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 "avcodec.h"
32#include "bswapdsp.h"
33#include "get_bits.h"
34#include "aandcttab.h"
35#include "eaidct.h"
36#include "idctdsp.h"
37#include "internal.h"
38#include "mpeg12.h"
39#include "mpeg12data.h"
40#include "libavutil/imgutils.h"
41
42#define EA_PREAMBLE_SIZE    8
43#define MADk_TAG MKTAG('M', 'A', 'D', 'k')    /* MAD i-frame */
44#define MADm_TAG MKTAG('M', 'A', 'D', 'm')    /* MAD p-frame */
45#define MADe_TAG MKTAG('M', 'A', 'D', 'e')    /* MAD lqp-frame */
46
47typedef struct MadContext {
48    AVCodecContext *avctx;
49    BlockDSPContext bdsp;
50    BswapDSPContext bbdsp;
51    IDCTDSPContext idsp;
52    AVFrame *last_frame;
53    GetBitContext gb;
54    void *bitstream_buf;
55    unsigned int bitstream_buf_size;
56    DECLARE_ALIGNED(16, int16_t, block)[64];
57    ScanTable scantable;
58    uint16_t quant_matrix[64];
59    int mb_x;
60    int mb_y;
61} MadContext;
62
63static av_cold int decode_init(AVCodecContext *avctx)
64{
65    MadContext *s = avctx->priv_data;
66    s->avctx = avctx;
67    avctx->pix_fmt = AV_PIX_FMT_YUV420P;
68    ff_blockdsp_init(&s->bdsp, avctx);
69    ff_bswapdsp_init(&s->bbdsp);
70    ff_idctdsp_init(&s->idsp, avctx);
71    ff_init_scantable_permutation(s->idsp.idct_permutation, FF_NO_IDCT_PERM);
72    ff_init_scantable(s->idsp.idct_permutation, &s->scantable, ff_zigzag_direct);
73    ff_mpeg12_init_vlcs();
74
75    s->last_frame = av_frame_alloc();
76    if (!s->last_frame)
77        return AVERROR(ENOMEM);
78
79    return 0;
80}
81
82static inline void comp(unsigned char *dst, int dst_stride,
83                        unsigned char *src, int src_stride, int add)
84{
85    int j, i;
86    for (j=0; j<8; j++)
87        for (i=0; i<8; i++)
88            dst[j*dst_stride + i] = av_clip_uint8(src[j*src_stride + i] + add);
89}
90
91static inline void comp_block(MadContext *t, AVFrame *frame,
92                              int mb_x, int mb_y,
93                              int j, int mv_x, int mv_y, int add)
94{
95    if (j < 4) {
96        unsigned offset = (mb_y*16 + ((j&2)<<2) + mv_y)*t->last_frame->linesize[0] + mb_x*16 + ((j&1)<<3) + mv_x;
97        if (offset >= (t->avctx->height - 7) * t->last_frame->linesize[0] - 7)
98            return;
99        comp(frame->data[0] + (mb_y*16 + ((j&2)<<2))*frame->linesize[0] + mb_x*16 + ((j&1)<<3),
100             frame->linesize[0],
101             t->last_frame->data[0] + offset,
102             t->last_frame->linesize[0], add);
103    } else if (!(t->avctx->flags & CODEC_FLAG_GRAY)) {
104        int index = j - 3;
105        unsigned offset = (mb_y * 8 + (mv_y/2))*t->last_frame->linesize[index] + mb_x * 8 + (mv_x/2);
106        if (offset >= (t->avctx->height/2 - 7) * t->last_frame->linesize[index] - 7)
107            return;
108        comp(frame->data[index] + (mb_y*8)*frame->linesize[index] + mb_x * 8,
109             frame->linesize[index],
110             t->last_frame->data[index] + offset,
111             t->last_frame->linesize[index], add);
112    }
113}
114
115static inline void idct_put(MadContext *t, AVFrame *frame, int16_t *block,
116                            int mb_x, int mb_y, int j)
117{
118    if (j < 4) {
119        ff_ea_idct_put_c(
120            frame->data[0] + (mb_y*16 + ((j&2)<<2))*frame->linesize[0] + mb_x*16 + ((j&1)<<3),
121            frame->linesize[0], block);
122    } else if (!(t->avctx->flags & CODEC_FLAG_GRAY)) {
123        int index = j - 3;
124        ff_ea_idct_put_c(
125            frame->data[index] + (mb_y*8)*frame->linesize[index] + mb_x*8,
126            frame->linesize[index], block);
127    }
128}
129
130static inline int decode_block_intra(MadContext *s, int16_t * block)
131{
132    int level, i, j, run;
133    RLTable *rl = &ff_rl_mpeg1;
134    const uint8_t *scantable = s->scantable.permutated;
135    int16_t *quant_matrix = s->quant_matrix;
136
137    block[0] = (128 + get_sbits(&s->gb, 8)) * quant_matrix[0];
138
139    /* The RL decoder is derived from mpeg1_decode_block_intra;
140       Escaped level and run values a decoded differently */
141    i = 0;
142    {
143        OPEN_READER(re, &s->gb);
144        /* now quantify & encode AC coefficients */
145        for (;;) {
146            UPDATE_CACHE(re, &s->gb);
147            GET_RL_VLC(level, run, re, &s->gb, rl->rl_vlc[0], TEX_VLC_BITS, 2, 0);
148
149            if (level == 127) {
150                break;
151            } else if (level != 0) {
152                i += run;
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                j = scantable[i];
168                if (level < 0) {
169                    level = -level;
170                    level = (level*quant_matrix[j]) >> 4;
171                    level = (level-1)|1;
172                    level = -level;
173                } else {
174                    level = (level*quant_matrix[j]) >> 4;
175                    level = (level-1)|1;
176                }
177            }
178            if (i > 63) {
179                av_log(s->avctx, AV_LOG_ERROR, "ac-tex damaged at %d %d\n", s->mb_x, s->mb_y);
180                return -1;
181            }
182
183            block[j] = level;
184        }
185        CLOSE_READER(re, &s->gb);
186    }
187    return 0;
188}
189
190static 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
201static int decode_mb(MadContext *s, AVFrame *frame, int inter)
202{
203    int mv_map = 0;
204    int av_uninit(mv_x), av_uninit(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        }
214    }
215
216    for (j=0; j<6; j++) {
217        if (mv_map & (1<<j)) {  // mv_x and mv_y are guarded by mv_map
218            int add = 2*decode_motion(&s->gb);
219            if (s->last_frame->data[0])
220                comp_block(s, frame, s->mb_x, s->mb_y, j, mv_x, mv_y, add);
221        } else {
222            s->bdsp.clear_block(s->block);
223            if(decode_block_intra(s, s->block) < 0)
224                return -1;
225            idct_put(s, frame, s->block, s->mb_x, s->mb_y, j);
226        }
227    }
228    return 0;
229}
230
231static void calc_quant_matrix(MadContext *s, int qscale)
232{
233    int i;
234
235    s->quant_matrix[0] = (ff_inv_aanscales[0]*ff_mpeg1_default_intra_matrix[0]) >> 11;
236    for (i=1; i<64; i++)
237        s->quant_matrix[i] = (ff_inv_aanscales[i]*ff_mpeg1_default_intra_matrix[i]*qscale + 32) >> 10;
238}
239
240static int decode_frame(AVCodecContext *avctx,
241                        void *data, int *got_frame,
242                        AVPacket *avpkt)
243{
244    const uint8_t *buf = avpkt->data;
245    int buf_size       = avpkt->size;
246    const uint8_t *buf_end = buf+buf_size;
247    MadContext *s     = avctx->priv_data;
248    AVFrame *frame    = data;
249    int width, height;
250    int chunk_type;
251    int inter, ret;
252
253    if (buf_size < 26) {
254        av_log(avctx, AV_LOG_ERROR, "Input buffer too small\n");
255        *got_frame = 0;
256        return AVERROR_INVALIDDATA;
257    }
258
259    chunk_type = AV_RL32(&buf[0]);
260    inter = (chunk_type == MADm_TAG || chunk_type == MADe_TAG);
261    buf += 8;
262
263    av_reduce(&avctx->time_base.num, &avctx->time_base.den,
264              AV_RL16(&buf[6]), 1000, 1<<30);
265
266    width  = AV_RL16(&buf[8]);
267    height = AV_RL16(&buf[10]);
268    calc_quant_matrix(s, buf[13]);
269    buf += 16;
270
271    if (width < 16 || height < 16) {
272        av_log(avctx, AV_LOG_ERROR, "Dimensions too small\n");
273        return AVERROR_INVALIDDATA;
274    }
275
276    if (avctx->width != width || avctx->height != height) {
277        av_frame_unref(s->last_frame);
278        if((width * height)/2048*7 > buf_end-buf)
279            return AVERROR_INVALIDDATA;
280        if ((ret = ff_set_dimensions(avctx, width, height)) < 0)
281            return ret;
282    }
283
284    if ((ret = ff_get_buffer(avctx, frame, AV_GET_BUFFER_FLAG_REF)) < 0)
285        return ret;
286
287    if (inter && !s->last_frame->data[0]) {
288        av_log(avctx, AV_LOG_WARNING, "Missing reference frame.\n");
289        ret = ff_get_buffer(avctx, s->last_frame, AV_GET_BUFFER_FLAG_REF);
290        if (ret < 0)
291            return ret;
292        memset(s->last_frame->data[0], 0, s->last_frame->height *
293               s->last_frame->linesize[0]);
294        memset(s->last_frame->data[1], 0x80, s->last_frame->height / 2 *
295               s->last_frame->linesize[1]);
296        memset(s->last_frame->data[2], 0x80, s->last_frame->height / 2 *
297               s->last_frame->linesize[2]);
298    }
299
300    av_fast_padded_malloc(&s->bitstream_buf, &s->bitstream_buf_size,
301                          buf_end - buf);
302    if (!s->bitstream_buf)
303        return AVERROR(ENOMEM);
304    s->bbdsp.bswap16_buf(s->bitstream_buf, (const uint16_t *) buf,
305                         (buf_end - buf) / 2);
306    memset((uint8_t*)s->bitstream_buf + (buf_end-buf), 0, FF_INPUT_BUFFER_PADDING_SIZE);
307    init_get_bits(&s->gb, s->bitstream_buf, 8*(buf_end-buf));
308
309    for (s->mb_y=0; s->mb_y < (avctx->height+15)/16; s->mb_y++)
310        for (s->mb_x=0; s->mb_x < (avctx->width +15)/16; s->mb_x++)
311            if(decode_mb(s, frame, inter) < 0)
312                return AVERROR_INVALIDDATA;
313
314    *got_frame = 1;
315
316    if (chunk_type != MADe_TAG) {
317        av_frame_unref(s->last_frame);
318        if ((ret = av_frame_ref(s->last_frame, frame)) < 0)
319            return ret;
320    }
321
322    return buf_size;
323}
324
325static av_cold int decode_end(AVCodecContext *avctx)
326{
327    MadContext *t = avctx->priv_data;
328    av_frame_free(&t->last_frame);
329    av_free(t->bitstream_buf);
330    return 0;
331}
332
333AVCodec ff_eamad_decoder = {
334    .name           = "eamad",
335    .long_name      = NULL_IF_CONFIG_SMALL("Electronic Arts Madcow Video"),
336    .type           = AVMEDIA_TYPE_VIDEO,
337    .id             = AV_CODEC_ID_MAD,
338    .priv_data_size = sizeof(MadContext),
339    .init           = decode_init,
340    .close          = decode_end,
341    .decode         = decode_frame,
342    .capabilities   = CODEC_CAP_DR1,
343};
344