libmpdemux/mpeg_hdr.c

   1 /*
   2  * based on libmpeg2/header.c by Aaron Holtzman <aholtzma@ess.engr.uvic.ca>
   3  *
   4  * This file is part of MPlayer.
   5  *
   6  * MPlayer is free software; you can redistribute it and/or modify
   7  * it under the terms of the GNU General Public License as published by
   8  * the Free Software Foundation; either version 2 of the License, or
   9  * (at your option) any later version.
  10  *
  11  * MPlayer is distributed in the hope that it will be useful,
  12  * but WITHOUT ANY WARRANTY; without even the implied warranty of
  13  * MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE.  See the
  14  * GNU General Public License for more details.
  15  *
  16  * You should have received a copy of the GNU General Public License along
  17  * with MPlayer; if not, write to the Free Software Foundation, Inc.,
  18  * 51 Franklin Street, Fifth Floor, Boston, MA 02110-1301 USA.
  19  */
  20
  21 #include <inttypes.h>
  22 #include <stdio.h>
  23 #include <stdlib.h>
  24 #include <string.h>
  25
  26 #include "config.h"
  27 #include "mpeg_hdr.h"
  28
  29 #include "mp_msg.h"
  30
  31 static float frameratecode2framerate[16] = {
  32   0,
  33   // Official mpeg1/2 framerates: (1-8)
  34   24000.0/1001, 24,25,
  35   30000.0/1001, 30,50,
  36   60000.0/1001, 60,
  37   // Xing's 15fps: (9)
  38   15,
  39   // libmpeg3's "Unofficial economy rates": (10-13)
  40   5,10,12,15,
  41   // some invalid ones: (14-15)
  42   0,0
  43 };
  44
  45
  46 int mp_header_process_sequence_header (mp_mpeg_header_t * picture, const unsigned char * buffer)
  47 {
  48     int width, height;
  49
  50     if ((buffer[6] & 0x20) != 0x20){
  51         fprintf(stderr, "missing marker bit!\n");
  52         return 1;       /* missing marker_bit */
  53     }
  54
  55     height = (buffer[0] << 16) | (buffer[1] << 8) | buffer[2];
  56
  57     picture->display_picture_width = (height >> 12);
  58     picture->display_picture_height = (height & 0xfff);
  59
  60     width = ((height >> 12) + 15) & ~15;
  61     height = ((height & 0xfff) + 15) & ~15;
  62
  63     picture->aspect_ratio_information = buffer[3] >> 4;
  64     picture->frame_rate_code = buffer[3] & 15;
  65     picture->fps=frameratecode2framerate[picture->frame_rate_code];
  66     picture->bitrate = (buffer[4]<<10)|(buffer[5]<<2)|(buffer[6]>>6);
  67     picture->mpeg1 = 1;
  68     picture->picture_structure = 3; //FRAME_PICTURE;
  69     picture->display_time=100;
  70     picture->frame_rate_extension_n = 1;
  71     picture->frame_rate_extension_d = 1;
  72     return 0;
  73 }
  74
  75 static int header_process_sequence_extension (mp_mpeg_header_t * picture,
  76                                               unsigned char * buffer)
  77 {
  78     /* check chroma format, size extensions, marker bit */
  79
  80     if ( ((buffer[1] & 0x06) == 0x00) ||
  81          ((buffer[1] & 0x01) != 0x00) || (buffer[2] & 0xe0) ||
  82          ((buffer[3] & 0x01) != 0x01) )
  83         return 1;
  84
  85     picture->progressive_sequence = (buffer[1] >> 3) & 1;
  86     picture->frame_rate_extension_n = ((buffer[5] >> 5) & 3) + 1;
  87     picture->frame_rate_extension_d = (buffer[5] & 0x1f) + 1;
  88
  89     picture->mpeg1 = 0;
  90     return 0;
  91 }
  92
  93 static int header_process_picture_coding_extension (mp_mpeg_header_t * picture, unsigned char * buffer)
  94 {
  95     picture->picture_structure = buffer[2] & 3;
  96     picture->top_field_first = buffer[3] >> 7;
  97     picture->repeat_first_field = (buffer[3] >> 1) & 1;
  98     picture->progressive_frame = buffer[4] >> 7;
  99
 100     // repeat_first implementation by A'rpi/ESP-team, based on libmpeg3:
 101     picture->display_time=100;
 102     if(picture->repeat_first_field){
 103         if(picture->progressive_sequence){
 104             if(picture->top_field_first)
 105                 picture->display_time+=200;
 106             else
 107                 picture->display_time+=100;
 108         } else
 109         if(picture->progressive_frame){
 110                 picture->display_time+=50;
 111         }
 112     }
 113     //temopral hack. We calc time on every field, so if we have 2 fields
 114     // interlaced we'll end with double time for 1 frame
 115     if( picture->picture_structure!=3 ) picture->display_time/=2;
 116     return 0;
 117 }
 118
 119 int mp_header_process_extension (mp_mpeg_header_t * picture, unsigned char * buffer)
 120 {
 121     switch (buffer[0] & 0xf0) {
 122     case 0x10:  /* sequence extension */
 123         return header_process_sequence_extension (picture, buffer);
 124     case 0x80:  /* picture coding extension */
 125         return header_process_picture_coding_extension (picture, buffer);
 126     }
 127     return 0;
 128 }
 129
 130 float mpeg12_aspect_info(mp_mpeg_header_t *picture)
 131 {
 132     float aspect = 0.0;
 133
 134     switch(picture->aspect_ratio_information) {
 135       case 2:  // PAL/NTSC SVCD/DVD 4:3
 136       case 8:  // PAL VCD 4:3
 137       case 12: // NTSC VCD 4:3
 138         aspect=4.0/3.0;
 139         break;
 140       case 3:  // PAL/NTSC Widescreen SVCD/DVD 16:9
 141       case 6:  // (PAL?)/NTSC Widescreen SVCD 16:9
 142         aspect=16.0/9.0;
 143         break;
 144       case 4:  // according to ISO-138182-2 Table 6.3
 145         aspect=2.21;
 146         break;
 147       case 1:  // VGA 1:1 - do not prescale
 148       case 9: // Movie Type ??? / 640x480
 149         aspect=0.0;
 150         break;
 151       default:
 152         mp_msg(MSGT_DECVIDEO,MSGL_ERR,"Detected unknown aspect_ratio_information in mpeg sequence header.\n"
 153                "Please report the aspect value (%i) along with the movie type (VGA,PAL,NTSC,"
 154                "SECAM) and the movie resolution (720x576,352x240,480x480,...) to the MPlayer"
 155                " developers, so that we can add support for it!\nAssuming 1:1 aspect for now.\n",
 156                picture->aspect_ratio_information);
 157     }
 158
 159     return aspect;
 160 }
 161
 162 //MPEG4 HEADERS
 163 unsigned char mp_getbits(unsigned char *buffer, unsigned int from, unsigned char len)
 164 {
 165     unsigned int n;
 166     unsigned char m, u, l, y;
 167
 168     n = from / 8;
 169     m = from % 8;
 170     u = 8 - m;
 171     l = (len > u ? len - u : 0);
 172
 173     y = (buffer[n] << m);
 174     if(8 > len)
 175         y  >>= (8-len);
 176     if(l)
 177         y |= (buffer[n+1] >> (8-l));
 178
 179     //fprintf(stderr, "GETBITS(%d -> %d): bytes=0x%x 0x%x, n=%d, m=%d, l=%d, u=%d, Y=%d\n",
 180     //  from, (int) len, (int) buffer[n],(int) buffer[n+1], n, (int) m, (int) l, (int) u, (int) y);
 181     return  y;
 182 }
 183
 184 static inline unsigned int mp_getbits16(unsigned char *buffer, unsigned int from, unsigned char len)
 185 {
 186     if(len > 8)
 187         return (mp_getbits(buffer, from, len - 8) << 8) | mp_getbits(buffer, from + len - 8, 8);
 188     else
 189         return mp_getbits(buffer, from, len);
 190 }
 191
 192 #define getbits mp_getbits
 193 #define getbits16 mp_getbits16
 194
 195 static int read_timeinc(mp_mpeg_header_t * picture, unsigned char * buffer, int n)
 196 {
 197     if(picture->timeinc_bits > 8) {
 198       picture->timeinc_unit = getbits(buffer, n, picture->timeinc_bits - 8) << 8;
 199       n += picture->timeinc_bits - 8;
 200       picture->timeinc_unit |= getbits(buffer, n, 8);
 201       n += 8;
 202     } else {
 203       picture->timeinc_unit = getbits(buffer, n, picture->timeinc_bits);
 204       n += picture->timeinc_bits;
 205     }
 206     //fprintf(stderr, "TIMEINC2: %d, bits: %d\n", picture->timeinc_unit, picture->timeinc_bits);
 207     return n;
 208 }
 209
 210 int mp4_header_process_vol(mp_mpeg_header_t * picture, unsigned char * buffer)
 211 {
 212     unsigned int n, aspect=0, aspectw=0, aspecth=0,  x=1, v;
 213
 214     //begins with 0x0000012x
 215     picture->fps = 0;
 216     picture->timeinc_bits = picture->timeinc_resolution = picture->timeinc_unit = 0;
 217     n = 9;
 218     if(getbits(buffer, n, 1))
 219       n += 7;
 220     n++;
 221     aspect=getbits(buffer, n, 4);
 222     n += 4;
 223     if(aspect == 0x0f) {
 224       aspectw = getbits(buffer, n, 8);
 225       n += 8;
 226       aspecth = getbits(buffer, n, 8);
 227       n += 8;
 228     }
 229
 230     if(getbits(buffer, n, 1)) {
 231       n += 4;
 232       if(getbits(buffer, n, 1))
 233         n += 79;
 234       n++;
 235     } else n++;
 236
 237     n+=3;
 238
 239     picture->timeinc_resolution = getbits(buffer, n, 8) << 8;
 240     n += 8;
 241     picture->timeinc_resolution |= getbits(buffer, n, 8);
 242     n += 8;
 243
 244     picture->timeinc_bits = 0;
 245     v = picture->timeinc_resolution - 1;
 246     while(v && (x<16)) {
 247       v>>=1;
 248       picture->timeinc_bits++;
 249     }
 250     picture->timeinc_bits = (picture->timeinc_bits > 1 ? picture->timeinc_bits : 1);
 251
 252     n++; //marker bit
 253
 254     if(getbits(buffer, n, 1)) { //fixed_vop_timeinc
 255       n++;
 256       n = read_timeinc(picture, buffer, n);
 257
 258       if(picture->timeinc_unit)
 259         picture->fps = (float) picture->timeinc_resolution / (float) picture->timeinc_unit;
 260     }
 261
 262     //fprintf(stderr, "ASPECT: %d, PARW=%d, PARH=%d, TIMEINCRESOLUTION: %d, FIXED_TIMEINC: %d (number of bits: %d), FPS: %u\n",
 263     //  aspect, aspectw, aspecth, picture->timeinc_resolution, picture->timeinc_unit, picture->timeinc_bits, picture->fps);
 264
 265     return 0;
 266 }
 267
 268 void mp4_header_process_vop(mp_mpeg_header_t * picture, unsigned char * buffer)
 269 {
 270   int n;
 271   n = 0;
 272   picture->picture_type = getbits(buffer, n, 2);
 273   n += 2;
 274   while(getbits(buffer, n, 1))
 275     n++;
 276   n++;
 277   getbits(buffer, n, 1);
 278   n++;
 279   n = read_timeinc(picture, buffer, n);
 280 }
 281
 282 #define min(a, b) ((a) <= (b) ? (a) : (b))
 283
 284 static unsigned int read_golomb(unsigned char *buffer, unsigned int *init)
 285 {
 286   unsigned int x, v = 0, v2 = 0, m, len = 0, n = *init;
 287
 288   while(getbits(buffer, n++, 1) == 0)
 289     len++;
 290
 291   x = len + n;
 292   while(n < x)
 293   {
 294     m = min(x - n, 8);
 295     v |= getbits(buffer, n, m);
 296     n += m;
 297     if(x - n > 8)
 298       v <<= 8;
 299   }
 300
 301   v2 = 1;
 302   for(n = 0; n < len; n++)
 303     v2 <<= 1;
 304   v2 = (v2 - 1) + v;
 305
 306   //fprintf(stderr, "READ_GOLOMB(%u), V=2^%u + %u-1 = %u\n", *init, len, v, v2);
 307   *init = x;
 308   return v2;
 309 }
 310
 311 inline static int read_golomb_s(unsigned char *buffer, unsigned int *init)
 312 {
 313   unsigned int v = read_golomb(buffer, init);
 314   return (v & 1) ? ((v + 1) >> 1) : -(v >> 1);
 315 }
 316
 317 static int h264_parse_vui(mp_mpeg_header_t * picture, unsigned char * buf, unsigned int n)
 318 {
 319   unsigned int overscan, vsp_color, chroma, timing, fixed_fps;
 320
 321   if(getbits(buf, n++, 1))
 322   {
 323     picture->aspect_ratio_information = getbits(buf, n, 8);
 324     n += 8;
 325     if(picture->aspect_ratio_information == 255)
 326     {
 327       picture->display_picture_width = (getbits(buf, n, 8) << 8) | getbits(buf, n + 8, 8);
 328       n += 16;
 329
 330       picture->display_picture_height = (getbits(buf, n, 8) << 8) | getbits(buf, n + 8, 8);
 331       n += 16;
 332     }
 333   }
 334
 335   if((overscan=getbits(buf, n++, 1)))
 336     n++;
 337   if((vsp_color=getbits(buf, n++, 1)))
 338   {
 339     n += 4;
 340     if(getbits(buf, n++, 1))
 341       n += 24;
 342   }
 343   if((chroma=getbits(buf, n++, 1)))
 344   {
 345     read_golomb(buf, &n);
 346     read_golomb(buf, &n);
 347   }
 348   if((timing=getbits(buf, n++, 1)))
 349   {
 350     picture->timeinc_unit = (getbits(buf, n, 8) << 24) | (getbits(buf, n+8, 8) << 16) | (getbits(buf, n+16, 8) << 8) | getbits(buf, n+24, 8);
 351     n += 32;
 352
 353     picture->timeinc_resolution = (getbits(buf, n, 8) << 24) | (getbits(buf, n+8, 8) << 16) | (getbits(buf, n+16, 8) << 8) | getbits(buf, n+24, 8);
 354     n += 32;
 355
 356     fixed_fps = getbits(buf, n, 1);
 357
 358     if(picture->timeinc_unit > 0 && picture->timeinc_resolution > 0)
 359       picture->fps = (float) picture->timeinc_resolution / (float) picture->timeinc_unit;
 360     if(fixed_fps)
 361       picture->fps /= 2;
 362   }
 363
 364   //fprintf(stderr, "H264_PARSE_VUI, OVESCAN=%u, VSP_COLOR=%u, CHROMA=%u, TIMING=%u, DISPW=%u, DISPH=%u, TIMERES=%u, TIMEINC=%u, FIXED_FPS=%u\n", overscan, vsp_color, chroma, timing, picture->display_picture_width, picture->display_picture_height,
 365   //    picture->timeinc_resolution, picture->timeinc_unit, picture->timeinc_unit, fixed_fps);
 366
 367   return n;
 368 }
 369
 370 static int mp_unescape03(unsigned char *buf, int len);
 371
 372 int h264_parse_sps(mp_mpeg_header_t * picture, unsigned char * buf, int len)
 373 {
 374   unsigned int n = 0, v, i, k, mbh;
 375   int frame_mbs_only;
 376
 377   len = mp_unescape03(buf, len);
 378
 379   picture->fps = picture->timeinc_unit = picture->timeinc_resolution = 0;
 380   n = 24;
 381   read_golomb(buf, &n);
 382   if(buf[0] >= 100){
 383     if(read_golomb(buf, &n) == 3)
 384       n++;
 385     read_golomb(buf, &n);
 386     read_golomb(buf, &n);
 387     n++;
 388     if(getbits(buf, n++, 1)){
 389       for(i = 0; i < 8; i++)
 390       {  // scaling list is skipped for now
 391         if(getbits(buf, n++, 1))
 392         {
 393           v = 8;
 394           for(k = (i < 6 ? 16 : 64); k && v; k--)
 395             v = (v + read_golomb_s(buf, &n)) & 255;
 396         }
 397       }
 398     }
 399   }
 400   read_golomb(buf, &n);
 401   v = read_golomb(buf, &n);
 402   if(v == 0)
 403     read_golomb(buf, &n);
 404   else if(v == 1)
 405   {
 406     getbits(buf, n++, 1);
 407     read_golomb(buf, &n);
 408     read_golomb(buf, &n);
 409     v = read_golomb(buf, &n);
 410     for(i = 0; i < v; i++)
 411       read_golomb(buf, &n);
 412   }
 413   read_golomb(buf, &n);
 414   getbits(buf, n++, 1);
 415   picture->display_picture_width = 16 *(read_golomb(buf, &n)+1);
 416   mbh = read_golomb(buf, &n)+1;
 417   frame_mbs_only = getbits(buf, n++, 1);
 418   picture->display_picture_height = 16 * (2 - frame_mbs_only) * mbh;
 419   if(!frame_mbs_only)
 420     getbits(buf, n++, 1);
 421   getbits(buf, n++, 1);
 422   if(getbits(buf, n++, 1))
 423   {
 424     read_golomb(buf, &n);
 425     read_golomb(buf, &n);
 426     read_golomb(buf, &n);
 427     read_golomb(buf, &n);
 428   }
 429   if(getbits(buf, n++, 1))
 430     n = h264_parse_vui(picture, buf, n);
 431
 432   return n;
 433 }
 434
 435 static int mp_unescape03(unsigned char *buf, int len)
 436 {
 437   unsigned char *dest;
 438   int i, j, skip;
 439
 440   dest = malloc(len);
 441   if(! dest)
 442     return 0;
 443
 444   j = i = skip = 0;
 445   while(i <= len-3)
 446   {
 447     if(buf[i] == 0 && buf[i+1] == 0 && buf[i+2] == 3)
 448     {
 449       dest[j] = dest[j+1] = 0;
 450       j += 2;
 451       i += 3;
 452       skip++;
 453     }
 454     else
 455     {
 456       dest[j] = buf[i];
 457       j++;
 458       i++;
 459     }
 460   }
 461   dest[j] = buf[len-2];
 462   dest[j+1] = buf[len-1];
 463   len -= skip;
 464   memcpy(buf, dest, len);
 465   free(dest);
 466
 467   return len;
 468 }
 469
 470 int mp_vc1_decode_sequence_header(mp_mpeg_header_t * picture, unsigned char * buf, int len)
 471 {
 472   int n, x;
 473
 474   len = mp_unescape03(buf, len);
 475
 476   picture->display_picture_width = picture->display_picture_height = 0;
 477   picture->fps = 0;
 478   n = 0;
 479   x = getbits(buf, n, 2);
 480   n += 2;
 481   if(x != 3) //not advanced profile
 482     return 0;
 483
 484   getbits16(buf, n, 14);
 485   n += 14;
 486   picture->display_picture_width = getbits16(buf, n, 12) * 2 + 2;
 487   n += 12;
 488   picture->display_picture_height = getbits16(buf, n, 12) * 2 + 2;
 489   n += 12;
 490   getbits(buf, n, 6);
 491   n += 6;
 492   x = getbits(buf, n, 1);
 493   n += 1;
 494   if(x) //display info
 495   {
 496     getbits16(buf, n, 14);
 497     n += 14;
 498     getbits16(buf, n, 14);
 499     n += 14;
 500     if(getbits(buf, n++, 1)) //aspect ratio
 501     {
 502       x = getbits(buf, n, 4);
 503       n += 4;
 504       if(x == 15)
 505       {
 506         getbits16(buf, n, 16);
 507         n += 16;
 508       }
 509     }
 510
 511     if(getbits(buf, n++, 1)) //framerates
 512     {
 513       int frexp=0, frnum=0, frden=0;
 514
 515       if(getbits(buf, n++, 1))
 516       {
 517         frexp = getbits16(buf, n, 16);
 518         n += 16;
 519         picture->fps = (double) (frexp+1) / 32.0;
 520       }
 521       else
 522       {
 523         float frates[] = {0, 24000, 25000, 30000, 50000, 60000, 48000, 72000, 0};
 524         float frdivs[] = {0, 1000, 1001, 0};
 525
 526         frnum = getbits(buf, n, 8);
 527         n += 8;
 528         frden = getbits(buf, n, 4);
 529         n += 4;
 530         if((frden == 1 || frden == 2) && (frnum < 8))
 531             picture->fps = frates[frnum] / frdivs[frden];
 532       }
 533     }
 534   }
 535
 536   //free(dest);
 537   return 1;
 538 }