libavcodec/truemotion1.c

   1 /*
   2  * Duck TrueMotion 1.0 Decoder
   3  * Copyright (C) 2003 Alex Beregszaszi & Mike Melanson
   4  *
   5  * This file is part of FFmpeg.
   6  *
   7  * FFmpeg is free software; you can redistribute it and/or
   8  * modify it under the terms of the GNU Lesser General Public
   9  * License as published by the Free Software Foundation; either
  10  * version 2.1 of the License, or (at your option) any later version.
  11  *
  12  * FFmpeg is distributed in the hope that it will be useful,
  13  * but WITHOUT ANY WARRANTY; without even the implied warranty of
  14  * MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE.  See the GNU
  15  * Lesser General Public License for more details.
  16  *
  17  * You should have received a copy of the GNU Lesser General Public
  18  * License along with FFmpeg; if not, write to the Free Software
  19  * Foundation, Inc., 51 Franklin Street, Fifth Floor, Boston, MA 02110-1301 USA
  20  */
  21
  22 /**
  23  * @file truemotion1.c
  24  * Duck TrueMotion v1 Video Decoder by
  25  * Alex Beregszaszi and
  26  * Mike Melanson (melanson@pcisys.net)
  27  *
  28  * The TrueMotion v1 decoder presently only decodes 16-bit TM1 data and
  29  * outputs RGB555 (or RGB565) data. 24-bit TM1 data is not supported yet.
  30  */
  31
  32 #include <stdio.h>
  33 #include <stdlib.h>
  34 #include <string.h>
  35 #include <unistd.h>
  36
  37 #include "avcodec.h"
  38 #include "dsputil.h"
  39
  40 #include "truemotion1data.h"
  41
  42 typedef struct TrueMotion1Context {
  43     AVCodecContext *avctx;
  44     AVFrame frame;
  45
  46     const uint8_t *buf;
  47     int size;
  48
  49     const uint8_t *mb_change_bits;
  50     int mb_change_bits_row_size;
  51     const uint8_t *index_stream;
  52     int index_stream_size;
  53
  54     int flags;
  55     int x, y, w, h;
  56
  57     uint32_t y_predictor_table[1024];
  58     uint32_t c_predictor_table[1024];
  59     uint32_t fat_y_predictor_table[1024];
  60     uint32_t fat_c_predictor_table[1024];
  61
  62     int compression;
  63     int block_type;
  64     int block_width;
  65     int block_height;
  66
  67     int16_t ydt[8];
  68     int16_t cdt[8];
  69     int16_t fat_ydt[8];
  70     int16_t fat_cdt[8];
  71
  72     int last_deltaset, last_vectable;
  73
  74     unsigned int *vert_pred;
  75
  76 } TrueMotion1Context;
  77
  78 #define FLAG_SPRITE         32
  79 #define FLAG_KEYFRAME       16
  80 #define FLAG_INTERFRAME      8
  81 #define FLAG_INTERPOLATED    4
  82
  83 struct frame_header {
  84     uint8_t header_size;
  85     uint8_t compression;
  86     uint8_t deltaset;
  87     uint8_t vectable;
  88     uint16_t ysize;
  89     uint16_t xsize;
  90     uint16_t checksum;
  91     uint8_t version;
  92     uint8_t header_type;
  93     uint8_t flags;
  94     uint8_t control;
  95     uint16_t xoffset;
  96     uint16_t yoffset;
  97     uint16_t width;
  98     uint16_t height;
  99 };
 100
 101 #define ALGO_NOP        0
 102 #define ALGO_RGB16V     1
 103 #define ALGO_RGB16H     2
 104 #define ALGO_RGB24H     3
 105
 106 /* these are the various block sizes that can occupy a 4x4 block */
 107 #define BLOCK_2x2  0
 108 #define BLOCK_2x4  1
 109 #define BLOCK_4x2  2
 110 #define BLOCK_4x4  3
 111
 112 typedef struct comp_types {
 113     int algorithm;
 114     int block_width; // vres
 115     int block_height; // hres
 116     int block_type;
 117 } comp_types;
 118
 119 /* { valid for metatype }, algorithm, num of deltas, vert res, horiz res */
 120 static const comp_types compression_types[17] = {
 121     { ALGO_NOP,    0, 0, 0 },
 122
 123     { ALGO_RGB16V, 4, 4, BLOCK_4x4 },
 124     { ALGO_RGB16H, 4, 4, BLOCK_4x4 },
 125     { ALGO_RGB16V, 4, 2, BLOCK_4x2 },
 126     { ALGO_RGB16H, 4, 2, BLOCK_4x2 },
 127
 128     { ALGO_RGB16V, 2, 4, BLOCK_2x4 },
 129     { ALGO_RGB16H, 2, 4, BLOCK_2x4 },
 130     { ALGO_RGB16V, 2, 2, BLOCK_2x2 },
 131     { ALGO_RGB16H, 2, 2, BLOCK_2x2 },
 132
 133     { ALGO_NOP,    4, 4, BLOCK_4x4 },
 134     { ALGO_RGB24H, 4, 4, BLOCK_4x4 },
 135     { ALGO_NOP,    4, 2, BLOCK_4x2 },
 136     { ALGO_RGB24H, 4, 2, BLOCK_4x2 },
 137
 138     { ALGO_NOP,    2, 4, BLOCK_2x4 },
 139     { ALGO_RGB24H, 2, 4, BLOCK_2x4 },
 140     { ALGO_NOP,    2, 2, BLOCK_2x2 },
 141     { ALGO_RGB24H, 2, 2, BLOCK_2x2 }
 142 };
 143
 144 static void select_delta_tables(TrueMotion1Context *s, int delta_table_index)
 145 {
 146     int i;
 147
 148     if (delta_table_index > 3)
 149         return;
 150
 151     memcpy(s->ydt, ydts[delta_table_index], 8 * sizeof(int16_t));
 152     memcpy(s->cdt, cdts[delta_table_index], 8 * sizeof(int16_t));
 153     memcpy(s->fat_ydt, fat_ydts[delta_table_index], 8 * sizeof(int16_t));
 154     memcpy(s->fat_cdt, fat_cdts[delta_table_index], 8 * sizeof(int16_t));
 155
 156     /* Y skinny deltas need to be halved for some reason; maybe the
 157      * skinny Y deltas should be modified */
 158     for (i = 0; i < 8; i++)
 159     {
 160         /* drop the lsb before dividing by 2-- net effect: round down
 161          * when dividing a negative number (e.g., -3/2 = -2, not -1) */
 162         s->ydt[i] &= 0xFFFE;
 163         s->ydt[i] /= 2;
 164     }
 165 }
 166
 167 #ifdef WORDS_BIGENDIAN
 168 static int make_ydt15_entry(int p2, int p1, int16_t *ydt)
 169 #else
 170 static int make_ydt15_entry(int p1, int p2, int16_t *ydt)
 171 #endif
 172 {
 173     int lo, hi;
 174
 175     lo = ydt[p1];
 176     lo += (lo << 5) + (lo << 10);
 177     hi = ydt[p2];
 178     hi += (hi << 5) + (hi << 10);
 179     return (lo + (hi << 16)) << 1;
 180 }
 181
 182 #ifdef WORDS_BIGENDIAN
 183 static int make_cdt15_entry(int p2, int p1, int16_t *cdt)
 184 #else
 185 static int make_cdt15_entry(int p1, int p2, int16_t *cdt)
 186 #endif
 187 {
 188     int r, b, lo;
 189
 190     b = cdt[p2];
 191     r = cdt[p1] << 10;
 192     lo = b + r;
 193     return (lo + (lo << 16)) << 1;
 194 }
 195
 196 #ifdef WORDS_BIGENDIAN
 197 static int make_ydt16_entry(int p2, int p1, int16_t *ydt)
 198 #else
 199 static int make_ydt16_entry(int p1, int p2, int16_t *ydt)
 200 #endif
 201 {
 202     int lo, hi;
 203
 204     lo = ydt[p1];
 205     lo += (lo << 6) + (lo << 11);
 206     hi = ydt[p2];
 207     hi += (hi << 6) + (hi << 11);
 208     return (lo + (hi << 16)) << 1;
 209 }
 210
 211 #ifdef WORDS_BIGENDIAN
 212 static int make_cdt16_entry(int p2, int p1, int16_t *cdt)
 213 #else
 214 static int make_cdt16_entry(int p1, int p2, int16_t *cdt)
 215 #endif
 216 {
 217     int r, b, lo;
 218
 219     b = cdt[p2];
 220     r = cdt[p1] << 11;
 221     lo = b + r;
 222     return (lo + (lo << 16)) << 1;
 223 }
 224
 225 #ifdef WORDS_BIGENDIAN
 226 static int make_ydt24_entry(int p2, int p1, int16_t *ydt)
 227 #else
 228 static int make_ydt24_entry(int p1, int p2, int16_t *ydt)
 229 #endif
 230 {
 231     int lo, hi;
 232
 233     lo = ydt[p1];
 234     hi = ydt[p2];
 235     return (lo + (hi << 8) + (hi << 16)) << 1;
 236 }
 237
 238 #ifdef WORDS_BIGENDIAN
 239 static int make_cdt24_entry(int p2, int p1, int16_t *cdt)
 240 #else
 241 static int make_cdt24_entry(int p1, int p2, int16_t *cdt)
 242 #endif
 243 {
 244     int r, b;
 245
 246     b = cdt[p2];
 247     r = cdt[p1]<<16;
 248     return (b+r) << 1;
 249 }
 250
 251 static void gen_vector_table15(TrueMotion1Context *s, const uint8_t *sel_vector_table)
 252 {
 253     int len, i, j;
 254     unsigned char delta_pair;
 255
 256     for (i = 0; i < 1024; i += 4)
 257     {
 258         len = *sel_vector_table++ / 2;
 259         for (j = 0; j < len; j++)
 260         {
 261             delta_pair = *sel_vector_table++;
 262             s->y_predictor_table[i+j] = 0xfffffffe &
 263                 make_ydt15_entry(delta_pair >> 4, delta_pair & 0xf, s->ydt);
 264             s->c_predictor_table[i+j] = 0xfffffffe &
 265                 make_cdt15_entry(delta_pair >> 4, delta_pair & 0xf, s->cdt);
 266         }
 267         s->y_predictor_table[i+(j-1)] |= 1;
 268         s->c_predictor_table[i+(j-1)] |= 1;
 269     }
 270 }
 271
 272 static void gen_vector_table16(TrueMotion1Context *s, const uint8_t *sel_vector_table)
 273 {
 274     int len, i, j;
 275     unsigned char delta_pair;
 276
 277     for (i = 0; i < 1024; i += 4)
 278     {
 279         len = *sel_vector_table++ / 2;
 280         for (j = 0; j < len; j++)
 281         {
 282             delta_pair = *sel_vector_table++;
 283             s->y_predictor_table[i+j] = 0xfffffffe &
 284                 make_ydt16_entry(delta_pair >> 4, delta_pair & 0xf, s->ydt);
 285             s->c_predictor_table[i+j] = 0xfffffffe &
 286                 make_cdt16_entry(delta_pair >> 4, delta_pair & 0xf, s->cdt);
 287         }
 288         s->y_predictor_table[i+(j-1)] |= 1;
 289         s->c_predictor_table[i+(j-1)] |= 1;
 290     }
 291 }
 292
 293 static void gen_vector_table24(TrueMotion1Context *s, const uint8_t *sel_vector_table)
 294 {
 295     int len, i, j;
 296     unsigned char delta_pair;
 297
 298     for (i = 0; i < 1024; i += 4)
 299     {
 300         len = *sel_vector_table++ / 2;
 301         for (j = 0; j < len; j++)
 302         {
 303             delta_pair = *sel_vector_table++;
 304             s->y_predictor_table[i+j] = 0xfffffffe &
 305                 make_ydt24_entry(delta_pair >> 4, delta_pair & 0xf, s->ydt);
 306             s->c_predictor_table[i+j] = 0xfffffffe &
 307                 make_cdt24_entry(delta_pair >> 4, delta_pair & 0xf, s->cdt);
 308             s->fat_y_predictor_table[i+j] = 0xfffffffe &
 309                 make_ydt24_entry(delta_pair >> 4, delta_pair & 0xf, s->fat_ydt);
 310             s->fat_c_predictor_table[i+j] = 0xfffffffe &
 311                 make_cdt24_entry(delta_pair >> 4, delta_pair & 0xf, s->fat_cdt);
 312         }
 313         s->y_predictor_table[i+(j-1)] |= 1;
 314         s->c_predictor_table[i+(j-1)] |= 1;
 315         s->fat_y_predictor_table[i+(j-1)] |= 1;
 316         s->fat_c_predictor_table[i+(j-1)] |= 1;
 317     }
 318 }
 319
 320 /* Returns the number of bytes consumed from the bytestream. Returns -1 if
 321  * there was an error while decoding the header */
 322 static int truemotion1_decode_header(TrueMotion1Context *s)
 323 {
 324     int i;
 325     struct frame_header header;
 326     uint8_t header_buffer[128];  /* logical maximum size of the header */
 327     const uint8_t *sel_vector_table;
 328
 329     /* There is 1 change bit per 4 pixels, so each change byte represents
 330      * 32 pixels; divide width by 4 to obtain the number of change bits and
 331      * then round up to the nearest byte. */
 332     s->mb_change_bits_row_size = ((s->avctx->width >> 2) + 7) >> 3;
 333
 334     header.header_size = ((s->buf[0] >> 5) | (s->buf[0] << 3)) & 0x7f;
 335     if (s->buf[0] < 0x10)
 336     {
 337         av_log(s->avctx, AV_LOG_ERROR, "invalid header size (%d)\n", s->buf[0]);
 338         return -1;
 339     }
 340
 341     /* unscramble the header bytes with a XOR operation */
 342     memset(header_buffer, 0, 128);
 343     for (i = 1; i < header.header_size; i++)
 344         header_buffer[i - 1] = s->buf[i] ^ s->buf[i + 1];
 345
 346     header.compression = header_buffer[0];
 347     header.deltaset = header_buffer[1];
 348     header.vectable = header_buffer[2];
 349     header.ysize = AV_RL16(&header_buffer[3]);
 350     header.xsize = AV_RL16(&header_buffer[5]);
 351     header.checksum = AV_RL16(&header_buffer[7]);
 352     header.version = header_buffer[9];
 353     header.header_type = header_buffer[10];
 354     header.flags = header_buffer[11];
 355     header.control = header_buffer[12];
 356
 357     /* Version 2 */
 358     if (header.version >= 2)
 359     {
 360         if (header.header_type > 3)
 361         {
 362             av_log(s->avctx, AV_LOG_ERROR, "invalid header type (%d)\n", header.header_type);
 363             return -1;
 364         } else if ((header.header_type == 2) || (header.header_type == 3)) {
 365             s->flags = header.flags;
 366             if (!(s->flags & FLAG_INTERFRAME))
 367                 s->flags |= FLAG_KEYFRAME;
 368         } else
 369             s->flags = FLAG_KEYFRAME;
 370     } else /* Version 1 */
 371         s->flags = FLAG_KEYFRAME;
 372
 373     if (s->flags & FLAG_SPRITE) {
 374         av_log(s->avctx, AV_LOG_INFO, "SPRITE frame found, please report the sample to the developers\n");
 375         /* FIXME header.width, height, xoffset and yoffset aren't initialized */
 376 #if 0
 377         s->w = header.width;
 378         s->h = header.height;
 379         s->x = header.xoffset;
 380         s->y = header.yoffset;
 381 #else
 382         return -1;
 383 #endif
 384     } else {
 385         s->w = header.xsize;
 386         s->h = header.ysize;
 387         if (header.header_type < 2) {
 388             if ((s->w < 213) && (s->h >= 176))
 389             {
 390                 s->flags |= FLAG_INTERPOLATED;
 391                 av_log(s->avctx, AV_LOG_INFO, "INTERPOLATION selected, please report the sample to the developers\n");
 392             }
 393         }
 394     }
 395
 396     if (header.compression >= 17) {
 397         av_log(s->avctx, AV_LOG_ERROR, "invalid compression type (%d)\n", header.compression);
 398         return -1;
 399     }
 400
 401     if ((header.deltaset != s->last_deltaset) ||
 402         (header.vectable != s->last_vectable))
 403         select_delta_tables(s, header.deltaset);
 404
 405     if ((header.compression & 1) && header.header_type)
 406         sel_vector_table = pc_tbl2;
 407     else {
 408         if (header.vectable < 4)
 409             sel_vector_table = tables[header.vectable - 1];
 410         else {
 411             av_log(s->avctx, AV_LOG_ERROR, "invalid vector table id (%d)\n", header.vectable);
 412             return -1;
 413         }
 414     }
 415
 416     // FIXME: where to place this ?!?!
 417     if (compression_types[header.compression].algorithm == ALGO_RGB24H)
 418         s->avctx->pix_fmt = PIX_FMT_RGB32;
 419     else
 420         s->avctx->pix_fmt = PIX_FMT_RGB555; // RGB565 is supported as well
 421
 422     if ((header.deltaset != s->last_deltaset) || (header.vectable != s->last_vectable))
 423     {
 424         if (compression_types[header.compression].algorithm == ALGO_RGB24H)
 425             gen_vector_table24(s, sel_vector_table);
 426         else
 427         if (s->avctx->pix_fmt == PIX_FMT_RGB555)
 428             gen_vector_table15(s, sel_vector_table);
 429         else
 430             gen_vector_table16(s, sel_vector_table);
 431     }
 432
 433     /* set up pointers to the other key data chunks */
 434     s->mb_change_bits = s->buf + header.header_size;
 435     if (s->flags & FLAG_KEYFRAME) {
 436         /* no change bits specified for a keyframe; only index bytes */
 437         s->index_stream = s->mb_change_bits;
 438     } else {
 439         /* one change bit per 4x4 block */
 440         s->index_stream = s->mb_change_bits +
 441             (s->mb_change_bits_row_size * (s->avctx->height >> 2));
 442     }
 443     s->index_stream_size = s->size - (s->index_stream - s->buf);
 444
 445     s->last_deltaset = header.deltaset;
 446     s->last_vectable = header.vectable;
 447     s->compression = header.compression;
 448     s->block_width = compression_types[header.compression].block_width;
 449     s->block_height = compression_types[header.compression].block_height;
 450     s->block_type = compression_types[header.compression].block_type;
 451
 452     if (s->avctx->debug & FF_DEBUG_PICT_INFO)
 453         av_log(s->avctx, AV_LOG_INFO, "tables: %d / %d c:%d %dx%d t:%d %s%s%s%s\n",
 454             s->last_deltaset, s->last_vectable, s->compression, s->block_width,
 455             s->block_height, s->block_type,
 456             s->flags & FLAG_KEYFRAME ? " KEY" : "",
 457             s->flags & FLAG_INTERFRAME ? " INTER" : "",
 458             s->flags & FLAG_SPRITE ? " SPRITE" : "",
 459             s->flags & FLAG_INTERPOLATED ? " INTERPOL" : "");
 460
 461     return header.header_size;
 462 }
 463
 464 static av_cold int truemotion1_decode_init(AVCodecContext *avctx)
 465 {
 466     TrueMotion1Context *s = avctx->priv_data;
 467
 468     s->avctx = avctx;
 469
 470     // FIXME: it may change ?
 471 //    if (avctx->bits_per_sample == 24)
 472 //        avctx->pix_fmt = PIX_FMT_RGB24;
 473 //    else
 474 //        avctx->pix_fmt = PIX_FMT_RGB555;
 475
 476     s->frame.data[0] = NULL;
 477
 478     /* there is a vertical predictor for each pixel in a line; each vertical
 479      * predictor is 0 to start with */
 480     s->vert_pred =
 481         (unsigned int *)av_malloc(s->avctx->width * sizeof(unsigned int));
 482
 483     return 0;
 484 }
 485
 486 /*
 487 Block decoding order:
 488
 489 dxi: Y-Y
 490 dxic: Y-C-Y
 491 dxic2: Y-C-Y-C
 492
 493 hres,vres,i,i%vres (0 < i < 4)
 494 2x2 0: 0 dxic2
 495 2x2 1: 1 dxi
 496 2x2 2: 0 dxic2
 497 2x2 3: 1 dxi
 498 2x4 0: 0 dxic2
 499 2x4 1: 1 dxi
 500 2x4 2: 2 dxi
 501 2x4 3: 3 dxi
 502 4x2 0: 0 dxic
 503 4x2 1: 1 dxi
 504 4x2 2: 0 dxic
 505 4x2 3: 1 dxi
 506 4x4 0: 0 dxic
 507 4x4 1: 1 dxi
 508 4x4 2: 2 dxi
 509 4x4 3: 3 dxi
 510 */
 511
 512 #define GET_NEXT_INDEX() \
 513 {\
 514     if (index_stream_index >= s->index_stream_size) { \
 515         av_log(s->avctx, AV_LOG_INFO, " help! truemotion1 decoder went out of bounds\n"); \
 516         return; \
 517     } \
 518     index = s->index_stream[index_stream_index++] * 4; \
 519 }
 520
 521 #define APPLY_C_PREDICTOR() \
 522     predictor_pair = s->c_predictor_table[index]; \
 523     horiz_pred += (predictor_pair >> 1); \
 524     if (predictor_pair & 1) { \
 525         GET_NEXT_INDEX() \
 526         if (!index) { \
 527             GET_NEXT_INDEX() \
 528             predictor_pair = s->c_predictor_table[index]; \
 529             horiz_pred += ((predictor_pair >> 1) * 5); \
 530             if (predictor_pair & 1) \
 531                 GET_NEXT_INDEX() \
 532             else \
 533                 index++; \
 534         } \
 535     } else \
 536         index++;
 537
 538 #define APPLY_C_PREDICTOR_24() \
 539     predictor_pair = s->c_predictor_table[index]; \
 540     horiz_pred += (predictor_pair >> 1); \
 541     if (predictor_pair & 1) { \
 542         GET_NEXT_INDEX() \
 543         if (!index) { \
 544             GET_NEXT_INDEX() \
 545             predictor_pair = s->fat_c_predictor_table[index]; \
 546             horiz_pred += (predictor_pair >> 1); \
 547             if (predictor_pair & 1) \
 548                 GET_NEXT_INDEX() \
 549             else \
 550                 index++; \
 551         } \
 552     } else \
 553         index++;
 554
 555
 556 #define APPLY_Y_PREDICTOR() \
 557     predictor_pair = s->y_predictor_table[index]; \
 558     horiz_pred += (predictor_pair >> 1); \
 559     if (predictor_pair & 1) { \
 560         GET_NEXT_INDEX() \
 561         if (!index) { \
 562             GET_NEXT_INDEX() \
 563             predictor_pair = s->y_predictor_table[index]; \
 564             horiz_pred += ((predictor_pair >> 1) * 5); \
 565             if (predictor_pair & 1) \
 566                 GET_NEXT_INDEX() \
 567             else \
 568                 index++; \
 569         } \
 570     } else \
 571         index++;
 572
 573 #define APPLY_Y_PREDICTOR_24() \
 574     predictor_pair = s->y_predictor_table[index]; \
 575     horiz_pred += (predictor_pair >> 1); \
 576     if (predictor_pair & 1) { \
 577         GET_NEXT_INDEX() \
 578         if (!index) { \
 579             GET_NEXT_INDEX() \
 580             predictor_pair = s->fat_y_predictor_table[index]; \
 581             horiz_pred += (predictor_pair >> 1); \
 582             if (predictor_pair & 1) \
 583                 GET_NEXT_INDEX() \
 584             else \
 585                 index++; \
 586         } \
 587     } else \
 588         index++;
 589
 590 #define OUTPUT_PIXEL_PAIR() \
 591     *current_pixel_pair = *vert_pred + horiz_pred; \
 592     *vert_pred++ = *current_pixel_pair++;
 593
 594 static void truemotion1_decode_16bit(TrueMotion1Context *s)
 595 {
 596     int y;
 597     int pixels_left;  /* remaining pixels on this line */
 598     unsigned int predictor_pair;
 599     unsigned int horiz_pred;
 600     unsigned int *vert_pred;
 601     unsigned int *current_pixel_pair;
 602     unsigned char *current_line = s->frame.data[0];
 603     int keyframe = s->flags & FLAG_KEYFRAME;
 604
 605     /* these variables are for managing the stream of macroblock change bits */
 606     const unsigned char *mb_change_bits = s->mb_change_bits;
 607     unsigned char mb_change_byte;
 608     unsigned char mb_change_byte_mask;
 609     int mb_change_index;
 610
 611     /* these variables are for managing the main index stream */
 612     int index_stream_index = 0;  /* yes, the index into the index stream */
 613     int index;
 614
 615     /* clean out the line buffer */
 616     memset(s->vert_pred, 0, s->avctx->width * sizeof(unsigned int));
 617
 618     GET_NEXT_INDEX();
 619
 620     for (y = 0; y < s->avctx->height; y++) {
 621
 622         /* re-init variables for the next line iteration */
 623         horiz_pred = 0;
 624         current_pixel_pair = (unsigned int *)current_line;
 625         vert_pred = s->vert_pred;
 626         mb_change_index = 0;
 627         mb_change_byte = mb_change_bits[mb_change_index++];
 628         mb_change_byte_mask = 0x01;
 629         pixels_left = s->avctx->width;
 630
 631         while (pixels_left > 0) {
 632
 633             if (keyframe || ((mb_change_byte & mb_change_byte_mask) == 0)) {
 634
 635                 switch (y & 3) {
 636                 case 0:
 637                     /* if macroblock width is 2, apply C-Y-C-Y; else
 638                      * apply C-Y-Y */
 639                     if (s->block_width == 2) {
 640                         APPLY_C_PREDICTOR();
 641                         APPLY_Y_PREDICTOR();
 642                         OUTPUT_PIXEL_PAIR();
 643                         APPLY_C_PREDICTOR();
 644                         APPLY_Y_PREDICTOR();
 645                         OUTPUT_PIXEL_PAIR();
 646                     } else {
 647                         APPLY_C_PREDICTOR();
 648                         APPLY_Y_PREDICTOR();
 649                         OUTPUT_PIXEL_PAIR();
 650                         APPLY_Y_PREDICTOR();
 651                         OUTPUT_PIXEL_PAIR();
 652                     }
 653                     break;
 654
 655                 case 1:
 656                 case 3:
 657                     /* always apply 2 Y predictors on these iterations */
 658                     APPLY_Y_PREDICTOR();
 659                     OUTPUT_PIXEL_PAIR();
 660                     APPLY_Y_PREDICTOR();
 661                     OUTPUT_PIXEL_PAIR();
 662                     break;
 663
 664                 case 2:
 665                     /* this iteration might be C-Y-C-Y, Y-Y, or C-Y-Y
 666                      * depending on the macroblock type */
 667                     if (s->block_type == BLOCK_2x2) {
 668                         APPLY_C_PREDICTOR();
 669                         APPLY_Y_PREDICTOR();
 670                         OUTPUT_PIXEL_PAIR();
 671                         APPLY_C_PREDICTOR();
 672                         APPLY_Y_PREDICTOR();
 673                         OUTPUT_PIXEL_PAIR();
 674                     } else if (s->block_type == BLOCK_4x2) {
 675                         APPLY_C_PREDICTOR();
 676                         APPLY_Y_PREDICTOR();
 677                         OUTPUT_PIXEL_PAIR();
 678                         APPLY_Y_PREDICTOR();
 679                         OUTPUT_PIXEL_PAIR();
 680                     } else {
 681                         APPLY_Y_PREDICTOR();
 682                         OUTPUT_PIXEL_PAIR();
 683                         APPLY_Y_PREDICTOR();
 684                         OUTPUT_PIXEL_PAIR();
 685                     }
 686                     break;
 687                 }
 688
 689             } else {
 690
 691                 /* skip (copy) four pixels, but reassign the horizontal
 692                  * predictor */
 693                 *vert_pred++ = *current_pixel_pair++;
 694                 horiz_pred = *current_pixel_pair - *vert_pred;
 695                 *vert_pred++ = *current_pixel_pair++;
 696
 697             }
 698
 699             if (!keyframe) {
 700                 mb_change_byte_mask <<= 1;
 701
 702                 /* next byte */
 703                 if (!mb_change_byte_mask) {
 704                     mb_change_byte = mb_change_bits[mb_change_index++];
 705                     mb_change_byte_mask = 0x01;
 706                 }
 707             }
 708
 709             pixels_left -= 4;
 710         }
 711
 712         /* next change row */
 713         if (((y + 1) & 3) == 0)
 714             mb_change_bits += s->mb_change_bits_row_size;
 715
 716         current_line += s->frame.linesize[0];
 717     }
 718 }
 719
 720 static void truemotion1_decode_24bit(TrueMotion1Context *s)
 721 {
 722     int y;
 723     int pixels_left;  /* remaining pixels on this line */
 724     unsigned int predictor_pair;
 725     unsigned int horiz_pred;
 726     unsigned int *vert_pred;
 727     unsigned int *current_pixel_pair;
 728     unsigned char *current_line = s->frame.data[0];
 729     int keyframe = s->flags & FLAG_KEYFRAME;
 730
 731     /* these variables are for managing the stream of macroblock change bits */
 732     const unsigned char *mb_change_bits = s->mb_change_bits;
 733     unsigned char mb_change_byte;
 734     unsigned char mb_change_byte_mask;
 735     int mb_change_index;
 736
 737     /* these variables are for managing the main index stream */
 738     int index_stream_index = 0;  /* yes, the index into the index stream */
 739     int index;
 740
 741     /* clean out the line buffer */
 742     memset(s->vert_pred, 0, s->avctx->width * sizeof(unsigned int));
 743
 744     GET_NEXT_INDEX();
 745
 746     for (y = 0; y < s->avctx->height; y++) {
 747
 748         /* re-init variables for the next line iteration */
 749         horiz_pred = 0;
 750         current_pixel_pair = (unsigned int *)current_line;
 751         vert_pred = s->vert_pred;
 752         mb_change_index = 0;
 753         mb_change_byte = mb_change_bits[mb_change_index++];
 754         mb_change_byte_mask = 0x01;
 755         pixels_left = s->avctx->width;
 756
 757         while (pixels_left > 0) {
 758
 759             if (keyframe || ((mb_change_byte & mb_change_byte_mask) == 0)) {
 760
 761                 switch (y & 3) {
 762                 case 0:
 763                     /* if macroblock width is 2, apply C-Y-C-Y; else
 764                      * apply C-Y-Y */
 765                     if (s->block_width == 2) {
 766                         APPLY_C_PREDICTOR_24();
 767                         APPLY_Y_PREDICTOR_24();
 768                         OUTPUT_PIXEL_PAIR();
 769                         APPLY_C_PREDICTOR_24();
 770                         APPLY_Y_PREDICTOR_24();
 771                         OUTPUT_PIXEL_PAIR();
 772                     } else {
 773                         APPLY_C_PREDICTOR_24();
 774                         APPLY_Y_PREDICTOR_24();
 775                         OUTPUT_PIXEL_PAIR();
 776                         APPLY_Y_PREDICTOR_24();
 777                         OUTPUT_PIXEL_PAIR();
 778                     }
 779                     break;
 780
 781                 case 1:
 782                 case 3:
 783                     /* always apply 2 Y predictors on these iterations */
 784                     APPLY_Y_PREDICTOR_24();
 785                     OUTPUT_PIXEL_PAIR();
 786                     APPLY_Y_PREDICTOR_24();
 787                     OUTPUT_PIXEL_PAIR();
 788                     break;
 789
 790                 case 2:
 791                     /* this iteration might be C-Y-C-Y, Y-Y, or C-Y-Y
 792                      * depending on the macroblock type */
 793                     if (s->block_type == BLOCK_2x2) {
 794                         APPLY_C_PREDICTOR_24();
 795                         APPLY_Y_PREDICTOR_24();
 796                         OUTPUT_PIXEL_PAIR();
 797                         APPLY_C_PREDICTOR_24();
 798                         APPLY_Y_PREDICTOR_24();
 799                         OUTPUT_PIXEL_PAIR();
 800                     } else if (s->block_type == BLOCK_4x2) {
 801                         APPLY_C_PREDICTOR_24();
 802                         APPLY_Y_PREDICTOR_24();
 803                         OUTPUT_PIXEL_PAIR();
 804                         APPLY_Y_PREDICTOR_24();
 805                         OUTPUT_PIXEL_PAIR();
 806                     } else {
 807                         APPLY_Y_PREDICTOR_24();
 808                         OUTPUT_PIXEL_PAIR();
 809                         APPLY_Y_PREDICTOR_24();
 810                         OUTPUT_PIXEL_PAIR();
 811                     }
 812                     break;
 813                 }
 814
 815             } else {
 816
 817                 /* skip (copy) four pixels, but reassign the horizontal
 818                  * predictor */
 819                 *vert_pred++ = *current_pixel_pair++;
 820                 horiz_pred = *current_pixel_pair - *vert_pred;
 821                 *vert_pred++ = *current_pixel_pair++;
 822
 823             }
 824
 825             if (!keyframe) {
 826                 mb_change_byte_mask <<= 1;
 827
 828                 /* next byte */
 829                 if (!mb_change_byte_mask) {
 830                     mb_change_byte = mb_change_bits[mb_change_index++];
 831                     mb_change_byte_mask = 0x01;
 832                 }
 833             }
 834
 835             pixels_left -= 4;
 836         }
 837
 838         /* next change row */
 839         if (((y + 1) & 3) == 0)
 840             mb_change_bits += s->mb_change_bits_row_size;
 841
 842         current_line += s->frame.linesize[0];
 843     }
 844 }
 845
 846
 847 static int truemotion1_decode_frame(AVCodecContext *avctx,
 848                                     void *data, int *data_size,
 849                                     const uint8_t *buf, int buf_size)
 850 {
 851     TrueMotion1Context *s = avctx->priv_data;
 852
 853     s->buf = buf;
 854     s->size = buf_size;
 855
 856     if (truemotion1_decode_header(s) == -1)
 857         return -1;
 858
 859     s->frame.reference = 1;
 860     s->frame.buffer_hints = FF_BUFFER_HINTS_VALID |
 861         FF_BUFFER_HINTS_PRESERVE | FF_BUFFER_HINTS_REUSABLE;
 862     if (avctx->reget_buffer(avctx, &s->frame) < 0) {
 863         av_log(s->avctx, AV_LOG_ERROR, "get_buffer() failed\n");
 864         return -1;
 865     }
 866
 867     if (compression_types[s->compression].algorithm == ALGO_RGB24H) {
 868         truemotion1_decode_24bit(s);
 869     } else if (compression_types[s->compression].algorithm != ALGO_NOP) {
 870         truemotion1_decode_16bit(s);
 871     }
 872
 873     *data_size = sizeof(AVFrame);
 874     *(AVFrame*)data = s->frame;
 875
 876     /* report that the buffer was completely consumed */
 877     return buf_size;
 878 }
 879
 880 static av_cold int truemotion1_decode_end(AVCodecContext *avctx)
 881 {
 882     TrueMotion1Context *s = avctx->priv_data;
 883
 884     if (s->frame.data[0])
 885         avctx->release_buffer(avctx, &s->frame);
 886
 887     av_free(s->vert_pred);
 888
 889     return 0;
 890 }
 891
 892 AVCodec truemotion1_decoder = {
 893     "truemotion1",
 894     CODEC_TYPE_VIDEO,
 895     CODEC_ID_TRUEMOTION1,
 896     sizeof(TrueMotion1Context),
 897     truemotion1_decode_init,
 898     NULL,
 899     truemotion1_decode_end,
 900     truemotion1_decode_frame,
 901     CODEC_CAP_DR1,
 902     .long_name = NULL_IF_CONFIG_SMALL("Duck TrueMotion 1.0"),
 903 };