| 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 <stdio.h> |
| 32 | #include <stdlib.h> |
| 33 | #include <string.h> |
| 34 | |
| 35 | #include "libavutil/intreadwrite.h" |
| 36 | #include "avcodec.h" |
| 37 | #include "bytestream.h" |
| 38 | #include "internal.h" |
| 39 | |
| 40 | #define CPAIR 2 |
| 41 | #define CQUAD 4 |
| 42 | #define COCTET 8 |
| 43 | |
| 44 | #define COLORS_PER_TABLE 256 |
| 45 | |
| 46 | typedef struct SmcContext { |
| 47 | |
| 48 | AVCodecContext *avctx; |
| 49 | AVFrame *frame; |
| 50 | |
| 51 | GetByteContext gb; |
| 52 | |
| 53 | /* SMC color tables */ |
| 54 | unsigned char color_pairs[COLORS_PER_TABLE * CPAIR]; |
| 55 | unsigned char color_quads[COLORS_PER_TABLE * CQUAD]; |
| 56 | unsigned char color_octets[COLORS_PER_TABLE * COCTET]; |
| 57 | |
| 58 | uint32_t pal[256]; |
| 59 | } SmcContext; |
| 60 | |
| 61 | #define GET_BLOCK_COUNT() \ |
| 62 | (opcode & 0x10) ? (1 + bytestream2_get_byte(&s->gb)) : 1 + (opcode & 0x0F); |
| 63 | |
| 64 | #define ADVANCE_BLOCK() \ |
| 65 | { \ |
| 66 | pixel_ptr += 4; \ |
| 67 | if (pixel_ptr >= width) \ |
| 68 | { \ |
| 69 | pixel_ptr = 0; \ |
| 70 | row_ptr += stride * 4; \ |
| 71 | } \ |
| 72 | total_blocks--; \ |
| 73 | if (total_blocks < 0 + !!n_blocks) \ |
| 74 | { \ |
| 75 | av_log(s->avctx, AV_LOG_INFO, "warning: block counter just went negative (this should not happen)\n"); \ |
| 76 | return; \ |
| 77 | } \ |
| 78 | } |
| 79 | |
| 80 | static void smc_decode_stream(SmcContext *s) |
| 81 | { |
| 82 | int width = s->avctx->width; |
| 83 | int height = s->avctx->height; |
| 84 | int stride = s->frame->linesize[0]; |
| 85 | int i; |
| 86 | int chunk_size; |
| 87 | int buf_size = bytestream2_size(&s->gb); |
| 88 | unsigned char opcode; |
| 89 | int n_blocks; |
| 90 | unsigned int color_flags; |
| 91 | unsigned int color_flags_a; |
| 92 | unsigned int color_flags_b; |
| 93 | unsigned int flag_mask; |
| 94 | |
| 95 | unsigned char *pixels = s->frame->data[0]; |
| 96 | |
| 97 | int image_size = height * s->frame->linesize[0]; |
| 98 | int row_ptr = 0; |
| 99 | int pixel_ptr = 0; |
| 100 | int pixel_x, pixel_y; |
| 101 | int row_inc = stride - 4; |
| 102 | int block_ptr; |
| 103 | int prev_block_ptr; |
| 104 | int prev_block_ptr1, prev_block_ptr2; |
| 105 | int prev_block_flag; |
| 106 | int total_blocks; |
| 107 | int color_table_index; /* indexes to color pair, quad, or octet tables */ |
| 108 | int pixel; |
| 109 | |
| 110 | int color_pair_index = 0; |
| 111 | int color_quad_index = 0; |
| 112 | int color_octet_index = 0; |
| 113 | |
| 114 | /* make the palette available */ |
| 115 | memcpy(s->frame->data[1], s->pal, AVPALETTE_SIZE); |
| 116 | |
| 117 | bytestream2_skip(&s->gb, 1); |
| 118 | chunk_size = bytestream2_get_be24(&s->gb); |
| 119 | if (chunk_size != buf_size) |
| 120 | av_log(s->avctx, AV_LOG_INFO, "warning: MOV chunk size != encoded chunk size (%d != %d); using MOV chunk size\n", |
| 121 | chunk_size, buf_size); |
| 122 | |
| 123 | chunk_size = buf_size; |
| 124 | total_blocks = ((s->avctx->width + 3) / 4) * ((s->avctx->height + 3) / 4); |
| 125 | |
| 126 | /* traverse through the blocks */ |
| 127 | while (total_blocks) { |
| 128 | /* sanity checks */ |
| 129 | /* make sure the row pointer hasn't gone wild */ |
| 130 | if (row_ptr >= image_size) { |
| 131 | av_log(s->avctx, AV_LOG_INFO, "SMC decoder just went out of bounds (row ptr = %d, height = %d)\n", |
| 132 | row_ptr, image_size); |
| 133 | return; |
| 134 | } |
| 135 | |
| 136 | opcode = bytestream2_get_byte(&s->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_INFO, "encountered repeat block opcode (%02X) but no blocks rendered yet\n", |
| 155 | opcode & 0xF0); |
| 156 | return; |
| 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_INFO, "encountered repeat block opcode (%02X) but not enough blocks rendered yet\n", |
| 189 | opcode & 0xF0); |
| 190 | return; |
| 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(&s->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(&s->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(&s->gb); |
| 267 | |
| 268 | while (n_blocks--) { |
| 269 | color_flags = bytestream2_get_be16(&s->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(&s->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(&s->gb); |
| 309 | |
| 310 | while (n_blocks--) { |
| 311 | color_flags = bytestream2_get_be32(&s->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(&s->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(&s->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(&s->gb); |
| 360 | int val2 = bytestream2_get_be16(&s->gb); |
| 361 | int val3 = bytestream2_get_be16(&s->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 | n_blocks = (opcode & 0x0F) + 1; |
| 391 | |
| 392 | while (n_blocks--) { |
| 393 | block_ptr = row_ptr + pixel_ptr; |
| 394 | for (pixel_y = 0; pixel_y < 4; pixel_y++) { |
| 395 | for (pixel_x = 0; pixel_x < 4; pixel_x++) { |
| 396 | pixels[block_ptr++] = bytestream2_get_byte(&s->gb); |
| 397 | } |
| 398 | block_ptr += row_inc; |
| 399 | } |
| 400 | ADVANCE_BLOCK(); |
| 401 | } |
| 402 | break; |
| 403 | |
| 404 | case 0xF0: |
| 405 | avpriv_request_sample(s->avctx, "0xF0 opcode"); |
| 406 | break; |
| 407 | } |
| 408 | } |
| 409 | |
| 410 | return; |
| 411 | } |
| 412 | |
| 413 | static av_cold int smc_decode_init(AVCodecContext *avctx) |
| 414 | { |
| 415 | SmcContext *s = avctx->priv_data; |
| 416 | |
| 417 | s->avctx = avctx; |
| 418 | avctx->pix_fmt = AV_PIX_FMT_PAL8; |
| 419 | |
| 420 | s->frame = av_frame_alloc(); |
| 421 | if (!s->frame) |
| 422 | return AVERROR(ENOMEM); |
| 423 | |
| 424 | return 0; |
| 425 | } |
| 426 | |
| 427 | static int smc_decode_frame(AVCodecContext *avctx, |
| 428 | void *data, int *got_frame, |
| 429 | AVPacket *avpkt) |
| 430 | { |
| 431 | const uint8_t *buf = avpkt->data; |
| 432 | int buf_size = avpkt->size; |
| 433 | SmcContext *s = avctx->priv_data; |
| 434 | const uint8_t *pal = av_packet_get_side_data(avpkt, AV_PKT_DATA_PALETTE, NULL); |
| 435 | int ret; |
| 436 | |
| 437 | bytestream2_init(&s->gb, buf, buf_size); |
| 438 | |
| 439 | if ((ret = ff_reget_buffer(avctx, s->frame)) < 0) |
| 440 | return ret; |
| 441 | |
| 442 | if (pal) { |
| 443 | s->frame->palette_has_changed = 1; |
| 444 | memcpy(s->pal, pal, AVPALETTE_SIZE); |
| 445 | } |
| 446 | |
| 447 | smc_decode_stream(s); |
| 448 | |
| 449 | *got_frame = 1; |
| 450 | if ((ret = av_frame_ref(data, s->frame)) < 0) |
| 451 | return ret; |
| 452 | |
| 453 | /* always report that the buffer was completely consumed */ |
| 454 | return buf_size; |
| 455 | } |
| 456 | |
| 457 | static av_cold int smc_decode_end(AVCodecContext *avctx) |
| 458 | { |
| 459 | SmcContext *s = avctx->priv_data; |
| 460 | |
| 461 | av_frame_free(&s->frame); |
| 462 | |
| 463 | return 0; |
| 464 | } |
| 465 | |
| 466 | AVCodec ff_smc_decoder = { |
| 467 | .name = "smc", |
| 468 | .long_name = NULL_IF_CONFIG_SMALL("QuickTime Graphics (SMC)"), |
| 469 | .type = AVMEDIA_TYPE_VIDEO, |
| 470 | .id = AV_CODEC_ID_SMC, |
| 471 | .priv_data_size = sizeof(SmcContext), |
| 472 | .init = smc_decode_init, |
| 473 | .close = smc_decode_end, |
| 474 | .decode = smc_decode_frame, |
| 475 | .capabilities = CODEC_CAP_DR1, |
| 476 | }; |