libavcodec/smc.c

   1 /*
   2  * Quicktime Graphics (SMC) Video Decoder
   3  * Copyright (C) 2003 The FFmpeg project
   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  * QT SMC Video Decoder by Mike Melanson (melanson@pcisys.net)
  25  * For more information about the SMC format, visit:
  26  *   http://www.pcisys.net/~melanson/codecs/
  27  *
  28  * The SMC decoder outputs PAL8 colorspace data.
  29  */
  30
  31 #include <string.h>
  32
  33 #include "avcodec.h"
  34 #include "bytestream.h"
  35 #include "codec_internal.h"
  36 #include "decode.h"
  37
  38 #define CPAIR 2
  39 #define CQUAD 4
  40 #define COCTET 8
  41
  42 #define COLORS_PER_TABLE 256
  43
  44 typedef struct SmcContext {
  45
  46     AVCodecContext *avctx;
  47     AVFrame *frame;
  48
  49     /* SMC color tables */
  50     uint8_t color_pairs[COLORS_PER_TABLE * CPAIR];
  51     uint8_t color_quads[COLORS_PER_TABLE * CQUAD];
  52     uint8_t color_octets[COLORS_PER_TABLE * COCTET];
  53
  54     uint32_t pal[256];
  55 } SmcContext;
  56
  57 #define GET_BLOCK_COUNT() \
  58   (opcode & 0x10) ? (1 + bytestream2_get_byte(gb)) : 1 + (opcode & 0x0F);
  59
  60 #define ADVANCE_BLOCK() \
  61 { \
  62     pixel_ptr += 4; \
  63     if (pixel_ptr >= width) \
  64     { \
  65         pixel_ptr = 0; \
  66         row_ptr += stride * 4; \
  67     } \
  68     total_blocks--; \
  69     if (total_blocks < !!n_blocks) \
  70     { \
  71         av_log(s->avctx, AV_LOG_ERROR, "block counter just went negative (this should not happen)\n"); \
  72         return AVERROR_INVALIDDATA; \
  73     } \
  74 }
  75
  76 static int smc_decode_stream(SmcContext *s, GetByteContext *gb)
  77 {
  78     int width = s->avctx->width;
  79     int height = s->avctx->height;
  80     int stride = s->frame->linesize[0];
  81     int i;
  82     int chunk_size;
  83     int buf_size = bytestream2_size(gb);
  84     uint8_t opcode;
  85     int n_blocks;
  86     unsigned int color_flags;
  87     unsigned int color_flags_a;
  88     unsigned int color_flags_b;
  89     unsigned int flag_mask;
  90
  91     uint8_t * const pixels = s->frame->data[0];
  92
  93     int image_size = height * s->frame->linesize[0];
  94     int row_ptr = 0;
  95     int pixel_ptr = 0;
  96     int pixel_x, pixel_y;
  97     int row_inc = stride - 4;
  98     int block_ptr;
  99     int prev_block_ptr;
 100     int prev_block_ptr1, prev_block_ptr2;
 101     int prev_block_flag;
 102     int total_blocks;
 103     int color_table_index;  /* indexes to color pair, quad, or octet tables */
 104     int pixel;
 105
 106     int color_pair_index = 0;
 107     int color_quad_index = 0;
 108     int color_octet_index = 0;
 109
 110     /* make the palette available */
 111     memcpy(s->frame->data[1], s->pal, AVPALETTE_SIZE);
 112
 113     bytestream2_skip(gb, 1);
 114     chunk_size = bytestream2_get_be24(gb);
 115     if (chunk_size != buf_size)
 116         av_log(s->avctx, AV_LOG_WARNING, "MOV chunk size != encoded chunk size (%d != %d); using MOV chunk size\n",
 117             chunk_size, buf_size);
 118
 119     chunk_size = buf_size;
 120     total_blocks = ((s->avctx->width + 3) / 4) * ((s->avctx->height + 3) / 4);
 121
 122     /* traverse through the blocks */
 123     while (total_blocks) {
 124         /* sanity checks */
 125         /* make sure the row pointer hasn't gone wild */
 126         if (row_ptr >= image_size) {
 127             av_log(s->avctx, AV_LOG_ERROR, "just went out of bounds (row ptr = %d, height = %d)\n",
 128                 row_ptr, image_size);
 129             return AVERROR_INVALIDDATA;
 130         }
 131         if (bytestream2_get_bytes_left(gb) < 1) {
 132             av_log(s->avctx, AV_LOG_ERROR, "input too small\n");
 133             return AVERROR_INVALIDDATA;
 134         }
 135
 136         opcode = bytestream2_get_byteu(gb);
 137         switch (opcode & 0xF0) {
 138         /* skip n blocks */
 139         case 0x00:
 140         case 0x10:
 141             n_blocks = GET_BLOCK_COUNT();
 142             while (n_blocks--) {
 143                 ADVANCE_BLOCK();
 144             }
 145             break;
 146
 147         /* repeat last block n times */
 148         case 0x20:
 149         case 0x30:
 150             n_blocks = GET_BLOCK_COUNT();
 151
 152             /* sanity check */
 153             if ((row_ptr == 0) && (pixel_ptr == 0)) {
 154                 av_log(s->avctx, AV_LOG_ERROR, "encountered repeat block opcode (%02X) but no blocks rendered yet\n",
 155                     opcode & 0xF0);
 156                 return AVERROR_INVALIDDATA;
 157             }
 158
 159             /* figure out where the previous block started */
 160             if (pixel_ptr == 0)
 161                 prev_block_ptr1 =
 162                     (row_ptr - s->avctx->width * 4) + s->avctx->width - 4;
 163             else
 164                 prev_block_ptr1 = row_ptr + pixel_ptr - 4;
 165
 166             while (n_blocks--) {
 167                 block_ptr = row_ptr + pixel_ptr;
 168                 prev_block_ptr = prev_block_ptr1;
 169                 for (pixel_y = 0; pixel_y < 4; pixel_y++) {
 170                     for (pixel_x = 0; pixel_x < 4; pixel_x++) {
 171                         pixels[block_ptr++] = pixels[prev_block_ptr++];
 172                     }
 173                     block_ptr += row_inc;
 174                     prev_block_ptr += row_inc;
 175                 }
 176                 ADVANCE_BLOCK();
 177             }
 178             break;
 179
 180         /* repeat previous pair of blocks n times */
 181         case 0x40:
 182         case 0x50:
 183             n_blocks = GET_BLOCK_COUNT();
 184             n_blocks *= 2;
 185
 186             /* sanity check */
 187             if ((row_ptr == 0) && (pixel_ptr < 2 * 4)) {
 188                 av_log(s->avctx, AV_LOG_ERROR, "encountered repeat block opcode (%02X) but not enough blocks rendered yet\n",
 189                     opcode & 0xF0);
 190                 return AVERROR_INVALIDDATA;
 191             }
 192
 193             /* figure out where the previous 2 blocks started */
 194             if (pixel_ptr == 0)
 195                 prev_block_ptr1 = (row_ptr - s->avctx->width * 4) +
 196                     s->avctx->width - 4 * 2;
 197             else if (pixel_ptr == 4)
 198                 prev_block_ptr1 = (row_ptr - s->avctx->width * 4) + row_inc;
 199             else
 200                 prev_block_ptr1 = row_ptr + pixel_ptr - 4 * 2;
 201
 202             if (pixel_ptr == 0)
 203                 prev_block_ptr2 = (row_ptr - s->avctx->width * 4) + row_inc;
 204             else
 205                 prev_block_ptr2 = row_ptr + pixel_ptr - 4;
 206
 207             prev_block_flag = 0;
 208             while (n_blocks--) {
 209                 block_ptr = row_ptr + pixel_ptr;
 210                 if (prev_block_flag)
 211                     prev_block_ptr = prev_block_ptr2;
 212                 else
 213                     prev_block_ptr = prev_block_ptr1;
 214                 prev_block_flag = !prev_block_flag;
 215
 216                 for (pixel_y = 0; pixel_y < 4; pixel_y++) {
 217                     for (pixel_x = 0; pixel_x < 4; pixel_x++) {
 218                         pixels[block_ptr++] = pixels[prev_block_ptr++];
 219                     }
 220                     block_ptr += row_inc;
 221                     prev_block_ptr += row_inc;
 222                 }
 223                 ADVANCE_BLOCK();
 224             }
 225             break;
 226
 227         /* 1-color block encoding */
 228         case 0x60:
 229         case 0x70:
 230             n_blocks = GET_BLOCK_COUNT();
 231             pixel = bytestream2_get_byte(gb);
 232
 233             while (n_blocks--) {
 234                 block_ptr = row_ptr + pixel_ptr;
 235                 for (pixel_y = 0; pixel_y < 4; pixel_y++) {
 236                     for (pixel_x = 0; pixel_x < 4; pixel_x++) {
 237                         pixels[block_ptr++] = pixel;
 238                     }
 239                     block_ptr += row_inc;
 240                 }
 241                 ADVANCE_BLOCK();
 242             }
 243             break;
 244
 245         /* 2-color block encoding */
 246         case 0x80:
 247         case 0x90:
 248             n_blocks = (opcode & 0x0F) + 1;
 249
 250             /* figure out which color pair to use to paint the 2-color block */
 251             if ((opcode & 0xF0) == 0x80) {
 252                 /* fetch the next 2 colors from bytestream and store in next
 253                  * available entry in the color pair table */
 254                 for (i = 0; i < CPAIR; i++) {
 255                     pixel = bytestream2_get_byte(gb);
 256                     color_table_index = CPAIR * color_pair_index + i;
 257                     s->color_pairs[color_table_index] = pixel;
 258                 }
 259                 /* this is the base index to use for this block */
 260                 color_table_index = CPAIR * color_pair_index;
 261                 color_pair_index++;
 262                 /* wraparound */
 263                 if (color_pair_index == COLORS_PER_TABLE)
 264                     color_pair_index = 0;
 265             } else
 266                 color_table_index = CPAIR * bytestream2_get_byte(gb);
 267
 268             while (n_blocks--) {
 269                 color_flags = bytestream2_get_be16(gb);
 270                 flag_mask = 0x8000;
 271                 block_ptr = row_ptr + pixel_ptr;
 272                 for (pixel_y = 0; pixel_y < 4; pixel_y++) {
 273                     for (pixel_x = 0; pixel_x < 4; pixel_x++) {
 274                         if (color_flags & flag_mask)
 275                             pixel = color_table_index + 1;
 276                         else
 277                             pixel = color_table_index;
 278                         flag_mask >>= 1;
 279                         pixels[block_ptr++] = s->color_pairs[pixel];
 280                     }
 281                     block_ptr += row_inc;
 282                 }
 283                 ADVANCE_BLOCK();
 284             }
 285             break;
 286
 287         /* 4-color block encoding */
 288         case 0xA0:
 289         case 0xB0:
 290             n_blocks = (opcode & 0x0F) + 1;
 291
 292             /* figure out which color quad to use to paint the 4-color block */
 293             if ((opcode & 0xF0) == 0xA0) {
 294                 /* fetch the next 4 colors from bytestream and store in next
 295                  * available entry in the color quad table */
 296                 for (i = 0; i < CQUAD; i++) {
 297                     pixel = bytestream2_get_byte(gb);
 298                     color_table_index = CQUAD * color_quad_index + i;
 299                     s->color_quads[color_table_index] = pixel;
 300                 }
 301                 /* this is the base index to use for this block */
 302                 color_table_index = CQUAD * color_quad_index;
 303                 color_quad_index++;
 304                 /* wraparound */
 305                 if (color_quad_index == COLORS_PER_TABLE)
 306                     color_quad_index = 0;
 307             } else
 308                 color_table_index = CQUAD * bytestream2_get_byte(gb);
 309
 310             while (n_blocks--) {
 311                 color_flags = bytestream2_get_be32(gb);
 312                 /* flag mask actually acts as a bit shift count here */
 313                 flag_mask = 30;
 314                 block_ptr = row_ptr + pixel_ptr;
 315                 for (pixel_y = 0; pixel_y < 4; pixel_y++) {
 316                     for (pixel_x = 0; pixel_x < 4; pixel_x++) {
 317                         pixel = color_table_index +
 318                             ((color_flags >> flag_mask) & 0x03);
 319                         flag_mask -= 2;
 320                         pixels[block_ptr++] = s->color_quads[pixel];
 321                     }
 322                     block_ptr += row_inc;
 323                 }
 324                 ADVANCE_BLOCK();
 325             }
 326             break;
 327
 328         /* 8-color block encoding */
 329         case 0xC0:
 330         case 0xD0:
 331             n_blocks = (opcode & 0x0F) + 1;
 332
 333             /* figure out which color octet to use to paint the 8-color block */
 334             if ((opcode & 0xF0) == 0xC0) {
 335                 /* fetch the next 8 colors from bytestream and store in next
 336                  * available entry in the color octet table */
 337                 for (i = 0; i < COCTET; i++) {
 338                     pixel = bytestream2_get_byte(gb);
 339                     color_table_index = COCTET * color_octet_index + i;
 340                     s->color_octets[color_table_index] = pixel;
 341                 }
 342                 /* this is the base index to use for this block */
 343                 color_table_index = COCTET * color_octet_index;
 344                 color_octet_index++;
 345                 /* wraparound */
 346                 if (color_octet_index == COLORS_PER_TABLE)
 347                     color_octet_index = 0;
 348             } else
 349                 color_table_index = COCTET * bytestream2_get_byte(gb);
 350
 351             while (n_blocks--) {
 352                 /*
 353                   For this input of 6 hex bytes:
 354                     01 23 45 67 89 AB
 355                   Mangle it to this output:
 356                     flags_a = xx012456, flags_b = xx89A37B
 357                 */
 358                 /* build the color flags */
 359                 int val1 = bytestream2_get_be16(gb);
 360                 int val2 = bytestream2_get_be16(gb);
 361                 int val3 = bytestream2_get_be16(gb);
 362                 color_flags_a = ((val1 & 0xFFF0) << 8) | (val2 >> 4);
 363                 color_flags_b = ((val3 & 0xFFF0) << 8) |
 364                     ((val1 & 0x0F) << 8) | ((val2 & 0x0F) << 4) | (val3 & 0x0F);
 365
 366                 color_flags = color_flags_a;
 367                 /* flag mask actually acts as a bit shift count here */
 368                 flag_mask = 21;
 369                 block_ptr = row_ptr + pixel_ptr;
 370                 for (pixel_y = 0; pixel_y < 4; pixel_y++) {
 371                     /* reload flags at third row (iteration pixel_y == 2) */
 372                     if (pixel_y == 2) {
 373                         color_flags = color_flags_b;
 374                         flag_mask = 21;
 375                     }
 376                     for (pixel_x = 0; pixel_x < 4; pixel_x++) {
 377                         pixel = color_table_index +
 378                             ((color_flags >> flag_mask) & 0x07);
 379                         flag_mask -= 3;
 380                         pixels[block_ptr++] = s->color_octets[pixel];
 381                     }
 382                     block_ptr += row_inc;
 383                 }
 384                 ADVANCE_BLOCK();
 385             }
 386             break;
 387
 388         /* 16-color block encoding (every pixel is a different color) */
 389         case 0xE0:
 390         case 0xF0:
 391             n_blocks = (opcode & 0x0F) + 1;
 392
 393             while (n_blocks--) {
 394                 block_ptr = row_ptr + pixel_ptr;
 395                 for (pixel_y = 0; pixel_y < 4; pixel_y++) {
 396                     for (pixel_x = 0; pixel_x < 4; pixel_x++) {
 397                         pixels[block_ptr++] = bytestream2_get_byte(gb);
 398                     }
 399                     block_ptr += row_inc;
 400                 }
 401                 ADVANCE_BLOCK();
 402             }
 403             break;
 404         }
 405     }
 406
 407     return 0;
 408 }
 409
 410 static av_cold int smc_decode_init(AVCodecContext *avctx)
 411 {
 412     SmcContext *s = avctx->priv_data;
 413
 414     s->avctx = avctx;
 415     avctx->pix_fmt = AV_PIX_FMT_PAL8;
 416
 417     s->frame = av_frame_alloc();
 418     if (!s->frame)
 419         return AVERROR(ENOMEM);
 420
 421     return 0;
 422 }
 423
 424 static int smc_decode_frame(AVCodecContext *avctx, AVFrame *rframe,
 425                             int *got_frame, AVPacket *avpkt)
 426 {
 427     const uint8_t *buf = avpkt->data;
 428     int buf_size = avpkt->size;
 429     SmcContext *s = avctx->priv_data;
 430     GetByteContext gb;
 431     int ret;
 432     int total_blocks = ((s->avctx->width + 3) / 4) * ((s->avctx->height + 3) / 4);
 433
 434     if (total_blocks / 1024 > avpkt->size)
 435         return AVERROR_INVALIDDATA;
 436
 437     if ((ret = ff_reget_buffer(avctx, s->frame, 0)) < 0)
 438         return ret;
 439
 440 #if FF_API_PALETTE_HAS_CHANGED
 441 FF_DISABLE_DEPRECATION_WARNINGS
 442     s->frame->palette_has_changed =
 443 #endif
 444     ff_copy_palette(s->pal, avpkt, avctx);
 445 #if FF_API_PALETTE_HAS_CHANGED
 446 FF_ENABLE_DEPRECATION_WARNINGS
 447 #endif
 448
 449     bytestream2_init(&gb, buf, buf_size);
 450     ret = smc_decode_stream(s, &gb);
 451     if (ret < 0)
 452         return ret;
 453
 454     *got_frame      = 1;
 455     if ((ret = av_frame_ref(rframe, s->frame)) < 0)
 456         return ret;
 457
 458     /* always report that the buffer was completely consumed */
 459     return buf_size;
 460 }
 461
 462 static av_cold int smc_decode_end(AVCodecContext *avctx)
 463 {
 464     SmcContext *s = avctx->priv_data;
 465
 466     av_frame_free(&s->frame);
 467
 468     return 0;
 469 }
 470
 471 const FFCodec ff_smc_decoder = {
 472     .p.name         = "smc",
 473     CODEC_LONG_NAME("QuickTime Graphics (SMC)"),
 474     .p.type         = AVMEDIA_TYPE_VIDEO,
 475     .p.id           = AV_CODEC_ID_SMC,
 476     .priv_data_size = sizeof(SmcContext),
 477     .init           = smc_decode_init,
 478     .close          = smc_decode_end,
 479     FF_CODEC_DECODE_CB(smc_decode_frame),
 480     .p.capabilities = AV_CODEC_CAP_DR1,
 481 };