1/* 2 * Electronic Arts TGV Video Decoder 3 * Copyright (c) 2007-2008 Peter Ross 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 St, Fifth Floor, Boston, MA 02110-1301 USA 20 */ 21 22/** 23 * @file 24 * Electronic Arts TGV Video Decoder 25 * by Peter Ross (pross@xvid.org) 26 * 27 * Technical details here: 28 * http://wiki.multimedia.cx/index.php?title=Electronic_Arts_TGV 29 */ 30 31#include "libavutil/imgutils.h" 32#include "libavutil/mem.h" 33 34#define BITSTREAM_READER_LE 35#include "avcodec.h" 36#include "get_bits.h" 37#include "codec_internal.h" 38#include "internal.h" 39 40#define EA_PREAMBLE_SIZE 8 41#define kVGT_TAG MKTAG('k', 'V', 'G', 'T') 42 43typedef struct TgvContext { 44 AVCodecContext *avctx; 45 AVFrame *last_frame; 46 uint8_t *frame_buffer; 47 int width,height; 48 uint32_t palette[AVPALETTE_COUNT]; 49 50 int (*mv_codebook)[2]; 51 uint8_t (*block_codebook)[16]; 52 int num_mvs; ///< current length of mv_codebook 53 int num_blocks_packed; ///< current length of block_codebook 54} TgvContext; 55 56static av_cold int tgv_decode_init(AVCodecContext *avctx) 57{ 58 TgvContext *s = avctx->priv_data; 59 s->avctx = avctx; 60 avctx->framerate = (AVRational){ 15, 1 }; 61 avctx->pix_fmt = AV_PIX_FMT_PAL8; 62 63 s->last_frame = av_frame_alloc(); 64 if (!s->last_frame) 65 return AVERROR(ENOMEM); 66 67 return 0; 68} 69 70/** 71 * Unpack buffer 72 * @return 0 on success, -1 on critical buffer underflow 73 */ 74static int unpack(const uint8_t *src, const uint8_t *src_end, 75 uint8_t *dst, int width, int height) 76{ 77 uint8_t *dst_end = dst + width*height; 78 int size, size1, size2, offset, run; 79 uint8_t *dst_start = dst; 80 81 if (src[0] & 0x01) 82 src += 5; 83 else 84 src += 2; 85 86 if (src_end - src < 3) 87 return AVERROR_INVALIDDATA; 88 size = AV_RB24(src); 89 src += 3; 90 91 while (size > 0 && src < src_end) { 92 93 /* determine size1 and size2 */ 94 size1 = (src[0] & 3); 95 if (src[0] & 0x80) { // 1 96 if (src[0] & 0x40 ) { // 11 97 if (src[0] & 0x20) { // 111 98 if (src[0] < 0xFC) // !(111111) 99 size1 = (((src[0] & 31) + 1) << 2); 100 src++; 101 size2 = 0; 102 } else { // 110 103 offset = ((src[0] & 0x10) << 12) + AV_RB16(&src[1]) + 1; 104 size2 = ((src[0] & 0xC) << 6) + src[3] + 5; 105 src += 4; 106 } 107 } else { // 10 108 size1 = ((src[1] & 0xC0) >> 6); 109 offset = (AV_RB16(&src[1]) & 0x3FFF) + 1; 110 size2 = (src[0] & 0x3F) + 4; 111 src += 3; 112 } 113 } else { // 0 114 offset = ((src[0] & 0x60) << 3) + src[1] + 1; 115 size2 = ((src[0] & 0x1C) >> 2) + 3; 116 src += 2; 117 } 118 119 120 /* fetch strip from src */ 121 if (size1 > src_end - src) 122 break; 123 124 if (size1 > 0) { 125 size -= size1; 126 run = FFMIN(size1, dst_end - dst); 127 memcpy(dst, src, run); 128 dst += run; 129 src += run; 130 } 131 132 if (size2 > 0) { 133 if (dst - dst_start < offset) 134 return 0; 135 size -= size2; 136 run = FFMIN(size2, dst_end - dst); 137 av_memcpy_backptr(dst, offset, run); 138 dst += run; 139 } 140 } 141 142 return 0; 143} 144 145/** 146 * Decode inter-frame 147 * @return 0 on success, -1 on critical buffer underflow 148 */ 149static int tgv_decode_inter(TgvContext *s, AVFrame *frame, 150 const uint8_t *buf, const uint8_t *buf_end) 151{ 152 int num_mvs; 153 int num_blocks_raw; 154 int num_blocks_packed; 155 int vector_bits; 156 int i,j,x,y; 157 GetBitContext gb; 158 int mvbits; 159 const uint8_t *blocks_raw; 160 161 if(buf_end - buf < 12) 162 return AVERROR_INVALIDDATA; 163 164 num_mvs = AV_RL16(&buf[0]); 165 num_blocks_raw = AV_RL16(&buf[2]); 166 num_blocks_packed = AV_RL16(&buf[4]); 167 vector_bits = AV_RL16(&buf[6]); 168 buf += 12; 169 170 if (vector_bits > MIN_CACHE_BITS || !vector_bits) { 171 av_log(s->avctx, AV_LOG_ERROR, 172 "Invalid value for motion vector bits: %d\n", vector_bits); 173 return AVERROR_INVALIDDATA; 174 } 175 176 /* allocate codebook buffers as necessary */ 177 if (num_mvs > s->num_mvs) { 178 int err = av_reallocp_array(&s->mv_codebook, num_mvs, sizeof(*s->mv_codebook)); 179 if (err < 0) { 180 s->num_mvs = 0; 181 return err; 182 } 183 s->num_mvs = num_mvs; 184 } 185 186 if (num_blocks_packed > s->num_blocks_packed) { 187 int err; 188 if ((err = av_reallocp(&s->block_codebook, num_blocks_packed * 16)) < 0) { 189 s->num_blocks_packed = 0; 190 return err; 191 } 192 s->num_blocks_packed = num_blocks_packed; 193 } 194 195 /* read motion vectors */ 196 mvbits = (num_mvs * 2 * 10 + 31) & ~31; 197 198 if (buf_end - buf < (mvbits>>3) + 16*num_blocks_raw + 8*num_blocks_packed) 199 return AVERROR_INVALIDDATA; 200 201 init_get_bits(&gb, buf, mvbits); 202 for (i = 0; i < num_mvs; i++) { 203 s->mv_codebook[i][0] = get_sbits(&gb, 10); 204 s->mv_codebook[i][1] = get_sbits(&gb, 10); 205 } 206 buf += mvbits >> 3; 207 208 /* note ptr to uncompressed blocks */ 209 blocks_raw = buf; 210 buf += num_blocks_raw * 16; 211 212 /* read compressed blocks */ 213 init_get_bits(&gb, buf, (buf_end - buf) << 3); 214 for (i = 0; i < num_blocks_packed; i++) { 215 int tmp[4]; 216 for (j = 0; j < 4; j++) 217 tmp[j] = get_bits(&gb, 8); 218 for (j = 0; j < 16; j++) 219 s->block_codebook[i][15-j] = tmp[get_bits(&gb, 2)]; 220 } 221 222 if (get_bits_left(&gb) < vector_bits * 223 (s->avctx->height / 4) * (s->avctx->width / 4)) 224 return AVERROR_INVALIDDATA; 225 226 /* read vectors and build frame */ 227 for (y = 0; y < s->avctx->height / 4; y++) 228 for (x = 0; x < s->avctx->width / 4; x++) { 229 unsigned int vector = get_bits(&gb, vector_bits); 230 const uint8_t *src; 231 ptrdiff_t src_stride; 232 233 if (vector < num_mvs) { 234 int mx = x * 4 + s->mv_codebook[vector][0]; 235 int my = y * 4 + s->mv_codebook[vector][1]; 236 237 if (mx < 0 || mx + 4 > s->avctx->width || 238 my < 0 || my + 4 > s->avctx->height) { 239 av_log(s->avctx, AV_LOG_ERROR, "MV %d %d out of picture\n", mx, my); 240 continue; 241 } 242 243 src = s->last_frame->data[0] + mx + my * s->last_frame->linesize[0]; 244 src_stride = s->last_frame->linesize[0]; 245 } else { 246 int offset = vector - num_mvs; 247 if (offset < num_blocks_raw) 248 src = blocks_raw + 16*offset; 249 else if (offset - num_blocks_raw < num_blocks_packed) 250 src = s->block_codebook[offset - num_blocks_raw]; 251 else 252 continue; 253 src_stride = 4; 254 } 255 256 for (j = 0; j < 4; j++) 257 for (i = 0; i < 4; i++) 258 frame->data[0][(y * 4 + j) * frame->linesize[0] + (x * 4 + i)] = 259 src[j * src_stride + i]; 260 } 261 262 return 0; 263} 264 265static int tgv_decode_frame(AVCodecContext *avctx, AVFrame *frame, 266 int *got_frame, AVPacket *avpkt) 267{ 268 const uint8_t *buf = avpkt->data; 269 int buf_size = avpkt->size; 270 TgvContext *s = avctx->priv_data; 271 const uint8_t *buf_end = buf + buf_size; 272 int chunk_type, ret; 273 274 if (buf_end - buf < EA_PREAMBLE_SIZE) 275 return AVERROR_INVALIDDATA; 276 277 chunk_type = AV_RL32(&buf[0]); 278 buf += EA_PREAMBLE_SIZE; 279 280 if (chunk_type == kVGT_TAG) { 281 int pal_count, i; 282 if(buf_end - buf < 12) { 283 av_log(avctx, AV_LOG_WARNING, "truncated header\n"); 284 return AVERROR_INVALIDDATA; 285 } 286 287 s->width = AV_RL16(&buf[0]); 288 s->height = AV_RL16(&buf[2]); 289 if (s->avctx->width != s->width || s->avctx->height != s->height) { 290 av_freep(&s->frame_buffer); 291 av_frame_unref(s->last_frame); 292 if ((ret = ff_set_dimensions(s->avctx, s->width, s->height)) < 0) 293 return ret; 294 } 295 296 pal_count = AV_RL16(&buf[6]); 297 buf += 12; 298 for(i = 0; i < pal_count && i < AVPALETTE_COUNT && buf_end - buf >= 3; i++) { 299 s->palette[i] = 0xFFU << 24 | AV_RB24(buf); 300 buf += 3; 301 } 302 if (buf_end - buf < 5) { 303 return AVERROR_INVALIDDATA; 304 } 305 } 306 307 if ((ret = ff_get_buffer(avctx, frame, AV_GET_BUFFER_FLAG_REF)) < 0) 308 return ret; 309 310 memcpy(frame->data[1], s->palette, AVPALETTE_SIZE); 311 312 if (chunk_type == kVGT_TAG) { 313 int y; 314 frame->key_frame = 1; 315 frame->pict_type = AV_PICTURE_TYPE_I; 316 317 if (!s->frame_buffer && 318 !(s->frame_buffer = av_mallocz(s->width * s->height))) 319 return AVERROR(ENOMEM); 320 321 if (unpack(buf, buf_end, s->frame_buffer, s->avctx->width, s->avctx->height) < 0) { 322 av_log(avctx, AV_LOG_WARNING, "truncated intra frame\n"); 323 return AVERROR_INVALIDDATA; 324 } 325 for (y = 0; y < s->height; y++) 326 memcpy(frame->data[0] + y * frame->linesize[0], 327 s->frame_buffer + y * s->width, 328 s->width); 329 } else { 330 if (!s->last_frame->data[0]) { 331 av_log(avctx, AV_LOG_WARNING, "inter frame without corresponding intra frame\n"); 332 return buf_size; 333 } 334 frame->key_frame = 0; 335 frame->pict_type = AV_PICTURE_TYPE_P; 336 if (tgv_decode_inter(s, frame, buf, buf_end) < 0) { 337 av_log(avctx, AV_LOG_WARNING, "truncated inter frame\n"); 338 return AVERROR_INVALIDDATA; 339 } 340 } 341 342 av_frame_unref(s->last_frame); 343 if ((ret = av_frame_ref(s->last_frame, frame)) < 0) 344 return ret; 345 346 *got_frame = 1; 347 348 return buf_size; 349} 350 351static av_cold int tgv_decode_end(AVCodecContext *avctx) 352{ 353 TgvContext *s = avctx->priv_data; 354 av_frame_free(&s->last_frame); 355 av_freep(&s->frame_buffer); 356 av_freep(&s->mv_codebook); 357 av_freep(&s->block_codebook); 358 return 0; 359} 360 361const FFCodec ff_eatgv_decoder = { 362 .p.name = "eatgv", 363 .p.long_name = NULL_IF_CONFIG_SMALL("Electronic Arts TGV video"), 364 .p.type = AVMEDIA_TYPE_VIDEO, 365 .p.id = AV_CODEC_ID_TGV, 366 .priv_data_size = sizeof(TgvContext), 367 .init = tgv_decode_init, 368 .close = tgv_decode_end, 369 FF_CODEC_DECODE_CB(tgv_decode_frame), 370 .p.capabilities = AV_CODEC_CAP_DR1, 371 .caps_internal = FF_CODEC_CAP_INIT_THREADSAFE, 372}; 373