quicktime/esds.c

   1 #include "funcprotos.h"
   2 #include "quicktime.h"
   3
   4
   5 static int decode_length(quicktime_t *file)
   6 {
   7         int bytes = 0;
   8         int result = 0;
   9         int byte;
  10         do
  11         {
  12                 byte = quicktime_read_char(file);
  13                 result = (result << 7) + (byte & 0x7f);
  14                 bytes++;
  15         }while((byte & 0x80) && bytes < 4);
  16         return result;
  17 }
  18
  19
  20 void quicktime_read_esds(quicktime_t *file,
  21         quicktime_atom_t *parent_atom,
  22         quicktime_stsd_table_t *table)
  23 {
  24 // version
  25         quicktime_read_char(file);
  26 // flags
  27         quicktime_read_int24(file);
  28 // elementary stream descriptor tag
  29
  30         if(quicktime_read_char(file) == 0x3)
  31         {
  32                 int len = decode_length(file);
  33 // elementary stream id
  34                 quicktime_read_int16(file);
  35 // stream priority
  36                 quicktime_read_char(file);
  37 // decoder configuration descripton tab
  38                 if(quicktime_read_char(file) == 0x4)
  39                 {
  40                         int len2 = decode_length(file);
  41 // object type id
  42                         quicktime_read_char(file);
  43 // stream type
  44                         quicktime_read_char(file);
  45 // buffer size
  46                         quicktime_read_int24(file);
  47 // max bitrate
  48                         quicktime_read_int32(file);
  49 // average bitrate
  50                         quicktime_read_int32(file);
  51
  52 // decoder specific description tag
  53                         if(quicktime_read_char(file) == 0x5)
  54                         {
  55                                 table->mpeg4_header_size = decode_length(file);
  56                                 if(!table->mpeg4_header_size) return;
  57
  58                                 table->mpeg4_header = calloc(1, table->mpeg4_header_size);
  59 // Get mpeg4 sequence header
  60                                 quicktime_read_data(file,
  61                                         table->mpeg4_header,
  62                                         table->mpeg4_header_size);
  63 // skip rest
  64                                 quicktime_atom_skip(file, parent_atom);
  65                                 return;
  66                         }
  67                         else
  68                         {
  69 // error
  70                                 quicktime_atom_skip(file, parent_atom);
  71                                 return;
  72                         }
  73                 }
  74                 else
  75                 {
  76 // error
  77                         quicktime_atom_skip(file, parent_atom);
  78                         return;
  79                 }
  80         }
  81         else
  82         {
  83 // error
  84                 quicktime_atom_skip(file, parent_atom);
  85                 return;
  86         }
  87 }
  88
  89
  90
  91 void quicktime_write_esds(quicktime_t *file,
  92         quicktime_stsd_table_t *table,
  93         int do_video,
  94         int do_audio)
  95 {
  96         quicktime_atom_t atom;
  97         quicktime_atom_write_header(file, &atom, "esds");
  98 // version
  99         quicktime_write_char(file, 0);
 100 // flags
 101         quicktime_write_int24(file, 0);
 102
 103 // elementary stream descriptor tag
 104         quicktime_write_char(file, 0x3);
 105
 106 // length placeholder
 107         int64_t length1 = quicktime_position(file);
 108 //      quicktime_write_int32(file, 0x80808080);
 109         quicktime_write_char(file, 0x00);
 110
 111 // elementary stream id
 112         quicktime_write_int16(file, 0);
 113 // stream priority
 114         if(do_video)
 115                 quicktime_write_char(file, 0x1f);
 116         else
 117                 quicktime_write_char(file, 0);
 118
 119
 120 // decoder configuration description tab
 121         quicktime_write_char(file, 0x4);
 122 // length placeholder
 123         int64_t length2 = quicktime_position(file);
 124 //      quicktime_write_int32(file, 0x80808080);
 125         quicktime_write_char(file, 0x00);
 126
 127 // video
 128         if(do_video)
 129         {
 130 // object type id
 131                 quicktime_write_char(file, 0x20);
 132 // stream type
 133                 quicktime_write_char(file, 0x11);
 134 // buffer size
 135                 quicktime_write_int24(file, 0x007b00);
 136 // max bitrate
 137                 quicktime_write_int32(file, 0x00014800);
 138 // average bitrate
 139                 quicktime_write_int32(file, 0x00014800);
 140         }
 141         else
 142         {
 143 // object type id
 144                 quicktime_write_char(file, 0x40);
 145 // stream type
 146                 quicktime_write_char(file, 0x15);
 147 // buffer size
 148                 quicktime_write_int24(file, 0x001800);
 149 // max bitrate
 150                 quicktime_write_int32(file, 0x00004e20);
 151 // average bitrate
 152                 quicktime_write_int32(file, 0x00003e80);
 153         }
 154
 155 // decoder specific description tag
 156         quicktime_write_char(file, 0x05);
 157 // length placeholder
 158         int64_t length3 = quicktime_position(file);
 159 //      quicktime_write_int32(file, 0x80808080);
 160         quicktime_write_char(file, 0x00);
 161
 162 // mpeg4 sequence header
 163         quicktime_write_data(file, table->mpeg4_header, table->mpeg4_header_size);
 164
 165
 166         int64_t current_length2 = quicktime_position(file) - length2 - 4;
 167         int64_t current_length3 = quicktime_position(file) - length3 - 4;
 168
 169 // unknown tag, length and data
 170         quicktime_write_char(file, 0x06);
 171 //      quicktime_write_int32(file, 0x80808001);
 172         quicktime_write_char(file, 0x01);
 173         quicktime_write_char(file, 0x02);
 174
 175
 176 // write lengths
 177         int64_t current_length1 = quicktime_position(file) - length1 - 4;
 178         quicktime_atom_write_footer(file, &atom);
 179         int64_t current_position = quicktime_position(file);
 180 //      quicktime_set_position(file, length1 + 3);
 181         quicktime_set_position(file, length1);
 182         quicktime_write_char(file, current_length1);
 183 //      quicktime_set_position(file, length2 + 3);
 184         quicktime_set_position(file, length2);
 185         quicktime_write_char(file, current_length2);
 186 //      quicktime_set_position(file, length3 + 3);
 187         quicktime_set_position(file, length3);
 188         quicktime_write_char(file, current_length3);
 189         quicktime_set_position(file, current_position);
 190 }
 191