
327  //case 0xEB: // video stream
328  //case 0xEC: // video stream
329  //case 0xED: // video stream
330  //case 0xEE: // video stream
331  //case 0xEF: // video stream
332  if (isset($ParsedAVchannels[$StartCodeValue])) {
333  break;
334  }
335  $ParsedAVchannels[$StartCodeValue] = $StartCodeValue;
336  // http://en.wikipedia.org/wiki/Packetized_elementary_stream
337  // http://dvd.sourceforge.net/dvdinfo/pes-hdr.html
338 /*
339  $PackedElementaryStream = array();
340  if ($StartCodeValue >= 0xE0) {
341  $PackedElementaryStream['stream_type'] = 'video';
342  $PackedElementaryStream['stream_id'] = $StartCodeValue - 0xE0;
343  } else {
344  $PackedElementaryStream['stream_type'] = 'audio';
345  $PackedElementaryStream['stream_id'] = $StartCodeValue - 0xC0;
346  }
347  $PackedElementaryStream['packet_length'] = getid3_lib::BigEndian2Int(substr($MPEGstreamData, $StartCodeOffset + 4, 2));
348 
349  $bitstream = getid3_lib::BigEndian2Bin(substr($MPEGstreamData, $StartCodeOffset + 6, 3)); // more may be needed below
350  $bitstreamoffset = 0;
351 
352  $PackedElementaryStream['marker_bits'] = self::readBitsFromStream($bitstream, $bitstreamoffset, 2); // 2 bits for marker_bits -- should be "10" = 2
353 echo 'marker_bits = '.$PackedElementaryStream['marker_bits'].'<br>';
354  $PackedElementaryStream['scrambling_control'] = self::readBitsFromStream($bitstream, $bitstreamoffset, 2); // 2 bits for scrambling_control -- 00 implies not scrambled
355  $PackedElementaryStream['priority'] = self::readBitsFromStream($bitstream, $bitstreamoffset, 1); // 1 bit flag: priority
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  $PackedElementaryStream['copyright'] = self::readBitsFromStream($bitstream, $bitstreamoffset, 1); // 1 bit flag: copyright -- 1 implies copyrighted
358  $PackedElementaryStream['original_or_copy'] = self::readBitsFromStream($bitstream, $bitstreamoffset, 1); // 1 bit flag: original_or_copy -- 1 implies original
359  $PackedElementaryStream['pts_flag'] = self::readBitsFromStream($bitstream, $bitstreamoffset, 1); // 1 bit flag: pts_flag -- Presentation Time Stamp
360  $PackedElementaryStream['dts_flag'] = self::readBitsFromStream($bitstream, $bitstreamoffset, 1); // 1 bit flag: dts_flag -- Decode Time Stamp
361  $PackedElementaryStream['escr_flag'] = self::readBitsFromStream($bitstream, $bitstreamoffset, 1); // 1 bit flag: escr_flag -- Elementary Stream Clock Reference
362  $PackedElementaryStream['es_rate_flag'] = self::readBitsFromStream($bitstream, $bitstreamoffset, 1); // 1 bit flag: es_rate_flag -- Elementary Stream [data] Rate
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  $PackedElementaryStream['additional_copy_info_flag'] = self::readBitsFromStream($bitstream, $bitstreamoffset, 1); // 1 bit flag: additional_copy_info_flag
365  $PackedElementaryStream['crc_flag'] = self::readBitsFromStream($bitstream, $bitstreamoffset, 1); // 1 bit flag: crc_flag
366  $PackedElementaryStream['extension_flag'] = self::readBitsFromStream($bitstream, $bitstreamoffset, 1); // 1 bit flag: extension_flag
367  $PackedElementaryStream['pes_remain_header_length'] = self::readBitsFromStream($bitstream, $bitstreamoffset, 8); // 1 bit flag: priority
368 
369  $additional_header_bytes = 0;
370  $additional_header_bytes += ($PackedElementaryStream['pts_flag'] ? 5 : 0);
371  $additional_header_bytes += ($PackedElementaryStream['dts_flag'] ? 5 : 0);
372  $additional_header_bytes += ($PackedElementaryStream['escr_flag'] ? 6 : 0);
373  $additional_header_bytes += ($PackedElementaryStream['es_rate_flag'] ? 3 : 0);
374  $additional_header_bytes += ($PackedElementaryStream['additional_copy_info_flag'] ? 1 : 0);
375  $additional_header_bytes += ($PackedElementaryStream['crc_flag'] ? 2 : 0);
376  $additional_header_bytes += ($PackedElementaryStream['extension_flag'] ? 1 : 0);
377 $PackedElementaryStream['additional_header_bytes'] = $additional_header_bytes;
378  $bitstream .= getid3_lib::BigEndian2Bin(substr($MPEGstreamData, $StartCodeOffset + 9, $additional_header_bytes));
379 
380  $info['mpeg']['packed_elementary_streams'][$PackedElementaryStream['stream_type']][$PackedElementaryStream['stream_id']][] = $PackedElementaryStream;
381 */
382  $getid3_temp = new getID3();
383  $getid3_temp->openfile($this->getid3->filename);
384  $getid3_temp->info = $info;
385  $getid3_mp3 = new getid3_mp3($getid3_temp);
386  for ($i = 0; $i <= 7; $i++) {
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  // I have no idea why or what the difference is, so this is a stupid hack.
389  // If anybody has any better idea of what's going on, please let me know - info@getid3.org
390  $getid3_temp->info = $info; // only overwrite real data if valid header found
391 //echo 'audio at? '.($MPEGstreamBaseOffset + $StartCodeOffset + 4 + 8 + $i).'<br>';
392  if ($getid3_mp3->decodeMPEGaudioHeader($MPEGstreamBaseOffset + $StartCodeOffset + 4 + 8 + $i, $getid3_temp->info, false)) {
393 //echo 'yes!<br>';
394  $info = $getid3_temp->info;
395  $info['audio']['bitrate_mode'] = 'cbr';
396  $info['audio']['lossless'] = false;
397  break;
398  }
399  }
400  unset($getid3_temp, $getid3_mp3);
401  break;
402 
403  case 0xBC: // Program Stream Map
404  case 0xBD: // Private stream 1 (non MPEG audio, subpictures)
405  case 0xBE: // Padding stream
406  case 0xBF: // Private stream 2 (navigation data)
407  case 0xF0: // ECM stream
408  case 0xF1: // EMM stream
409  case 0xF2: // DSM-CC stream
410  case 0xF3: // ISO/IEC_13522_stream
411  case 0xF4: // ITU-I Rec. H.222.1 type A
412  case 0xF5: // ITU-I Rec. H.222.1 type B
413  case 0xF6: // ITU-I Rec. H.222.1 type C
414  case 0xF7: // ITU-I Rec. H.222.1 type D
415  case 0xF8: // ITU-I Rec. H.222.1 type E
416  case 0xF9: // ancilliary stream
417  case 0xFA: // ISO/IEC 14496-1 SL-packtized stream
418  case 0xFB: // ISO/IEC 14496-1 FlexMux stream
419  case 0xFC: // metadata stream
420  case 0xFD: // extended stream ID
421  case 0xFE: // reserved data stream
422  case 0xFF: // program stream directory
423  // ignore
424  break;
425 
426  default:
427  // ignore
428  break;
429  }
430  } while (true);
431 
432 
433 
434 // // Temporary hack to account for interleaving overhead:
435 // if (!empty($info['video']['bitrate']) && !empty($info['audio']['bitrate'])) {
436 // $info['playtime_seconds'] = (($info['avdataend'] - $info['avdataoffset']) * 8) / ($info['video']['bitrate'] + $info['audio']['bitrate']);
437 //
438 // // Interleaved MPEG audio/video files have a certain amount of overhead that varies
439 // // by both video and audio bitrates, and not in any sensible, linear/logarithmic pattern
440 // // Use interpolated lookup tables to approximately guess how much is overhead, because
441 // // playtime is calculated as filesize / total-bitrate
442 // $info['playtime_seconds'] *= self::systemNonOverheadPercentage($info['video']['bitrate'], $info['audio']['bitrate']);
443 //
444 // //switch ($info['video']['bitrate']) {
445 // // case('5000000'):
446 // // $multiplier = 0.93292642112380355828048824319889;
447 // // break;
448 // // case('5500000'):
449 // // $multiplier = 0.93582895375200989965359777343219;
450 // // break;
451 // // case('6000000'):
452 // // $multiplier = 0.93796247714820932532911373859139;
453 // // break;
454 // // case('7000000'):
455 // // $multiplier = 0.9413264083635103463010117778776;
456 // // break;
457 // // default:
458 // // $multiplier = 1;
459 // // break;
460 // //}
461 // //$info['playtime_seconds'] *= $multiplier;
462 // //$this->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 // if ($info['video']['bitrate'] < 50000) {
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 // }
466 // }
467 //
468 /*
469 $time_prev = 0;
470 $byte_prev = 0;
471 $vbr_bitrates = array();
472 foreach ($info['mpeg']['group_of_pictures'] as $gopkey => $gopdata) {
473  $time_this = ($gopdata['time_code_hours'] * 3600) + ($gopdata['time_code_minutes'] * 60) + $gopdata['time_code_seconds'] + ($gopdata['time_code_seconds'] / 30);
474  $byte_this = $gopdata['byte_offset'];
475  if ($gopkey > 0) {
476  if ($time_this > $time_prev) {
477  $bytedelta = $byte_this - $byte_prev;
478  $timedelta = $time_this - $time_prev;
479  $this_bitrate = ($bytedelta * 8) / $timedelta;
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  $time_prev = $time_this;
482  $byte_prev = $byte_this;
483  $vbr_bitrates[] = $this_bitrate;
484  }
485  }
486 }
487 echo 'average_File_bitrate = '.number_format(array_sum($vbr_bitrates) / count($vbr_bitrates), 1).'<br>';
488 */
489 //echo '<pre>'.print_r($FramesByGOP, true).'</pre>';
490  if (!empty($info['mpeg']['video']['bitrate_mode']) && ($info['mpeg']['video']['bitrate_mode'] == 'vbr')) {
491  $last_GOP_id = max(array_keys($FramesByGOP));
492  $frames_in_last_GOP = count($FramesByGOP[$last_GOP_id]);
493  $gopdata = &$info['mpeg']['group_of_pictures'][$last_GOP_id];
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) / $info['mpeg']['video']['frame_rate']);
495  if (!isset($info['video']['bitrate'])) {
496  $overall_bitrate = ($info['avdataend'] - $info['avdataoffset']) * 8 / $info['playtime_seconds'];
497  $info['video']['bitrate'] = $overall_bitrate - (isset($info['audio']['bitrate']) ? $info['audio']['bitrate'] : 0);
498  }
499  unset($info['mpeg']['group_of_pictures']);
500  }
501 
502  return true;
503  }
getid3_handler\warning
warning($text)
Definition: getid3.php:1758
getid3_lib\BigEndian2Bin
static BigEndian2Bin($byteword)
Definition: getid3.lib.php:297
getid3_handler\fread
fread($bytes)
Definition: getid3.php:1683
getid3_mp3
Definition: module.audio.mp3.php:25
$i
$i
Definition: disco.tpl.php:19
getid3_handler\fseek
fseek($bytes, $whence=SEEK_SET)
Definition: getid3.php:1711
$info
$info
Definition: index.php:5
+ Here is the call graph for this function:

◆ chromaFormatTextLookup()

static getid3_mpeg::chromaFormatTextLookup (   $chroma_format)
static

Definition at line 600 of file module.audio-video.mpeg.php.

600  {
601  // ISO/IEC 13818-2, section 6.3.11, Table 6-14 Meaning of picture_structure
602  $lookup = array('reserved', '4:2:0', '4:2:2', '4:4:4');
603  return (isset($lookup[$chroma_format]) ? $lookup[$chroma_format] : '');
604  }

◆ pictureStructureTextLookup()

static getid3_mpeg::pictureStructureTextLookup (   $picture_structure)
static

Definition at line 594 of file module.audio-video.mpeg.php.

594  {
595  // ISO/IEC 13818-2, section 6.3.11, Table 6-14 Meaning of picture_structure
596  $lookup = array('reserved', 'Top Field', 'Bottom Field', 'Frame picture');
597  return (isset($lookup[$picture_structure]) ? $lookup[$picture_structure] : '');
598  }

◆ readBitsFromStream()

getid3_mpeg::readBitsFromStream ( &  $bitstream,
&  $bitstreamoffset,
  $bits_to_read,
  $return_singlebit_as_boolean = true 
)
private

Definition at line 505 of file module.audio-video.mpeg.php.

505  {
506  $return = bindec(substr($bitstream, $bitstreamoffset, $bits_to_read));
507  $bitstreamoffset += $bits_to_read;
508  if (($bits_to_read == 1) && $return_singlebit_as_boolean) {
509  $return = (bool) $return;
510  }
511  return $return;
512  }

◆ scalableModeTextLookup()

static getid3_mpeg::scalableModeTextLookup (   $scalable_mode)
static

Definition at line 588 of file module.audio-video.mpeg.php.

588  {
589  // ISO/IEC 13818-2, section 6.3.8, Table 6-10. Definition of scalable_mode
590  $lookup = array('data partitioning', 'spatial scalability', 'SNR scalability', 'temporal scalability');
591  return (isset($lookup[$scalable_mode]) ? $lookup[$scalable_mode] : '');
592  }

◆ systemNonOverheadPercentage()

static getid3_mpeg::systemNonOverheadPercentage (   $VideoBitrate,
  $AudioBitrate 
)
static

Definition at line 515 of file module.audio-video.mpeg.php.

References $key.

515  {
516  $OverheadPercentage = 0;
517 
518  $AudioBitrate = max(min($AudioBitrate / 1000, 384), 32); // limit to range of 32kbps - 384kbps (should be only legal bitrates, but maybe VBR?)
519  $VideoBitrate = max(min($VideoBitrate / 1000, 10000), 10); // limit to range of 10kbps - 10Mbps (beyond that curves flatten anyways, no big loss)
520 
521 
522  //OMBB[audiobitrate] = array(video-10kbps, video-100kbps, video-1000kbps, video-10000kbps)
523  $OverheadMultiplierByBitrate[32] = array(0, 0.9676287944368530, 0.9802276264360310, 0.9844916183244460, 0.9852821845179940);
524  $OverheadMultiplierByBitrate[48] = array(0, 0.9779100089209830, 0.9787770035359320, 0.9846738664076130, 0.9852683013799960);
525  $OverheadMultiplierByBitrate[56] = array(0, 0.9731249855367600, 0.9776624308938040, 0.9832606361852130, 0.9843922606633340);
526  $OverheadMultiplierByBitrate[64] = array(0, 0.9755642683275760, 0.9795256705493390, 0.9836573009193170, 0.9851122539404470);
527  $OverheadMultiplierByBitrate[96] = array(0, 0.9788025247497290, 0.9798553314148700, 0.9822956869792560, 0.9834815119124690);
528  $OverheadMultiplierByBitrate[128] = array(0, 0.9816940050925480, 0.9821675936072120, 0.9829756927470870, 0.9839763420152050);
529  $OverheadMultiplierByBitrate[160] = array(0, 0.9825894094561180, 0.9820913399073960, 0.9823907143253970, 0.9832821783651570);
530  $OverheadMultiplierByBitrate[192] = array(0, 0.9832038474336260, 0.9825731694317960, 0.9821028622712400, 0.9828262076447620);
531  $OverheadMultiplierByBitrate[224] = array(0, 0.9836516298538770, 0.9824718601823890, 0.9818302180625380, 0.9823735101626480);
532  $OverheadMultiplierByBitrate[256] = array(0, 0.9845863022094920, 0.9837229411967540, 0.9824521662210830, 0.9828645172100790);
533  $OverheadMultiplierByBitrate[320] = array(0, 0.9849565280263180, 0.9837683142805110, 0.9822885275960400, 0.9824424382727190);
534  $OverheadMultiplierByBitrate[384] = array(0, 0.9856094774357600, 0.9844573394432720, 0.9825970399837330, 0.9824673808303890);
535 
536  $BitrateToUseMin = 32;
537  $BitrateToUseMax = 32;
538  $previousBitrate = 32;
539  foreach ($OverheadMultiplierByBitrate as $key => $value) {
540  if ($AudioBitrate >= $previousBitrate) {
541  $BitrateToUseMin = $previousBitrate;
542  }
543  if ($AudioBitrate < $key) {
544  $BitrateToUseMax = $key;
545  break;
546  }
547  $previousBitrate = $key;
548  }
549  $FactorA = ($BitrateToUseMax - $AudioBitrate) / ($BitrateToUseMax - $BitrateToUseMin);
550 
551  $VideoBitrateLog10 = log10($VideoBitrate);
552  $VideoFactorMin1 = $OverheadMultiplierByBitrate[$BitrateToUseMin][floor($VideoBitrateLog10)];
553  $VideoFactorMin2 = $OverheadMultiplierByBitrate[$BitrateToUseMax][floor($VideoBitrateLog10)];
554  $VideoFactorMax1 = $OverheadMultiplierByBitrate[$BitrateToUseMin][ceil($VideoBitrateLog10)];
555  $VideoFactorMax2 = $OverheadMultiplierByBitrate[$BitrateToUseMax][ceil($VideoBitrateLog10)];
556  $FactorV = $VideoBitrateLog10 - floor($VideoBitrateLog10);
557 
558  $OverheadPercentage = $VideoFactorMin1 * $FactorA * $FactorV;
559  $OverheadPercentage += $VideoFactorMin2 * (1 - $FactorA) * $FactorV;
560  $OverheadPercentage += $VideoFactorMax1 * $FactorA * (1 - $FactorV);
561  $OverheadPercentage += $VideoFactorMax2 * (1 - $FactorA) * (1 - $FactorV);
562 
563  return $OverheadPercentage;
564  }
$key
$key
Definition: croninfo.php:18

◆ videoAspectRatioLookup()

static getid3_mpeg::videoAspectRatioLookup (   $rawaspectratio)
static

Definition at line 572 of file module.audio-video.mpeg.php.

572  {
573  $lookup = array(0, 1, 0.6735, 0.7031, 0.7615, 0.8055, 0.8437, 0.8935, 0.9157, 0.9815, 1.0255, 1.0695, 1.0950, 1.1575, 1.2015, 0);
574  return (isset($lookup[$rawaspectratio]) ? (float) $lookup[$rawaspectratio] : (float) 0);
575  }

◆ videoAspectRatioTextLookup()

static getid3_mpeg::videoAspectRatioTextLookup (   $rawaspectratio)
static

Definition at line 577 of file module.audio-video.mpeg.php.

577  {
578  $lookup = array('forbidden', 'square pixels', '0.6735', '16:9, 625 line, PAL', '0.7615', '0.8055', '16:9, 525 line, NTSC', '0.8935', '4:3, 625 line, PAL, CCIR601', '0.9815', '1.0255', '1.0695', '4:3, 525 line, NTSC, CCIR601', '1.1575', '1.2015', 'reserved');
579  return (isset($lookup[$rawaspectratio]) ? $lookup[$rawaspectratio] : '');
580  }

◆ videoFormatTextLookup()

static getid3_mpeg::videoFormatTextLookup (   $video_format)
static

Definition at line 582 of file module.audio-video.mpeg.php.

582  {
583  // ISO/IEC 13818-2, section 6.3.6, Table 6-6. Meaning of video_format
584  $lookup = array('component', 'PAL', 'NTSC', 'SECAM', 'MAC', 'Unspecified video format', 'reserved(6)', 'reserved(7)');
585  return (isset($lookup[$video_format]) ? $lookup[$video_format] : '');
586  }

◆ videoFramerateLookup()

static getid3_mpeg::videoFramerateLookup (   $rawframerate)
static

Definition at line 567 of file module.audio-video.mpeg.php.

567  {
568  $lookup = array(0, 23.976, 24, 25, 29.97, 30, 50, 59.94, 60);
569  return (isset($lookup[$rawframerate]) ? (float) $lookup[$rawframerate] : (float) 0);
570  }

Field Documentation

◆ AUDIO_START

const getid3_mpeg::AUDIO_START = "\x00\x00\x01\xC0"

Definition at line 29 of file module.audio-video.mpeg.php.

◆ START_CODE_BASE

const getid3_mpeg::START_CODE_BASE = "\x00\x00\x01"

Definition at line 21 of file module.audio-video.mpeg.php.

◆ VIDEO_EXTENSION_START

const getid3_mpeg::VIDEO_EXTENSION_START = "\x00\x00\x01\xB5"

Definition at line 26 of file module.audio-video.mpeg.php.

◆ VIDEO_GROUP_START

const getid3_mpeg::VIDEO_GROUP_START = "\x00\x00\x01\xB8"

Definition at line 28 of file module.audio-video.mpeg.php.

◆ VIDEO_PICTURE_START

const getid3_mpeg::VIDEO_PICTURE_START = "\x00\x00\x01\x00"

Definition at line 22 of file module.audio-video.mpeg.php.

◆ VIDEO_SEQUENCE_END

const getid3_mpeg::VIDEO_SEQUENCE_END = "\x00\x00\x01\xB7"

Definition at line 27 of file module.audio-video.mpeg.php.

◆ VIDEO_SEQUENCE_ERROR

const getid3_mpeg::VIDEO_SEQUENCE_ERROR = "\x00\x00\x01\xB4"

Definition at line 25 of file module.audio-video.mpeg.php.

◆ VIDEO_SEQUENCE_HEADER

const getid3_mpeg::VIDEO_SEQUENCE_HEADER = "\x00\x00\x01\xB3"

Definition at line 24 of file module.audio-video.mpeg.php.

◆ VIDEO_USER_DATA_START

const getid3_mpeg::VIDEO_USER_DATA_START = "\x00\x00\x01\xB2"

Definition at line 23 of file module.audio-video.mpeg.php.

The documentation for this class was generated from the following file: