aboutsummaryrefslogtreecommitdiffstats
path: root/libavcodec/eamad.c
blob: 6457e2a134260e871be73cf480276f75c566f8f0 (plain) (blame)
1
2
3
4
5
6
7
8
9
10
11
12
13
14
15
16
17
18
19
20
21
22
23
24
25
26
27
28
29
30
31
32
33
34
35
36
37
38
39
40
41
42
43
44
45
46
47
48
49
50
51
52
53
54
55
56
57
58
59
60
61
62
63
64
65
66
67
68
69
70
71
72
73
74
75
76
77
78
79
80
81
82
83
84
85
86
87
88
89
90
91
92
93
94
95
96
97
98
99
100
101
102
103
104
105
106
107
108
109
110
111
112
113
114
115
116
117
118
119
120
121
122
123
124
125
126
127
128
129
130
131
132
133
134
135
136
137
138
139
140
141
142
143
144
145
146
147
148
149
150
151
152
153
154
155
156
157
158
159
160
161
162
163
164
165
166
167
168
169
170
171
172
173
174
175
176
177
178
179
180
181
182
183
184
185
186
187
188
189
190
191
192
193
194
195
196
197
198
199
200
201
202
203
204
205
206
207
208
209
210
211
212
213
214
215
216
217
218
219
220
221
222
223
224
225
226
227
228
229
230
231
232
233
234
235
236
237
238
239
240
241
242
243
244
245
246
247
248
249
250
251
252
253
254
255
256
257
258
259
260
261
262
263
264
265
266
267
268
269
270
271
272
273
274
275
276
277
278
279
280
281
282
283
284
285
286
287
288
289
290
291
292
293
294
295
296
297
298
299
300
301
302
303
304
305
306
307
308
309
310
311
312
313
314
315
316
317
318
319
320
321
322
323
324
325
326
327
328
329
330
331
332
333
334
335
336
337
338
339
340
341
342
343
/*
 * Electronic Arts Madcow Video Decoder
 * Copyright (c) 2007-2009 Peter Ross
 *
 * This file is part of FFmpeg.
 *
 * FFmpeg is free software; you can redistribute it and/or
 * modify it under the terms of the GNU Lesser General Public
 * License as published by the Free Software Foundation; either
 * version 2.1 of the License, or (at your option) any later version.
 *
 * FFmpeg is distributed in the hope that it will be useful,
 * but WITHOUT ANY WARRANTY; without even the implied warranty of
 * MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE.  See the GNU
 * Lesser General Public License for more details.
 *
 * You should have received a copy of the GNU Lesser General Public
 * License along with FFmpeg; if not, write to the Free Software
 * Foundation, Inc., 51 Franklin St, Fifth Floor, Boston, MA  02110-1301  USA
 */

/**
 * @file
 * Electronic Arts Madcow Video Decoder
 * @author Peter Ross <pross@xvid.org>
 *
 * @see technical details at
 * http://wiki.multimedia.cx/index.php?title=Electronic_Arts_MAD
 */

#include "avcodec.h"
#include "bswapdsp.h"
#include "get_bits.h"
#include "aandcttab.h"
#include "eaidct.h"
#include "idctdsp.h"
#include "internal.h"
#include "mpeg12.h"
#include "mpeg12data.h"
#include "libavutil/imgutils.h"

#define EA_PREAMBLE_SIZE    8
#define MADk_TAG MKTAG('M', 'A', 'D', 'k')    /* MAD i-frame */
#define MADm_TAG MKTAG('M', 'A', 'D', 'm')    /* MAD p-frame */
#define MADe_TAG MKTAG('M', 'A', 'D', 'e')    /* MAD lqp-frame */

typedef struct MadContext {
    AVCodecContext *avctx;
    BlockDSPContext bdsp;
    BswapDSPContext bbdsp;
    IDCTDSPContext idsp;
    AVFrame *last_frame;
    GetBitContext gb;
    void *bitstream_buf;
    unsigned int bitstream_buf_size;
    DECLARE_ALIGNED(16, int16_t, block)[64];
    ScanTable scantable;
    uint16_t quant_matrix[64];
    int mb_x;
    int mb_y;
} MadContext;

static av_cold int decode_init(AVCodecContext *avctx)
{
    MadContext *s = avctx->priv_data;
    s->avctx = avctx;
    avctx->pix_fmt = AV_PIX_FMT_YUV420P;
    ff_blockdsp_init(&s->bdsp, avctx);
    ff_bswapdsp_init(&s->bbdsp);
    ff_idctdsp_init(&s->idsp, avctx);
    ff_init_scantable_permutation(s->idsp.idct_permutation, FF_IDCT_PERM_NONE);
    ff_init_scantable(s->idsp.idct_permutation, &s->scantable, ff_zigzag_direct);
    ff_mpeg12_init_vlcs();

    s->last_frame = av_frame_alloc();
    if (!s->last_frame)
        return AVERROR(ENOMEM);

    return 0;
}

static inline void comp(unsigned char *dst, int dst_stride,
                        unsigned char *src, int src_stride, int add)
{
    int j, i;
    for (j=0; j<8; j++)
        for (i=0; i<8; i++)
            dst[j*dst_stride + i] = av_clip_uint8(src[j*src_stride + i] + add);
}

static inline void comp_block(MadContext *t, AVFrame *frame,
                              int mb_x, int mb_y,
                              int j, int mv_x, int mv_y, int add)
{
    if (j < 4) {
        unsigned offset = (mb_y*16 + ((j&2)<<2) + mv_y)*t->last_frame->linesize[0] + mb_x*16 + ((j&1)<<3) + mv_x;
        if (offset >= (t->avctx->height - 7) * t->last_frame->linesize[0] - 7)
            return;
        comp(frame->data[0] + (mb_y*16 + ((j&2)<<2))*frame->linesize[0] + mb_x*16 + ((j&1)<<3),
             frame->linesize[0],
             t->last_frame->data[0] + offset,
             t->last_frame->linesize[0], add);
    } else if (!(t->avctx->flags & CODEC_FLAG_GRAY)) {
        int index = j - 3;
        unsigned offset = (mb_y * 8 + (mv_y/2))*t->last_frame->linesize[index] + mb_x * 8 + (mv_x/2);
        if (offset >= (t->avctx->height/2 - 7) * t->last_frame->linesize[index] - 7)
            return;
        comp(frame->data[index] + (mb_y*8)*frame->linesize[index] + mb_x * 8,
             frame->linesize[index],
             t->last_frame->data[index] + offset,
             t->last_frame->linesize[index], add);
    }
}

static inline void idct_put(MadContext *t, AVFrame *frame, int16_t *block,
                            int mb_x, int mb_y, int j)
{
    if (j < 4) {
        ff_ea_idct_put_c(
            frame->data[0] + (mb_y*16 + ((j&2)<<2))*frame->linesize[0] + mb_x*16 + ((j&1)<<3),
            frame->linesize[0], block);
    } else if (!(t->avctx->flags & CODEC_FLAG_GRAY)) {
        int index = j - 3;
        ff_ea_idct_put_c(
            frame->data[index] + (mb_y*8)*frame->linesize[index] + mb_x*8,
            frame->linesize[index], block);
    }
}

static inline int decode_block_intra(MadContext *s, int16_t * block)
{
    int level, i, j, run;
    RLTable *rl = &ff_rl_mpeg1;
    const uint8_t *scantable = s->scantable.permutated;
    int16_t *quant_matrix = s->quant_matrix;

    block[0] = (128 + get_sbits(&s->gb, 8)) * quant_matrix[0];

    /* The RL decoder is derived from mpeg1_decode_block_intra;
       Escaped level and run values a decoded differently */
    i = 0;
    {
        OPEN_READER(re, &s->gb);
        /* now quantify & encode AC coefficients */
        for (;;) {
            UPDATE_CACHE(re, &s->gb);
            GET_RL_VLC(level, run, re, &s->gb, rl->rl_vlc[0], TEX_VLC_BITS, 2, 0);

            if (level == 127) {
                break;
            } else if (level != 0) {
                i += run;
                j = scantable[i];
                level = (level*quant_matrix[j]) >> 4;
                level = (level-1)|1;
                level = (level ^ SHOW_SBITS(re, &s->gb, 1)) - SHOW_SBITS(re, &s->gb, 1);
                LAST_SKIP_BITS(re, &s->gb, 1);
            } else {
                /* escape */
                UPDATE_CACHE(re, &s->gb);
                level = SHOW_SBITS(re, &s->gb, 10); SKIP_BITS(re, &s->gb, 10);

                UPDATE_CACHE(re, &s->gb);
                run = SHOW_UBITS(re, &s->gb, 6)+1; LAST_SKIP_BITS(re, &s->gb, 6);

                i += run;
                j = scantable[i];
                if (level < 0) {
                    level = -level;
                    level = (level*quant_matrix[j]) >> 4;
                    level = (level-1)|1;
                    level = -level;
                } else {
                    level = (level*quant_matrix[j]) >> 4;
                    level = (level-1)|1;
                }
            }
            if (i > 63) {
                av_log(s->avctx, AV_LOG_ERROR, "ac-tex damaged at %d %d\n", s->mb_x, s->mb_y);
                return -1;
            }

            block[j] = level;
        }
        CLOSE_READER(re, &s->gb);
    }
    return 0;
}

static int decode_motion(GetBitContext *gb)
{
    int value = 0;
    if (get_bits1(gb)) {
        if (get_bits1(gb))
            value = -17;
        value += get_bits(gb, 4) + 1;
    }
    return value;
}

static int decode_mb(MadContext *s, AVFrame *frame, int inter)
{
    int mv_map = 0;
    int av_uninit(mv_x), av_uninit(mv_y);
    int j;

    if (inter) {
        int v = decode210(&s->gb);
        if (v < 2) {
            mv_map = v ? get_bits(&s->gb, 6) : 63;
            mv_x = decode_motion(&s->gb);
            mv_y = decode_motion(&s->gb);
        }
    }

    for (j=0; j<6; j++) {
        if (mv_map & (1<<j)) {  // mv_x and mv_y are guarded by mv_map
            int add = 2*decode_motion(&s->gb);
            if (s->last_frame->data[0])
                comp_block(s, frame, s->mb_x, s->mb_y, j, mv_x, mv_y, add);
        } else {
            s->bdsp.clear_block(s->block);
            if(decode_block_intra(s, s->block) < 0)
                return -1;
            idct_put(s, frame, s->block, s->mb_x, s->mb_y, j);
        }
    }
    return 0;
}

static void calc_quant_matrix(MadContext *s, int qscale)
{
    int i;

    s->quant_matrix[0] = (ff_inv_aanscales[0]*ff_mpeg1_default_intra_matrix[0]) >> 11;
    for (i=1; i<64; i++)
        s->quant_matrix[i] = (ff_inv_aanscales[i]*ff_mpeg1_default_intra_matrix[i]*qscale + 32) >> 10;
}

static int decode_frame(AVCodecContext *avctx,
                        void *data, int *got_frame,
                        AVPacket *avpkt)
{
    const uint8_t *buf = avpkt->data;
    int buf_size       = avpkt->size;
    const uint8_t *buf_end = buf+buf_size;
    MadContext *s     = avctx->priv_data;
    AVFrame *frame    = data;
    int width, height;
    int chunk_type;
    int inter, ret;

    if (buf_size < 26) {
        av_log(avctx, AV_LOG_ERROR, "Input buffer too small\n");
        *got_frame = 0;
        return AVERROR_INVALIDDATA;
    }

    chunk_type = AV_RL32(&buf[0]);
    inter = (chunk_type == MADm_TAG || chunk_type == MADe_TAG);
    buf += 8;

    av_reduce(&avctx->time_base.num, &avctx->time_base.den,
              AV_RL16(&buf[6]), 1000, 1<<30);

    width  = AV_RL16(&buf[8]);
    height = AV_RL16(&buf[10]);
    calc_quant_matrix(s, buf[13]);
    buf += 16;

    if (width < 16 || height < 16) {
        av_log(avctx, AV_LOG_ERROR, "Dimensions too small\n");
        return AVERROR_INVALIDDATA;
    }

    if (avctx->width != width || avctx->height != height) {
        av_frame_unref(s->last_frame);
        if((width * height)/2048*7 > buf_end-buf)
            return AVERROR_INVALIDDATA;
        if ((ret = ff_set_dimensions(avctx, width, height)) < 0)
            return ret;
    }

    if ((ret = ff_get_buffer(avctx, frame, AV_GET_BUFFER_FLAG_REF)) < 0)
        return ret;

    if (inter && !s->last_frame->data[0]) {
        av_log(avctx, AV_LOG_WARNING, "Missing reference frame.\n");
        ret = ff_get_buffer(avctx, s->last_frame, AV_GET_BUFFER_FLAG_REF);
        if (ret < 0)
            return ret;
        memset(s->last_frame->data[0], 0, s->last_frame->height *
               s->last_frame->linesize[0]);
        memset(s->last_frame->data[1], 0x80, s->last_frame->height / 2 *
               s->last_frame->linesize[1]);
        memset(s->last_frame->data[2], 0x80, s->last_frame->height / 2 *
               s->last_frame->linesize[2]);
    }

    av_fast_padded_malloc(&s->bitstream_buf, &s->bitstream_buf_size,
                          buf_end - buf);
    if (!s->bitstream_buf)
        return AVERROR(ENOMEM);
    s->bbdsp.bswap16_buf(s->bitstream_buf, (const uint16_t *) buf,
                         (buf_end - buf) / 2);
    memset((uint8_t*)s->bitstream_buf + (buf_end-buf), 0, FF_INPUT_BUFFER_PADDING_SIZE);
    init_get_bits(&s->gb, s->bitstream_buf, 8*(buf_end-buf));

    for (s->mb_y=0; s->mb_y < (avctx->height+15)/16; s->mb_y++)
        for (s->mb_x=0; s->mb_x < (avctx->width +15)/16; s->mb_x++)
            if(decode_mb(s, frame, inter) < 0)
                return AVERROR_INVALIDDATA;

    *got_frame = 1;

    if (chunk_type != MADe_TAG) {
        av_frame_unref(s->last_frame);
        if ((ret = av_frame_ref(s->last_frame, frame)) < 0)
            return ret;
    }

    return buf_size;
}

static av_cold int decode_end(AVCodecContext *avctx)
{
    MadContext *t = avctx->priv_data;
    av_frame_free(&t->last_frame);
    av_free(t->bitstream_buf);
    return 0;
}

AVCodec ff_eamad_decoder = {
    .name           = "eamad",
    .long_name      = NULL_IF_CONFIG_SMALL("Electronic Arts Madcow Video"),
    .type           = AVMEDIA_TYPE_VIDEO,
    .id             = AV_CODEC_ID_MAD,
    .priv_data_size = sizeof(MadContext),
    .init           = decode_init,
    .close          = decode_end,
    .decode         = decode_frame,
    .capabilities   = CODEC_CAP_DR1,
};