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 "bytestream.h"
  33 #include "bswapdsp.h"
  34 #include "get_bits.h"
  35 #include "aandcttab.h"
  36 #include "eaidct.h"
  37 #include "idctdsp.h"
  38 #include "internal.h"
  39 #include "mpeg12.h"
  40 #include "mpeg12data.h"
  41 #include "libavutil/imgutils.h"
  42
  43 #define EA_PREAMBLE_SIZE    8
  44 #define MADk_TAG MKTAG('M', 'A', 'D', 'k')    /* MAD i-frame */
  45 #define MADm_TAG MKTAG('M', 'A', 'D', 'm')    /* MAD p-frame */
  46 #define MADe_TAG MKTAG('M', 'A', 'D', 'e')    /* MAD lqp-frame */
  47
  48 typedef struct MadContext {
  49     AVCodecContext *avctx;
  50     BlockDSPContext bdsp;
  51     BswapDSPContext bbdsp;
  52     IDCTDSPContext idsp;
  53     AVFrame *last_frame;
  54     GetBitContext gb;
  55     void *bitstream_buf;
  56     unsigned int bitstream_buf_size;
  57     DECLARE_ALIGNED(16, int16_t, block)[64];
  58     ScanTable scantable;
  59     uint16_t quant_matrix[64];
  60     int mb_x;
  61     int mb_y;
  62 } MadContext;
  63
  64 static av_cold int decode_init(AVCodecContext *avctx)
  65 {
  66     MadContext *s = avctx->priv_data;
  67     s->avctx = avctx;
  68     avctx->pix_fmt = AV_PIX_FMT_YUV420P;
  69     ff_blockdsp_init(&s->bdsp, avctx);
  70     ff_bswapdsp_init(&s->bbdsp);
  71     ff_idctdsp_init(&s->idsp, avctx);
  72     ff_init_scantable_permutation(s->idsp.idct_permutation, FF_IDCT_PERM_NONE);
  73     ff_init_scantable(s->idsp.idct_permutation, &s->scantable, ff_zigzag_direct);
  74     ff_mpeg12_init_vlcs();
  75
  76     s->last_frame = av_frame_alloc();
  77     if (!s->last_frame)
  78         return AVERROR(ENOMEM);
  79
  80     return 0;
  81 }
  82
  83 static inline void comp(unsigned char *dst, int dst_stride,
  84                         unsigned char *src, int src_stride, int add)
  85 {
  86     int j, i;
  87     for (j=0; j<8; j++)
  88         for (i=0; i<8; i++)
  89             dst[j*dst_stride + i] = av_clip_uint8(src[j*src_stride + i] + add);
  90 }
  91
  92 static inline void comp_block(MadContext *t, AVFrame *frame,
  93                               int mb_x, int mb_y,
  94                               int j, int mv_x, int mv_y, int add)
  95 {
  96     if (j < 4) {
  97         comp(frame->data[0] + (mb_y*16 + ((j&2)<<2))*frame->linesize[0] + mb_x*16 + ((j&1)<<3),
  98              frame->linesize[0],
  99              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,
 100              t->last_frame->linesize[0], add);
 101     } else if (!(t->avctx->flags & CODEC_FLAG_GRAY)) {
 102         int index = j - 3;
 103         comp(frame->data[index] + (mb_y*8)*frame->linesize[index] + mb_x * 8,
 104              frame->linesize[index],
 105              t->last_frame->data[index] + (mb_y * 8 + (mv_y/2))*t->last_frame->linesize[index] + mb_x * 8 + (mv_x/2),
 106              t->last_frame->linesize[index], add);
 107     }
 108 }
 109
 110 static inline void idct_put(MadContext *t, AVFrame *frame, int16_t *block,
 111                             int mb_x, int mb_y, int j)
 112 {
 113     if (j < 4) {
 114         ff_ea_idct_put_c(
 115             frame->data[0] + (mb_y*16 + ((j&2)<<2))*frame->linesize[0] + mb_x*16 + ((j&1)<<3),
 116             frame->linesize[0], block);
 117     } else if (!(t->avctx->flags & CODEC_FLAG_GRAY)) {
 118         int index = j - 3;
 119         ff_ea_idct_put_c(
 120             frame->data[index] + (mb_y*8)*frame->linesize[index] + mb_x*8,
 121             frame->linesize[index], block);
 122     }
 123 }
 124
 125 static inline void decode_block_intra(MadContext *s, int16_t * block)
 126 {
 127     int level, i, j, run;
 128     RLTable *rl = &ff_rl_mpeg1;
 129     const uint8_t *scantable = s->scantable.permutated;
 130     int16_t *quant_matrix = s->quant_matrix;
 131
 132     block[0] = (128 + get_sbits(&s->gb, 8)) * quant_matrix[0];
 133
 134     /* The RL decoder is derived from mpeg1_decode_block_intra;
 135        Escaped level and run values a decoded differently */
 136     i = 0;
 137     {
 138         OPEN_READER(re, &s->gb);
 139         /* now quantify & encode AC coefficients */
 140         for (;;) {
 141             UPDATE_CACHE(re, &s->gb);
 142             GET_RL_VLC(level, run, re, &s->gb, rl->rl_vlc[0], TEX_VLC_BITS, 2, 0);
 143
 144             if (level == 127) {
 145                 break;
 146             } else if (level != 0) {
 147                 i += run;
 148                 if (i > 63) {
 149                     av_log(s->avctx, AV_LOG_ERROR,
 150                            "ac-tex damaged at %d %d\n", s->mb_x, s->mb_y);
 151                     return;
 152                 }
 153                 j = scantable[i];
 154                 level = (level*quant_matrix[j]) >> 4;
 155                 level = (level-1)|1;
 156                 level = (level ^ SHOW_SBITS(re, &s->gb, 1)) - SHOW_SBITS(re, &s->gb, 1);
 157                 LAST_SKIP_BITS(re, &s->gb, 1);
 158             } else {
 159                 /* escape */
 160                 UPDATE_CACHE(re, &s->gb);
 161                 level = SHOW_SBITS(re, &s->gb, 10); SKIP_BITS(re, &s->gb, 10);
 162
 163                 UPDATE_CACHE(re, &s->gb);
 164                 run = SHOW_UBITS(re, &s->gb, 6)+1; LAST_SKIP_BITS(re, &s->gb, 6);
 165
 166                 i += run;
 167                 if (i > 63) {
 168                     av_log(s->avctx, AV_LOG_ERROR,
 169                            "ac-tex damaged at %d %d\n", s->mb_x, s->mb_y);
 170                     return;
 171                 }
 172                 j = scantable[i];
 173                 if (level < 0) {
 174                     level = -level;
 175                     level = (level*quant_matrix[j]) >> 4;
 176                     level = (level-1)|1;
 177                     level = -level;
 178                 } else {
 179                     level = (level*quant_matrix[j]) >> 4;
 180                     level = (level-1)|1;
 181                 }
 182             }
 183
 184             block[j] = level;
 185         }
 186         CLOSE_READER(re, &s->gb);
 187     }
 188 }
 189
 190 static int decode_motion(GetBitContext *gb)
 191 {
 192     int value = 0;
 193     if (get_bits1(gb)) {
 194         if (get_bits1(gb))
 195             value = -17;
 196         value += get_bits(gb, 4) + 1;
 197     }
 198     return value;
 199 }
 200
 201 static void decode_mb(MadContext *s, AVFrame *frame, int inter)
 202 {
 203     int mv_map = 0;
 204     int mv_x, mv_y;
 205     int j;
 206
 207     if (inter) {
 208         int v = decode210(&s->gb);
 209         if (v < 2) {
 210             mv_map = v ? get_bits(&s->gb, 6) : 63;
 211             mv_x = decode_motion(&s->gb);
 212             mv_y = decode_motion(&s->gb);
 213         } else {
 214             mv_map = 0;
 215         }
 216     }
 217
 218     for (j=0; j<6; j++) {
 219         if (mv_map & (1<<j)) {  // mv_x and mv_y are guarded by mv_map
 220             int add = 2*decode_motion(&s->gb);
 221             comp_block(s, frame, s->mb_x, s->mb_y, j, mv_x, mv_y, add);
 222         } else {
 223             s->bdsp.clear_block(s->block);
 224             decode_block_intra(s, s->block);
 225             idct_put(s, frame, s->block, s->mb_x, s->mb_y, j);
 226         }
 227     }
 228 }
 229
 230 static void calc_quant_matrix(MadContext *s, int qscale)
 231 {
 232     int i;
 233
 234     s->quant_matrix[0] = (ff_inv_aanscales[0]*ff_mpeg1_default_intra_matrix[0]) >> 11;
 235     for (i=1; i<64; i++)
 236         s->quant_matrix[i] = (ff_inv_aanscales[i]*ff_mpeg1_default_intra_matrix[i]*qscale + 32) >> 10;
 237 }
 238
 239 static int decode_frame(AVCodecContext *avctx,
 240                         void *data, int *got_frame,
 241                         AVPacket *avpkt)
 242 {
 243     const uint8_t *buf = avpkt->data;
 244     int buf_size       = avpkt->size;
 245     MadContext *s     = avctx->priv_data;
 246     AVFrame *frame    = data;
 247     GetByteContext gb;
 248     int width, height;
 249     int chunk_type;
 250     int inter, ret;
 251
 252     bytestream2_init(&gb, buf, buf_size);
 253
 254     chunk_type = bytestream2_get_le32(&gb);
 255     inter = (chunk_type == MADm_TAG || chunk_type == MADe_TAG);
 256     bytestream2_skip(&gb, 10);
 257
 258     av_reduce(&avctx->framerate.den, &avctx->framerate.num,
 259               bytestream2_get_le16(&gb), 1000, 1<<30);
 260
 261     width  = bytestream2_get_le16(&gb);
 262     height = bytestream2_get_le16(&gb);
 263     bytestream2_skip(&gb, 1);
 264     calc_quant_matrix(s, bytestream2_get_byte(&gb));
 265     bytestream2_skip(&gb, 2);
 266
 267     if (bytestream2_get_bytes_left(&gb) < 2) {
 268         av_log(avctx, AV_LOG_ERROR, "Input data too small\n");
 269         return AVERROR_INVALIDDATA;
 270     }
 271
 272     if (avctx->width != width || avctx->height != height) {
 273         av_frame_unref(s->last_frame);
 274         if ((ret = ff_set_dimensions(avctx, width, height)) < 0)
 275             return ret;
 276     }
 277
 278     if ((ret = ff_get_buffer(avctx, frame, AV_GET_BUFFER_FLAG_REF)) < 0) {
 279         av_log(avctx, AV_LOG_ERROR, "get_buffer() failed\n");
 280         return ret;
 281     }
 282
 283     if (inter && !s->last_frame->data[0]) {
 284         av_log(avctx, AV_LOG_WARNING, "Missing reference frame.\n");
 285         ret = ff_get_buffer(avctx, s->last_frame, AV_GET_BUFFER_FLAG_REF);
 286         if (ret < 0)
 287             return ret;
 288         memset(s->last_frame->data[0], 0, s->last_frame->height *
 289                s->last_frame->linesize[0]);
 290         memset(s->last_frame->data[1], 0x80, s->last_frame->height / 2 *
 291                s->last_frame->linesize[1]);
 292         memset(s->last_frame->data[2], 0x80, s->last_frame->height / 2 *
 293                s->last_frame->linesize[2]);
 294     }
 295
 296     av_fast_padded_malloc(&s->bitstream_buf, &s->bitstream_buf_size,
 297                           bytestream2_get_bytes_left(&gb));
 298     if (!s->bitstream_buf)
 299         return AVERROR(ENOMEM);
 300     s->bbdsp.bswap16_buf(s->bitstream_buf, (const uint16_t *)(buf + bytestream2_tell(&gb)),
 301                          bytestream2_get_bytes_left(&gb) / 2);
 302     init_get_bits(&s->gb, s->bitstream_buf, 8*(bytestream2_get_bytes_left(&gb)));
 303
 304     for (s->mb_y=0; s->mb_y < (avctx->height+15)/16; s->mb_y++)
 305         for (s->mb_x=0; s->mb_x < (avctx->width +15)/16; s->mb_x++)
 306             decode_mb(s, frame, inter);
 307
 308     *got_frame = 1;
 309
 310     if (chunk_type != MADe_TAG) {
 311         av_frame_unref(s->last_frame);
 312         if ((ret = av_frame_ref(s->last_frame, frame)) < 0)
 313             return ret;
 314     }
 315
 316     return buf_size;
 317 }
 318
 319 static av_cold int decode_end(AVCodecContext *avctx)
 320 {
 321     MadContext *t = avctx->priv_data;
 322     av_frame_free(&t->last_frame);
 323     av_free(t->bitstream_buf);
 324     return 0;
 325 }
 326
 327 AVCodec ff_eamad_decoder = {
 328     .name           = "eamad",
 329     .long_name      = NULL_IF_CONFIG_SMALL("Electronic Arts Madcow Video"),
 330     .type           = AVMEDIA_TYPE_VIDEO,
 331     .id             = AV_CODEC_ID_MAD,
 332     .priv_data_size = sizeof(MadContext),
 333     .init           = decode_init,
 334     .close          = decode_end,
 335     .decode         = decode_frame,
 336     .capabilities   = CODEC_CAP_DR1,
 337 };