| 1 | /* |
| 2 | * Microsoft Screen 4 (aka Microsoft Expression Encoder Screen) decoder |
| 3 | * Copyright (c) 2012 Konstantin Shishkov |
| 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 | * Microsoft Screen 4 (aka Microsoft Titanium Screen 2, |
| 25 | * aka Microsoft Expression Encoder Screen) decoder |
| 26 | */ |
| 27 | |
| 28 | #include "avcodec.h" |
| 29 | #include "bytestream.h" |
| 30 | #include "get_bits.h" |
| 31 | #include "internal.h" |
| 32 | #include "mss34dsp.h" |
| 33 | #include "unary.h" |
| 34 | |
| 35 | #define HEADER_SIZE 8 |
| 36 | |
| 37 | enum FrameType { |
| 38 | INTRA_FRAME = 0, |
| 39 | INTER_FRAME, |
| 40 | SKIP_FRAME |
| 41 | }; |
| 42 | |
| 43 | enum BlockType { |
| 44 | SKIP_BLOCK = 0, |
| 45 | DCT_BLOCK, |
| 46 | IMAGE_BLOCK, |
| 47 | }; |
| 48 | |
| 49 | enum CachePos { |
| 50 | LEFT = 0, |
| 51 | TOP_LEFT, |
| 52 | TOP, |
| 53 | }; |
| 54 | |
| 55 | static const uint8_t mss4_dc_vlc_lens[2][16] = { |
| 56 | { 0, 1, 5, 1, 1, 1, 1, 2, 0, 0, 0, 0, 0, 0, 0, 0 }, |
| 57 | { 0, 3, 1, 1, 1, 1, 1, 1, 1, 2, 0, 0, 0, 0, 0, 0 } |
| 58 | }; |
| 59 | |
| 60 | static const uint8_t mss4_ac_vlc_lens[2][16] = { |
| 61 | { 0, 2, 1, 3, 3, 2, 4, 3, 5, 5, 4, 4, 0, 0, 1, 125 }, |
| 62 | { 0, 2, 1, 2, 4, 4, 3, 4, 7, 5, 4, 4, 0, 1, 2, 119 } |
| 63 | }; |
| 64 | |
| 65 | static const uint8_t mss4_ac_vlc_syms[2][162] = { |
| 66 | { 0x01, 0x02, 0x03, 0x00, 0x04, 0x11, 0x05, 0x12, |
| 67 | 0x21, 0x31, 0x41, 0x06, 0x13, 0x51, 0x61, 0x07, |
| 68 | 0x22, 0x71, 0x14, 0x32, 0x81, 0x91, 0xA1, 0x08, |
| 69 | 0x23, 0x42, 0xB1, 0xC1, 0x15, 0x52, 0xD1, 0xF0, |
| 70 | 0x24, 0x33, 0x62, 0x72, 0x82, 0x09, 0x0A, 0x16, |
| 71 | 0x17, 0x18, 0x19, 0x1A, 0x25, 0x26, 0x27, 0x28, |
| 72 | 0x29, 0x2A, 0x34, 0x35, 0x36, 0x37, 0x38, 0x39, |
| 73 | 0x3A, 0x43, 0x44, 0x45, 0x46, 0x47, 0x48, 0x49, |
| 74 | 0x4A, 0x53, 0x54, 0x55, 0x56, 0x57, 0x58, 0x59, |
| 75 | 0x5A, 0x63, 0x64, 0x65, 0x66, 0x67, 0x68, 0x69, |
| 76 | 0x6A, 0x73, 0x74, 0x75, 0x76, 0x77, 0x78, 0x79, |
| 77 | 0x7A, 0x83, 0x84, 0x85, 0x86, 0x87, 0x88, 0x89, |
| 78 | 0x8A, 0x92, 0x93, 0x94, 0x95, 0x96, 0x97, 0x98, |
| 79 | 0x99, 0x9A, 0xA2, 0xA3, 0xA4, 0xA5, 0xA6, 0xA7, |
| 80 | 0xA8, 0xA9, 0xAA, 0xB2, 0xB3, 0xB4, 0xB5, 0xB6, |
| 81 | 0xB7, 0xB8, 0xB9, 0xBA, 0xC2, 0xC3, 0xC4, 0xC5, |
| 82 | 0xC6, 0xC7, 0xC8, 0xC9, 0xCA, 0xD2, 0xD3, 0xD4, |
| 83 | 0xD5, 0xD6, 0xD7, 0xD8, 0xD9, 0xDA, 0xE1, 0xE2, |
| 84 | 0xE3, 0xE4, 0xE5, 0xE6, 0xE7, 0xE8, 0xE9, 0xEA, |
| 85 | 0xF1, 0xF2, 0xF3, 0xF4, 0xF5, 0xF6, 0xF7, 0xF8, |
| 86 | 0xF9, 0xFA }, |
| 87 | { 0x00, 0x01, 0x02, 0x03, 0x11, 0x04, 0x05, 0x21, |
| 88 | 0x31, 0x06, 0x12, 0x41, 0x51, 0x07, 0x61, 0x71, |
| 89 | 0x13, 0x22, 0x32, 0x81, 0x08, 0x14, 0x42, 0x91, |
| 90 | 0xA1, 0xB1, 0xC1, 0x09, 0x23, 0x33, 0x52, 0xF0, |
| 91 | 0x15, 0x62, 0x72, 0xD1, 0x0A, 0x16, 0x24, 0x34, |
| 92 | 0xE1, 0x25, 0xF1, 0x17, 0x18, 0x19, 0x1A, 0x26, |
| 93 | 0x27, 0x28, 0x29, 0x2A, 0x35, 0x36, 0x37, 0x38, |
| 94 | 0x39, 0x3A, 0x43, 0x44, 0x45, 0x46, 0x47, 0x48, |
| 95 | 0x49, 0x4A, 0x53, 0x54, 0x55, 0x56, 0x57, 0x58, |
| 96 | 0x59, 0x5A, 0x63, 0x64, 0x65, 0x66, 0x67, 0x68, |
| 97 | 0x69, 0x6A, 0x73, 0x74, 0x75, 0x76, 0x77, 0x78, |
| 98 | 0x79, 0x7A, 0x82, 0x83, 0x84, 0x85, 0x86, 0x87, |
| 99 | 0x88, 0x89, 0x8A, 0x92, 0x93, 0x94, 0x95, 0x96, |
| 100 | 0x97, 0x98, 0x99, 0x9A, 0xA2, 0xA3, 0xA4, 0xA5, |
| 101 | 0xA6, 0xA7, 0xA8, 0xA9, 0xAA, 0xB2, 0xB3, 0xB4, |
| 102 | 0xB5, 0xB6, 0xB7, 0xB8, 0xB9, 0xBA, 0xC2, 0xC3, |
| 103 | 0xC4, 0xC5, 0xC6, 0xC7, 0xC8, 0xC9, 0xCA, 0xD2, |
| 104 | 0xD3, 0xD4, 0xD5, 0xD6, 0xD7, 0xD8, 0xD9, 0xDA, |
| 105 | 0xE2, 0xE3, 0xE4, 0xE5, 0xE6, 0xE7, 0xE8, 0xE9, |
| 106 | 0xEA, 0xF2, 0xF3, 0xF4, 0xF5, 0xF6, 0xF7, 0xF8, |
| 107 | 0xF9, 0xFA } |
| 108 | }; |
| 109 | |
| 110 | static const uint8_t vec_len_syms[2][4] = { |
| 111 | { 4, 2, 3, 1 }, |
| 112 | { 4, 1, 2, 3 } |
| 113 | }; |
| 114 | |
| 115 | static const uint8_t mss4_vec_entry_vlc_lens[2][16] = { |
| 116 | { 0, 2, 2, 3, 2, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0 }, |
| 117 | { 0, 1, 5, 1, 2, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0 } |
| 118 | }; |
| 119 | |
| 120 | static const uint8_t mss4_vec_entry_vlc_syms[2][9] = { |
| 121 | { 0, 7, 6, 5, 8, 4, 3, 1, 2 }, |
| 122 | { 0, 2, 3, 4, 5, 6, 7, 1, 8 } |
| 123 | }; |
| 124 | |
| 125 | #define MAX_ENTRIES 162 |
| 126 | |
| 127 | typedef struct MSS4Context { |
| 128 | AVFrame *pic; |
| 129 | |
| 130 | VLC dc_vlc[2], ac_vlc[2]; |
| 131 | VLC vec_entry_vlc[2]; |
| 132 | int block[64]; |
| 133 | uint8_t imgbuf[3][16 * 16]; |
| 134 | |
| 135 | int quality; |
| 136 | uint16_t quant_mat[2][64]; |
| 137 | |
| 138 | int *prev_dc[3]; |
| 139 | int dc_stride[3]; |
| 140 | int dc_cache[4][4]; |
| 141 | |
| 142 | int prev_vec[3][4]; |
| 143 | } MSS4Context; |
| 144 | |
| 145 | static av_cold int mss4_init_vlc(VLC *vlc, const uint8_t *lens, |
| 146 | const uint8_t *syms, int num_syms) |
| 147 | { |
| 148 | uint8_t bits[MAX_ENTRIES]; |
| 149 | uint16_t codes[MAX_ENTRIES]; |
| 150 | int i, j; |
| 151 | int prefix = 0, max_bits = 0, idx = 0; |
| 152 | |
| 153 | for (i = 0; i < 16; i++) { |
| 154 | for (j = 0; j < lens[i]; j++) { |
| 155 | bits[idx] = i + 1; |
| 156 | codes[idx] = prefix++; |
| 157 | max_bits = i + 1; |
| 158 | idx++; |
| 159 | } |
| 160 | prefix <<= 1; |
| 161 | } |
| 162 | |
| 163 | return ff_init_vlc_sparse(vlc, FFMIN(max_bits, 9), num_syms, bits, 1, 1, |
| 164 | codes, 2, 2, syms, 1, 1, 0); |
| 165 | } |
| 166 | |
| 167 | static av_cold int mss4_init_vlcs(MSS4Context *ctx) |
| 168 | { |
| 169 | int ret, i; |
| 170 | |
| 171 | for (i = 0; i < 2; i++) { |
| 172 | ret = mss4_init_vlc(&ctx->dc_vlc[i], mss4_dc_vlc_lens[i], NULL, 12); |
| 173 | if (ret) |
| 174 | return ret; |
| 175 | ret = mss4_init_vlc(&ctx->ac_vlc[i], mss4_ac_vlc_lens[i], |
| 176 | mss4_ac_vlc_syms[i], 162); |
| 177 | if (ret) |
| 178 | return ret; |
| 179 | ret = mss4_init_vlc(&ctx->vec_entry_vlc[i], mss4_vec_entry_vlc_lens[i], |
| 180 | mss4_vec_entry_vlc_syms[i], 9); |
| 181 | if (ret) |
| 182 | return ret; |
| 183 | } |
| 184 | return 0; |
| 185 | } |
| 186 | |
| 187 | static av_cold void mss4_free_vlcs(MSS4Context *ctx) |
| 188 | { |
| 189 | int i; |
| 190 | |
| 191 | for (i = 0; i < 2; i++) { |
| 192 | ff_free_vlc(&ctx->dc_vlc[i]); |
| 193 | ff_free_vlc(&ctx->ac_vlc[i]); |
| 194 | ff_free_vlc(&ctx->vec_entry_vlc[i]); |
| 195 | } |
| 196 | } |
| 197 | |
| 198 | /* This function returns values in the range |
| 199 | * (-range + 1; -range/2] U [range/2; range - 1) |
| 200 | * i.e. |
| 201 | * nbits = 0 -> 0 |
| 202 | * nbits = 1 -> -1, 1 |
| 203 | * nbits = 2 -> -3, -2, 2, 3 |
| 204 | */ |
| 205 | static av_always_inline int get_coeff_bits(GetBitContext *gb, int nbits) |
| 206 | { |
| 207 | int val; |
| 208 | |
| 209 | if (!nbits) |
| 210 | return 0; |
| 211 | |
| 212 | val = get_bits(gb, nbits); |
| 213 | if (val < (1 << (nbits - 1))) |
| 214 | val -= (1 << nbits) - 1; |
| 215 | |
| 216 | return val; |
| 217 | } |
| 218 | |
| 219 | static inline int get_coeff(GetBitContext *gb, VLC *vlc) |
| 220 | { |
| 221 | int val = get_vlc2(gb, vlc->table, vlc->bits, 2); |
| 222 | |
| 223 | return get_coeff_bits(gb, val); |
| 224 | } |
| 225 | |
| 226 | static int mss4_decode_dct(GetBitContext *gb, VLC *dc_vlc, VLC *ac_vlc, |
| 227 | int *block, int *dc_cache, |
| 228 | int bx, int by, uint16_t *quant_mat) |
| 229 | { |
| 230 | int skip, val, pos = 1, zz_pos, dc; |
| 231 | |
| 232 | memset(block, 0, sizeof(*block) * 64); |
| 233 | |
| 234 | dc = get_coeff(gb, dc_vlc); |
| 235 | // DC prediction is the same as in MSS3 |
| 236 | if (by) { |
| 237 | if (bx) { |
| 238 | int l, tl, t; |
| 239 | |
| 240 | l = dc_cache[LEFT]; |
| 241 | tl = dc_cache[TOP_LEFT]; |
| 242 | t = dc_cache[TOP]; |
| 243 | |
| 244 | if (FFABS(t - tl) <= FFABS(l - tl)) |
| 245 | dc += l; |
| 246 | else |
| 247 | dc += t; |
| 248 | } else { |
| 249 | dc += dc_cache[TOP]; |
| 250 | } |
| 251 | } else if (bx) { |
| 252 | dc += dc_cache[LEFT]; |
| 253 | } |
| 254 | dc_cache[LEFT] = dc; |
| 255 | block[0] = dc * quant_mat[0]; |
| 256 | |
| 257 | while (pos < 64) { |
| 258 | val = get_vlc2(gb, ac_vlc->table, 9, 2); |
| 259 | if (!val) |
| 260 | return 0; |
| 261 | if (val == -1) |
| 262 | return -1; |
| 263 | if (val == 0xF0) { |
| 264 | pos += 16; |
| 265 | continue; |
| 266 | } |
| 267 | skip = val >> 4; |
| 268 | val = get_coeff_bits(gb, val & 0xF); |
| 269 | pos += skip; |
| 270 | if (pos >= 64) |
| 271 | return -1; |
| 272 | |
| 273 | zz_pos = ff_zigzag_direct[pos]; |
| 274 | block[zz_pos] = val * quant_mat[zz_pos]; |
| 275 | pos++; |
| 276 | } |
| 277 | |
| 278 | return pos == 64 ? 0 : -1; |
| 279 | } |
| 280 | |
| 281 | static int mss4_decode_dct_block(MSS4Context *c, GetBitContext *gb, |
| 282 | uint8_t *dst[3], int mb_x, int mb_y) |
| 283 | { |
| 284 | int i, j, k, ret; |
| 285 | uint8_t *out = dst[0]; |
| 286 | |
| 287 | for (j = 0; j < 2; j++) { |
| 288 | for (i = 0; i < 2; i++) { |
| 289 | int xpos = mb_x * 2 + i; |
| 290 | c->dc_cache[j][TOP_LEFT] = c->dc_cache[j][TOP]; |
| 291 | c->dc_cache[j][TOP] = c->prev_dc[0][mb_x * 2 + i]; |
| 292 | ret = mss4_decode_dct(gb, c->dc_vlc, c->ac_vlc, c->block, |
| 293 | c->dc_cache[j], |
| 294 | xpos, mb_y * 2 + j, c->quant_mat[0]); |
| 295 | if (ret) |
| 296 | return ret; |
| 297 | c->prev_dc[0][mb_x * 2 + i] = c->dc_cache[j][LEFT]; |
| 298 | |
| 299 | ff_mss34_dct_put(out + xpos * 8, c->pic->linesize[0], |
| 300 | c->block); |
| 301 | } |
| 302 | out += 8 * c->pic->linesize[0]; |
| 303 | } |
| 304 | |
| 305 | for (i = 1; i < 3; i++) { |
| 306 | c->dc_cache[i + 1][TOP_LEFT] = c->dc_cache[i + 1][TOP]; |
| 307 | c->dc_cache[i + 1][TOP] = c->prev_dc[i][mb_x]; |
| 308 | ret = mss4_decode_dct(gb, c->dc_vlc + 1, c->ac_vlc + 1, |
| 309 | c->block, c->dc_cache[i + 1], mb_x, mb_y, |
| 310 | c->quant_mat[1]); |
| 311 | if (ret) |
| 312 | return ret; |
| 313 | c->prev_dc[i][mb_x] = c->dc_cache[i + 1][LEFT]; |
| 314 | |
| 315 | ff_mss34_dct_put(c->imgbuf[i], 8, c->block); |
| 316 | out = dst[i] + mb_x * 16; |
| 317 | // Since the DCT block is coded as YUV420 and the whole frame as YUV444, |
| 318 | // we need to scale chroma. |
| 319 | for (j = 0; j < 16; j++) { |
| 320 | for (k = 0; k < 8; k++) |
| 321 | AV_WN16A(out + k * 2, c->imgbuf[i][k + (j & ~1) * 4] * 0x101); |
| 322 | out += c->pic->linesize[i]; |
| 323 | } |
| 324 | } |
| 325 | |
| 326 | return 0; |
| 327 | } |
| 328 | |
| 329 | static void read_vec_pos(GetBitContext *gb, int *vec_pos, int *sel_flag, |
| 330 | int *sel_len, int *prev) |
| 331 | { |
| 332 | int i, y_flag = 0; |
| 333 | |
| 334 | for (i = 2; i >= 0; i--) { |
| 335 | if (!sel_flag[i]) { |
| 336 | vec_pos[i] = 0; |
| 337 | continue; |
| 338 | } |
| 339 | if ((!i && !y_flag) || get_bits1(gb)) { |
| 340 | if (sel_len[i] > 0) { |
| 341 | int pval = prev[i]; |
| 342 | vec_pos[i] = get_bits(gb, sel_len[i]); |
| 343 | if (vec_pos[i] >= pval) |
| 344 | vec_pos[i]++; |
| 345 | } else { |
| 346 | vec_pos[i] = !prev[i]; |
| 347 | } |
| 348 | y_flag = 1; |
| 349 | } else { |
| 350 | vec_pos[i] = prev[i]; |
| 351 | } |
| 352 | } |
| 353 | } |
| 354 | |
| 355 | static int get_value_cached(GetBitContext *gb, int vec_pos, uint8_t *vec, |
| 356 | int vec_size, int component, int shift, int *prev) |
| 357 | { |
| 358 | if (vec_pos < vec_size) |
| 359 | return vec[vec_pos]; |
| 360 | if (!get_bits1(gb)) |
| 361 | return prev[component]; |
| 362 | prev[component] = get_bits(gb, 8 - shift) << shift; |
| 363 | return prev[component]; |
| 364 | } |
| 365 | |
| 366 | #define MKVAL(vals) ((vals)[0] | ((vals)[1] << 3) | ((vals)[2] << 6)) |
| 367 | |
| 368 | /* Image mode - the hardest to comprehend MSS4 coding mode. |
| 369 | * |
| 370 | * In this mode all three 16x16 blocks are coded together with a method |
| 371 | * remotely similar to the methods employed in MSS1-MSS3. |
| 372 | * The idea is that every component has a vector of 1-4 most common symbols |
| 373 | * and an escape mode for reading new value from the bitstream. Decoding |
| 374 | * consists of retrieving pixel values from the vector or reading new ones |
| 375 | * from the bitstream; depending on flags read from the bitstream, these vector |
| 376 | * positions can be updated or reused from the state of the previous line |
| 377 | * or previous pixel. |
| 378 | */ |
| 379 | static int mss4_decode_image_block(MSS4Context *ctx, GetBitContext *gb, |
| 380 | uint8_t *picdst[3], int mb_x, int mb_y) |
| 381 | { |
| 382 | uint8_t vec[3][4]; |
| 383 | int vec_len[3]; |
| 384 | int sel_len[3], sel_flag[3]; |
| 385 | int i, j, k, mode, split; |
| 386 | int prev_vec1 = 0, prev_split = 0; |
| 387 | int vals[3] = { 0 }; |
| 388 | int prev_pix[3] = { 0 }; |
| 389 | int prev_mode[16] = { 0 }; |
| 390 | uint8_t *dst[3]; |
| 391 | |
| 392 | const int val_shift = ctx->quality == 100 ? 0 : 2; |
| 393 | |
| 394 | for (i = 0; i < 3; i++) |
| 395 | dst[i] = ctx->imgbuf[i]; |
| 396 | |
| 397 | for (i = 0; i < 3; i++) { |
| 398 | vec_len[i] = vec_len_syms[!!i][get_unary(gb, 0, 3)]; |
| 399 | for (j = 0; j < vec_len[i]; j++) { |
| 400 | vec[i][j] = get_coeff(gb, &ctx->vec_entry_vlc[!!i]); |
| 401 | vec[i][j] += ctx->prev_vec[i][j]; |
| 402 | ctx->prev_vec[i][j] = vec[i][j]; |
| 403 | } |
| 404 | sel_flag[i] = vec_len[i] > 1; |
| 405 | sel_len[i] = vec_len[i] > 2 ? vec_len[i] - 2 : 0; |
| 406 | } |
| 407 | |
| 408 | for (j = 0; j < 16; j++) { |
| 409 | if (get_bits1(gb)) { |
| 410 | split = 0; |
| 411 | if (get_bits1(gb)) { |
| 412 | prev_mode[0] = 0; |
| 413 | vals[0] = vals[1] = vals[2] = 0; |
| 414 | mode = 2; |
| 415 | } else { |
| 416 | mode = get_bits1(gb); |
| 417 | if (mode) |
| 418 | split = get_bits(gb, 4); |
| 419 | } |
| 420 | for (i = 0; i < 16; i++) { |
| 421 | if (mode <= 1) { |
| 422 | vals[0] = prev_mode[i] & 7; |
| 423 | vals[1] = (prev_mode[i] >> 3) & 7; |
| 424 | vals[2] = prev_mode[i] >> 6; |
| 425 | if (mode == 1 && i == split) { |
| 426 | read_vec_pos(gb, vals, sel_flag, sel_len, vals); |
| 427 | } |
| 428 | } else if (mode == 2) { |
| 429 | if (get_bits1(gb)) |
| 430 | read_vec_pos(gb, vals, sel_flag, sel_len, vals); |
| 431 | } |
| 432 | for (k = 0; k < 3; k++) |
| 433 | *dst[k]++ = get_value_cached(gb, vals[k], vec[k], |
| 434 | vec_len[k], k, |
| 435 | val_shift, prev_pix); |
| 436 | prev_mode[i] = MKVAL(vals); |
| 437 | } |
| 438 | } else { |
| 439 | if (get_bits1(gb)) { |
| 440 | split = get_bits(gb, 4); |
| 441 | if (split >= prev_split) |
| 442 | split++; |
| 443 | prev_split = split; |
| 444 | } else { |
| 445 | split = prev_split; |
| 446 | } |
| 447 | if (split) { |
| 448 | vals[0] = prev_mode[0] & 7; |
| 449 | vals[1] = (prev_mode[0] >> 3) & 7; |
| 450 | vals[2] = prev_mode[0] >> 6; |
| 451 | for (i = 0; i < 3; i++) { |
| 452 | for (k = 0; k < split; k++) { |
| 453 | *dst[i]++ = get_value_cached(gb, vals[i], vec[i], |
| 454 | vec_len[i], i, val_shift, |
| 455 | prev_pix); |
| 456 | prev_mode[k] = MKVAL(vals); |
| 457 | } |
| 458 | } |
| 459 | } |
| 460 | |
| 461 | if (split != 16) { |
| 462 | vals[0] = prev_vec1 & 7; |
| 463 | vals[1] = (prev_vec1 >> 3) & 7; |
| 464 | vals[2] = prev_vec1 >> 6; |
| 465 | if (get_bits1(gb)) { |
| 466 | read_vec_pos(gb, vals, sel_flag, sel_len, vals); |
| 467 | prev_vec1 = MKVAL(vals); |
| 468 | } |
| 469 | for (i = 0; i < 3; i++) { |
| 470 | for (k = 0; k < 16 - split; k++) { |
| 471 | *dst[i]++ = get_value_cached(gb, vals[i], vec[i], |
| 472 | vec_len[i], i, val_shift, |
| 473 | prev_pix); |
| 474 | prev_mode[split + k] = MKVAL(vals); |
| 475 | } |
| 476 | } |
| 477 | } |
| 478 | } |
| 479 | } |
| 480 | |
| 481 | for (i = 0; i < 3; i++) |
| 482 | for (j = 0; j < 16; j++) |
| 483 | memcpy(picdst[i] + mb_x * 16 + j * ctx->pic->linesize[i], |
| 484 | ctx->imgbuf[i] + j * 16, 16); |
| 485 | |
| 486 | return 0; |
| 487 | } |
| 488 | |
| 489 | static inline void mss4_update_dc_cache(MSS4Context *c, int mb_x) |
| 490 | { |
| 491 | int i; |
| 492 | |
| 493 | c->dc_cache[0][TOP] = c->prev_dc[0][mb_x * 2 + 1]; |
| 494 | c->dc_cache[0][LEFT] = 0; |
| 495 | c->dc_cache[1][TOP] = 0; |
| 496 | c->dc_cache[1][LEFT] = 0; |
| 497 | |
| 498 | for (i = 0; i < 2; i++) |
| 499 | c->prev_dc[0][mb_x * 2 + i] = 0; |
| 500 | |
| 501 | for (i = 1; i < 3; i++) { |
| 502 | c->dc_cache[i + 1][TOP] = c->prev_dc[i][mb_x]; |
| 503 | c->dc_cache[i + 1][LEFT] = 0; |
| 504 | c->prev_dc[i][mb_x] = 0; |
| 505 | } |
| 506 | } |
| 507 | |
| 508 | static int mss4_decode_frame(AVCodecContext *avctx, void *data, int *got_frame, |
| 509 | AVPacket *avpkt) |
| 510 | { |
| 511 | const uint8_t *buf = avpkt->data; |
| 512 | int buf_size = avpkt->size; |
| 513 | MSS4Context *c = avctx->priv_data; |
| 514 | GetBitContext gb; |
| 515 | GetByteContext bc; |
| 516 | uint8_t *dst[3]; |
| 517 | int width, height, quality, frame_type; |
| 518 | int x, y, i, mb_width, mb_height, blk_type; |
| 519 | int ret; |
| 520 | |
| 521 | if (buf_size < HEADER_SIZE) { |
| 522 | av_log(avctx, AV_LOG_ERROR, |
| 523 | "Frame should have at least %d bytes, got %d instead\n", |
| 524 | HEADER_SIZE, buf_size); |
| 525 | return AVERROR_INVALIDDATA; |
| 526 | } |
| 527 | |
| 528 | bytestream2_init(&bc, buf, buf_size); |
| 529 | width = bytestream2_get_be16(&bc); |
| 530 | height = bytestream2_get_be16(&bc); |
| 531 | bytestream2_skip(&bc, 2); |
| 532 | quality = bytestream2_get_byte(&bc); |
| 533 | frame_type = bytestream2_get_byte(&bc); |
| 534 | |
| 535 | if (width > avctx->width || |
| 536 | height != avctx->height) { |
| 537 | av_log(avctx, AV_LOG_ERROR, "Invalid frame dimensions %dx%d\n", |
| 538 | width, height); |
| 539 | return AVERROR_INVALIDDATA; |
| 540 | } |
| 541 | if (quality < 1 || quality > 100) { |
| 542 | av_log(avctx, AV_LOG_ERROR, "Invalid quality setting %d\n", quality); |
| 543 | return AVERROR_INVALIDDATA; |
| 544 | } |
| 545 | if ((frame_type & ~3) || frame_type == 3) { |
| 546 | av_log(avctx, AV_LOG_ERROR, "Invalid frame type %d\n", frame_type); |
| 547 | return AVERROR_INVALIDDATA; |
| 548 | } |
| 549 | |
| 550 | if (frame_type != SKIP_FRAME && !bytestream2_get_bytes_left(&bc)) { |
| 551 | av_log(avctx, AV_LOG_ERROR, |
| 552 | "Empty frame found but it is not a skip frame.\n"); |
| 553 | return AVERROR_INVALIDDATA; |
| 554 | } |
| 555 | |
| 556 | if ((ret = ff_reget_buffer(avctx, c->pic)) < 0) |
| 557 | return ret; |
| 558 | c->pic->key_frame = (frame_type == INTRA_FRAME); |
| 559 | c->pic->pict_type = (frame_type == INTRA_FRAME) ? AV_PICTURE_TYPE_I |
| 560 | : AV_PICTURE_TYPE_P; |
| 561 | if (frame_type == SKIP_FRAME) { |
| 562 | *got_frame = 1; |
| 563 | if ((ret = av_frame_ref(data, c->pic)) < 0) |
| 564 | return ret; |
| 565 | |
| 566 | return buf_size; |
| 567 | } |
| 568 | |
| 569 | if (c->quality != quality) { |
| 570 | c->quality = quality; |
| 571 | for (i = 0; i < 2; i++) |
| 572 | ff_mss34_gen_quant_mat(c->quant_mat[i], quality, !i); |
| 573 | } |
| 574 | |
| 575 | init_get_bits8(&gb, buf + HEADER_SIZE, (buf_size - HEADER_SIZE)); |
| 576 | |
| 577 | mb_width = FFALIGN(width, 16) >> 4; |
| 578 | mb_height = FFALIGN(height, 16) >> 4; |
| 579 | dst[0] = c->pic->data[0]; |
| 580 | dst[1] = c->pic->data[1]; |
| 581 | dst[2] = c->pic->data[2]; |
| 582 | |
| 583 | memset(c->prev_vec, 0, sizeof(c->prev_vec)); |
| 584 | for (y = 0; y < mb_height; y++) { |
| 585 | memset(c->dc_cache, 0, sizeof(c->dc_cache)); |
| 586 | for (x = 0; x < mb_width; x++) { |
| 587 | blk_type = decode012(&gb); |
| 588 | switch (blk_type) { |
| 589 | case DCT_BLOCK: |
| 590 | if (mss4_decode_dct_block(c, &gb, dst, x, y) < 0) { |
| 591 | av_log(avctx, AV_LOG_ERROR, |
| 592 | "Error decoding DCT block %d,%d\n", |
| 593 | x, y); |
| 594 | return AVERROR_INVALIDDATA; |
| 595 | } |
| 596 | break; |
| 597 | case IMAGE_BLOCK: |
| 598 | if (mss4_decode_image_block(c, &gb, dst, x, y) < 0) { |
| 599 | av_log(avctx, AV_LOG_ERROR, |
| 600 | "Error decoding VQ block %d,%d\n", |
| 601 | x, y); |
| 602 | return AVERROR_INVALIDDATA; |
| 603 | } |
| 604 | break; |
| 605 | case SKIP_BLOCK: |
| 606 | if (frame_type == INTRA_FRAME) { |
| 607 | av_log(avctx, AV_LOG_ERROR, "Skip block in intra frame\n"); |
| 608 | return AVERROR_INVALIDDATA; |
| 609 | } |
| 610 | break; |
| 611 | } |
| 612 | if (blk_type != DCT_BLOCK) |
| 613 | mss4_update_dc_cache(c, x); |
| 614 | } |
| 615 | dst[0] += c->pic->linesize[0] * 16; |
| 616 | dst[1] += c->pic->linesize[1] * 16; |
| 617 | dst[2] += c->pic->linesize[2] * 16; |
| 618 | } |
| 619 | |
| 620 | if ((ret = av_frame_ref(data, c->pic)) < 0) |
| 621 | return ret; |
| 622 | |
| 623 | *got_frame = 1; |
| 624 | |
| 625 | return buf_size; |
| 626 | } |
| 627 | |
| 628 | static av_cold int mss4_decode_end(AVCodecContext *avctx) |
| 629 | { |
| 630 | MSS4Context * const c = avctx->priv_data; |
| 631 | int i; |
| 632 | |
| 633 | av_frame_free(&c->pic); |
| 634 | for (i = 0; i < 3; i++) |
| 635 | av_freep(&c->prev_dc[i]); |
| 636 | mss4_free_vlcs(c); |
| 637 | |
| 638 | return 0; |
| 639 | } |
| 640 | |
| 641 | static av_cold int mss4_decode_init(AVCodecContext *avctx) |
| 642 | { |
| 643 | MSS4Context * const c = avctx->priv_data; |
| 644 | int i; |
| 645 | |
| 646 | if (mss4_init_vlcs(c)) { |
| 647 | av_log(avctx, AV_LOG_ERROR, "Cannot initialise VLCs\n"); |
| 648 | mss4_free_vlcs(c); |
| 649 | return AVERROR(ENOMEM); |
| 650 | } |
| 651 | for (i = 0; i < 3; i++) { |
| 652 | c->dc_stride[i] = FFALIGN(avctx->width, 16) >> (2 + !!i); |
| 653 | c->prev_dc[i] = av_malloc(sizeof(**c->prev_dc) * c->dc_stride[i]); |
| 654 | if (!c->prev_dc[i]) { |
| 655 | av_log(avctx, AV_LOG_ERROR, "Cannot allocate buffer\n"); |
| 656 | mss4_free_vlcs(c); |
| 657 | return AVERROR(ENOMEM); |
| 658 | } |
| 659 | } |
| 660 | |
| 661 | c->pic = av_frame_alloc(); |
| 662 | if (!c->pic) { |
| 663 | mss4_decode_end(avctx); |
| 664 | return AVERROR(ENOMEM); |
| 665 | } |
| 666 | |
| 667 | avctx->pix_fmt = AV_PIX_FMT_YUV444P; |
| 668 | |
| 669 | return 0; |
| 670 | } |
| 671 | |
| 672 | AVCodec ff_mts2_decoder = { |
| 673 | .name = "mts2", |
| 674 | .long_name = NULL_IF_CONFIG_SMALL("MS Expression Encoder Screen"), |
| 675 | .type = AVMEDIA_TYPE_VIDEO, |
| 676 | .id = AV_CODEC_ID_MTS2, |
| 677 | .priv_data_size = sizeof(MSS4Context), |
| 678 | .init = mss4_decode_init, |
| 679 | .close = mss4_decode_end, |
| 680 | .decode = mss4_decode_frame, |
| 681 | .capabilities = CODEC_CAP_DR1, |
| 682 | }; |