| 1 | /* |
| 2 | * TechSmith Screen Codec 2 (aka Dora) 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 | * TechSmith Screen Codec 2 decoder |
| 25 | */ |
| 26 | |
| 27 | #include <inttypes.h> |
| 28 | |
| 29 | #define BITSTREAM_READER_LE |
| 30 | #include "avcodec.h" |
| 31 | #include "get_bits.h" |
| 32 | #include "bytestream.h" |
| 33 | #include "internal.h" |
| 34 | #include "tscc2data.h" |
| 35 | |
| 36 | typedef struct TSCC2Context { |
| 37 | AVCodecContext *avctx; |
| 38 | AVFrame *pic; |
| 39 | int mb_width, mb_height; |
| 40 | uint8_t *slice_quants; |
| 41 | int quant[2]; |
| 42 | int q[2][3]; |
| 43 | GetBitContext gb; |
| 44 | |
| 45 | VLC dc_vlc, nc_vlc[NUM_VLC_SETS], ac_vlc[NUM_VLC_SETS]; |
| 46 | int block[16]; |
| 47 | } TSCC2Context; |
| 48 | |
| 49 | static av_cold void free_vlcs(TSCC2Context *c) |
| 50 | { |
| 51 | int i; |
| 52 | |
| 53 | ff_free_vlc(&c->dc_vlc); |
| 54 | for (i = 0; i < NUM_VLC_SETS; i++) { |
| 55 | ff_free_vlc(c->nc_vlc + i); |
| 56 | ff_free_vlc(c->ac_vlc + i); |
| 57 | } |
| 58 | } |
| 59 | |
| 60 | static av_cold int init_vlcs(TSCC2Context *c) |
| 61 | { |
| 62 | int i, ret; |
| 63 | |
| 64 | ret = ff_init_vlc_sparse(&c->dc_vlc, 9, DC_VLC_COUNT, |
| 65 | tscc2_dc_vlc_bits, 1, 1, |
| 66 | tscc2_dc_vlc_codes, 2, 2, |
| 67 | tscc2_dc_vlc_syms, 2, 2, INIT_VLC_LE); |
| 68 | if (ret) |
| 69 | return ret; |
| 70 | |
| 71 | for (i = 0; i < NUM_VLC_SETS; i++) { |
| 72 | ret = ff_init_vlc_sparse(c->nc_vlc + i, 9, 16, |
| 73 | tscc2_nc_vlc_bits[i], 1, 1, |
| 74 | tscc2_nc_vlc_codes[i], 2, 2, |
| 75 | tscc2_nc_vlc_syms, 1, 1, INIT_VLC_LE); |
| 76 | if (ret) { |
| 77 | free_vlcs(c); |
| 78 | return ret; |
| 79 | } |
| 80 | ret = ff_init_vlc_sparse(c->ac_vlc + i, 9, tscc2_ac_vlc_sizes[i], |
| 81 | tscc2_ac_vlc_bits[i], 1, 1, |
| 82 | tscc2_ac_vlc_codes[i], 2, 2, |
| 83 | tscc2_ac_vlc_syms[i], 2, 2, INIT_VLC_LE); |
| 84 | if (ret) { |
| 85 | free_vlcs(c); |
| 86 | return ret; |
| 87 | } |
| 88 | } |
| 89 | |
| 90 | return 0; |
| 91 | } |
| 92 | |
| 93 | #define DEQUANT(val, q) (((q) * (val) + 0x80) >> 8) |
| 94 | #define DCT1D(d0, d1, d2, d3, s0, s1, s2, s3, OP) \ |
| 95 | OP(d0, 5 * ((s0) + (s1) + (s2)) + 2 * (s3)); \ |
| 96 | OP(d1, 5 * ((s0) - (s2) - (s3)) + 2 * (s1)); \ |
| 97 | OP(d2, 5 * ((s0) - (s2) + (s3)) - 2 * (s1)); \ |
| 98 | OP(d3, 5 * ((s0) - (s1) + (s2)) - 2 * (s3)); \ |
| 99 | |
| 100 | #define COL_OP(a, b) a = (b) |
| 101 | #define ROW_OP(a, b) a = ((b) + 0x20) >> 6 |
| 102 | |
| 103 | static void tscc2_idct4_put(int *in, int q[3], uint8_t *dst, int stride) |
| 104 | { |
| 105 | int i; |
| 106 | int tblk[4 * 4]; |
| 107 | int t0, t1, t2, t3; |
| 108 | |
| 109 | for (i = 0; i < 4; i++) { |
| 110 | t0 = DEQUANT(q[0 + (i & 1)], in[0 * 4 + i]); |
| 111 | t1 = DEQUANT(q[1 + (i & 1)], in[1 * 4 + i]); |
| 112 | t2 = DEQUANT(q[0 + (i & 1)], in[2 * 4 + i]); |
| 113 | t3 = DEQUANT(q[1 + (i & 1)], in[3 * 4 + i]); |
| 114 | DCT1D(tblk[0 * 4 + i], tblk[1 * 4 + i], |
| 115 | tblk[2 * 4 + i], tblk[3 * 4 + i], |
| 116 | t0, t1, t2, t3, COL_OP); |
| 117 | } |
| 118 | for (i = 0; i < 4; i++) { |
| 119 | DCT1D(dst[0], dst[1], dst[2], dst[3], |
| 120 | tblk[i * 4 + 0], tblk[i * 4 + 1], |
| 121 | tblk[i * 4 + 2], tblk[i * 4 + 3], ROW_OP); |
| 122 | dst += stride; |
| 123 | } |
| 124 | } |
| 125 | |
| 126 | static int tscc2_decode_mb(TSCC2Context *c, int *q, int vlc_set, |
| 127 | uint8_t *dst, int stride, int plane) |
| 128 | { |
| 129 | GetBitContext *gb = &c->gb; |
| 130 | int prev_dc, dc, nc, ac, bpos, val; |
| 131 | int i, j, k, l; |
| 132 | |
| 133 | if (get_bits1(gb)) { |
| 134 | if (get_bits1(gb)) { |
| 135 | val = get_bits(gb, 8); |
| 136 | for (i = 0; i < 8; i++, dst += stride) |
| 137 | memset(dst, val, 16); |
| 138 | } else { |
| 139 | if (get_bits_left(gb) < 16 * 8 * 8) |
| 140 | return AVERROR_INVALIDDATA; |
| 141 | for (i = 0; i < 8; i++) { |
| 142 | for (j = 0; j < 16; j++) |
| 143 | dst[j] = get_bits(gb, 8); |
| 144 | dst += stride; |
| 145 | } |
| 146 | } |
| 147 | return 0; |
| 148 | } |
| 149 | |
| 150 | prev_dc = 0; |
| 151 | for (j = 0; j < 2; j++) { |
| 152 | for (k = 0; k < 4; k++) { |
| 153 | if (!(j | k)) { |
| 154 | dc = get_bits(gb, 8); |
| 155 | } else { |
| 156 | dc = get_vlc2(gb, c->dc_vlc.table, 9, 2); |
| 157 | if (dc == -1) |
| 158 | return AVERROR_INVALIDDATA; |
| 159 | if (dc == 0x100) |
| 160 | dc = get_bits(gb, 8); |
| 161 | } |
| 162 | dc = (dc + prev_dc) & 0xFF; |
| 163 | prev_dc = dc; |
| 164 | c->block[0] = dc; |
| 165 | |
| 166 | nc = get_vlc2(gb, c->nc_vlc[vlc_set].table, 9, 1); |
| 167 | if (nc == -1) |
| 168 | return AVERROR_INVALIDDATA; |
| 169 | |
| 170 | bpos = 1; |
| 171 | memset(c->block + 1, 0, 15 * sizeof(*c->block)); |
| 172 | for (l = 0; l < nc; l++) { |
| 173 | ac = get_vlc2(gb, c->ac_vlc[vlc_set].table, 9, 2); |
| 174 | if (ac == -1) |
| 175 | return AVERROR_INVALIDDATA; |
| 176 | if (ac == 0x1000) |
| 177 | ac = get_bits(gb, 12); |
| 178 | bpos += ac & 0xF; |
| 179 | if (bpos >= 16) |
| 180 | return AVERROR_INVALIDDATA; |
| 181 | val = sign_extend(ac >> 4, 8); |
| 182 | c->block[tscc2_zigzag[bpos++]] = val; |
| 183 | } |
| 184 | tscc2_idct4_put(c->block, q, dst + k * 4, stride); |
| 185 | } |
| 186 | dst += 4 * stride; |
| 187 | } |
| 188 | return 0; |
| 189 | } |
| 190 | |
| 191 | static int tscc2_decode_slice(TSCC2Context *c, int mb_y, |
| 192 | const uint8_t *buf, int buf_size) |
| 193 | { |
| 194 | int i, mb_x, q, ret; |
| 195 | int off; |
| 196 | |
| 197 | if ((ret = init_get_bits8(&c->gb, buf, buf_size)) < 0) |
| 198 | return ret; |
| 199 | |
| 200 | for (mb_x = 0; mb_x < c->mb_width; mb_x++) { |
| 201 | q = c->slice_quants[mb_x + c->mb_width * mb_y]; |
| 202 | |
| 203 | if (q == 0 || q == 3) // skip block |
| 204 | continue; |
| 205 | for (i = 0; i < 3; i++) { |
| 206 | off = mb_x * 16 + mb_y * 8 * c->pic->linesize[i]; |
| 207 | ret = tscc2_decode_mb(c, c->q[q - 1], c->quant[q - 1] - 2, |
| 208 | c->pic->data[i] + off, c->pic->linesize[i], i); |
| 209 | if (ret) |
| 210 | return ret; |
| 211 | } |
| 212 | } |
| 213 | |
| 214 | return 0; |
| 215 | } |
| 216 | |
| 217 | static int tscc2_decode_frame(AVCodecContext *avctx, void *data, |
| 218 | int *got_frame, AVPacket *avpkt) |
| 219 | { |
| 220 | const uint8_t *buf = avpkt->data; |
| 221 | int buf_size = avpkt->size; |
| 222 | TSCC2Context *c = avctx->priv_data; |
| 223 | GetByteContext gb; |
| 224 | uint32_t frame_type, size; |
| 225 | int i, val, len, pos = 0; |
| 226 | int num_mb = c->mb_width * c->mb_height; |
| 227 | int ret; |
| 228 | |
| 229 | bytestream2_init(&gb, buf, buf_size); |
| 230 | frame_type = bytestream2_get_byte(&gb); |
| 231 | if (frame_type > 1) { |
| 232 | av_log(avctx, AV_LOG_ERROR, "Incorrect frame type %"PRIu32"\n", |
| 233 | frame_type); |
| 234 | return AVERROR_INVALIDDATA; |
| 235 | } |
| 236 | |
| 237 | if ((ret = ff_reget_buffer(avctx, c->pic)) < 0) { |
| 238 | return ret; |
| 239 | } |
| 240 | |
| 241 | if (frame_type == 0) { |
| 242 | *got_frame = 1; |
| 243 | if ((ret = av_frame_ref(data, c->pic)) < 0) |
| 244 | return ret; |
| 245 | |
| 246 | return buf_size; |
| 247 | } |
| 248 | |
| 249 | if (bytestream2_get_bytes_left(&gb) < 4) { |
| 250 | av_log(avctx, AV_LOG_ERROR, "Frame is too short\n"); |
| 251 | return AVERROR_INVALIDDATA; |
| 252 | } |
| 253 | |
| 254 | c->quant[0] = bytestream2_get_byte(&gb); |
| 255 | c->quant[1] = bytestream2_get_byte(&gb); |
| 256 | if (c->quant[0] < 2 || c->quant[0] > NUM_VLC_SETS + 1 || |
| 257 | c->quant[1] < 2 || c->quant[1] > NUM_VLC_SETS + 1) { |
| 258 | av_log(avctx, AV_LOG_ERROR, "Invalid quantisers %d / %d\n", |
| 259 | c->quant[0], c->quant[1]); |
| 260 | return AVERROR_INVALIDDATA; |
| 261 | } |
| 262 | |
| 263 | for (i = 0; i < 3; i++) { |
| 264 | c->q[0][i] = tscc2_quants[c->quant[0] - 2][i]; |
| 265 | c->q[1][i] = tscc2_quants[c->quant[1] - 2][i]; |
| 266 | } |
| 267 | |
| 268 | bytestream2_skip(&gb, 1); |
| 269 | |
| 270 | size = bytestream2_get_le32(&gb); |
| 271 | if (size > bytestream2_get_bytes_left(&gb)) { |
| 272 | av_log(avctx, AV_LOG_ERROR, "Slice properties chunk is too large\n"); |
| 273 | return AVERROR_INVALIDDATA; |
| 274 | } |
| 275 | |
| 276 | for (i = 0; i < size; i++) { |
| 277 | val = bytestream2_get_byte(&gb); |
| 278 | len = val & 0x3F; |
| 279 | val >>= 6; |
| 280 | if (pos + len > num_mb) { |
| 281 | av_log(avctx, AV_LOG_ERROR, "Too many slice properties\n"); |
| 282 | return AVERROR_INVALIDDATA; |
| 283 | } |
| 284 | memset(c->slice_quants + pos, val, len); |
| 285 | pos += len; |
| 286 | } |
| 287 | if (pos < num_mb) { |
| 288 | av_log(avctx, AV_LOG_ERROR, "Too few slice properties (%d / %d)\n", |
| 289 | pos, num_mb); |
| 290 | return AVERROR_INVALIDDATA; |
| 291 | } |
| 292 | |
| 293 | for (i = 0; i < c->mb_height; i++) { |
| 294 | size = bytestream2_peek_byte(&gb); |
| 295 | if (size & 1) { |
| 296 | size = bytestream2_get_byte(&gb) - 1; |
| 297 | } else { |
| 298 | size = bytestream2_get_le32(&gb) >> 1; |
| 299 | } |
| 300 | if (!size) { |
| 301 | int skip_row = 1, j, off = i * c->mb_width; |
| 302 | for (j = 0; j < c->mb_width; j++) { |
| 303 | if (c->slice_quants[off + j] == 1 || |
| 304 | c->slice_quants[off + j] == 2) { |
| 305 | skip_row = 0; |
| 306 | break; |
| 307 | } |
| 308 | } |
| 309 | if (!skip_row) { |
| 310 | av_log(avctx, AV_LOG_ERROR, "Non-skip row with zero size\n"); |
| 311 | return AVERROR_INVALIDDATA; |
| 312 | } |
| 313 | } |
| 314 | if (bytestream2_get_bytes_left(&gb) < size) { |
| 315 | av_log(avctx, AV_LOG_ERROR, "Invalid slice size (%"PRIu32"/%u)\n", |
| 316 | size, bytestream2_get_bytes_left(&gb)); |
| 317 | return AVERROR_INVALIDDATA; |
| 318 | } |
| 319 | ret = tscc2_decode_slice(c, i, buf + bytestream2_tell(&gb), size); |
| 320 | if (ret) { |
| 321 | av_log(avctx, AV_LOG_ERROR, "Error decoding slice %d\n", i); |
| 322 | return ret; |
| 323 | } |
| 324 | bytestream2_skip(&gb, size); |
| 325 | } |
| 326 | |
| 327 | *got_frame = 1; |
| 328 | if ((ret = av_frame_ref(data, c->pic)) < 0) |
| 329 | return ret; |
| 330 | |
| 331 | /* always report that the buffer was completely consumed */ |
| 332 | return buf_size; |
| 333 | } |
| 334 | |
| 335 | static av_cold int tscc2_decode_end(AVCodecContext *avctx) |
| 336 | { |
| 337 | TSCC2Context * const c = avctx->priv_data; |
| 338 | |
| 339 | av_frame_free(&c->pic); |
| 340 | av_freep(&c->slice_quants); |
| 341 | free_vlcs(c); |
| 342 | |
| 343 | return 0; |
| 344 | } |
| 345 | |
| 346 | static av_cold int tscc2_decode_init(AVCodecContext *avctx) |
| 347 | { |
| 348 | TSCC2Context * const c = avctx->priv_data; |
| 349 | int ret; |
| 350 | |
| 351 | c->avctx = avctx; |
| 352 | |
| 353 | avctx->pix_fmt = AV_PIX_FMT_YUV444P; |
| 354 | |
| 355 | if ((ret = init_vlcs(c)) < 0) { |
| 356 | av_log(avctx, AV_LOG_ERROR, "Cannot initialise VLCs\n"); |
| 357 | return ret; |
| 358 | } |
| 359 | |
| 360 | c->mb_width = FFALIGN(avctx->width, 16) >> 4; |
| 361 | c->mb_height = FFALIGN(avctx->height, 8) >> 3; |
| 362 | c->slice_quants = av_malloc(c->mb_width * c->mb_height); |
| 363 | if (!c->slice_quants) { |
| 364 | av_log(avctx, AV_LOG_ERROR, "Cannot allocate slice information\n"); |
| 365 | free_vlcs(c); |
| 366 | return AVERROR(ENOMEM); |
| 367 | } |
| 368 | |
| 369 | c->pic = av_frame_alloc(); |
| 370 | if (!c->pic) { |
| 371 | tscc2_decode_end(avctx); |
| 372 | return AVERROR(ENOMEM); |
| 373 | } |
| 374 | |
| 375 | return 0; |
| 376 | } |
| 377 | |
| 378 | AVCodec ff_tscc2_decoder = { |
| 379 | .name = "tscc2", |
| 380 | .long_name = NULL_IF_CONFIG_SMALL("TechSmith Screen Codec 2"), |
| 381 | .type = AVMEDIA_TYPE_VIDEO, |
| 382 | .id = AV_CODEC_ID_TSCC2, |
| 383 | .priv_data_size = sizeof(TSCC2Context), |
| 384 | .init = tscc2_decode_init, |
| 385 | .close = tscc2_decode_end, |
| 386 | .decode = tscc2_decode_frame, |
| 387 | .capabilities = CODEC_CAP_DR1, |
| 388 | }; |