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 += read_timeinc(picture, buffer, n);
 256
 257       if(picture->timeinc_unit)
 258         picture->fps = (float) picture->timeinc_resolution / (float) picture->timeinc_unit;
 259     }
 260
 261     n++; //marker bit
 262     picture->display_picture_width = getbits16(buffer, n, 13);
 263     n += 13;
 264     n++; //marker bit
 265     picture->display_picture_height = getbits16(buffer, n, 13);
 266     n += 13;
 267
 268     //fprintf(stderr, "ASPECT: %d, PARW=%d, PARH=%d, TIMEINCRESOLUTION: %d, FIXED_TIMEINC: %d (number of bits: %d), FPS: %u\n",
 269     //  aspect, aspectw, aspecth, picture->timeinc_resolution, picture->timeinc_unit, picture->timeinc_bits, picture->fps);
 270
 271     return 0;
 272 }
 273
 274 void mp4_header_process_vop(mp_mpeg_header_t * picture, unsigned char * buffer)
 275 {
 276   int n;
 277   n = 0;
 278   picture->picture_type = getbits(buffer, n, 2);
 279   n += 2;
 280   while(getbits(buffer, n, 1))
 281     n++;
 282   n++;
 283   getbits(buffer, n, 1);
 284   n++;
 285   n += read_timeinc(picture, buffer, n);
 286 }
 287
 288 #define min(a, b) ((a) <= (b) ? (a) : (b))
 289
 290 static unsigned int read_golomb(unsigned char *buffer, unsigned int *init)
 291 {
 292   unsigned int x, v = 0, v2 = 0, m, len = 0, n = *init;
 293
 294   while(getbits(buffer, n++, 1) == 0)
 295     len++;
 296
 297   x = len + n;
 298   while(n < x)
 299   {
 300     m = min(x - n, 8);
 301     v |= getbits(buffer, n, m);
 302     n += m;
 303     if(x - n > 8)
 304       v <<= 8;
 305   }
 306
 307   v2 = 1;
 308   for(n = 0; n < len; n++)
 309     v2 <<= 1;
 310   v2 = (v2 - 1) + v;
 311
 312   //fprintf(stderr, "READ_GOLOMB(%u), V=2^%u + %u-1 = %u\n", *init, len, v, v2);
 313   *init = x;
 314   return v2;
 315 }
 316
 317 inline static int read_golomb_s(unsigned char *buffer, unsigned int *init)
 318 {
 319   unsigned int v = read_golomb(buffer, init);
 320   return (v & 1) ? ((v + 1) >> 1) : -(v >> 1);
 321 }
 322
 323 static int h264_parse_vui(mp_mpeg_header_t * picture, unsigned char * buf, unsigned int n)
 324 {
 325   unsigned int overscan, vsp_color, chroma, timing, fixed_fps;
 326
 327   if(getbits(buf, n++, 1))
 328   {
 329     picture->aspect_ratio_information = getbits(buf, n, 8);
 330     n += 8;
 331     if(picture->aspect_ratio_information == 255)
 332     {
 333       picture->display_picture_width = (getbits(buf, n, 8) << 8) | getbits(buf, n + 8, 8);
 334       n += 16;
 335
 336       picture->display_picture_height = (getbits(buf, n, 8) << 8) | getbits(buf, n + 8, 8);
 337       n += 16;
 338     }
 339   }
 340
 341   if((overscan=getbits(buf, n++, 1)))
 342     n++;
 343   if((vsp_color=getbits(buf, n++, 1)))
 344   {
 345     n += 4;
 346     if(getbits(buf, n++, 1))
 347       n += 24;
 348   }
 349   if((chroma=getbits(buf, n++, 1)))
 350   {
 351     read_golomb(buf, &n);
 352     read_golomb(buf, &n);
 353   }
 354   if((timing=getbits(buf, n++, 1)))
 355   {
 356     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);
 357     n += 32;
 358
 359     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);
 360     n += 32;
 361
 362     fixed_fps = getbits(buf, n, 1);
 363
 364     if(picture->timeinc_unit > 0 && picture->timeinc_resolution > 0)
 365       picture->fps = (float) picture->timeinc_resolution / (float) picture->timeinc_unit;
 366     if(fixed_fps)
 367       picture->fps /= 2;
 368   }
 369
 370   //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,
 371   //    picture->timeinc_resolution, picture->timeinc_unit, picture->timeinc_unit, fixed_fps);
 372
 373   return n;
 374 }
 375
 376 static int mp_unescape03(unsigned char *buf, int len);
 377
 378 int h264_parse_sps(mp_mpeg_header_t * picture, unsigned char * buf, int len)
 379 {
 380   unsigned int n = 0, v, i, k, mbh;
 381   int frame_mbs_only;
 382
 383   len = mp_unescape03(buf, len);
 384
 385   picture->fps = picture->timeinc_unit = picture->timeinc_resolution = 0;
 386   n = 24;
 387   read_golomb(buf, &n);
 388   if(buf[0] >= 100){
 389     if(read_golomb(buf, &n) == 3)
 390       n++;
 391     read_golomb(buf, &n);
 392     read_golomb(buf, &n);
 393     n++;
 394     if(getbits(buf, n++, 1)){
 395       for(i = 0; i < 8; i++)
 396       {  // scaling list is skipped for now
 397         if(getbits(buf, n++, 1))
 398         {
 399           v = 8;
 400           for(k = (i < 6 ? 16 : 64); k && v; k--)
 401             v = (v + read_golomb_s(buf, &n)) & 255;
 402         }
 403       }
 404     }
 405   }
 406   read_golomb(buf, &n);
 407   v = read_golomb(buf, &n);
 408   if(v == 0)
 409     read_golomb(buf, &n);
 410   else if(v == 1)
 411   {
 412     getbits(buf, n++, 1);
 413     read_golomb(buf, &n);
 414     read_golomb(buf, &n);
 415     v = read_golomb(buf, &n);
 416     for(i = 0; i < v; i++)
 417       read_golomb(buf, &n);
 418   }
 419   read_golomb(buf, &n);
 420   getbits(buf, n++, 1);
 421   picture->display_picture_width = 16 *(read_golomb(buf, &n)+1);
 422   mbh = read_golomb(buf, &n)+1;
 423   frame_mbs_only = getbits(buf, n++, 1);
 424   picture->display_picture_height = 16 * (2 - frame_mbs_only) * mbh;
 425   if(!frame_mbs_only)
 426     getbits(buf, n++, 1);
 427   getbits(buf, n++, 1);
 428   if(getbits(buf, n++, 1))
 429   {
 430     read_golomb(buf, &n);
 431     read_golomb(buf, &n);
 432     read_golomb(buf, &n);
 433     read_golomb(buf, &n);
 434   }
 435   if(getbits(buf, n++, 1))
 436     n = h264_parse_vui(picture, buf, n);
 437
 438   return n;
 439 }
 440
 441 static int mp_unescape03(unsigned char *buf, int len)
 442 {
 443   unsigned char *dest;
 444   int i, j, skip;
 445
 446   dest = malloc(len);
 447   if(! dest)
 448     return 0;
 449
 450   j = i = skip = 0;
 451   while(i <= len-3)
 452   {
 453     if(buf[i] == 0 && buf[i+1] == 0 && buf[i+2] == 3)
 454     {
 455       dest[j] = dest[j+1] = 0;
 456       j += 2;
 457       i += 3;
 458       skip++;
 459     }
 460     else
 461     {
 462       dest[j] = buf[i];
 463       j++;
 464       i++;
 465     }
 466   }
 467   dest[j] = buf[len-2];
 468   dest[j+1] = buf[len-1];
 469   len -= skip;
 470   memcpy(buf, dest, len);
 471   free(dest);
 472
 473   return len;
 474 }
 475
 476 int mp_vc1_decode_sequence_header(mp_mpeg_header_t * picture, unsigned char * buf, int len)
 477 {
 478   int n, x;
 479
 480   len = mp_unescape03(buf, len);
 481
 482   picture->display_picture_width = picture->display_picture_height = 0;
 483   picture->fps = 0;
 484   n = 0;
 485   x = getbits(buf, n, 2);
 486   n += 2;
 487   if(x != 3) //not advanced profile
 488     return 0;
 489
 490   getbits16(buf, n, 14);
 491   n += 14;
 492   picture->display_picture_width = getbits16(buf, n, 12) * 2 + 2;
 493   n += 12;
 494   picture->display_picture_height = getbits16(buf, n, 12) * 2 + 2;
 495   n += 12;
 496   getbits(buf, n, 6);
 497   n += 6;
 498   x = getbits(buf, n, 1);
 499   n += 1;
 500   if(x) //display info
 501   {
 502     getbits16(buf, n, 14);
 503     n += 14;
 504     getbits16(buf, n, 14);
 505     n += 14;
 506     if(getbits(buf, n++, 1)) //aspect ratio
 507     {
 508       x = getbits(buf, n, 4);
 509       n += 4;
 510       if(x == 15)
 511       {
 512         getbits16(buf, n, 16);
 513         n += 16;
 514       }
 515     }
 516
 517     if(getbits(buf, n++, 1)) //framerates
 518     {
 519       int frexp=0, frnum=0, frden=0;
 520
 521       if(getbits(buf, n++, 1))
 522       {
 523         frexp = getbits16(buf, n, 16);
 524         n += 16;
 525         picture->fps = (double) (frexp+1) / 32.0;
 526       }
 527       else
 528       {
 529         float frates[] = {0, 24000, 25000, 30000, 50000, 60000, 48000, 72000, 0};
 530         float frdivs[] = {0, 1000, 1001, 0};
 531
 532         frnum = getbits(buf, n, 8);
 533         n += 8;
 534         frden = getbits(buf, n, 4);
 535         n += 4;
 536         if((frden == 1 || frden == 2) && (frnum < 8))
 537             picture->fps = frates[frnum] / frdivs[frden];
 538       }
 539     }
 540   }
 541
 542   //free(dest);
 543   return 1;
 544 }