libavcodec/eamad.c

   1 /*
   2  * Electronic Arts Madcow Video Decoder
   3  * Copyright (c) 2007-2009 Peter Ross
   4  *
   5  * This file is part of Libav.
   6  *
   7  * Libav 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  * Libav 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 Libav; 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 "avcodec.h"
  32 #include "bitstream.h"
  33 #include "blockdsp.h"
  34 #include "bytestream.h"
  35 #include "bswapdsp.h"
  36 #include "aandcttab.h"
  37 #include "eaidct.h"
  38 #include "idctdsp.h"
  39 #include "internal.h"
  40 #include "mpeg12data.h"
  41 #include "mpeg12vlc.h"
  42 #include "vlc.h"
  43
  44 #define EA_PREAMBLE_SIZE    8
  45 #define MADk_TAG MKTAG('M', 'A', 'D', 'k')    /* MAD I-frame */
  46 #define MADm_TAG MKTAG('M', 'A', 'D', 'm')    /* MAD P-frame */
  47 #define MADe_TAG MKTAG('M', 'A', 'D', 'e')    /* MAD lqp-frame */
  48
  49 typedef struct MadContext {
  50     AVCodecContext *avctx;
  51     BlockDSPContext bdsp;
  52     BswapDSPContext bbdsp;
  53     IDCTDSPContext idsp;
  54     AVFrame *last_frame;
  55     BitstreamContext bc;
  56     void *bitstream_buf;
  57     unsigned int bitstream_buf_size;
  58     DECLARE_ALIGNED(16, int16_t, block)[64];
  59     ScanTable scantable;
  60     uint16_t quant_matrix[64];
  61     int mb_x;
  62     int mb_y;
  63 } MadContext;
  64
  65 static av_cold int decode_init(AVCodecContext *avctx)
  66 {
  67     MadContext *s = avctx->priv_data;
  68     s->avctx = avctx;
  69     avctx->pix_fmt = AV_PIX_FMT_YUV420P;
  70     ff_blockdsp_init(&s->bdsp);
  71     ff_bswapdsp_init(&s->bbdsp);
  72     ff_idctdsp_init(&s->idsp, avctx);
  73     ff_init_scantable_permutation(s->idsp.idct_permutation, FF_IDCT_PERM_NONE);
  74     ff_init_scantable(s->idsp.idct_permutation, &s->scantable, ff_zigzag_direct);
  75     ff_mpeg12_init_vlcs();
  76
  77     s->last_frame = av_frame_alloc();
  78     if (!s->last_frame)
  79         return AVERROR(ENOMEM);
  80
  81     return 0;
  82 }
  83
  84 static inline void comp(unsigned char *dst, ptrdiff_t dst_stride,
  85                         unsigned char *src, ptrdiff_t src_stride, int add)
  86 {
  87     int j, i;
  88     for (j=0; j<8; j++)
  89         for (i=0; i<8; i++)
  90             dst[j*dst_stride + i] = av_clip_uint8(src[j*src_stride + i] + add);
  91 }
  92
  93 static inline void comp_block(MadContext *t, AVFrame *frame,
  94                               int mb_x, int mb_y,
  95                               int j, int mv_x, int mv_y, int add)
  96 {
  97     if (j < 4) {
  98         comp(frame->data[0] + (mb_y*16 + ((j&2)<<2))*frame->linesize[0] + mb_x*16 + ((j&1)<<3),
  99              frame->linesize[0],
 100              t->last_frame->data[0] + (mb_y*16 + ((j&2)<<2) + mv_y)*t->last_frame->linesize[0] + mb_x*16 + ((j&1)<<3) + mv_x,
 101              t->last_frame->linesize[0], add);
 102     } else if (!(t->avctx->flags & AV_CODEC_FLAG_GRAY)) {
 103         int index = j - 3;
 104         comp(frame->data[index] + (mb_y*8)*frame->linesize[index] + mb_x * 8,
 105              frame->linesize[index],
 106              t->last_frame->data[index] + (mb_y * 8 + (mv_y/2))*t->last_frame->linesize[index] + mb_x * 8 + (mv_x/2),
 107              t->last_frame->linesize[index], add);
 108     }
 109 }
 110
 111 static inline void idct_put(MadContext *t, AVFrame *frame, int16_t *block,
 112                             int mb_x, int mb_y, int j)
 113 {
 114     if (j < 4) {
 115         ff_ea_idct_put_c(
 116             frame->data[0] + (mb_y*16 + ((j&2)<<2))*frame->linesize[0] + mb_x*16 + ((j&1)<<3),
 117             frame->linesize[0], block);
 118     } else if (!(t->avctx->flags & AV_CODEC_FLAG_GRAY)) {
 119         int index = j - 3;
 120         ff_ea_idct_put_c(
 121             frame->data[index] + (mb_y*8)*frame->linesize[index] + mb_x*8,
 122             frame->linesize[index], block);
 123     }
 124 }
 125
 126 static inline void decode_block_intra(MadContext *s, int16_t * block)
 127 {
 128     int level, i, j, run;
 129     RLTable *rl = &ff_rl_mpeg1;
 130     const uint8_t *scantable = s->scantable.permutated;
 131     int16_t *quant_matrix = s->quant_matrix;
 132
 133     block[0] = (128 + bitstream_read_signed(&s->bc, 8)) * quant_matrix[0];
 134
 135     /* The RL decoder is derived from mpeg1_decode_block_intra;
 136        Escaped level and run values a decoded differently */
 137     i = 0;
 138     {
 139         /* now quantify & encode AC coefficients */
 140         for (;;) {
 141             BITSTREAM_RL_VLC(level, run, &s->bc, rl->rl_vlc[0], TEX_VLC_BITS, 2);
 142
 143             if (level == 127) {
 144                 break;
 145             } else if (level != 0) {
 146                 i += run;
 147                 if (i > 63) {
 148                     av_log(s->avctx, AV_LOG_ERROR,
 149                            "ac-tex damaged at %d %d\n", s->mb_x, s->mb_y);
 150                     return;
 151                 }
 152                 j = scantable[i];
 153                 level = (level*quant_matrix[j]) >> 4;
 154                 level = (level-1)|1;
 155                 level = bitstream_apply_sign(&s->bc, level);
 156             } else {
 157                 /* escape */
 158                 level = bitstream_read_signed(&s->bc, 10);
 159
 160                 run = bitstream_read(&s->bc, 6) + 1;
 161
 162                 i += run;
 163                 if (i > 63) {
 164                     av_log(s->avctx, AV_LOG_ERROR,
 165                            "ac-tex damaged at %d %d\n", s->mb_x, s->mb_y);
 166                     return;
 167                 }
 168                 j = scantable[i];
 169                 if (level < 0) {
 170                     level = -level;
 171                     level = (level*quant_matrix[j]) >> 4;
 172                     level = (level-1)|1;
 173                     level = -level;
 174                 } else {
 175                     level = (level*quant_matrix[j]) >> 4;
 176                     level = (level-1)|1;
 177                 }
 178             }
 179
 180             block[j] = level;
 181         }
 182     }
 183 }
 184
 185 static int decode_motion(BitstreamContext *bc)
 186 {
 187     int value = 0;
 188
 189     if (bitstream_read_bit(bc)) {
 190         if (bitstream_read_bit(bc))
 191             value = -17;
 192         value += bitstream_read(bc, 4) + 1;
 193     }
 194     return value;
 195 }
 196
 197 static void decode_mb(MadContext *s, AVFrame *frame, int inter)
 198 {
 199     int mv_map = 0;
 200     int mv_x, mv_y;
 201     int j;
 202
 203     if (inter) {
 204         int v = bitstream_decode210(&s->bc);
 205         if (v < 2) {
 206             mv_map = v ? bitstream_read(&s->bc, 6) : 63;
 207             mv_x = decode_motion(&s->bc);
 208             mv_y = decode_motion(&s->bc);
 209         } else {
 210             mv_map = 0;
 211         }
 212     }
 213
 214     for (j=0; j<6; j++) {
 215         if (mv_map & (1<<j)) {  // mv_x and mv_y are guarded by mv_map
 216             int add = 2 * decode_motion(&s->bc);
 217             comp_block(s, frame, s->mb_x, s->mb_y, j, mv_x, mv_y, add);
 218         } else {
 219             s->bdsp.clear_block(s->block);
 220             decode_block_intra(s, s->block);
 221             idct_put(s, frame, s->block, s->mb_x, s->mb_y, j);
 222         }
 223     }
 224 }
 225
 226 static void calc_quant_matrix(MadContext *s, int qscale)
 227 {
 228     int i;
 229
 230     s->quant_matrix[0] = (ff_inv_aanscales[0]*ff_mpeg1_default_intra_matrix[0]) >> 11;
 231     for (i=1; i<64; i++)
 232         s->quant_matrix[i] = (ff_inv_aanscales[i]*ff_mpeg1_default_intra_matrix[i]*qscale + 32) >> 10;
 233 }
 234
 235 static int decode_frame(AVCodecContext *avctx,
 236                         void *data, int *got_frame,
 237                         AVPacket *avpkt)
 238 {
 239     const uint8_t *buf = avpkt->data;
 240     int buf_size       = avpkt->size;
 241     MadContext *s     = avctx->priv_data;
 242     AVFrame *frame    = data;
 243     GetByteContext gb;
 244     int width, height;
 245     int chunk_type;
 246     int inter, ret;
 247
 248     bytestream2_init(&gb, buf, buf_size);
 249
 250     chunk_type = bytestream2_get_le32(&gb);
 251     inter = (chunk_type == MADm_TAG || chunk_type == MADe_TAG);
 252     bytestream2_skip(&gb, 10);
 253
 254     av_reduce(&avctx->framerate.den, &avctx->framerate.num,
 255               bytestream2_get_le16(&gb), 1000, 1<<30);
 256
 257     width  = bytestream2_get_le16(&gb);
 258     height = bytestream2_get_le16(&gb);
 259     bytestream2_skip(&gb, 1);
 260     calc_quant_matrix(s, bytestream2_get_byte(&gb));
 261     bytestream2_skip(&gb, 2);
 262
 263     if (bytestream2_get_bytes_left(&gb) < 2) {
 264         av_log(avctx, AV_LOG_ERROR, "Input data too small\n");
 265         return AVERROR_INVALIDDATA;
 266     }
 267
 268     if (avctx->width != width || avctx->height != height) {
 269         av_frame_unref(s->last_frame);
 270         if ((ret = ff_set_dimensions(avctx, width, height)) < 0)
 271             return ret;
 272     }
 273
 274     if ((ret = ff_get_buffer(avctx, frame, AV_GET_BUFFER_FLAG_REF)) < 0) {
 275         av_log(avctx, AV_LOG_ERROR, "get_buffer() failed\n");
 276         return ret;
 277     }
 278
 279     if (inter && !s->last_frame->data[0]) {
 280         av_log(avctx, AV_LOG_WARNING, "Missing reference frame.\n");
 281         ret = ff_get_buffer(avctx, s->last_frame, AV_GET_BUFFER_FLAG_REF);
 282         if (ret < 0)
 283             return ret;
 284         memset(s->last_frame->data[0], 0, s->last_frame->height *
 285                s->last_frame->linesize[0]);
 286         memset(s->last_frame->data[1], 0x80, s->last_frame->height / 2 *
 287                s->last_frame->linesize[1]);
 288         memset(s->last_frame->data[2], 0x80, s->last_frame->height / 2 *
 289                s->last_frame->linesize[2]);
 290     }
 291
 292     av_fast_padded_malloc(&s->bitstream_buf, &s->bitstream_buf_size,
 293                           bytestream2_get_bytes_left(&gb));
 294     if (!s->bitstream_buf)
 295         return AVERROR(ENOMEM);
 296     s->bbdsp.bswap16_buf(s->bitstream_buf, (const uint16_t *)(buf + bytestream2_tell(&gb)),
 297                          bytestream2_get_bytes_left(&gb) / 2);
 298     bitstream_init8(&s->bc, s->bitstream_buf, bytestream2_get_bytes_left(&gb));
 299
 300     for (s->mb_y=0; s->mb_y < (avctx->height+15)/16; s->mb_y++)
 301         for (s->mb_x=0; s->mb_x < (avctx->width +15)/16; s->mb_x++)
 302             decode_mb(s, frame, inter);
 303
 304     *got_frame = 1;
 305
 306     if (chunk_type != MADe_TAG) {
 307         av_frame_unref(s->last_frame);
 308         if ((ret = av_frame_ref(s->last_frame, frame)) < 0)
 309             return ret;
 310     }
 311
 312     return buf_size;
 313 }
 314
 315 static av_cold int decode_end(AVCodecContext *avctx)
 316 {
 317     MadContext *t = avctx->priv_data;
 318     av_frame_free(&t->last_frame);
 319     av_free(t->bitstream_buf);
 320     return 0;
 321 }
 322
 323 AVCodec ff_eamad_decoder = {
 324     .name           = "eamad",
 325     .long_name      = NULL_IF_CONFIG_SMALL("Electronic Arts Madcow Video"),
 326     .type           = AVMEDIA_TYPE_VIDEO,
 327     .id             = AV_CODEC_ID_MAD,
 328     .priv_data_size = sizeof(MadContext),
 329     .init           = decode_init,
 330     .close          = decode_end,
 331     .decode         = decode_frame,
 332     .capabilities   = AV_CODEC_CAP_DR1,
 333 };