f9b43a147b7c6f0f1384427cba59d918aa32769a
[libav.git] / 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 "get_bits.h"
33 #include "aandcttab.h"
34 #include "eaidct.h"
35 #include "internal.h"
36 #include "mpeg12.h"
37 #include "mpeg12data.h"
38 #include "libavutil/imgutils.h"
39
40 #define EA_PREAMBLE_SIZE 8
41 #define MADk_TAG MKTAG('M', 'A', 'D', 'k') /* MAD i-frame */
42 #define MADm_TAG MKTAG('M', 'A', 'D', 'm') /* MAD p-frame */
43 #define MADe_TAG MKTAG('M', 'A', 'D', 'e') /* MAD lqp-frame */
44
45 typedef struct MadContext {
46 AVCodecContext *avctx;
47 DSPContext dsp;
48 AVFrame frame;
49 AVFrame last_frame;
50 GetBitContext gb;
51 void *bitstream_buf;
52 unsigned int bitstream_buf_size;
53 DECLARE_ALIGNED(16, int16_t, block)[64];
54 ScanTable scantable;
55 uint16_t quant_matrix[64];
56 int mb_x;
57 int mb_y;
58 } MadContext;
59
60 static av_cold int decode_init(AVCodecContext *avctx)
61 {
62 MadContext *s = avctx->priv_data;
63 s->avctx = avctx;
64 avctx->pix_fmt = AV_PIX_FMT_YUV420P;
65 ff_dsputil_init(&s->dsp, avctx);
66 ff_init_scantable_permutation(s->dsp.idct_permutation, FF_NO_IDCT_PERM);
67 ff_init_scantable(s->dsp.idct_permutation, &s->scantable, ff_zigzag_direct);
68 ff_mpeg12_init_vlcs();
69 return 0;
70 }
71
72 static inline void comp(unsigned char *dst, int dst_stride,
73 unsigned char *src, int src_stride, int add)
74 {
75 int j, i;
76 for (j=0; j<8; j++)
77 for (i=0; i<8; i++)
78 dst[j*dst_stride + i] = av_clip_uint8(src[j*src_stride + i] + add);
79 }
80
81 static inline void comp_block(MadContext *t, int mb_x, int mb_y,
82 int j, int mv_x, int mv_y, int add)
83 {
84 if (j < 4) {
85 comp(t->frame.data[0] + (mb_y*16 + ((j&2)<<2))*t->frame.linesize[0] + mb_x*16 + ((j&1)<<3),
86 t->frame.linesize[0],
87 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,
88 t->last_frame.linesize[0], add);
89 } else if (!(t->avctx->flags & CODEC_FLAG_GRAY)) {
90 int index = j - 3;
91 comp(t->frame.data[index] + (mb_y*8)*t->frame.linesize[index] + mb_x * 8,
92 t->frame.linesize[index],
93 t->last_frame.data[index] + (mb_y * 8 + (mv_y/2))*t->last_frame.linesize[index] + mb_x * 8 + (mv_x/2),
94 t->last_frame.linesize[index], add);
95 }
96 }
97
98 static inline void idct_put(MadContext *t, int16_t *block, int mb_x, int mb_y, int j)
99 {
100 if (j < 4) {
101 ff_ea_idct_put_c(
102 t->frame.data[0] + (mb_y*16 + ((j&2)<<2))*t->frame.linesize[0] + mb_x*16 + ((j&1)<<3),
103 t->frame.linesize[0], block);
104 } else if (!(t->avctx->flags & CODEC_FLAG_GRAY)) {
105 int index = j - 3;
106 ff_ea_idct_put_c(
107 t->frame.data[index] + (mb_y*8)*t->frame.linesize[index] + mb_x*8,
108 t->frame.linesize[index], block);
109 }
110 }
111
112 static inline void decode_block_intra(MadContext *s, int16_t * block)
113 {
114 int level, i, j, run;
115 RLTable *rl = &ff_rl_mpeg1;
116 const uint8_t *scantable = s->scantable.permutated;
117 int16_t *quant_matrix = s->quant_matrix;
118
119 block[0] = (128 + get_sbits(&s->gb, 8)) * quant_matrix[0];
120
121 /* The RL decoder is derived from mpeg1_decode_block_intra;
122 Escaped level and run values a decoded differently */
123 i = 0;
124 {
125 OPEN_READER(re, &s->gb);
126 /* now quantify & encode AC coefficients */
127 for (;;) {
128 UPDATE_CACHE(re, &s->gb);
129 GET_RL_VLC(level, run, re, &s->gb, rl->rl_vlc[0], TEX_VLC_BITS, 2, 0);
130
131 if (level == 127) {
132 break;
133 } else if (level != 0) {
134 i += run;
135 j = scantable[i];
136 level = (level*quant_matrix[j]) >> 4;
137 level = (level-1)|1;
138 level = (level ^ SHOW_SBITS(re, &s->gb, 1)) - SHOW_SBITS(re, &s->gb, 1);
139 LAST_SKIP_BITS(re, &s->gb, 1);
140 } else {
141 /* escape */
142 UPDATE_CACHE(re, &s->gb);
143 level = SHOW_SBITS(re, &s->gb, 10); SKIP_BITS(re, &s->gb, 10);
144
145 UPDATE_CACHE(re, &s->gb);
146 run = SHOW_UBITS(re, &s->gb, 6)+1; LAST_SKIP_BITS(re, &s->gb, 6);
147
148 i += run;
149 j = scantable[i];
150 if (level < 0) {
151 level = -level;
152 level = (level*quant_matrix[j]) >> 4;
153 level = (level-1)|1;
154 level = -level;
155 } else {
156 level = (level*quant_matrix[j]) >> 4;
157 level = (level-1)|1;
158 }
159 }
160 if (i > 63) {
161 av_log(s->avctx, AV_LOG_ERROR, "ac-tex damaged at %d %d\n", s->mb_x, s->mb_y);
162 return;
163 }
164
165 block[j] = level;
166 }
167 CLOSE_READER(re, &s->gb);
168 }
169 }
170
171 static int decode_motion(GetBitContext *gb)
172 {
173 int value = 0;
174 if (get_bits1(gb)) {
175 if (get_bits1(gb))
176 value = -17;
177 value += get_bits(gb, 4) + 1;
178 }
179 return value;
180 }
181
182 static void decode_mb(MadContext *s, int inter)
183 {
184 int mv_map = 0;
185 int mv_x, mv_y;
186 int j;
187
188 if (inter) {
189 int v = decode210(&s->gb);
190 if (v < 2) {
191 mv_map = v ? get_bits(&s->gb, 6) : 63;
192 mv_x = decode_motion(&s->gb);
193 mv_y = decode_motion(&s->gb);
194 } else {
195 mv_map = 0;
196 }
197 }
198
199 for (j=0; j<6; j++) {
200 if (mv_map & (1<<j)) { // mv_x and mv_y are guarded by mv_map
201 int add = 2*decode_motion(&s->gb);
202 comp_block(s, s->mb_x, s->mb_y, j, mv_x, mv_y, add);
203 } else {
204 s->dsp.clear_block(s->block);
205 decode_block_intra(s, s->block);
206 idct_put(s, s->block, s->mb_x, s->mb_y, j);
207 }
208 }
209 }
210
211 static void calc_quant_matrix(MadContext *s, int qscale)
212 {
213 int i;
214
215 s->quant_matrix[0] = (ff_inv_aanscales[0]*ff_mpeg1_default_intra_matrix[0]) >> 11;
216 for (i=1; i<64; i++)
217 s->quant_matrix[i] = (ff_inv_aanscales[i]*ff_mpeg1_default_intra_matrix[i]*qscale + 32) >> 10;
218 }
219
220 static int decode_frame(AVCodecContext *avctx,
221 void *data, int *got_frame,
222 AVPacket *avpkt)
223 {
224 const uint8_t *buf = avpkt->data;
225 int buf_size = avpkt->size;
226 const uint8_t *buf_end = buf+buf_size;
227 MadContext *s = avctx->priv_data;
228 int width, height;
229 int chunk_type;
230 int inter;
231
232 if (buf_size < 17) {
233 av_log(avctx, AV_LOG_ERROR, "Input buffer too small\n");
234 *got_frame = 0;
235 return -1;
236 }
237
238 chunk_type = AV_RL32(&buf[0]);
239 inter = (chunk_type == MADm_TAG || chunk_type == MADe_TAG);
240 buf += 8;
241
242 av_reduce(&avctx->time_base.num, &avctx->time_base.den,
243 AV_RL16(&buf[6]), 1000, 1<<30);
244
245 width = AV_RL16(&buf[8]);
246 height = AV_RL16(&buf[10]);
247 calc_quant_matrix(s, buf[13]);
248 buf += 16;
249
250 if (avctx->width != width || avctx->height != height) {
251 if (av_image_check_size(width, height, 0, avctx) < 0)
252 return -1;
253 avcodec_set_dimensions(avctx, width, height);
254 if (s->frame.data[0])
255 avctx->release_buffer(avctx, &s->frame);
256 }
257
258 s->frame.reference = 1;
259 if (!s->frame.data[0]) {
260 if (ff_get_buffer(avctx, &s->frame) < 0) {
261 av_log(avctx, AV_LOG_ERROR, "get_buffer() failed\n");
262 return -1;
263 }
264 }
265
266 av_fast_padded_malloc(&s->bitstream_buf, &s->bitstream_buf_size,
267 buf_end - buf);
268 if (!s->bitstream_buf)
269 return AVERROR(ENOMEM);
270 s->dsp.bswap16_buf(s->bitstream_buf, (const uint16_t*)buf, (buf_end-buf)/2);
271 init_get_bits(&s->gb, s->bitstream_buf, 8*(buf_end-buf));
272
273 for (s->mb_y=0; s->mb_y < (avctx->height+15)/16; s->mb_y++)
274 for (s->mb_x=0; s->mb_x < (avctx->width +15)/16; s->mb_x++)
275 decode_mb(s, inter);
276
277 *got_frame = 1;
278 *(AVFrame*)data = s->frame;
279
280 if (chunk_type != MADe_TAG)
281 FFSWAP(AVFrame, s->frame, s->last_frame);
282
283 return buf_size;
284 }
285
286 static av_cold int decode_end(AVCodecContext *avctx)
287 {
288 MadContext *t = avctx->priv_data;
289 if (t->frame.data[0])
290 avctx->release_buffer(avctx, &t->frame);
291 if (t->last_frame.data[0])
292 avctx->release_buffer(avctx, &t->last_frame);
293 av_free(t->bitstream_buf);
294 return 0;
295 }
296
297 AVCodec ff_eamad_decoder = {
298 .name = "eamad",
299 .type = AVMEDIA_TYPE_VIDEO,
300 .id = AV_CODEC_ID_MAD,
301 .priv_data_size = sizeof(MadContext),
302 .init = decode_init,
303 .close = decode_end,
304 .decode = decode_frame,
305 .capabilities = CODEC_CAP_DR1,
306 .long_name = NULL_IF_CONFIG_SMALL("Electronic Arts Madcow Video")
307 };