ffmpeg/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
  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
  36 #include "avcodec.h"
  37 #include "internal.h"
  38 #include "libavutil/imgutils.h"
  39 #include "libavutil/internal.h"
  40 #include "libavutil/intreadwrite.h"
  41 #include "libavutil/mem.h"
  42
  43 #include "truemotion1data.h"
  44
  45 typedef struct TrueMotion1Context {
  46     AVCodecContext *avctx;
  47     AVFrame *frame;
  48
  49     const uint8_t *buf;
  50     int size;
  51
  52     const uint8_t *mb_change_bits;
  53     int mb_change_bits_row_size;
  54     const uint8_t *index_stream;
  55     int index_stream_size;
  56
  57     int flags;
  58     int x, y, w, h;
  59
  60     uint32_t y_predictor_table[1024];
  61     uint32_t c_predictor_table[1024];
  62     uint32_t fat_y_predictor_table[1024];
  63     uint32_t fat_c_predictor_table[1024];
  64
  65     int compression;
  66     int block_type;
  67     int block_width;
  68     int block_height;
  69
  70     int16_t ydt[8];
  71     int16_t cdt[8];
  72     int16_t fat_ydt[8];
  73     int16_t fat_cdt[8];
  74
  75     int last_deltaset, last_vectable;
  76
  77     unsigned int *vert_pred;
  78     int vert_pred_size;
  79
  80 } TrueMotion1Context;
  81
  82 #define FLAG_SPRITE         32
  83 #define FLAG_KEYFRAME       16
  84 #define FLAG_INTERFRAME      8
  85 #define FLAG_INTERPOLATED    4
  86
  87 struct frame_header {
  88     uint8_t header_size;
  89     uint8_t compression;
  90     uint8_t deltaset;
  91     uint8_t vectable;
  92     uint16_t ysize;
  93     uint16_t xsize;
  94     uint16_t checksum;
  95     uint8_t version;
  96     uint8_t header_type;
  97     uint8_t flags;
  98     uint8_t control;
  99     uint16_t xoffset;
 100     uint16_t yoffset;
 101     uint16_t width;
 102     uint16_t height;
 103 };
 104
 105 #define ALGO_NOP        0
 106 #define ALGO_RGB16V     1
 107 #define ALGO_RGB16H     2
 108 #define ALGO_RGB24H     3
 109
 110 /* these are the various block sizes that can occupy a 4x4 block */
 111 #define BLOCK_2x2  0
 112 #define BLOCK_2x4  1
 113 #define BLOCK_4x2  2
 114 #define BLOCK_4x4  3
 115
 116 typedef struct comp_types {
 117     int algorithm;
 118     int block_width; // vres
 119     int block_height; // hres
 120     int block_type;
 121 } comp_types;
 122
 123 /* { valid for metatype }, algorithm, num of deltas, vert res, horiz res */
 124 static const comp_types compression_types[17] = {
 125     { ALGO_NOP,    0, 0, 0 },
 126
 127     { ALGO_RGB16V, 4, 4, BLOCK_4x4 },
 128     { ALGO_RGB16H, 4, 4, BLOCK_4x4 },
 129     { ALGO_RGB16V, 4, 2, BLOCK_4x2 },
 130     { ALGO_RGB16H, 4, 2, BLOCK_4x2 },
 131
 132     { ALGO_RGB16V, 2, 4, BLOCK_2x4 },
 133     { ALGO_RGB16H, 2, 4, BLOCK_2x4 },
 134     { ALGO_RGB16V, 2, 2, BLOCK_2x2 },
 135     { ALGO_RGB16H, 2, 2, BLOCK_2x2 },
 136
 137     { ALGO_NOP,    4, 4, BLOCK_4x4 },
 138     { ALGO_RGB24H, 4, 4, BLOCK_4x4 },
 139     { ALGO_NOP,    4, 2, BLOCK_4x2 },
 140     { ALGO_RGB24H, 4, 2, BLOCK_4x2 },
 141
 142     { ALGO_NOP,    2, 4, BLOCK_2x4 },
 143     { ALGO_RGB24H, 2, 4, BLOCK_2x4 },
 144     { ALGO_NOP,    2, 2, BLOCK_2x2 },
 145     { ALGO_RGB24H, 2, 2, BLOCK_2x2 }
 146 };
 147
 148 static void select_delta_tables(TrueMotion1Context *s, int delta_table_index)
 149 {
 150     int i;
 151
 152     if (delta_table_index > 3)
 153         return;
 154
 155     memcpy(s->ydt, ydts[delta_table_index], 8 * sizeof(int16_t));
 156     memcpy(s->cdt, cdts[delta_table_index], 8 * sizeof(int16_t));
 157     memcpy(s->fat_ydt, fat_ydts[delta_table_index], 8 * sizeof(int16_t));
 158     memcpy(s->fat_cdt, fat_cdts[delta_table_index], 8 * sizeof(int16_t));
 159
 160     /* Y skinny deltas need to be halved for some reason; maybe the
 161      * skinny Y deltas should be modified */
 162     for (i = 0; i < 8; i++)
 163     {
 164         /* drop the lsb before dividing by 2-- net effect: round down
 165          * when dividing a negative number (e.g., -3/2 = -2, not -1) */
 166         s->ydt[i] &= 0xFFFE;
 167         s->ydt[i] /= 2;
 168     }
 169 }
 170
 171 #if HAVE_BIGENDIAN
 172 static int make_ydt15_entry(int p2, int p1, int16_t *ydt)
 173 #else
 174 static int make_ydt15_entry(int p1, int p2, int16_t *ydt)
 175 #endif
 176 {
 177     int lo, hi;
 178
 179     lo = ydt[p1];
 180     lo += (lo << 5) + (lo << 10);
 181     hi = ydt[p2];
 182     hi += (hi << 5) + (hi << 10);
 183     return (lo + (hi << 16)) << 1;
 184 }
 185
 186 static int make_cdt15_entry(int p1, int p2, int16_t *cdt)
 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 #if HAVE_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 static int make_cdt16_entry(int p1, int p2, int16_t *cdt)
 212 {
 213     int r, b, lo;
 214
 215     b = cdt[p2];
 216     r = cdt[p1] << 11;
 217     lo = b + r;
 218     return (lo + (lo << 16)) << 1;
 219 }
 220
 221 static int make_ydt24_entry(int p1, int p2, int16_t *ydt)
 222 {
 223     int lo, hi;
 224
 225     lo = ydt[p1];
 226     hi = ydt[p2];
 227     return (lo + (hi << 8) + (hi << 16)) << 1;
 228 }
 229
 230 static int make_cdt24_entry(int p1, int p2, int16_t *cdt)
 231 {
 232     int r, b;
 233
 234     b = cdt[p2];
 235     r = cdt[p1]<<16;
 236     return (b+r) << 1;
 237 }
 238
 239 static void gen_vector_table15(TrueMotion1Context *s, const uint8_t *sel_vector_table)
 240 {
 241     int len, i, j;
 242     unsigned char delta_pair;
 243
 244     for (i = 0; i < 1024; i += 4)
 245     {
 246         len = *sel_vector_table++ / 2;
 247         for (j = 0; j < len; j++)
 248         {
 249             delta_pair = *sel_vector_table++;
 250             s->y_predictor_table[i+j] = 0xfffffffe &
 251                 make_ydt15_entry(delta_pair >> 4, delta_pair & 0xf, s->ydt);
 252             s->c_predictor_table[i+j] = 0xfffffffe &
 253                 make_cdt15_entry(delta_pair >> 4, delta_pair & 0xf, s->cdt);
 254         }
 255         s->y_predictor_table[i+(j-1)] |= 1;
 256         s->c_predictor_table[i+(j-1)] |= 1;
 257     }
 258 }
 259
 260 static void gen_vector_table16(TrueMotion1Context *s, const uint8_t *sel_vector_table)
 261 {
 262     int len, i, j;
 263     unsigned char delta_pair;
 264
 265     for (i = 0; i < 1024; i += 4)
 266     {
 267         len = *sel_vector_table++ / 2;
 268         for (j = 0; j < len; j++)
 269         {
 270             delta_pair = *sel_vector_table++;
 271             s->y_predictor_table[i+j] = 0xfffffffe &
 272                 make_ydt16_entry(delta_pair >> 4, delta_pair & 0xf, s->ydt);
 273             s->c_predictor_table[i+j] = 0xfffffffe &
 274                 make_cdt16_entry(delta_pair >> 4, delta_pair & 0xf, s->cdt);
 275         }
 276         s->y_predictor_table[i+(j-1)] |= 1;
 277         s->c_predictor_table[i+(j-1)] |= 1;
 278     }
 279 }
 280
 281 static void gen_vector_table24(TrueMotion1Context *s, const uint8_t *sel_vector_table)
 282 {
 283     int len, i, j;
 284     unsigned char delta_pair;
 285
 286     for (i = 0; i < 1024; i += 4)
 287     {
 288         len = *sel_vector_table++ / 2;
 289         for (j = 0; j < len; j++)
 290         {
 291             delta_pair = *sel_vector_table++;
 292             s->y_predictor_table[i+j] = 0xfffffffe &
 293                 make_ydt24_entry(delta_pair >> 4, delta_pair & 0xf, s->ydt);
 294             s->c_predictor_table[i+j] = 0xfffffffe &
 295                 make_cdt24_entry(delta_pair >> 4, delta_pair & 0xf, s->cdt);
 296             s->fat_y_predictor_table[i+j] = 0xfffffffe &
 297                 make_ydt24_entry(delta_pair >> 4, delta_pair & 0xf, s->fat_ydt);
 298             s->fat_c_predictor_table[i+j] = 0xfffffffe &
 299                 make_cdt24_entry(delta_pair >> 4, delta_pair & 0xf, s->fat_cdt);
 300         }
 301         s->y_predictor_table[i+(j-1)] |= 1;
 302         s->c_predictor_table[i+(j-1)] |= 1;
 303         s->fat_y_predictor_table[i+(j-1)] |= 1;
 304         s->fat_c_predictor_table[i+(j-1)] |= 1;
 305     }
 306 }
 307
 308 /* Returns the number of bytes consumed from the bytestream. Returns -1 if
 309  * there was an error while decoding the header */
 310 static int truemotion1_decode_header(TrueMotion1Context *s)
 311 {
 312     int i, ret;
 313     int width_shift = 0;
 314     int new_pix_fmt;
 315     struct frame_header header;
 316     uint8_t header_buffer[128] = { 0 };  /* logical maximum size of the header */
 317     const uint8_t *sel_vector_table;
 318
 319     header.header_size = ((s->buf[0] >> 5) | (s->buf[0] << 3)) & 0x7f;
 320     if (s->buf[0] < 0x10)
 321     {
 322         av_log(s->avctx, AV_LOG_ERROR, "invalid header size (%d)\n", s->buf[0]);
 323         return AVERROR_INVALIDDATA;
 324     }
 325
 326     if (header.header_size + 1 > s->size) {
 327         av_log(s->avctx, AV_LOG_ERROR, "Input packet too small.\n");
 328         return AVERROR_INVALIDDATA;
 329     }
 330
 331     /* unscramble the header bytes with a XOR operation */
 332     for (i = 1; i < header.header_size; i++)
 333         header_buffer[i - 1] = s->buf[i] ^ s->buf[i + 1];
 334
 335     header.compression = header_buffer[0];
 336     header.deltaset = header_buffer[1];
 337     header.vectable = header_buffer[2];
 338     header.ysize = AV_RL16(&header_buffer[3]);
 339     header.xsize = AV_RL16(&header_buffer[5]);
 340     header.checksum = AV_RL16(&header_buffer[7]);
 341     header.version = header_buffer[9];
 342     header.header_type = header_buffer[10];
 343     header.flags = header_buffer[11];
 344     header.control = header_buffer[12];
 345
 346     /* Version 2 */
 347     if (header.version >= 2)
 348     {
 349         if (header.header_type > 3)
 350         {
 351             av_log(s->avctx, AV_LOG_ERROR, "invalid header type (%d)\n", header.header_type);
 352             return AVERROR_INVALIDDATA;
 353         } else if ((header.header_type == 2) || (header.header_type == 3)) {
 354             s->flags = header.flags;
 355             if (!(s->flags & FLAG_INTERFRAME))
 356                 s->flags |= FLAG_KEYFRAME;
 357         } else
 358             s->flags = FLAG_KEYFRAME;
 359     } else /* Version 1 */
 360         s->flags = FLAG_KEYFRAME;
 361
 362     if (s->flags & FLAG_SPRITE) {
 363         avpriv_request_sample(s->avctx, "Frame with sprite");
 364         /* FIXME header.width, height, xoffset and yoffset aren't initialized */
 365         return AVERROR_PATCHWELCOME;
 366     } else {
 367         s->w = header.xsize;
 368         s->h = header.ysize;
 369         if (header.header_type < 2) {
 370             if ((s->w < 213) && (s->h >= 176))
 371             {
 372                 s->flags |= FLAG_INTERPOLATED;
 373                 avpriv_request_sample(s->avctx, "Interpolated frame");
 374             }
 375         }
 376     }
 377
 378     if (header.compression >= 17) {
 379         av_log(s->avctx, AV_LOG_ERROR, "invalid compression type (%d)\n", header.compression);
 380         return AVERROR_INVALIDDATA;
 381     }
 382
 383     if ((header.deltaset != s->last_deltaset) ||
 384         (header.vectable != s->last_vectable))
 385         select_delta_tables(s, header.deltaset);
 386
 387     if ((header.compression & 1) && header.header_type)
 388         sel_vector_table = pc_tbl2;
 389     else {
 390         if (header.vectable > 0 && header.vectable < 4)
 391             sel_vector_table = tables[header.vectable - 1];
 392         else {
 393             av_log(s->avctx, AV_LOG_ERROR, "invalid vector table id (%d)\n", header.vectable);
 394             return AVERROR_INVALIDDATA;
 395         }
 396     }
 397
 398     if (compression_types[header.compression].algorithm == ALGO_RGB24H) {
 399         new_pix_fmt = AV_PIX_FMT_RGB32;
 400         width_shift = 1;
 401     } else
 402         new_pix_fmt = AV_PIX_FMT_RGB555; // RGB565 is supported as well
 403
 404     s->w >>= width_shift;
 405
 406     if (s->w != s->avctx->width || s->h != s->avctx->height ||
 407         new_pix_fmt != s->avctx->pix_fmt) {
 408         av_frame_unref(s->frame);
 409         s->avctx->sample_aspect_ratio = (AVRational){ 1 << width_shift, 1 };
 410         s->avctx->pix_fmt = new_pix_fmt;
 411
 412         if ((ret = ff_set_dimensions(s->avctx, s->w, s->h)) < 0)
 413             return ret;
 414
 415         ff_set_sar(s->avctx, s->avctx->sample_aspect_ratio);
 416
 417         av_fast_malloc(&s->vert_pred, &s->vert_pred_size, s->avctx->width * sizeof(unsigned int));
 418         if (!s->vert_pred)
 419             return AVERROR(ENOMEM);
 420     }
 421
 422     /* There is 1 change bit per 4 pixels, so each change byte represents
 423      * 32 pixels; divide width by 4 to obtain the number of change bits and
 424      * then round up to the nearest byte. */
 425     s->mb_change_bits_row_size = ((s->avctx->width >> (2 - width_shift)) + 7) >> 3;
 426
 427     if ((header.deltaset != s->last_deltaset) || (header.vectable != s->last_vectable))
 428     {
 429         if (compression_types[header.compression].algorithm == ALGO_RGB24H)
 430             gen_vector_table24(s, sel_vector_table);
 431         else
 432         if (s->avctx->pix_fmt == AV_PIX_FMT_RGB555)
 433             gen_vector_table15(s, sel_vector_table);
 434         else
 435             gen_vector_table16(s, sel_vector_table);
 436     }
 437
 438     /* set up pointers to the other key data chunks */
 439     s->mb_change_bits = s->buf + header.header_size;
 440     if (s->flags & FLAG_KEYFRAME) {
 441         /* no change bits specified for a keyframe; only index bytes */
 442         s->index_stream = s->mb_change_bits;
 443     } else {
 444         /* one change bit per 4x4 block */
 445         s->index_stream = s->mb_change_bits +
 446             (s->mb_change_bits_row_size * (s->avctx->height >> 2));
 447     }
 448     s->index_stream_size = s->size - (s->index_stream - s->buf);
 449
 450     s->last_deltaset = header.deltaset;
 451     s->last_vectable = header.vectable;
 452     s->compression = header.compression;
 453     s->block_width = compression_types[header.compression].block_width;
 454     s->block_height = compression_types[header.compression].block_height;
 455     s->block_type = compression_types[header.compression].block_type;
 456
 457     if (s->avctx->debug & FF_DEBUG_PICT_INFO)
 458         av_log(s->avctx, AV_LOG_INFO, "tables: %d / %d c:%d %dx%d t:%d %s%s%s%s\n",
 459             s->last_deltaset, s->last_vectable, s->compression, s->block_width,
 460             s->block_height, s->block_type,
 461             s->flags & FLAG_KEYFRAME ? " KEY" : "",
 462             s->flags & FLAG_INTERFRAME ? " INTER" : "",
 463             s->flags & FLAG_SPRITE ? " SPRITE" : "",
 464             s->flags & FLAG_INTERPOLATED ? " INTERPOL" : "");
 465
 466     return header.header_size;
 467 }
 468
 469 static av_cold int truemotion1_decode_init(AVCodecContext *avctx)
 470 {
 471     TrueMotion1Context *s = avctx->priv_data;
 472
 473     s->avctx = avctx;
 474
 475     // FIXME: it may change ?
 476 //    if (avctx->bits_per_sample == 24)
 477 //        avctx->pix_fmt = AV_PIX_FMT_RGB24;
 478 //    else
 479 //        avctx->pix_fmt = AV_PIX_FMT_RGB555;
 480
 481     s->frame = av_frame_alloc();
 482     if (!s->frame)
 483         return AVERROR(ENOMEM);
 484
 485     /* there is a vertical predictor for each pixel in a line; each vertical
 486      * predictor is 0 to start with */
 487     av_fast_malloc(&s->vert_pred, &s->vert_pred_size, s->avctx->width * sizeof(unsigned int));
 488     if (!s->vert_pred)
 489         return AVERROR(ENOMEM);
 490
 491     return 0;
 492 }
 493
 494 /*
 495 Block decoding order:
 496
 497 dxi: Y-Y
 498 dxic: Y-C-Y
 499 dxic2: Y-C-Y-C
 500
 501 hres,vres,i,i%vres (0 < i < 4)
 502 2x2 0: 0 dxic2
 503 2x2 1: 1 dxi
 504 2x2 2: 0 dxic2
 505 2x2 3: 1 dxi
 506 2x4 0: 0 dxic2
 507 2x4 1: 1 dxi
 508 2x4 2: 2 dxi
 509 2x4 3: 3 dxi
 510 4x2 0: 0 dxic
 511 4x2 1: 1 dxi
 512 4x2 2: 0 dxic
 513 4x2 3: 1 dxi
 514 4x4 0: 0 dxic
 515 4x4 1: 1 dxi
 516 4x4 2: 2 dxi
 517 4x4 3: 3 dxi
 518 */
 519
 520 #define GET_NEXT_INDEX() \
 521 {\
 522     if (index_stream_index >= s->index_stream_size) { \
 523         av_log(s->avctx, AV_LOG_INFO, " help! truemotion1 decoder went out of bounds\n"); \
 524         return; \
 525     } \
 526     index = s->index_stream[index_stream_index++] * 4; \
 527 }
 528
 529 #define INC_INDEX                                                   \
 530 do {                                                                \
 531     if (index >= 1023) {                                            \
 532         av_log(s->avctx, AV_LOG_ERROR, "Invalid index value.\n");   \
 533         return;                                                     \
 534     }                                                               \
 535     index++;                                                        \
 536 } while (0)
 537
 538 #define APPLY_C_PREDICTOR() \
 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->c_predictor_table[index]; \
 546             horiz_pred += ((predictor_pair >> 1) * 5); \
 547             if (predictor_pair & 1) \
 548                 GET_NEXT_INDEX() \
 549             else \
 550                 INC_INDEX; \
 551         } \
 552     } else \
 553         INC_INDEX;
 554
 555 #define APPLY_C_PREDICTOR_24() \
 556     predictor_pair = s->c_predictor_table[index]; \
 557     horiz_pred += (predictor_pair >> 1); \
 558     if (predictor_pair & 1) { \
 559         GET_NEXT_INDEX() \
 560         if (!index) { \
 561             GET_NEXT_INDEX() \
 562             predictor_pair = s->fat_c_predictor_table[index]; \
 563             horiz_pred += (predictor_pair >> 1); \
 564             if (predictor_pair & 1) \
 565                 GET_NEXT_INDEX() \
 566             else \
 567                 INC_INDEX; \
 568         } \
 569     } else \
 570         INC_INDEX;
 571
 572
 573 #define APPLY_Y_PREDICTOR() \
 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->y_predictor_table[index]; \
 581             horiz_pred += ((predictor_pair >> 1) * 5); \
 582             if (predictor_pair & 1) \
 583                 GET_NEXT_INDEX() \
 584             else \
 585                 INC_INDEX; \
 586         } \
 587     } else \
 588         INC_INDEX;
 589
 590 #define APPLY_Y_PREDICTOR_24() \
 591     predictor_pair = s->y_predictor_table[index]; \
 592     horiz_pred += (predictor_pair >> 1); \
 593     if (predictor_pair & 1) { \
 594         GET_NEXT_INDEX() \
 595         if (!index) { \
 596             GET_NEXT_INDEX() \
 597             predictor_pair = s->fat_y_predictor_table[index]; \
 598             horiz_pred += (predictor_pair >> 1); \
 599             if (predictor_pair & 1) \
 600                 GET_NEXT_INDEX() \
 601             else \
 602                 INC_INDEX; \
 603         } \
 604     } else \
 605         INC_INDEX;
 606
 607 #define OUTPUT_PIXEL_PAIR() \
 608     *current_pixel_pair = *vert_pred + horiz_pred; \
 609     *vert_pred++ = *current_pixel_pair++;
 610
 611 static void truemotion1_decode_16bit(TrueMotion1Context *s)
 612 {
 613     int y;
 614     int pixels_left;  /* remaining pixels on this line */
 615     unsigned int predictor_pair;
 616     unsigned int horiz_pred;
 617     unsigned int *vert_pred;
 618     unsigned int *current_pixel_pair;
 619     unsigned char *current_line = s->frame->data[0];
 620     int keyframe = s->flags & FLAG_KEYFRAME;
 621
 622     /* these variables are for managing the stream of macroblock change bits */
 623     const unsigned char *mb_change_bits = s->mb_change_bits;
 624     unsigned char mb_change_byte;
 625     unsigned char mb_change_byte_mask;
 626     int mb_change_index;
 627
 628     /* these variables are for managing the main index stream */
 629     int index_stream_index = 0;  /* yes, the index into the index stream */
 630     int index;
 631
 632     /* clean out the line buffer */
 633     memset(s->vert_pred, 0, s->avctx->width * sizeof(unsigned int));
 634
 635     GET_NEXT_INDEX();
 636
 637     for (y = 0; y < s->avctx->height; y++) {
 638
 639         /* re-init variables for the next line iteration */
 640         horiz_pred = 0;
 641         current_pixel_pair = (unsigned int *)current_line;
 642         vert_pred = s->vert_pred;
 643         mb_change_index = 0;
 644         mb_change_byte = mb_change_bits[mb_change_index++];
 645         mb_change_byte_mask = 0x01;
 646         pixels_left = s->avctx->width;
 647
 648         while (pixels_left > 0) {
 649
 650             if (keyframe || ((mb_change_byte & mb_change_byte_mask) == 0)) {
 651
 652                 switch (y & 3) {
 653                 case 0:
 654                     /* if macroblock width is 2, apply C-Y-C-Y; else
 655                      * apply C-Y-Y */
 656                     if (s->block_width == 2) {
 657                         APPLY_C_PREDICTOR();
 658                         APPLY_Y_PREDICTOR();
 659                         OUTPUT_PIXEL_PAIR();
 660                         APPLY_C_PREDICTOR();
 661                         APPLY_Y_PREDICTOR();
 662                         OUTPUT_PIXEL_PAIR();
 663                     } else {
 664                         APPLY_C_PREDICTOR();
 665                         APPLY_Y_PREDICTOR();
 666                         OUTPUT_PIXEL_PAIR();
 667                         APPLY_Y_PREDICTOR();
 668                         OUTPUT_PIXEL_PAIR();
 669                     }
 670                     break;
 671
 672                 case 1:
 673                 case 3:
 674                     /* always apply 2 Y predictors on these iterations */
 675                     APPLY_Y_PREDICTOR();
 676                     OUTPUT_PIXEL_PAIR();
 677                     APPLY_Y_PREDICTOR();
 678                     OUTPUT_PIXEL_PAIR();
 679                     break;
 680
 681                 case 2:
 682                     /* this iteration might be C-Y-C-Y, Y-Y, or C-Y-Y
 683                      * depending on the macroblock type */
 684                     if (s->block_type == BLOCK_2x2) {
 685                         APPLY_C_PREDICTOR();
 686                         APPLY_Y_PREDICTOR();
 687                         OUTPUT_PIXEL_PAIR();
 688                         APPLY_C_PREDICTOR();
 689                         APPLY_Y_PREDICTOR();
 690                         OUTPUT_PIXEL_PAIR();
 691                     } else if (s->block_type == BLOCK_4x2) {
 692                         APPLY_C_PREDICTOR();
 693                         APPLY_Y_PREDICTOR();
 694                         OUTPUT_PIXEL_PAIR();
 695                         APPLY_Y_PREDICTOR();
 696                         OUTPUT_PIXEL_PAIR();
 697                     } else {
 698                         APPLY_Y_PREDICTOR();
 699                         OUTPUT_PIXEL_PAIR();
 700                         APPLY_Y_PREDICTOR();
 701                         OUTPUT_PIXEL_PAIR();
 702                     }
 703                     break;
 704                 }
 705
 706             } else {
 707
 708                 /* skip (copy) four pixels, but reassign the horizontal
 709                  * predictor */
 710                 *vert_pred++ = *current_pixel_pair++;
 711                 horiz_pred = *current_pixel_pair - *vert_pred;
 712                 *vert_pred++ = *current_pixel_pair++;
 713
 714             }
 715
 716             if (!keyframe) {
 717                 mb_change_byte_mask <<= 1;
 718
 719                 /* next byte */
 720                 if (!mb_change_byte_mask) {
 721                     mb_change_byte = mb_change_bits[mb_change_index++];
 722                     mb_change_byte_mask = 0x01;
 723                 }
 724             }
 725
 726             pixels_left -= 4;
 727         }
 728
 729         /* next change row */
 730         if (((y + 1) & 3) == 0)
 731             mb_change_bits += s->mb_change_bits_row_size;
 732
 733         current_line += s->frame->linesize[0];
 734     }
 735 }
 736
 737 static void truemotion1_decode_24bit(TrueMotion1Context *s)
 738 {
 739     int y;
 740     int pixels_left;  /* remaining pixels on this line */
 741     unsigned int predictor_pair;
 742     unsigned int horiz_pred;
 743     unsigned int *vert_pred;
 744     unsigned int *current_pixel_pair;
 745     unsigned char *current_line = s->frame->data[0];
 746     int keyframe = s->flags & FLAG_KEYFRAME;
 747
 748     /* these variables are for managing the stream of macroblock change bits */
 749     const unsigned char *mb_change_bits = s->mb_change_bits;
 750     unsigned char mb_change_byte;
 751     unsigned char mb_change_byte_mask;
 752     int mb_change_index;
 753
 754     /* these variables are for managing the main index stream */
 755     int index_stream_index = 0;  /* yes, the index into the index stream */
 756     int index;
 757
 758     /* clean out the line buffer */
 759     memset(s->vert_pred, 0, s->avctx->width * sizeof(unsigned int));
 760
 761     GET_NEXT_INDEX();
 762
 763     for (y = 0; y < s->avctx->height; y++) {
 764
 765         /* re-init variables for the next line iteration */
 766         horiz_pred = 0;
 767         current_pixel_pair = (unsigned int *)current_line;
 768         vert_pred = s->vert_pred;
 769         mb_change_index = 0;
 770         mb_change_byte = mb_change_bits[mb_change_index++];
 771         mb_change_byte_mask = 0x01;
 772         pixels_left = s->avctx->width;
 773
 774         while (pixels_left > 0) {
 775
 776             if (keyframe || ((mb_change_byte & mb_change_byte_mask) == 0)) {
 777
 778                 switch (y & 3) {
 779                 case 0:
 780                     /* if macroblock width is 2, apply C-Y-C-Y; else
 781                      * apply C-Y-Y */
 782                     if (s->block_width == 2) {
 783                         APPLY_C_PREDICTOR_24();
 784                         APPLY_Y_PREDICTOR_24();
 785                         OUTPUT_PIXEL_PAIR();
 786                         APPLY_C_PREDICTOR_24();
 787                         APPLY_Y_PREDICTOR_24();
 788                         OUTPUT_PIXEL_PAIR();
 789                     } else {
 790                         APPLY_C_PREDICTOR_24();
 791                         APPLY_Y_PREDICTOR_24();
 792                         OUTPUT_PIXEL_PAIR();
 793                         APPLY_Y_PREDICTOR_24();
 794                         OUTPUT_PIXEL_PAIR();
 795                     }
 796                     break;
 797
 798                 case 1:
 799                 case 3:
 800                     /* always apply 2 Y predictors on these iterations */
 801                     APPLY_Y_PREDICTOR_24();
 802                     OUTPUT_PIXEL_PAIR();
 803                     APPLY_Y_PREDICTOR_24();
 804                     OUTPUT_PIXEL_PAIR();
 805                     break;
 806
 807                 case 2:
 808                     /* this iteration might be C-Y-C-Y, Y-Y, or C-Y-Y
 809                      * depending on the macroblock type */
 810                     if (s->block_type == BLOCK_2x2) {
 811                         APPLY_C_PREDICTOR_24();
 812                         APPLY_Y_PREDICTOR_24();
 813                         OUTPUT_PIXEL_PAIR();
 814                         APPLY_C_PREDICTOR_24();
 815                         APPLY_Y_PREDICTOR_24();
 816                         OUTPUT_PIXEL_PAIR();
 817                     } else if (s->block_type == BLOCK_4x2) {
 818                         APPLY_C_PREDICTOR_24();
 819                         APPLY_Y_PREDICTOR_24();
 820                         OUTPUT_PIXEL_PAIR();
 821                         APPLY_Y_PREDICTOR_24();
 822                         OUTPUT_PIXEL_PAIR();
 823                     } else {
 824                         APPLY_Y_PREDICTOR_24();
 825                         OUTPUT_PIXEL_PAIR();
 826                         APPLY_Y_PREDICTOR_24();
 827                         OUTPUT_PIXEL_PAIR();
 828                     }
 829                     break;
 830                 }
 831
 832             } else {
 833
 834                 /* skip (copy) four pixels, but reassign the horizontal
 835                  * predictor */
 836                 *vert_pred++ = *current_pixel_pair++;
 837                 horiz_pred = *current_pixel_pair - *vert_pred;
 838                 *vert_pred++ = *current_pixel_pair++;
 839
 840             }
 841
 842             if (!keyframe) {
 843                 mb_change_byte_mask <<= 1;
 844
 845                 /* next byte */
 846                 if (!mb_change_byte_mask) {
 847                     mb_change_byte = mb_change_bits[mb_change_index++];
 848                     mb_change_byte_mask = 0x01;
 849                 }
 850             }
 851
 852             pixels_left -= 2;
 853         }
 854
 855         /* next change row */
 856         if (((y + 1) & 3) == 0)
 857             mb_change_bits += s->mb_change_bits_row_size;
 858
 859         current_line += s->frame->linesize[0];
 860     }
 861 }
 862
 863
 864 static int truemotion1_decode_frame(AVCodecContext *avctx,
 865                                     void *data, int *got_frame,
 866                                     AVPacket *avpkt)
 867 {
 868     const uint8_t *buf = avpkt->data;
 869     int ret, buf_size = avpkt->size;
 870     TrueMotion1Context *s = avctx->priv_data;
 871
 872     s->buf = buf;
 873     s->size = buf_size;
 874
 875     if ((ret = truemotion1_decode_header(s)) < 0)
 876         return ret;
 877
 878     if ((ret = ff_reget_buffer(avctx, s->frame)) < 0)
 879         return ret;
 880
 881     if (compression_types[s->compression].algorithm == ALGO_RGB24H) {
 882         truemotion1_decode_24bit(s);
 883     } else if (compression_types[s->compression].algorithm != ALGO_NOP) {
 884         truemotion1_decode_16bit(s);
 885     }
 886
 887     if ((ret = av_frame_ref(data, s->frame)) < 0)
 888         return ret;
 889
 890     *got_frame      = 1;
 891
 892     /* report that the buffer was completely consumed */
 893     return buf_size;
 894 }
 895
 896 static av_cold int truemotion1_decode_end(AVCodecContext *avctx)
 897 {
 898     TrueMotion1Context *s = avctx->priv_data;
 899
 900     av_frame_free(&s->frame);
 901     av_freep(&s->vert_pred);
 902
 903     return 0;
 904 }
 905
 906 AVCodec ff_truemotion1_decoder = {
 907     .name           = "truemotion1",
 908     .long_name      = NULL_IF_CONFIG_SMALL("Duck TrueMotion 1.0"),
 909     .type           = AVMEDIA_TYPE_VIDEO,
 910     .id             = AV_CODEC_ID_TRUEMOTION1,
 911     .priv_data_size = sizeof(TrueMotion1Context),
 912     .init           = truemotion1_decode_init,
 913     .close          = truemotion1_decode_end,
 914     .decode         = truemotion1_decode_frame,
 915     .capabilities   = CODEC_CAP_DR1,
 916 };