libavcodec/truemotion1.c

   1 /*
   2  * Duck TrueMotion 1.0 Decoder
   3  * Copyright (C) 2003 Alex Beregszaszi & Mike Melanson
   4  *
   5  * This library is free software; you can redistribute it and/or
   6  * modify it under the terms of the GNU Lesser General Public
   7  * License as published by the Free Software Foundation; either
   8  * version 2 of the License, or (at your option) any later version.
   9  *
  10  * This library is distributed in the hope that it will be useful,
  11  * but WITHOUT ANY WARRANTY; without even the implied warranty of
  12  * MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE.  See the GNU
  13  * Lesser General Public License for more details.
  14  *
  15  * You should have received a copy of the GNU Lesser General Public
  16  * License along with this library; if not, write to the Free Software
  17  * Foundation, Inc., 59 Temple Place, Suite 330, Boston, MA  02111-1307  USA
  18  */
  19
  20 /**
  21  * @file truemotion1.c
  22  * Duck TrueMotion v1 Video Decoder by
  23  * Alex Beregszaszi (alex@fsn.hu) and
  24  * Mike Melanson (melanson@pcisys.net)
  25  *
  26  * The TrueMotion v1 decoder presently only decodes 16-bit TM1 data and
  27  * outputs RGB555 data. 24-bit TM1 data is not supported yet.
  28  */
  29
  30 #include <stdio.h>
  31 #include <stdlib.h>
  32 #include <string.h>
  33 #include <unistd.h>
  34
  35 #include "common.h"
  36 #include "avcodec.h"
  37 #include "dsputil.h"
  38
  39 #include "truemotion1data.h"
  40
  41 typedef struct TrueMotion1Context {
  42     AVCodecContext *avctx;
  43     AVFrame frame;
  44     AVFrame prev_frame;
  45
  46     unsigned char *buf;
  47     int size;
  48
  49     unsigned char *mb_change_bits;
  50     int mb_change_bits_row_size;
  51     unsigned char *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
  60     int compression;
  61     int block_type;
  62     int block_width;
  63     int block_height;
  64
  65     int16_t ydt[8];
  66     int16_t cdt[8];
  67     int16_t fat_ydt[8];
  68     int16_t fat_cdt[8];
  69
  70     int last_deltaset, last_vectable;
  71
  72     unsigned int *vert_pred;
  73
  74 } TrueMotion1Context;
  75
  76 #define FLAG_SPRITE         32
  77 #define FLAG_KEYFRAME       16
  78 #define FLAG_INTERFRAME      8
  79 #define FLAG_INTERPOLATED    4
  80
  81 struct frame_header {
  82     uint8_t header_size;
  83     uint8_t compression;
  84     uint8_t deltaset;
  85     uint8_t vectable;
  86     uint16_t ysize;
  87     uint16_t xsize;
  88     uint16_t checksum;
  89     uint8_t version;
  90     uint8_t header_type;
  91     uint8_t flags;
  92     uint8_t control;
  93     uint16_t xoffset;
  94     uint16_t yoffset;
  95     uint16_t width;
  96     uint16_t height;
  97 };
  98
  99 #define ALGO_NOP        0
 100 #define ALGO_RGB16V     1
 101 #define ALGO_RGB16H     2
 102 #define ALGO_RGB24H     3
 103
 104 /* these are the various block sizes that can occupy a 4x4 block */
 105 #define BLOCK_2x2  0
 106 #define BLOCK_2x4  1
 107 #define BLOCK_4x2  2
 108 #define BLOCK_4x4  3
 109
 110 typedef struct comp_types {
 111     int algorithm;
 112     int block_width;
 113     int block_height;
 114     int block_type;
 115 } comp_types;
 116
 117 /* { valid for metatype }, algorithm, num of deltas, horiz res, vert res */
 118 static comp_types compression_types[17] = {
 119     { ALGO_NOP,    0, 0, 0 },
 120
 121     { ALGO_RGB16V, 4, 4, BLOCK_4x4 },
 122     { ALGO_RGB16H, 4, 4, BLOCK_4x4 },
 123     { ALGO_RGB16V, 4, 2, BLOCK_4x2 },
 124     { ALGO_RGB16H, 4, 2, BLOCK_4x2 },
 125
 126     { ALGO_RGB16V, 2, 4, BLOCK_2x4 },
 127     { ALGO_RGB16H, 2, 4, BLOCK_2x4 },
 128     { ALGO_RGB16V, 2, 2, BLOCK_2x2 },
 129     { ALGO_RGB16H, 2, 2, BLOCK_2x2 },
 130
 131     { ALGO_NOP,    4, 4, BLOCK_4x4 },
 132     { ALGO_RGB24H, 4, 4, BLOCK_4x4 },
 133     { ALGO_NOP,    4, 2, BLOCK_4x2 },
 134     { ALGO_RGB24H, 4, 2, BLOCK_4x2 },
 135
 136     { ALGO_NOP,    2, 4, BLOCK_2x4 },
 137     { ALGO_RGB24H, 2, 4, BLOCK_2x4 },
 138     { ALGO_NOP,    2, 2, BLOCK_2x2 },
 139     { ALGO_RGB24H, 2, 2, BLOCK_2x2 }
 140 };
 141
 142 static void select_delta_tables(TrueMotion1Context *s, int delta_table_index)
 143 {
 144     int i;
 145
 146     if (delta_table_index > 3)
 147         return;
 148
 149     memcpy(s->ydt, ydts[delta_table_index], 8 * sizeof(int16_t));
 150     memcpy(s->cdt, cdts[delta_table_index], 8 * sizeof(int16_t));
 151     memcpy(s->fat_ydt, fat_ydts[delta_table_index], 8 * sizeof(int16_t));
 152     memcpy(s->fat_cdt, fat_cdts[delta_table_index], 8 * sizeof(int16_t));
 153
 154     /* Y skinny deltas need to be halved for some reason; maybe the
 155      * skinny Y deltas should be modified */
 156     for (i = 0; i < 8; i++)
 157     {
 158         /* drop the lsb before dividing by 2-- net effect: round down
 159          * when dividing a negative number (e.g., -3/2 = -2, not -1) */
 160         s->ydt[i] &= 0xFFFE;
 161         s->ydt[i] /= 2;
 162     }
 163 }
 164
 165 #ifdef WORDS_BIGENDIAN
 166 static int make_ydt_entry(int p2, int p1, int16_t *ydt)
 167 #else
 168 static int make_ydt_entry(int p1, int p2, int16_t *ydt)
 169 #endif
 170 {
 171     int lo, hi;
 172
 173     lo = ydt[p1];
 174     lo += (lo << 5) + (lo << 10);
 175     hi = ydt[p2];
 176     hi += (hi << 5) + (hi << 10);
 177     return ((lo + (hi << 16)) << 1);
 178 }
 179
 180 #ifdef WORDS_BIGENDIAN
 181 static int make_cdt_entry(int p2, int p1, int16_t *cdt)
 182 #else
 183 static int make_cdt_entry(int p1, int p2, int16_t *cdt)
 184 #endif
 185 {
 186     int r, b, lo;
 187
 188     b = cdt[p2];
 189     r = cdt[p1] << 10;
 190     lo = b + r;
 191     return ((lo + (lo << 16)) << 1);
 192 }
 193
 194 static void gen_vector_table(TrueMotion1Context *s, uint8_t *sel_vector_table)
 195 {
 196     int len, i, j;
 197     unsigned char delta_pair;
 198
 199     for (i = 0; i < 1024; i += 4)
 200     {
 201         len = *sel_vector_table++ / 2;
 202         for (j = 0; j < len; j++)
 203         {
 204             delta_pair = *sel_vector_table++;
 205             s->y_predictor_table[i+j] = 0xfffffffe &
 206                 make_ydt_entry(delta_pair >> 4, delta_pair & 0xf, s->ydt);
 207             s->c_predictor_table[i+j] = 0xfffffffe &
 208                 make_cdt_entry(delta_pair >> 4, delta_pair & 0xf, s->cdt);
 209         }
 210         s->y_predictor_table[i+(j-1)] |= 1;
 211         s->c_predictor_table[i+(j-1)] |= 1;
 212     }
 213 }
 214
 215 /* Returns the number of bytes consumed from the bytestream. Returns -1 if
 216  * there was an error while decoding the header */
 217 static int truemotion1_decode_header(TrueMotion1Context *s)
 218 {
 219     int i;
 220     struct frame_header header;
 221     uint8_t header_buffer[128];  /* logical maximum size of the header */
 222     uint8_t *sel_vector_table;
 223
 224     /* There is 1 change bit per 4 pixels, so each change byte represents
 225      * 32 pixels; divide width by 4 to obtain the number of change bits and
 226      * then round up to the nearest byte. */
 227     s->mb_change_bits_row_size = ((s->avctx->width >> 2) + 7) >> 3;
 228
 229     header.header_size = ((s->buf[0] >> 5) | (s->buf[0] << 3)) & 0x7f;
 230     if (s->buf[0] < 0x10)
 231     {
 232         av_log(s->avctx, AV_LOG_ERROR, "invalid header size\n");
 233         return -1;
 234     }
 235
 236     /* unscramble the header bytes with a XOR operation */
 237     memset(header_buffer, 0, 128);
 238     for (i = 1; i < header.header_size; i++)
 239     header_buffer[i - 1] = s->buf[i] ^ s->buf[i + 1];
 240     header.compression = header_buffer[0];
 241     header.deltaset = header_buffer[1];
 242     header.vectable = header_buffer[2];
 243     header.ysize = LE_16(&header_buffer[3]);
 244     header.xsize = LE_16(&header_buffer[5]);
 245     header.checksum = LE_16(&header_buffer[7]);
 246     header.version = header_buffer[9];
 247     header.header_type = header_buffer[10];
 248     header.flags = header_buffer[11];
 249     header.control = header_buffer[12];
 250
 251     /* Version 2 */
 252     if (header.version >= 2)
 253     {
 254         if (header.header_type > 3)
 255         {
 256             av_log(s->avctx, AV_LOG_ERROR, "truemotion1: invalid header type\n");
 257             return -1;
 258         } else if ((header.header_type == 2) || (header.header_type == 3)) {
 259             s->flags = header.flags;
 260             if (!(s->flags & FLAG_INTERFRAME))
 261                 s->flags |= FLAG_KEYFRAME;
 262         } else
 263             s->flags = FLAG_KEYFRAME;
 264     } else /* Version 1 */
 265         s->flags = FLAG_KEYFRAME;
 266
 267     if (s->flags & FLAG_SPRITE) {
 268         s->w = header.width;
 269         s->h = header.height;
 270         s->x = header.xoffset;
 271         s->y = header.yoffset;
 272     } else {
 273         s->w = header.xsize;
 274         s->h = header.ysize;
 275         if (header.header_type < 2) {
 276             if ((s->w < 213) && (s->h >= 176))
 277                 s->flags |= FLAG_INTERPOLATED;
 278         }
 279     }
 280
 281     if (header.compression > 17) {
 282         av_log(s->avctx, AV_LOG_ERROR, "invalid compression type (%d)\n", header.compression);
 283         return -1;
 284     }
 285
 286     if ((header.deltaset != s->last_deltaset) ||
 287         (header.vectable != s->last_vectable))
 288         select_delta_tables(s, header.deltaset);
 289
 290     if ((header.compression & 1) && header.header_type)
 291         sel_vector_table = pc_tbl2;
 292     else {
 293         if (header.vectable < 4)
 294             sel_vector_table = tables[header.vectable - 1];
 295         else {
 296             av_log(s->avctx, AV_LOG_ERROR, "invalid vector table id (%d)\n", header.vectable);
 297             return -1;
 298         }
 299     }
 300
 301     if ((header.deltaset != s->last_deltaset) || (header.vectable != s->last_vectable))
 302     {
 303         if (compression_types[header.compression].algorithm == ALGO_RGB24H)
 304         {
 305             av_log(s->avctx, AV_LOG_ERROR, "24bit compression not yet supported\n");
 306         }
 307         else
 308             gen_vector_table(s, sel_vector_table);
 309     }
 310
 311     /* set up pointers to the other key data chunks */
 312     s->mb_change_bits = s->buf + header.header_size;
 313     if (s->flags & FLAG_KEYFRAME) {
 314         /* no change bits specified for a keyframe; only index bytes */
 315         s->index_stream = s->mb_change_bits;
 316     } else {
 317         /* one change bit per 4x4 block */
 318         s->index_stream = s->mb_change_bits +
 319             (s->mb_change_bits_row_size * (s->avctx->height >> 2));
 320     }
 321     s->index_stream_size = s->size - (s->index_stream - s->buf);
 322
 323     s->last_deltaset = header.deltaset;
 324     s->last_vectable = header.vectable;
 325     s->compression = header.compression;
 326     s->block_width = compression_types[header.compression].block_width;
 327     s->block_height = compression_types[header.compression].block_height;
 328     s->block_type = compression_types[header.compression].block_type;
 329
 330     return header.header_size;
 331 }
 332
 333 static int truemotion1_decode_init(AVCodecContext *avctx)
 334 {
 335     TrueMotion1Context *s = (TrueMotion1Context *)avctx->priv_data;
 336
 337     s->avctx = avctx;
 338
 339     avctx->pix_fmt = PIX_FMT_RGB555;
 340     avctx->has_b_frames = 0;
 341     s->frame.data[0] = s->prev_frame.data[0] = NULL;
 342
 343     /* there is a vertical predictor for each pixel in a line; each vertical
 344      * predictor is 0 to start with */
 345     s->vert_pred =
 346         (unsigned int *)av_malloc(s->avctx->width * sizeof(unsigned short));
 347
 348     return 0;
 349 }
 350
 351 #define GET_NEXT_INDEX() \
 352 {\
 353     if (index_stream_index >= s->index_stream_size) { \
 354         av_log(s->avctx, AV_LOG_INFO, " help! truemotion1 decoder went out of bounds\n"); \
 355         return; \
 356     } \
 357     index = s->index_stream[index_stream_index++] * 4; \
 358 }
 359
 360 #define APPLY_C_PREDICTOR() \
 361     predictor_pair = s->c_predictor_table[index]; \
 362     horiz_pred += (predictor_pair >> 1); \
 363     if (predictor_pair & 1) { \
 364         GET_NEXT_INDEX() \
 365         if (!index) { \
 366             GET_NEXT_INDEX() \
 367             predictor_pair = s->c_predictor_table[index]; \
 368             horiz_pred += ((predictor_pair >> 1) * 5); \
 369             if (predictor_pair & 1) \
 370                 GET_NEXT_INDEX() \
 371             else \
 372                 index++; \
 373         } \
 374     } else \
 375         index++;
 376
 377 #define APPLY_Y_PREDICTOR() \
 378     predictor_pair = s->y_predictor_table[index]; \
 379     horiz_pred += (predictor_pair >> 1); \
 380     if (predictor_pair & 1) { \
 381         GET_NEXT_INDEX() \
 382         if (!index) { \
 383             GET_NEXT_INDEX() \
 384             predictor_pair = s->y_predictor_table[index]; \
 385             horiz_pred += ((predictor_pair >> 1) * 5); \
 386             if (predictor_pair & 1) \
 387                 GET_NEXT_INDEX() \
 388             else \
 389                 index++; \
 390         } \
 391     } else \
 392         index++;
 393
 394 #define OUTPUT_PIXEL_PAIR() \
 395     *current_pixel_pair = *vert_pred + horiz_pred; \
 396     *vert_pred++ = *current_pixel_pair++; \
 397     prev_pixel_pair++;
 398
 399 static void truemotion1_decode_16bit(TrueMotion1Context *s)
 400 {
 401     int y;
 402     int pixels_left;  /* remaining pixels on this line */
 403     unsigned int predictor_pair;
 404     unsigned int horiz_pred;
 405     unsigned int *vert_pred;
 406     unsigned int *current_pixel_pair;
 407     unsigned int *prev_pixel_pair;
 408     unsigned char *current_line = s->frame.data[0];
 409     unsigned char *prev_line = s->prev_frame.data[0];
 410     int keyframe = s->flags & FLAG_KEYFRAME;
 411
 412     /* these variables are for managing the stream of macroblock change bits */
 413     unsigned char *mb_change_bits = s->mb_change_bits;
 414     unsigned char mb_change_byte;
 415     unsigned char mb_change_byte_mask;
 416     int mb_change_index;
 417
 418     /* these variables are for managing the main index stream */
 419     int index_stream_index = 0;  /* yes, the index into the index stream */
 420     int index;
 421
 422     /* clean out the line buffer */
 423     memset(s->vert_pred, 0, s->avctx->width * sizeof(unsigned short));
 424
 425     GET_NEXT_INDEX();
 426
 427     for (y = 0; y < s->avctx->height; y++) {
 428
 429         /* re-init variables for the next line iteration */
 430         horiz_pred = 0;
 431         current_pixel_pair = (unsigned int *)current_line;
 432         prev_pixel_pair = (unsigned int *)prev_line;
 433         vert_pred = s->vert_pred;
 434         mb_change_index = 0;
 435         mb_change_byte = mb_change_bits[mb_change_index++];
 436         mb_change_byte_mask = 0x01;
 437         pixels_left = s->avctx->width;
 438
 439         while (pixels_left > 0) {
 440
 441             if (keyframe || ((mb_change_byte & mb_change_byte_mask) == 0)) {
 442
 443                 switch (y & 3) {
 444                 case 0:
 445                     /* if macroblock width is 2, apply C-Y-C-Y; else
 446                      * apply C-Y-Y */
 447                     if (s->block_width == 2) {
 448                         APPLY_C_PREDICTOR();
 449                         APPLY_Y_PREDICTOR();
 450                         OUTPUT_PIXEL_PAIR();
 451                         APPLY_C_PREDICTOR();
 452                         APPLY_Y_PREDICTOR();
 453                         OUTPUT_PIXEL_PAIR();
 454                     } else {
 455                         APPLY_C_PREDICTOR();
 456                         APPLY_Y_PREDICTOR();
 457                         OUTPUT_PIXEL_PAIR();
 458                         APPLY_Y_PREDICTOR();
 459                         OUTPUT_PIXEL_PAIR();
 460                     }
 461                     break;
 462
 463                 case 1:
 464                 case 3:
 465                     /* always apply 2 Y predictors on these iterations */
 466                     APPLY_Y_PREDICTOR();
 467                     OUTPUT_PIXEL_PAIR();
 468                     APPLY_Y_PREDICTOR();
 469                     OUTPUT_PIXEL_PAIR();
 470                     break;
 471
 472                 case 2:
 473                     /* this iteration might be C-Y-C-Y, Y-Y, or C-Y-Y
 474                      * depending on the macroblock type */
 475                     if (s->block_type == BLOCK_2x2) {
 476                         APPLY_C_PREDICTOR();
 477                         APPLY_Y_PREDICTOR();
 478                         OUTPUT_PIXEL_PAIR();
 479                         APPLY_C_PREDICTOR();
 480                         APPLY_Y_PREDICTOR();
 481                         OUTPUT_PIXEL_PAIR();
 482                     } else if (s->block_type == BLOCK_4x2) {
 483                         APPLY_C_PREDICTOR();
 484                         APPLY_Y_PREDICTOR();
 485                         OUTPUT_PIXEL_PAIR();
 486                         APPLY_Y_PREDICTOR();
 487                         OUTPUT_PIXEL_PAIR();
 488                     } else {
 489                         APPLY_Y_PREDICTOR();
 490                         OUTPUT_PIXEL_PAIR();
 491                         APPLY_Y_PREDICTOR();
 492                         OUTPUT_PIXEL_PAIR();
 493                     }
 494                     break;
 495                 }
 496
 497             } else {
 498
 499                 /* skip (copy) four pixels, but reassign the horizontal
 500                  * predictor */
 501                 *current_pixel_pair = *prev_pixel_pair++;
 502                 *vert_pred++ = *current_pixel_pair++;
 503                 *current_pixel_pair = *prev_pixel_pair++;
 504                 horiz_pred = *current_pixel_pair - *vert_pred;
 505                 *vert_pred++ = *current_pixel_pair++;
 506
 507             }
 508
 509             if (!keyframe) {
 510                 mb_change_byte_mask <<= 1;
 511
 512                 /* next byte */
 513                 if (!mb_change_byte_mask) {
 514                     mb_change_byte = mb_change_bits[mb_change_index++];
 515                     mb_change_byte_mask = 0x01;
 516                 }
 517             }
 518
 519             pixels_left -= 4;
 520         }
 521
 522         /* next change row */
 523         if (((y + 1) & 3) == 0)
 524             mb_change_bits += s->mb_change_bits_row_size;
 525
 526         current_line += s->frame.linesize[0];
 527         prev_line += s->prev_frame.linesize[0];
 528     }
 529 }
 530
 531 static int truemotion1_decode_frame(AVCodecContext *avctx,
 532                                     void *data, int *data_size,
 533                                     uint8_t *buf, int buf_size)
 534 {
 535     TrueMotion1Context *s = (TrueMotion1Context *)avctx->priv_data;
 536
 537     s->buf = buf;
 538     s->size = buf_size;
 539
 540     s->frame.reference = 1;
 541     if (avctx->get_buffer(avctx, &s->frame) < 0) {
 542         av_log(s->avctx, AV_LOG_ERROR, "truemotion1: get_buffer() failed\n");
 543         return -1;
 544     }
 545
 546     /* no supplementary picture */
 547     if (buf_size == 0)
 548         return 0;
 549
 550     if (truemotion1_decode_header(s) == -1)
 551         return -1;
 552
 553     /* check for a do-nothing frame and copy the previous frame */
 554     if (compression_types[s->compression].algorithm == ALGO_NOP)
 555     {
 556         memcpy(s->frame.data[0], s->prev_frame.data[0],
 557             s->frame.linesize[0] * s->avctx->height);
 558     } else if (compression_types[s->compression].algorithm == ALGO_RGB24H) {
 559         av_log(s->avctx, AV_LOG_ERROR, "24bit compression not yet supported\n");
 560     } else {
 561         truemotion1_decode_16bit(s);
 562     }
 563
 564     if (s->prev_frame.data[0])
 565         avctx->release_buffer(avctx, &s->prev_frame);
 566
 567     /* shuffle frames */
 568     s->prev_frame = s->frame;
 569
 570     *data_size = sizeof(AVFrame);
 571     *(AVFrame*)data = s->frame;
 572
 573     /* report that the buffer was completely consumed */
 574     return buf_size;
 575 }
 576
 577 static int truemotion1_decode_end(AVCodecContext *avctx)
 578 {
 579     TrueMotion1Context *s = (TrueMotion1Context *)avctx->priv_data;
 580
 581     /* release the last frame */
 582     if (s->prev_frame.data[0])
 583         avctx->release_buffer(avctx, &s->prev_frame);
 584
 585     av_free(s->vert_pred);
 586
 587     return 0;
 588 }
 589
 590 AVCodec truemotion1_decoder = {
 591     "truemotion1",
 592     CODEC_TYPE_VIDEO,
 593     CODEC_ID_TRUEMOTION1,
 594     sizeof(TrueMotion1Context),
 595     truemotion1_decode_init,
 596     NULL,
 597     truemotion1_decode_end,
 598     truemotion1_decode_frame,
 599     CODEC_CAP_DR1,
 600 };