1/* 2 * KMVC decoder 3 * Copyright (c) 2006 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 * Karl Morton's Video Codec decoder 25 */ 26 27#include <stdio.h> 28#include <stdlib.h> 29 30#include "avcodec.h" 31#include "bytestream.h" 32#include "codec_internal.h" 33#include "decode.h" 34#include "internal.h" 35#include "libavutil/common.h" 36 37#define KMVC_KEYFRAME 0x80 38#define KMVC_PALETTE 0x40 39#define KMVC_METHOD 0x0F 40#define MAX_PALSIZE 256 41 42/* 43 * Decoder context 44 */ 45typedef struct KmvcContext { 46 AVCodecContext *avctx; 47 48 GetByteContext g; 49 uint8_t *cur, *prev; 50 int setpal; 51 int palsize; 52 uint32_t pal[MAX_PALSIZE]; 53 uint8_t frm0[320 * 200], frm1[320 * 200]; 54} KmvcContext; 55 56typedef struct BitBuf { 57 int bits; 58 int bitbuf; 59} BitBuf; 60 61#define BLK(data, x, y) data[av_clip((x) + (y) * 320, 0, 320 * 200 -1)] 62 63#define kmvc_init_getbits(bb, g) bb.bits = 7; bb.bitbuf = bytestream2_get_byte(g); 64 65#define kmvc_getbit(bb, g, res) {\ 66 res = 0; \ 67 if (bb.bitbuf & (1 << bb.bits)) res = 1; \ 68 bb.bits--; \ 69 if(bb.bits == -1) { \ 70 bb.bitbuf = bytestream2_get_byte(g); \ 71 bb.bits = 7; \ 72 } \ 73} 74 75static int kmvc_decode_intra_8x8(KmvcContext * ctx, int w, int h) 76{ 77 BitBuf bb; 78 int res, val; 79 int i, j; 80 int bx, by; 81 int l0x, l1x, l0y, l1y; 82 int mx, my; 83 84 kmvc_init_getbits(bb, &ctx->g); 85 86 for (by = 0; by < h; by += 8) 87 for (bx = 0; bx < w; bx += 8) { 88 if (!bytestream2_get_bytes_left(&ctx->g)) { 89 av_log(ctx->avctx, AV_LOG_ERROR, "Data overrun\n"); 90 return AVERROR_INVALIDDATA; 91 } 92 kmvc_getbit(bb, &ctx->g, res); 93 if (!res) { // fill whole 8x8 block 94 val = bytestream2_get_byte(&ctx->g); 95 for (i = 0; i < 64; i++) 96 BLK(ctx->cur, bx + (i & 0x7), by + (i >> 3)) = val; 97 } else { // handle four 4x4 subblocks 98 for (i = 0; i < 4; i++) { 99 l0x = bx + (i & 1) * 4; 100 l0y = by + (i & 2) * 2; 101 kmvc_getbit(bb, &ctx->g, res); 102 if (!res) { 103 kmvc_getbit(bb, &ctx->g, res); 104 if (!res) { // fill whole 4x4 block 105 val = bytestream2_get_byte(&ctx->g); 106 for (j = 0; j < 16; j++) 107 BLK(ctx->cur, l0x + (j & 3), l0y + (j >> 2)) = val; 108 } else { // copy block from already decoded place 109 val = bytestream2_get_byte(&ctx->g); 110 mx = val & 0xF; 111 my = val >> 4; 112 if ((l0x-mx) + 320*(l0y-my) < 0 || (l0x-mx) + 320*(l0y-my) > 320*197 - 4) { 113 av_log(ctx->avctx, AV_LOG_ERROR, "Invalid MV\n"); 114 return AVERROR_INVALIDDATA; 115 } 116 for (j = 0; j < 16; j++) 117 BLK(ctx->cur, l0x + (j & 3), l0y + (j >> 2)) = 118 BLK(ctx->cur, l0x + (j & 3) - mx, l0y + (j >> 2) - my); 119 } 120 } else { // descend to 2x2 sub-sub-blocks 121 for (j = 0; j < 4; j++) { 122 l1x = l0x + (j & 1) * 2; 123 l1y = l0y + (j & 2); 124 kmvc_getbit(bb, &ctx->g, res); 125 if (!res) { 126 kmvc_getbit(bb, &ctx->g, res); 127 if (!res) { // fill whole 2x2 block 128 val = bytestream2_get_byte(&ctx->g); 129 BLK(ctx->cur, l1x, l1y) = val; 130 BLK(ctx->cur, l1x + 1, l1y) = val; 131 BLK(ctx->cur, l1x, l1y + 1) = val; 132 BLK(ctx->cur, l1x + 1, l1y + 1) = val; 133 } else { // copy block from already decoded place 134 val = bytestream2_get_byte(&ctx->g); 135 mx = val & 0xF; 136 my = val >> 4; 137 if ((l1x-mx) + 320*(l1y-my) < 0 || (l1x-mx) + 320*(l1y-my) > 320*199 - 2) { 138 av_log(ctx->avctx, AV_LOG_ERROR, "Invalid MV\n"); 139 return AVERROR_INVALIDDATA; 140 } 141 BLK(ctx->cur, l1x, l1y) = BLK(ctx->cur, l1x - mx, l1y - my); 142 BLK(ctx->cur, l1x + 1, l1y) = 143 BLK(ctx->cur, l1x + 1 - mx, l1y - my); 144 BLK(ctx->cur, l1x, l1y + 1) = 145 BLK(ctx->cur, l1x - mx, l1y + 1 - my); 146 BLK(ctx->cur, l1x + 1, l1y + 1) = 147 BLK(ctx->cur, l1x + 1 - mx, l1y + 1 - my); 148 } 149 } else { // read values for block 150 BLK(ctx->cur, l1x, l1y) = bytestream2_get_byte(&ctx->g); 151 BLK(ctx->cur, l1x + 1, l1y) = bytestream2_get_byte(&ctx->g); 152 BLK(ctx->cur, l1x, l1y + 1) = bytestream2_get_byte(&ctx->g); 153 BLK(ctx->cur, l1x + 1, l1y + 1) = bytestream2_get_byte(&ctx->g); 154 } 155 } 156 } 157 } 158 } 159 } 160 161 return 0; 162} 163 164static int kmvc_decode_inter_8x8(KmvcContext * ctx, int w, int h) 165{ 166 BitBuf bb; 167 int res, val; 168 int i, j; 169 int bx, by; 170 int l0x, l1x, l0y, l1y; 171 int mx, my; 172 173 kmvc_init_getbits(bb, &ctx->g); 174 175 for (by = 0; by < h; by += 8) 176 for (bx = 0; bx < w; bx += 8) { 177 kmvc_getbit(bb, &ctx->g, res); 178 if (!res) { 179 kmvc_getbit(bb, &ctx->g, res); 180 if (!res) { // fill whole 8x8 block 181 if (!bytestream2_get_bytes_left(&ctx->g)) { 182 av_log(ctx->avctx, AV_LOG_ERROR, "Data overrun\n"); 183 return AVERROR_INVALIDDATA; 184 } 185 val = bytestream2_get_byte(&ctx->g); 186 for (i = 0; i < 64; i++) 187 BLK(ctx->cur, bx + (i & 0x7), by + (i >> 3)) = val; 188 } else { // copy block from previous frame 189 for (i = 0; i < 64; i++) 190 BLK(ctx->cur, bx + (i & 0x7), by + (i >> 3)) = 191 BLK(ctx->prev, bx + (i & 0x7), by + (i >> 3)); 192 } 193 } else { // handle four 4x4 subblocks 194 if (!bytestream2_get_bytes_left(&ctx->g)) { 195 av_log(ctx->avctx, AV_LOG_ERROR, "Data overrun\n"); 196 return AVERROR_INVALIDDATA; 197 } 198 for (i = 0; i < 4; i++) { 199 l0x = bx + (i & 1) * 4; 200 l0y = by + (i & 2) * 2; 201 kmvc_getbit(bb, &ctx->g, res); 202 if (!res) { 203 kmvc_getbit(bb, &ctx->g, res); 204 if (!res) { // fill whole 4x4 block 205 val = bytestream2_get_byte(&ctx->g); 206 for (j = 0; j < 16; j++) 207 BLK(ctx->cur, l0x + (j & 3), l0y + (j >> 2)) = val; 208 } else { // copy block 209 val = bytestream2_get_byte(&ctx->g); 210 mx = (val & 0xF) - 8; 211 my = (val >> 4) - 8; 212 if ((l0x+mx) + 320*(l0y+my) < 0 || (l0x+mx) + 320*(l0y+my) > 320*197 - 4) { 213 av_log(ctx->avctx, AV_LOG_ERROR, "Invalid MV\n"); 214 return AVERROR_INVALIDDATA; 215 } 216 for (j = 0; j < 16; j++) 217 BLK(ctx->cur, l0x + (j & 3), l0y + (j >> 2)) = 218 BLK(ctx->prev, l0x + (j & 3) + mx, l0y + (j >> 2) + my); 219 } 220 } else { // descend to 2x2 sub-sub-blocks 221 for (j = 0; j < 4; j++) { 222 l1x = l0x + (j & 1) * 2; 223 l1y = l0y + (j & 2); 224 kmvc_getbit(bb, &ctx->g, res); 225 if (!res) { 226 kmvc_getbit(bb, &ctx->g, res); 227 if (!res) { // fill whole 2x2 block 228 val = bytestream2_get_byte(&ctx->g); 229 BLK(ctx->cur, l1x, l1y) = val; 230 BLK(ctx->cur, l1x + 1, l1y) = val; 231 BLK(ctx->cur, l1x, l1y + 1) = val; 232 BLK(ctx->cur, l1x + 1, l1y + 1) = val; 233 } else { // copy block 234 val = bytestream2_get_byte(&ctx->g); 235 mx = (val & 0xF) - 8; 236 my = (val >> 4) - 8; 237 if ((l1x+mx) + 320*(l1y+my) < 0 || (l1x+mx) + 320*(l1y+my) > 320*199 - 2) { 238 av_log(ctx->avctx, AV_LOG_ERROR, "Invalid MV\n"); 239 return AVERROR_INVALIDDATA; 240 } 241 BLK(ctx->cur, l1x, l1y) = BLK(ctx->prev, l1x + mx, l1y + my); 242 BLK(ctx->cur, l1x + 1, l1y) = 243 BLK(ctx->prev, l1x + 1 + mx, l1y + my); 244 BLK(ctx->cur, l1x, l1y + 1) = 245 BLK(ctx->prev, l1x + mx, l1y + 1 + my); 246 BLK(ctx->cur, l1x + 1, l1y + 1) = 247 BLK(ctx->prev, l1x + 1 + mx, l1y + 1 + my); 248 } 249 } else { // read values for block 250 BLK(ctx->cur, l1x, l1y) = bytestream2_get_byte(&ctx->g); 251 BLK(ctx->cur, l1x + 1, l1y) = bytestream2_get_byte(&ctx->g); 252 BLK(ctx->cur, l1x, l1y + 1) = bytestream2_get_byte(&ctx->g); 253 BLK(ctx->cur, l1x + 1, l1y + 1) = bytestream2_get_byte(&ctx->g); 254 } 255 } 256 } 257 } 258 } 259 } 260 261 return 0; 262} 263 264static int decode_frame(AVCodecContext * avctx, AVFrame *frame, 265 int *got_frame, AVPacket *avpkt) 266{ 267 KmvcContext *const ctx = avctx->priv_data; 268 uint8_t *out, *src; 269 int i, ret; 270 int header; 271 int blocksize; 272 273 bytestream2_init(&ctx->g, avpkt->data, avpkt->size); 274 275 if ((ret = ff_get_buffer(avctx, frame, 0)) < 0) 276 return ret; 277 278 frame->palette_has_changed = ff_copy_palette(ctx->pal, avpkt, avctx); 279 280 header = bytestream2_get_byte(&ctx->g); 281 282 /* blocksize 127 is really palette change event */ 283 if (bytestream2_peek_byte(&ctx->g) == 127) { 284 bytestream2_skip(&ctx->g, 3); 285 for (i = 0; i < 127; i++) { 286 ctx->pal[i + (header & 0x81)] = 0xFFU << 24 | bytestream2_get_be24(&ctx->g); 287 bytestream2_skip(&ctx->g, 1); 288 } 289 bytestream2_seek(&ctx->g, -127 * 4 - 3, SEEK_CUR); 290 } 291 292 if (header & KMVC_KEYFRAME) { 293 frame->key_frame = 1; 294 frame->pict_type = AV_PICTURE_TYPE_I; 295 } else { 296 frame->key_frame = 0; 297 frame->pict_type = AV_PICTURE_TYPE_P; 298 } 299 300 if (header & KMVC_PALETTE) { 301 frame->palette_has_changed = 1; 302 // palette starts from index 1 and has 127 entries 303 for (i = 1; i <= ctx->palsize; i++) { 304 ctx->pal[i] = 0xFFU << 24 | bytestream2_get_be24(&ctx->g); 305 } 306 } 307 308 if (ctx->setpal) { 309 ctx->setpal = 0; 310 frame->palette_has_changed = 1; 311 } 312 313 /* make the palette available on the way out */ 314 memcpy(frame->data[1], ctx->pal, 1024); 315 316 blocksize = bytestream2_get_byte(&ctx->g); 317 318 if (blocksize != 8 && blocksize != 127) { 319 av_log(avctx, AV_LOG_ERROR, "Block size = %i\n", blocksize); 320 return AVERROR_INVALIDDATA; 321 } 322 memset(ctx->cur, 0, 320 * 200); 323 switch (header & KMVC_METHOD) { 324 case 0: 325 case 1: // used in palette changed event 326 memcpy(ctx->cur, ctx->prev, 320 * 200); 327 break; 328 case 3: 329 kmvc_decode_intra_8x8(ctx, avctx->width, avctx->height); 330 break; 331 case 4: 332 kmvc_decode_inter_8x8(ctx, avctx->width, avctx->height); 333 break; 334 default: 335 av_log(avctx, AV_LOG_ERROR, "Unknown compression method %i\n", header & KMVC_METHOD); 336 return AVERROR_INVALIDDATA; 337 } 338 339 out = frame->data[0]; 340 src = ctx->cur; 341 for (i = 0; i < avctx->height; i++) { 342 memcpy(out, src, avctx->width); 343 src += 320; 344 out += frame->linesize[0]; 345 } 346 347 /* flip buffers */ 348 FFSWAP(uint8_t *, ctx->cur, ctx->prev); 349 350 *got_frame = 1; 351 352 /* always report that the buffer was completely consumed */ 353 return avpkt->size; 354} 355 356 357 358/* 359 * Init kmvc decoder 360 */ 361static av_cold int decode_init(AVCodecContext * avctx) 362{ 363 KmvcContext *const c = avctx->priv_data; 364 int i; 365 366 c->avctx = avctx; 367 368 if (avctx->width > 320 || avctx->height > 200) { 369 av_log(avctx, AV_LOG_ERROR, "KMVC supports frames <= 320x200\n"); 370 return AVERROR(EINVAL); 371 } 372 373 c->cur = c->frm0; 374 c->prev = c->frm1; 375 376 for (i = 0; i < 256; i++) { 377 c->pal[i] = 0xFFU << 24 | i * 0x10101; 378 } 379 380 if (avctx->extradata_size < 12) { 381 av_log(avctx, AV_LOG_WARNING, 382 "Extradata missing, decoding may not work properly...\n"); 383 c->palsize = 127; 384 } else { 385 c->palsize = AV_RL16(avctx->extradata + 10); 386 if (c->palsize >= (unsigned)MAX_PALSIZE) { 387 c->palsize = 127; 388 av_log(avctx, AV_LOG_ERROR, "KMVC palette too large\n"); 389 return AVERROR_INVALIDDATA; 390 } 391 } 392 393 if (avctx->extradata_size == 1036) { // palette in extradata 394 uint8_t *src = avctx->extradata + 12; 395 for (i = 0; i < 256; i++) { 396 c->pal[i] = AV_RL32(src); 397 src += 4; 398 } 399 c->setpal = 1; 400 } 401 402 avctx->pix_fmt = AV_PIX_FMT_PAL8; 403 404 return 0; 405} 406 407const FFCodec ff_kmvc_decoder = { 408 .p.name = "kmvc", 409 .p.long_name = NULL_IF_CONFIG_SMALL("Karl Morton's video codec"), 410 .p.type = AVMEDIA_TYPE_VIDEO, 411 .p.id = AV_CODEC_ID_KMVC, 412 .priv_data_size = sizeof(KmvcContext), 413 .init = decode_init, 414 FF_CODEC_DECODE_CB(decode_frame), 415 .p.capabilities = AV_CODEC_CAP_DR1, 416 .caps_internal = FF_CODEC_CAP_INIT_THREADSAFE, 417}; 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