1/* 2 * Electronic Arts Madcow Video Decoder 3 * Copyright (c) 2007-2009 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 Madcow Video Decoder 25 * @author Peter Ross <pross@xvid.org> 26 * 27 * @see technical details at 28 * http://wiki.multimedia.cx/index.php?title=Electronic_Arts_MAD 29 */ 30 31#include "libavutil/mem_internal.h" 32 33#include "avcodec.h" 34#include "blockdsp.h" 35#include "bytestream.h" 36#include "bswapdsp.h" 37#include "codec_internal.h" 38#include "get_bits.h" 39#include "aandcttab.h" 40#include "eaidct.h" 41#include "idctdsp.h" 42#include "internal.h" 43#include "mpeg12data.h" 44#include "mpeg12vlc.h" 45 46#define EA_PREAMBLE_SIZE 8 47#define MADk_TAG MKTAG('M', 'A', 'D', 'k') /* MAD I-frame */ 48#define MADm_TAG MKTAG('M', 'A', 'D', 'm') /* MAD P-frame */ 49#define MADe_TAG MKTAG('M', 'A', 'D', 'e') /* MAD lqp-frame */ 50 51typedef struct MadContext { 52 AVCodecContext *avctx; 53 BlockDSPContext bdsp; 54 BswapDSPContext bbdsp; 55 IDCTDSPContext idsp; 56 AVFrame *last_frame; 57 GetBitContext gb; 58 void *bitstream_buf; 59 unsigned int bitstream_buf_size; 60 DECLARE_ALIGNED(32, int16_t, block)[64]; 61 ScanTable scantable; 62 uint16_t quant_matrix[64]; 63 int mb_x; 64 int mb_y; 65} MadContext; 66 67static av_cold int decode_init(AVCodecContext *avctx) 68{ 69 MadContext *s = avctx->priv_data; 70 s->avctx = avctx; 71 avctx->pix_fmt = AV_PIX_FMT_YUV420P; 72 ff_blockdsp_init(&s->bdsp, avctx); 73 ff_bswapdsp_init(&s->bbdsp); 74 ff_idctdsp_init(&s->idsp, avctx); 75 ff_init_scantable_permutation(s->idsp.idct_permutation, FF_IDCT_PERM_NONE); 76 ff_init_scantable(s->idsp.idct_permutation, &s->scantable, ff_zigzag_direct); 77 ff_mpeg12_init_vlcs(); 78 79 s->last_frame = av_frame_alloc(); 80 if (!s->last_frame) 81 return AVERROR(ENOMEM); 82 83 return 0; 84} 85 86static inline void comp(unsigned char *dst, ptrdiff_t dst_stride, 87 unsigned char *src, ptrdiff_t src_stride, int add) 88{ 89 int j, i; 90 for (j=0; j<8; j++) 91 for (i=0; i<8; i++) 92 dst[j*dst_stride + i] = av_clip_uint8(src[j*src_stride + i] + add); 93} 94 95static inline void comp_block(MadContext *t, AVFrame *frame, 96 int mb_x, int mb_y, 97 int j, int mv_x, int mv_y, int add) 98{ 99 if (j < 4) { 100 unsigned offset = (mb_y*16 + ((j&2)<<2) + mv_y)*t->last_frame->linesize[0] + mb_x*16 + ((j&1)<<3) + mv_x; 101 if (offset >= (t->avctx->height - 7) * t->last_frame->linesize[0] - 7) 102 return; 103 comp(frame->data[0] + (mb_y*16 + ((j&2)<<2))*frame->linesize[0] + mb_x*16 + ((j&1)<<3), 104 frame->linesize[0], 105 t->last_frame->data[0] + offset, 106 t->last_frame->linesize[0], add); 107 } else if (!(t->avctx->flags & AV_CODEC_FLAG_GRAY)) { 108 int index = j - 3; 109 unsigned offset = (mb_y * 8 + (mv_y/2))*t->last_frame->linesize[index] + mb_x * 8 + (mv_x/2); 110 if (offset >= (t->avctx->height/2 - 7) * t->last_frame->linesize[index] - 7) 111 return; 112 comp(frame->data[index] + (mb_y*8)*frame->linesize[index] + mb_x * 8, 113 frame->linesize[index], 114 t->last_frame->data[index] + offset, 115 t->last_frame->linesize[index], add); 116 } 117} 118 119static inline void idct_put(MadContext *t, AVFrame *frame, int16_t *block, 120 int mb_x, int mb_y, int j) 121{ 122 if (j < 4) { 123 ff_ea_idct_put_c( 124 frame->data[0] + (mb_y*16 + ((j&2)<<2))*frame->linesize[0] + mb_x*16 + ((j&1)<<3), 125 frame->linesize[0], block); 126 } else if (!(t->avctx->flags & AV_CODEC_FLAG_GRAY)) { 127 int index = j - 3; 128 ff_ea_idct_put_c( 129 frame->data[index] + (mb_y*8)*frame->linesize[index] + mb_x*8, 130 frame->linesize[index], block); 131 } 132} 133 134static inline int decode_block_intra(MadContext *s, int16_t * block) 135{ 136 int level, i, j, run; 137 RLTable *rl = &ff_rl_mpeg1; 138 const uint8_t *scantable = s->scantable.permutated; 139 int16_t *quant_matrix = s->quant_matrix; 140 141 block[0] = (128 + get_sbits(&s->gb, 8)) * quant_matrix[0]; 142 143 /* The RL decoder is derived from mpeg1_decode_block_intra; 144 Escaped level and run values a decoded differently */ 145 i = 0; 146 { 147 OPEN_READER(re, &s->gb); 148 /* now quantify & encode AC coefficients */ 149 for (;;) { 150 UPDATE_CACHE(re, &s->gb); 151 GET_RL_VLC(level, run, re, &s->gb, rl->rl_vlc[0], TEX_VLC_BITS, 2, 0); 152 153 if (level == 127) { 154 break; 155 } else if (level != 0) { 156 i += run; 157 if (i > 63) { 158 av_log(s->avctx, AV_LOG_ERROR, 159 "ac-tex damaged at %d %d\n", s->mb_x, s->mb_y); 160 return -1; 161 } 162 j = scantable[i]; 163 level = (level*quant_matrix[j]) >> 4; 164 level = (level-1)|1; 165 level = (level ^ SHOW_SBITS(re, &s->gb, 1)) - SHOW_SBITS(re, &s->gb, 1); 166 LAST_SKIP_BITS(re, &s->gb, 1); 167 } else { 168 /* escape */ 169 UPDATE_CACHE(re, &s->gb); 170 level = SHOW_SBITS(re, &s->gb, 10); SKIP_BITS(re, &s->gb, 10); 171 172 UPDATE_CACHE(re, &s->gb); 173 run = SHOW_UBITS(re, &s->gb, 6)+1; LAST_SKIP_BITS(re, &s->gb, 6); 174 175 i += run; 176 if (i > 63) { 177 av_log(s->avctx, AV_LOG_ERROR, 178 "ac-tex damaged at %d %d\n", s->mb_x, s->mb_y); 179 return -1; 180 } 181 j = scantable[i]; 182 if (level < 0) { 183 level = -level; 184 level = (level*quant_matrix[j]) >> 4; 185 level = (level-1)|1; 186 level = -level; 187 } else { 188 level = (level*quant_matrix[j]) >> 4; 189 level = (level-1)|1; 190 } 191 } 192 193 block[j] = level; 194 } 195 CLOSE_READER(re, &s->gb); 196 } 197 return 0; 198} 199 200static int decode_motion(GetBitContext *gb) 201{ 202 int value = 0; 203 if (get_bits1(gb)) { 204 if (get_bits1(gb)) 205 value = -17; 206 value += get_bits(gb, 4) + 1; 207 } 208 return value; 209} 210 211static int decode_mb(MadContext *s, AVFrame *frame, int inter) 212{ 213 int mv_map = 0; 214 int av_uninit(mv_x), av_uninit(mv_y); 215 int j; 216 217 if (inter) { 218 int v = decode210(&s->gb); 219 if (v < 2) { 220 mv_map = v ? get_bits(&s->gb, 6) : 63; 221 mv_x = decode_motion(&s->gb); 222 mv_y = decode_motion(&s->gb); 223 } 224 } 225 226 for (j=0; j<6; j++) { 227 if (mv_map & (1<<j)) { // mv_x and mv_y are guarded by mv_map 228 int add = 2*decode_motion(&s->gb); 229 if (s->last_frame->data[0]) 230 comp_block(s, frame, s->mb_x, s->mb_y, j, mv_x, mv_y, add); 231 } else { 232 s->bdsp.clear_block(s->block); 233 if(decode_block_intra(s, s->block) < 0) 234 return -1; 235 idct_put(s, frame, s->block, s->mb_x, s->mb_y, j); 236 } 237 } 238 return 0; 239} 240 241static void calc_quant_matrix(MadContext *s, int qscale) 242{ 243 int i; 244 245 s->quant_matrix[0] = (ff_inv_aanscales[0]*ff_mpeg1_default_intra_matrix[0]) >> 11; 246 for (i=1; i<64; i++) 247 s->quant_matrix[i] = (ff_inv_aanscales[i]*ff_mpeg1_default_intra_matrix[i]*qscale + 32) >> 10; 248} 249 250static int decode_frame(AVCodecContext *avctx, AVFrame *frame, 251 int *got_frame, AVPacket *avpkt) 252{ 253 const uint8_t *buf = avpkt->data; 254 int buf_size = avpkt->size; 255 MadContext *s = avctx->priv_data; 256 GetByteContext gb; 257 int width, height; 258 int chunk_type; 259 int inter, ret; 260 261 bytestream2_init(&gb, buf, buf_size); 262 263 chunk_type = bytestream2_get_le32(&gb); 264 inter = (chunk_type == MADm_TAG || chunk_type == MADe_TAG); 265 bytestream2_skip(&gb, 10); 266 267 av_reduce(&avctx->framerate.den, &avctx->framerate.num, 268 bytestream2_get_le16(&gb), 1000, 1<<30); 269 270 width = bytestream2_get_le16(&gb); 271 height = bytestream2_get_le16(&gb); 272 bytestream2_skip(&gb, 1); 273 calc_quant_matrix(s, bytestream2_get_byte(&gb)); 274 bytestream2_skip(&gb, 2); 275 276 if (bytestream2_get_bytes_left(&gb) < 2) { 277 av_log(avctx, AV_LOG_ERROR, "Input data too small\n"); 278 return AVERROR_INVALIDDATA; 279 } 280 281 if (width < 16 || height < 16) { 282 av_log(avctx, AV_LOG_ERROR, "Dimensions too small\n"); 283 return AVERROR_INVALIDDATA; 284 } 285 286 if (avctx->width != width || avctx->height != height) { 287 av_frame_unref(s->last_frame); 288 if((width * (int64_t)height)/2048*7 > bytestream2_get_bytes_left(&gb)) 289 return AVERROR_INVALIDDATA; 290 if ((ret = ff_set_dimensions(avctx, width, height)) < 0) 291 return ret; 292 } 293 294 if ((ret = ff_get_buffer(avctx, frame, AV_GET_BUFFER_FLAG_REF)) < 0) 295 return ret; 296 297 if (inter && !s->last_frame->data[0]) { 298 av_log(avctx, AV_LOG_WARNING, "Missing reference frame.\n"); 299 ret = ff_get_buffer(avctx, s->last_frame, AV_GET_BUFFER_FLAG_REF); 300 if (ret < 0) 301 return ret; 302 memset(s->last_frame->data[0], 0, s->last_frame->height * 303 s->last_frame->linesize[0]); 304 memset(s->last_frame->data[1], 0x80, s->last_frame->height / 2 * 305 s->last_frame->linesize[1]); 306 memset(s->last_frame->data[2], 0x80, s->last_frame->height / 2 * 307 s->last_frame->linesize[2]); 308 } 309 310 av_fast_padded_malloc(&s->bitstream_buf, &s->bitstream_buf_size, 311 bytestream2_get_bytes_left(&gb)); 312 if (!s->bitstream_buf) 313 return AVERROR(ENOMEM); 314 s->bbdsp.bswap16_buf(s->bitstream_buf, (const uint16_t *)(buf + bytestream2_tell(&gb)), 315 bytestream2_get_bytes_left(&gb) / 2); 316 memset((uint8_t*)s->bitstream_buf + bytestream2_get_bytes_left(&gb), 0, AV_INPUT_BUFFER_PADDING_SIZE); 317 init_get_bits(&s->gb, s->bitstream_buf, 8*(bytestream2_get_bytes_left(&gb))); 318 319 for (s->mb_y=0; s->mb_y < (avctx->height+15)/16; s->mb_y++) 320 for (s->mb_x=0; s->mb_x < (avctx->width +15)/16; s->mb_x++) 321 if(decode_mb(s, frame, inter) < 0) 322 return AVERROR_INVALIDDATA; 323 324 *got_frame = 1; 325 326 if (chunk_type != MADe_TAG) { 327 av_frame_unref(s->last_frame); 328 if ((ret = av_frame_ref(s->last_frame, frame)) < 0) 329 return ret; 330 } 331 332 return buf_size; 333} 334 335static av_cold int decode_end(AVCodecContext *avctx) 336{ 337 MadContext *t = avctx->priv_data; 338 av_frame_free(&t->last_frame); 339 av_freep(&t->bitstream_buf); 340 return 0; 341} 342 343const FFCodec ff_eamad_decoder = { 344 .p.name = "eamad", 345 .p.long_name = NULL_IF_CONFIG_SMALL("Electronic Arts Madcow Video"), 346 .p.type = AVMEDIA_TYPE_VIDEO, 347 .p.id = AV_CODEC_ID_MAD, 348 .priv_data_size = sizeof(MadContext), 349 .init = decode_init, 350 .close = decode_end, 351 FF_CODEC_DECODE_CB(decode_frame), 352 .p.capabilities = AV_CODEC_CAP_DR1, 353 .caps_internal = FF_CODEC_CAP_INIT_THREADSAFE, 354}; 355