libavcodec/smc.c

   1 /*
   2  * Quicktime Graphics (SMC) Video Decoder
   3  * Copyright (C) 2003 the ffmpeg project
   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 /**
  22  * @file smc.c
  23  * QT SMC Video Decoder by Mike Melanson (melanson@pcisys.net)
  24  * For more information about the SMC format, visit:
  25  *   http://www.pcisys.net/~melanson/codecs/
  26  *
  27  * The SMC decoder outputs PAL8 colorspace data.
  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 #define CPAIR 2
  40 #define CQUAD 4
  41 #define COCTET 8
  42
  43 #define COLORS_PER_TABLE 256
  44
  45 typedef struct SmcContext {
  46
  47     AVCodecContext *avctx;
  48     DSPContext dsp;
  49     AVFrame frame;
  50
  51     unsigned char *buf;
  52     int size;
  53
  54     /* SMC color tables */
  55     unsigned char color_pairs[COLORS_PER_TABLE * CPAIR];
  56     unsigned char color_quads[COLORS_PER_TABLE * CQUAD];
  57     unsigned char color_octets[COLORS_PER_TABLE * COCTET];
  58
  59 } SmcContext;
  60
  61 #define BE_16(x)  ((((uint8_t*)(x))[0] << 8) | ((uint8_t*)(x))[1])
  62 #define BE_32(x)  ((((uint8_t*)(x))[0] << 24) | \
  63                    (((uint8_t*)(x))[1] << 16) | \
  64                    (((uint8_t*)(x))[2] << 8) | \
  65                     ((uint8_t*)(x))[3])
  66 #define GET_BLOCK_COUNT() \
  67   (opcode & 0x10) ? (1 + s->buf[stream_ptr++]) : 1 + (opcode & 0x0F);
  68
  69 #define ADVANCE_BLOCK() \
  70 { \
  71     pixel_ptr += 4; \
  72     if (pixel_ptr >= width) \
  73     { \
  74         pixel_ptr = 0; \
  75         row_ptr += stride * 4; \
  76     } \
  77     total_blocks--; \
  78     if (total_blocks < 0) \
  79     { \
  80         printf("warning: block counter just went negative (this should not happen)\n"); \
  81         return; \
  82     } \
  83 }
  84
  85 static void smc_decode_stream(SmcContext *s)
  86 {
  87     int width = s->avctx->width;
  88     int height = s->avctx->height;
  89     int stride = s->frame.linesize[0];
  90     int i;
  91     int stream_ptr = 0;
  92     int chunk_size;
  93     unsigned char opcode;
  94     int n_blocks;
  95     unsigned int color_flags;
  96     unsigned int color_flags_a;
  97     unsigned int color_flags_b;
  98     unsigned int flag_mask;
  99
 100     unsigned char *pixels = s->frame.data[0];
 101
 102     int image_size = height * s->frame.linesize[0];
 103     int row_ptr = 0;
 104     int pixel_ptr = 0;
 105     int pixel_x, pixel_y;
 106     int row_inc = stride - 4;
 107     int block_ptr;
 108     int prev_block_ptr;
 109     int prev_block_ptr1, prev_block_ptr2;
 110     int prev_block_flag;
 111     int total_blocks;
 112     int color_table_index;  /* indexes to color pair, quad, or octet tables */
 113     int pixel;
 114
 115     int color_pair_index = 0;
 116     int color_quad_index = 0;
 117     int color_octet_index = 0;
 118
 119     /* make the palette available */
 120     memcpy(s->frame.data[1], s->avctx->palctrl->palette, AVPALETTE_SIZE);
 121     if (s->avctx->palctrl->palette_changed) {
 122         s->frame.palette_has_changed = 1;
 123         s->avctx->palctrl->palette_changed = 0;
 124     }
 125
 126     chunk_size = BE_32(&s->buf[stream_ptr]) & 0x00FFFFFF;
 127     stream_ptr += 4;
 128     if (chunk_size != s->size)
 129         printf("warning: MOV chunk size != encoded chunk size (%d != %d); using MOV chunk size\n",
 130             chunk_size, s->size);
 131
 132     chunk_size = s->size;
 133     total_blocks = (s->avctx->width * s->avctx->height) / (4 * 4);
 134
 135     /* traverse through the blocks */
 136     while (total_blocks) {
 137         /* sanity checks */
 138         /* make sure stream ptr hasn't gone out of bounds */
 139         if (stream_ptr > chunk_size) {
 140             printf("SMC decoder just went out of bounds (stream ptr = %d, chunk size = %d)\n",
 141                 stream_ptr, chunk_size);
 142             return;
 143         }
 144         /* make sure the row pointer hasn't gone wild */
 145         if (row_ptr >= image_size) {
 146             printf("SMC decoder just went out of bounds (row ptr = %d, height = %d)\n",
 147                 row_ptr, image_size);
 148             return;
 149         }
 150
 151         opcode = s->buf[stream_ptr++];
 152         switch (opcode & 0xF0) {
 153         /* skip n blocks */
 154         case 0x00:
 155         case 0x10:
 156             n_blocks = GET_BLOCK_COUNT();
 157             while (n_blocks--) {
 158                 ADVANCE_BLOCK();
 159             }
 160             break;
 161
 162         /* repeat last block n times */
 163         case 0x20:
 164         case 0x30:
 165             n_blocks = GET_BLOCK_COUNT();
 166
 167             /* sanity check */
 168             if ((row_ptr == 0) && (pixel_ptr == 0)) {
 169                 printf("encountered repeat block opcode (%02X) but no blocks rendered yet\n",
 170                     opcode & 0xF0);
 171                 break;
 172             }
 173
 174             /* figure out where the previous block started */
 175             if (pixel_ptr == 0)
 176                 prev_block_ptr1 =
 177                     (row_ptr - s->avctx->width * 4) + s->avctx->width - 4;
 178             else
 179                 prev_block_ptr1 = row_ptr + pixel_ptr - 4;
 180
 181             while (n_blocks--) {
 182                 block_ptr = row_ptr + pixel_ptr;
 183                 prev_block_ptr = prev_block_ptr1;
 184                 for (pixel_y = 0; pixel_y < 4; pixel_y++) {
 185                     for (pixel_x = 0; pixel_x < 4; pixel_x++) {
 186                         pixels[block_ptr++] = pixels[prev_block_ptr++];
 187                     }
 188                     block_ptr += row_inc;
 189                     prev_block_ptr += row_inc;
 190                 }
 191                 ADVANCE_BLOCK();
 192             }
 193             break;
 194
 195         /* repeat previous pair of blocks n times */
 196         case 0x40:
 197         case 0x50:
 198             n_blocks = GET_BLOCK_COUNT();
 199             n_blocks *= 2;
 200
 201             /* sanity check */
 202             if ((row_ptr == 0) && (pixel_ptr < 2 * 4)) {
 203                 printf("encountered repeat block opcode (%02X) but not enough blocks rendered yet\n",
 204                     opcode & 0xF0);
 205                 break;
 206             }
 207
 208             /* figure out where the previous 2 blocks started */
 209             if (pixel_ptr == 0)
 210                 prev_block_ptr1 = (row_ptr - s->avctx->width * 4) +
 211                     s->avctx->width - 4 * 2;
 212             else if (pixel_ptr == 4)
 213                 prev_block_ptr1 = (row_ptr - s->avctx->width * 4) + row_inc;
 214             else
 215                 prev_block_ptr1 = row_ptr + pixel_ptr - 4 * 2;
 216
 217             if (pixel_ptr == 0)
 218                 prev_block_ptr2 = (row_ptr - s->avctx->width * 4) + row_inc;
 219             else
 220                 prev_block_ptr2 = row_ptr + pixel_ptr - 4;
 221
 222             prev_block_flag = 0;
 223             while (n_blocks--) {
 224                 block_ptr = row_ptr + pixel_ptr;
 225                 if (prev_block_flag)
 226                     prev_block_ptr = prev_block_ptr2;
 227                 else
 228                     prev_block_ptr = prev_block_ptr1;
 229                 prev_block_flag = !prev_block_flag;
 230
 231                 for (pixel_y = 0; pixel_y < 4; pixel_y++) {
 232                     for (pixel_x = 0; pixel_x < 4; pixel_x++) {
 233                         pixels[block_ptr++] = pixels[prev_block_ptr++];
 234                     }
 235                     block_ptr += row_inc;
 236                     prev_block_ptr += row_inc;
 237                 }
 238                 ADVANCE_BLOCK();
 239             }
 240             break;
 241
 242         /* 1-color block encoding */
 243         case 0x60:
 244         case 0x70:
 245             n_blocks = GET_BLOCK_COUNT();
 246             pixel = s->buf[stream_ptr++];
 247
 248             while (n_blocks--) {
 249                 block_ptr = row_ptr + pixel_ptr;
 250                 for (pixel_y = 0; pixel_y < 4; pixel_y++) {
 251                     for (pixel_x = 0; pixel_x < 4; pixel_x++) {
 252                         pixels[block_ptr++] = pixel;
 253                     }
 254                     block_ptr += row_inc;
 255                 }
 256                 ADVANCE_BLOCK();
 257             }
 258             break;
 259
 260         /* 2-color block encoding */
 261         case 0x80:
 262         case 0x90:
 263             n_blocks = (opcode & 0x0F) + 1;
 264
 265             /* figure out which color pair to use to paint the 2-color block */
 266             if ((opcode & 0xF0) == 0x80) {
 267                 /* fetch the next 2 colors from bytestream and store in next
 268                  * available entry in the color pair table */
 269                 for (i = 0; i < CPAIR; i++) {
 270                     pixel = s->buf[stream_ptr++];
 271                     color_table_index = CPAIR * color_pair_index + i;
 272                     s->color_pairs[color_table_index] = pixel;
 273                 }
 274                 /* this is the base index to use for this block */
 275                 color_table_index = CPAIR * color_pair_index;
 276                 color_pair_index++;
 277                 /* wraparound */
 278                 if (color_pair_index == COLORS_PER_TABLE)
 279                     color_pair_index = 0;
 280             } else
 281                 color_table_index = CPAIR * s->buf[stream_ptr++];
 282
 283             while (n_blocks--) {
 284                 color_flags = BE_16(&s->buf[stream_ptr]);
 285                 stream_ptr += 2;
 286                 flag_mask = 0x8000;
 287                 block_ptr = row_ptr + pixel_ptr;
 288                 for (pixel_y = 0; pixel_y < 4; pixel_y++) {
 289                     for (pixel_x = 0; pixel_x < 4; pixel_x++) {
 290                         if (color_flags & flag_mask)
 291                             pixel = color_table_index + 1;
 292                         else
 293                             pixel = color_table_index;
 294                         flag_mask >>= 1;
 295                         pixels[block_ptr++] = s->color_pairs[pixel];
 296                     }
 297                     block_ptr += row_inc;
 298                 }
 299                 ADVANCE_BLOCK();
 300             }
 301             break;
 302
 303         /* 4-color block encoding */
 304         case 0xA0:
 305         case 0xB0:
 306             n_blocks = (opcode & 0x0F) + 1;
 307
 308             /* figure out which color quad to use to paint the 4-color block */
 309             if ((opcode & 0xF0) == 0xA0) {
 310                 /* fetch the next 4 colors from bytestream and store in next
 311                  * available entry in the color quad table */
 312                 for (i = 0; i < CQUAD; i++) {
 313                     pixel = s->buf[stream_ptr++];
 314                     color_table_index = CQUAD * color_quad_index + i;
 315                     s->color_quads[color_table_index] = pixel;
 316                 }
 317                 /* this is the base index to use for this block */
 318                 color_table_index = CQUAD * color_quad_index;
 319                 color_quad_index++;
 320                 /* wraparound */
 321                 if (color_quad_index == COLORS_PER_TABLE)
 322                     color_quad_index = 0;
 323             } else
 324                 color_table_index = CQUAD * s->buf[stream_ptr++];
 325
 326             while (n_blocks--) {
 327                 color_flags = BE_32(&s->buf[stream_ptr]);
 328                 stream_ptr += 4;
 329                 /* flag mask actually acts as a bit shift count here */
 330                 flag_mask = 30;
 331                 block_ptr = row_ptr + pixel_ptr;
 332                 for (pixel_y = 0; pixel_y < 4; pixel_y++) {
 333                     for (pixel_x = 0; pixel_x < 4; pixel_x++) {
 334                         pixel = color_table_index +
 335                             ((color_flags >> flag_mask) & 0x03);
 336                         flag_mask -= 2;
 337                         pixels[block_ptr++] = s->color_quads[pixel];
 338                     }
 339                     block_ptr += row_inc;
 340                 }
 341                 ADVANCE_BLOCK();
 342             }
 343             break;
 344
 345         /* 8-color block encoding */
 346         case 0xC0:
 347         case 0xD0:
 348             n_blocks = (opcode & 0x0F) + 1;
 349
 350             /* figure out which color octet to use to paint the 8-color block */
 351             if ((opcode & 0xF0) == 0xC0) {
 352                 /* fetch the next 8 colors from bytestream and store in next
 353                  * available entry in the color octet table */
 354                 for (i = 0; i < COCTET; i++) {
 355                     pixel = s->buf[stream_ptr++];
 356                     color_table_index = COCTET * color_octet_index + i;
 357                     s->color_octets[color_table_index] = pixel;
 358                 }
 359                 /* this is the base index to use for this block */
 360                 color_table_index = COCTET * color_octet_index;
 361                 color_octet_index++;
 362                 /* wraparound */
 363                 if (color_octet_index == COLORS_PER_TABLE)
 364                     color_octet_index = 0;
 365             } else
 366                 color_table_index = COCTET * s->buf[stream_ptr++];
 367
 368             while (n_blocks--) {
 369                 /*
 370                   For this input of 6 hex bytes:
 371                     01 23 45 67 89 AB
 372                   Mangle it to this output:
 373                     flags_a = xx012456, flags_b = xx89A37B
 374                 */
 375                 /* build the color flags */
 376                 color_flags_a = color_flags_b = 0;
 377                 color_flags_a =
 378                     (s->buf[stream_ptr + 0] << 16) |
 379                     ((s->buf[stream_ptr + 1] & 0xF0) << 8) |
 380                     ((s->buf[stream_ptr + 2] & 0xF0) << 4) |
 381                     ((s->buf[stream_ptr + 2] & 0x0F) << 4) |
 382                     ((s->buf[stream_ptr + 3] & 0xF0) >> 4);
 383                 color_flags_b =
 384                     (s->buf[stream_ptr + 4] << 16) |
 385                     ((s->buf[stream_ptr + 5] & 0xF0) << 8) |
 386                     ((s->buf[stream_ptr + 1] & 0x0F) << 8) |
 387                     ((s->buf[stream_ptr + 3] & 0x0F) << 4) |
 388                     (s->buf[stream_ptr + 5] & 0x0F);
 389                 stream_ptr += 6;
 390
 391                 color_flags = color_flags_a;
 392                 /* flag mask actually acts as a bit shift count here */
 393                 flag_mask = 21;
 394                 block_ptr = row_ptr + pixel_ptr;
 395                 for (pixel_y = 0; pixel_y < 4; pixel_y++) {
 396                     /* reload flags at third row (iteration pixel_y == 2) */
 397                     if (pixel_y == 2) {
 398                         color_flags = color_flags_b;
 399                         flag_mask = 21;
 400                     }
 401                     for (pixel_x = 0; pixel_x < 4; pixel_x++) {
 402                         pixel = color_table_index +
 403                             ((color_flags >> flag_mask) & 0x07);
 404                         flag_mask -= 3;
 405                         pixels[block_ptr++] = s->color_octets[pixel];
 406                     }
 407                     block_ptr += row_inc;
 408                 }
 409                 ADVANCE_BLOCK();
 410             }
 411             break;
 412
 413         /* 16-color block encoding (every pixel is a different color) */
 414         case 0xE0:
 415             n_blocks = (opcode & 0x0F) + 1;
 416
 417             while (n_blocks--) {
 418                 block_ptr = row_ptr + pixel_ptr;
 419                 for (pixel_y = 0; pixel_y < 4; pixel_y++) {
 420                     for (pixel_x = 0; pixel_x < 4; pixel_x++) {
 421                         pixels[block_ptr++] = s->buf[stream_ptr++];
 422                     }
 423                     block_ptr += row_inc;
 424                 }
 425                 ADVANCE_BLOCK();
 426             }
 427             break;
 428
 429         case 0xF0:
 430             printf("0xF0 opcode seen in SMC chunk (xine developers would like to know)\n");
 431             break;
 432         }
 433     }
 434 }
 435
 436 static int smc_decode_init(AVCodecContext *avctx)
 437 {
 438     SmcContext *s = (SmcContext *)avctx->priv_data;
 439
 440     s->avctx = avctx;
 441     avctx->pix_fmt = PIX_FMT_PAL8;
 442     avctx->has_b_frames = 0;
 443     dsputil_init(&s->dsp, avctx);
 444
 445     s->frame.data[0] = NULL;
 446
 447     return 0;
 448 }
 449
 450 static int smc_decode_frame(AVCodecContext *avctx,
 451                              void *data, int *data_size,
 452                              uint8_t *buf, int buf_size)
 453 {
 454     SmcContext *s = (SmcContext *)avctx->priv_data;
 455
 456         /* no supplementary picture */
 457         if (buf_size == 0)
 458                 return 0;
 459
 460     s->buf = buf;
 461     s->size = buf_size;
 462
 463     s->frame.reference = 1;
 464         s->frame.buffer_hints = FF_BUFFER_HINTS_VALID | FF_BUFFER_HINTS_PRESERVE |
 465                                 FF_BUFFER_HINTS_REUSABLE | FF_BUFFER_HINTS_READABLE;
 466     if (avctx->reget_buffer(avctx, &s->frame)) {
 467         printf ("reget_buffer() failed\n");
 468         return -1;
 469     }
 470
 471     smc_decode_stream(s);
 472
 473     *data_size = sizeof(AVFrame);
 474     *(AVFrame*)data = s->frame;
 475
 476     /* always report that the buffer was completely consumed */
 477     return buf_size;
 478 }
 479
 480 static int smc_decode_end(AVCodecContext *avctx)
 481 {
 482     SmcContext *s = (SmcContext *)avctx->priv_data;
 483
 484     if (s->frame.data[0])
 485         avctx->release_buffer(avctx, &s->frame);
 486
 487     return 0;
 488 }
 489
 490 AVCodec smc_decoder = {
 491     "smc",
 492     CODEC_TYPE_VIDEO,
 493     CODEC_ID_SMC,
 494     sizeof(SmcContext),
 495     smc_decode_init,
 496     NULL,
 497     smc_decode_end,
 498     smc_decode_frame,
 499     CODEC_CAP_DR1,
 500 };