| 1 | /* |
| 2 | * Escape 130 video decoder |
| 3 | * Copyright (C) 2008 Eli Friedman (eli.friedman <at> gmail.com) |
| 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 | #include "libavutil/attributes.h" |
| 23 | #include "libavutil/mem.h" |
| 24 | #include "avcodec.h" |
| 25 | #define BITSTREAM_READER_LE |
| 26 | #include "get_bits.h" |
| 27 | #include "internal.h" |
| 28 | |
| 29 | typedef struct Escape130Context { |
| 30 | uint8_t *old_y_avg; |
| 31 | |
| 32 | uint8_t *new_y, *old_y; |
| 33 | uint8_t *new_u, *old_u; |
| 34 | uint8_t *new_v, *old_v; |
| 35 | |
| 36 | uint8_t *buf1, *buf2; |
| 37 | int linesize[3]; |
| 38 | } Escape130Context; |
| 39 | |
| 40 | static const uint8_t offset_table[] = { 2, 4, 10, 20 }; |
| 41 | static const int8_t sign_table[64][4] = { |
| 42 | { 0, 0, 0, 0 }, |
| 43 | { -1, 1, 0, 0 }, |
| 44 | { 1, -1, 0, 0 }, |
| 45 | { -1, 0, 1, 0 }, |
| 46 | { -1, 1, 1, 0 }, |
| 47 | { 0, -1, 1, 0 }, |
| 48 | { 1, -1, 1, 0 }, |
| 49 | { -1, -1, 1, 0 }, |
| 50 | { 1, 0, -1, 0 }, |
| 51 | { 0, 1, -1, 0 }, |
| 52 | { 1, 1, -1, 0 }, |
| 53 | { -1, 1, -1, 0 }, |
| 54 | { 1, -1, -1, 0 }, |
| 55 | { -1, 0, 0, 1 }, |
| 56 | { -1, 1, 0, 1 }, |
| 57 | { 0, -1, 0, 1 }, |
| 58 | |
| 59 | { 0, 0, 0, 0 }, |
| 60 | { 1, -1, 0, 1 }, |
| 61 | { -1, -1, 0, 1 }, |
| 62 | { -1, 0, 1, 1 }, |
| 63 | { -1, 1, 1, 1 }, |
| 64 | { 0, -1, 1, 1 }, |
| 65 | { 1, -1, 1, 1 }, |
| 66 | { -1, -1, 1, 1 }, |
| 67 | { 0, 0, -1, 1 }, |
| 68 | { 1, 0, -1, 1 }, |
| 69 | { -1, 0, -1, 1 }, |
| 70 | { 0, 1, -1, 1 }, |
| 71 | { 1, 1, -1, 1 }, |
| 72 | { -1, 1, -1, 1 }, |
| 73 | { 0, -1, -1, 1 }, |
| 74 | { 1, -1, -1, 1 }, |
| 75 | |
| 76 | { 0, 0, 0, 0 }, |
| 77 | { -1, -1, -1, 1 }, |
| 78 | { 1, 0, 0, -1 }, |
| 79 | { 0, 1, 0, -1 }, |
| 80 | { 1, 1, 0, -1 }, |
| 81 | { -1, 1, 0, -1 }, |
| 82 | { 1, -1, 0, -1 }, |
| 83 | { 0, 0, 1, -1 }, |
| 84 | { 1, 0, 1, -1 }, |
| 85 | { -1, 0, 1, -1 }, |
| 86 | { 0, 1, 1, -1 }, |
| 87 | { 1, 1, 1, -1 }, |
| 88 | { -1, 1, 1, -1 }, |
| 89 | { 0, -1, 1, -1 }, |
| 90 | { 1, -1, 1, -1 }, |
| 91 | { -1, -1, 1, -1 }, |
| 92 | |
| 93 | { 0, 0, 0, 0 }, |
| 94 | { 1, 0, -1, -1 }, |
| 95 | { 0, 1, -1, -1 }, |
| 96 | { 1, 1, -1, -1 }, |
| 97 | { -1, 1, -1, -1 }, |
| 98 | { 1, -1, -1, -1 } |
| 99 | }; |
| 100 | |
| 101 | static const int8_t luma_adjust[] = { -4, -3, -2, -1, 1, 2, 3, 4 }; |
| 102 | |
| 103 | static const int8_t chroma_adjust[2][8] = { |
| 104 | { 1, 1, 0, -1, -1, -1, 0, 1 }, |
| 105 | { 0, 1, 1, 1, 0, -1, -1, -1 } |
| 106 | }; |
| 107 | |
| 108 | static const uint8_t chroma_vals[] = { |
| 109 | 20, 28, 36, 44, 52, 60, 68, 76, |
| 110 | 84, 92, 100, 106, 112, 116, 120, 124, |
| 111 | 128, 132, 136, 140, 144, 150, 156, 164, |
| 112 | 172, 180, 188, 196, 204, 212, 220, 228 |
| 113 | }; |
| 114 | |
| 115 | static av_cold int escape130_decode_init(AVCodecContext *avctx) |
| 116 | { |
| 117 | Escape130Context *s = avctx->priv_data; |
| 118 | avctx->pix_fmt = AV_PIX_FMT_YUV420P; |
| 119 | |
| 120 | if ((avctx->width & 1) || (avctx->height & 1)) { |
| 121 | av_log(avctx, AV_LOG_ERROR, |
| 122 | "Dimensions should be a multiple of two.\n"); |
| 123 | return AVERROR_INVALIDDATA; |
| 124 | } |
| 125 | |
| 126 | s->old_y_avg = av_malloc(avctx->width * avctx->height / 4); |
| 127 | s->buf1 = av_malloc(avctx->width * avctx->height * 3 / 2); |
| 128 | s->buf2 = av_malloc(avctx->width * avctx->height * 3 / 2); |
| 129 | if (!s->old_y_avg || !s->buf1 || !s->buf2) { |
| 130 | av_freep(&s->old_y_avg); |
| 131 | av_freep(&s->buf1); |
| 132 | av_freep(&s->buf2); |
| 133 | av_log(avctx, AV_LOG_ERROR, "Could not allocate buffer.\n"); |
| 134 | return AVERROR(ENOMEM); |
| 135 | } |
| 136 | |
| 137 | s->linesize[0] = avctx->width; |
| 138 | s->linesize[1] = |
| 139 | s->linesize[2] = avctx->width / 2; |
| 140 | |
| 141 | s->new_y = s->buf1; |
| 142 | s->new_u = s->new_y + avctx->width * avctx->height; |
| 143 | s->new_v = s->new_u + avctx->width * avctx->height / 4; |
| 144 | s->old_y = s->buf2; |
| 145 | s->old_u = s->old_y + avctx->width * avctx->height; |
| 146 | s->old_v = s->old_u + avctx->width * avctx->height / 4; |
| 147 | memset(s->old_y, 0, avctx->width * avctx->height); |
| 148 | memset(s->old_u, 0x10, avctx->width * avctx->height / 4); |
| 149 | memset(s->old_v, 0x10, avctx->width * avctx->height / 4); |
| 150 | |
| 151 | return 0; |
| 152 | } |
| 153 | |
| 154 | static av_cold int escape130_decode_close(AVCodecContext *avctx) |
| 155 | { |
| 156 | Escape130Context *s = avctx->priv_data; |
| 157 | |
| 158 | av_freep(&s->old_y_avg); |
| 159 | av_freep(&s->buf1); |
| 160 | av_freep(&s->buf2); |
| 161 | |
| 162 | return 0; |
| 163 | } |
| 164 | |
| 165 | static int decode_skip_count(GetBitContext* gb) |
| 166 | { |
| 167 | int value; |
| 168 | |
| 169 | if (get_bits_left(gb) < 1+3) |
| 170 | return -1; |
| 171 | |
| 172 | value = get_bits1(gb); |
| 173 | if (value) |
| 174 | return 0; |
| 175 | |
| 176 | value = get_bits(gb, 3); |
| 177 | if (value) |
| 178 | return value; |
| 179 | |
| 180 | value = get_bits(gb, 8); |
| 181 | if (value) |
| 182 | return value + 7; |
| 183 | |
| 184 | value = get_bits(gb, 15); |
| 185 | if (value) |
| 186 | return value + 262; |
| 187 | |
| 188 | return -1; |
| 189 | } |
| 190 | |
| 191 | static int escape130_decode_frame(AVCodecContext *avctx, void *data, |
| 192 | int *got_frame, AVPacket *avpkt) |
| 193 | { |
| 194 | int buf_size = avpkt->size; |
| 195 | Escape130Context *s = avctx->priv_data; |
| 196 | AVFrame *pic = data; |
| 197 | GetBitContext gb; |
| 198 | int ret; |
| 199 | |
| 200 | uint8_t *old_y, *old_cb, *old_cr, |
| 201 | *new_y, *new_cb, *new_cr; |
| 202 | uint8_t *dstY, *dstU, *dstV; |
| 203 | unsigned old_y_stride, old_cb_stride, old_cr_stride, |
| 204 | new_y_stride, new_cb_stride, new_cr_stride; |
| 205 | unsigned total_blocks = avctx->width * avctx->height / 4, |
| 206 | block_index, block_x = 0; |
| 207 | unsigned y[4] = { 0 }, cb = 0x10, cr = 0x10; |
| 208 | int skip = -1, y_avg = 0, i, j; |
| 209 | uint8_t *ya = s->old_y_avg; |
| 210 | |
| 211 | // first 16 bytes are header; no useful information in here |
| 212 | if (buf_size <= 16) { |
| 213 | av_log(avctx, AV_LOG_ERROR, "Insufficient frame data\n"); |
| 214 | return AVERROR_INVALIDDATA; |
| 215 | } |
| 216 | |
| 217 | if ((ret = ff_get_buffer(avctx, pic, 0)) < 0) |
| 218 | return ret; |
| 219 | |
| 220 | if ((ret = init_get_bits8(&gb, avpkt->data, avpkt->size)) < 0) |
| 221 | return ret; |
| 222 | skip_bits_long(&gb, 16 * 8); |
| 223 | |
| 224 | new_y = s->new_y; |
| 225 | new_cb = s->new_u; |
| 226 | new_cr = s->new_v; |
| 227 | new_y_stride = s->linesize[0]; |
| 228 | new_cb_stride = s->linesize[1]; |
| 229 | new_cr_stride = s->linesize[2]; |
| 230 | old_y = s->old_y; |
| 231 | old_cb = s->old_u; |
| 232 | old_cr = s->old_v; |
| 233 | old_y_stride = s->linesize[0]; |
| 234 | old_cb_stride = s->linesize[1]; |
| 235 | old_cr_stride = s->linesize[2]; |
| 236 | |
| 237 | for (block_index = 0; block_index < total_blocks; block_index++) { |
| 238 | // Note that this call will make us skip the rest of the blocks |
| 239 | // if the frame ends prematurely. |
| 240 | if (skip == -1) |
| 241 | skip = decode_skip_count(&gb); |
| 242 | if (skip == -1) { |
| 243 | av_log(avctx, AV_LOG_ERROR, "Error decoding skip value\n"); |
| 244 | return AVERROR_INVALIDDATA; |
| 245 | } |
| 246 | |
| 247 | if (skip) { |
| 248 | y[0] = old_y[0]; |
| 249 | y[1] = old_y[1]; |
| 250 | y[2] = old_y[old_y_stride]; |
| 251 | y[3] = old_y[old_y_stride + 1]; |
| 252 | y_avg = ya[0]; |
| 253 | cb = old_cb[0]; |
| 254 | cr = old_cr[0]; |
| 255 | } else { |
| 256 | if (get_bits1(&gb)) { |
| 257 | unsigned sign_selector = get_bits(&gb, 6); |
| 258 | unsigned difference_selector = get_bits(&gb, 2); |
| 259 | y_avg = 2 * get_bits(&gb, 5); |
| 260 | for (i = 0; i < 4; i++) { |
| 261 | y[i] = av_clip(y_avg + offset_table[difference_selector] * |
| 262 | sign_table[sign_selector][i], 0, 63); |
| 263 | } |
| 264 | } else if (get_bits1(&gb)) { |
| 265 | if (get_bits1(&gb)) { |
| 266 | y_avg = get_bits(&gb, 6); |
| 267 | } else { |
| 268 | unsigned adjust_index = get_bits(&gb, 3); |
| 269 | y_avg = (y_avg + luma_adjust[adjust_index]) & 63; |
| 270 | } |
| 271 | for (i = 0; i < 4; i++) |
| 272 | y[i] = y_avg; |
| 273 | } |
| 274 | |
| 275 | if (get_bits1(&gb)) { |
| 276 | if (get_bits1(&gb)) { |
| 277 | cb = get_bits(&gb, 5); |
| 278 | cr = get_bits(&gb, 5); |
| 279 | } else { |
| 280 | unsigned adjust_index = get_bits(&gb, 3); |
| 281 | cb = (cb + chroma_adjust[0][adjust_index]) & 31; |
| 282 | cr = (cr + chroma_adjust[1][adjust_index]) & 31; |
| 283 | } |
| 284 | } |
| 285 | } |
| 286 | *ya++ = y_avg; |
| 287 | |
| 288 | new_y[0] = y[0]; |
| 289 | new_y[1] = y[1]; |
| 290 | new_y[new_y_stride] = y[2]; |
| 291 | new_y[new_y_stride + 1] = y[3]; |
| 292 | *new_cb = cb; |
| 293 | *new_cr = cr; |
| 294 | |
| 295 | old_y += 2; |
| 296 | old_cb++; |
| 297 | old_cr++; |
| 298 | new_y += 2; |
| 299 | new_cb++; |
| 300 | new_cr++; |
| 301 | block_x++; |
| 302 | if (block_x * 2 == avctx->width) { |
| 303 | block_x = 0; |
| 304 | old_y += old_y_stride * 2 - avctx->width; |
| 305 | old_cb += old_cb_stride - avctx->width / 2; |
| 306 | old_cr += old_cr_stride - avctx->width / 2; |
| 307 | new_y += new_y_stride * 2 - avctx->width; |
| 308 | new_cb += new_cb_stride - avctx->width / 2; |
| 309 | new_cr += new_cr_stride - avctx->width / 2; |
| 310 | } |
| 311 | |
| 312 | skip--; |
| 313 | } |
| 314 | |
| 315 | new_y = s->new_y; |
| 316 | new_cb = s->new_u; |
| 317 | new_cr = s->new_v; |
| 318 | dstY = pic->data[0]; |
| 319 | dstU = pic->data[1]; |
| 320 | dstV = pic->data[2]; |
| 321 | for (j = 0; j < avctx->height; j++) { |
| 322 | for (i = 0; i < avctx->width; i++) |
| 323 | dstY[i] = new_y[i] << 2; |
| 324 | dstY += pic->linesize[0]; |
| 325 | new_y += new_y_stride; |
| 326 | } |
| 327 | for (j = 0; j < avctx->height / 2; j++) { |
| 328 | for (i = 0; i < avctx->width / 2; i++) { |
| 329 | dstU[i] = chroma_vals[new_cb[i]]; |
| 330 | dstV[i] = chroma_vals[new_cr[i]]; |
| 331 | } |
| 332 | dstU += pic->linesize[1]; |
| 333 | dstV += pic->linesize[2]; |
| 334 | new_cb += new_cb_stride; |
| 335 | new_cr += new_cr_stride; |
| 336 | } |
| 337 | |
| 338 | av_dlog(avctx, "Frame data: provided %d bytes, used %d bytes\n", |
| 339 | buf_size, get_bits_count(&gb) >> 3); |
| 340 | |
| 341 | FFSWAP(uint8_t*, s->old_y, s->new_y); |
| 342 | FFSWAP(uint8_t*, s->old_u, s->new_u); |
| 343 | FFSWAP(uint8_t*, s->old_v, s->new_v); |
| 344 | |
| 345 | *got_frame = 1; |
| 346 | |
| 347 | return buf_size; |
| 348 | } |
| 349 | |
| 350 | AVCodec ff_escape130_decoder = { |
| 351 | .name = "escape130", |
| 352 | .long_name = NULL_IF_CONFIG_SMALL("Escape 130"), |
| 353 | .type = AVMEDIA_TYPE_VIDEO, |
| 354 | .id = AV_CODEC_ID_ESCAPE130, |
| 355 | .priv_data_size = sizeof(Escape130Context), |
| 356 | .init = escape130_decode_init, |
| 357 | .close = escape130_decode_close, |
| 358 | .decode = escape130_decode_frame, |
| 359 | .capabilities = CODEC_CAP_DR1, |
| 360 | }; |