1/**
2 * @file libavcodec/vp5.c
3 * VP5 compatible video decoder
4 *
5 * Copyright (C) 2006  Aurelien Jacobs <aurel@gnuage.org>
6 *
7 * This file is part of FFmpeg.
8 *
9 * FFmpeg is free software; you can redistribute it and/or
10 * modify it under the terms of the GNU Lesser General Public
11 * License as published by the Free Software Foundation; either
12 * version 2.1 of the License, or (at your option) any later version.
13 *
14 * FFmpeg is distributed in the hope that it will be useful,
15 * but WITHOUT ANY WARRANTY; without even the implied warranty of
16 * MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE.  See the GNU
17 * Lesser General Public License for more details.
18 *
19 * You should have received a copy of the GNU Lesser General Public
20 * License along with FFmpeg; if not, write to the Free Software
21 * Foundation, Inc., 51 Franklin Street, Fifth Floor, Boston, MA 02110-1301 USA
22 */
23
24#include <stdlib.h>
25#include <string.h>
26
27#include "avcodec.h"
28#include "dsputil.h"
29#include "bitstream.h"
30
31#include "vp56.h"
32#include "vp56data.h"
33#include "vp5data.h"
34
35
36static int vp5_parse_header(VP56Context *s, const uint8_t *buf, int buf_size,
37                            int *golden_frame)
38{
39    VP56RangeCoder *c = &s->c;
40    int rows, cols;
41
42    vp56_init_range_decoder(&s->c, buf, buf_size);
43    s->framep[VP56_FRAME_CURRENT]->key_frame = !vp56_rac_get(c);
44    vp56_rac_get(c);
45    vp56_init_dequant(s, vp56_rac_gets(c, 6));
46    if (s->framep[VP56_FRAME_CURRENT]->key_frame)
47    {
48        vp56_rac_gets(c, 8);
49        if(vp56_rac_gets(c, 5) > 5)
50            return 0;
51        vp56_rac_gets(c, 2);
52        if (vp56_rac_get(c)) {
53            av_log(s->avctx, AV_LOG_ERROR, "interlacing not supported\n");
54            return 0;
55        }
56        rows = vp56_rac_gets(c, 8);  /* number of stored macroblock rows */
57        cols = vp56_rac_gets(c, 8);  /* number of stored macroblock cols */
58        vp56_rac_gets(c, 8);  /* number of displayed macroblock rows */
59        vp56_rac_gets(c, 8);  /* number of displayed macroblock cols */
60        vp56_rac_gets(c, 2);
61        if (!s->macroblocks || /* first frame */
62            16*cols != s->avctx->coded_width ||
63            16*rows != s->avctx->coded_height) {
64            avcodec_set_dimensions(s->avctx, 16*cols, 16*rows);
65            return 2;
66        }
67    } else if (!s->macroblocks)
68        return 0;
69    return 1;
70}
71
72/* Gives very similar result than the vp6 version except in a few cases */
73static int vp5_adjust(int v, int t)
74{
75    int s2, s1 = v >> 31;
76    v ^= s1;
77    v -= s1;
78    v *= v < 2*t;
79    v -= t;
80    s2 = v >> 31;
81    v ^= s2;
82    v -= s2;
83    v = t - v;
84    v += s1;
85    v ^= s1;
86    return v;
87}
88
89static void vp5_parse_vector_adjustment(VP56Context *s, VP56mv *vect)
90{
91    VP56RangeCoder *c = &s->c;
92    VP56Model *model = s->modelp;
93    int comp, di;
94
95    for (comp=0; comp<2; comp++) {
96        int delta = 0;
97        if (vp56_rac_get_prob(c, model->vector_dct[comp])) {
98            int sign = vp56_rac_get_prob(c, model->vector_sig[comp]);
99            di  = vp56_rac_get_prob(c, model->vector_pdi[comp][0]);
100            di |= vp56_rac_get_prob(c, model->vector_pdi[comp][1]) << 1;
101            delta = vp56_rac_get_tree(c, vp56_pva_tree,
102                                      model->vector_pdv[comp]);
103            delta = di | (delta << 2);
104            delta = (delta ^ -sign) + sign;
105        }
106        if (!comp)
107            vect->x = delta;
108        else
109            vect->y = delta;
110    }
111}
112
113static void vp5_parse_vector_models(VP56Context *s)
114{
115    VP56RangeCoder *c = &s->c;
116    VP56Model *model = s->modelp;
117    int comp, node;
118
119    for (comp=0; comp<2; comp++) {
120        if (vp56_rac_get_prob(c, vp5_vmc_pct[comp][0]))
121            model->vector_dct[comp] = vp56_rac_gets_nn(c, 7);
122        if (vp56_rac_get_prob(c, vp5_vmc_pct[comp][1]))
123            model->vector_sig[comp] = vp56_rac_gets_nn(c, 7);
124        if (vp56_rac_get_prob(c, vp5_vmc_pct[comp][2]))
125            model->vector_pdi[comp][0] = vp56_rac_gets_nn(c, 7);
126        if (vp56_rac_get_prob(c, vp5_vmc_pct[comp][3]))
127            model->vector_pdi[comp][1] = vp56_rac_gets_nn(c, 7);
128    }
129
130    for (comp=0; comp<2; comp++)
131        for (node=0; node<7; node++)
132            if (vp56_rac_get_prob(c, vp5_vmc_pct[comp][4 + node]))
133                model->vector_pdv[comp][node] = vp56_rac_gets_nn(c, 7);
134}
135
136static void vp5_parse_coeff_models(VP56Context *s)
137{
138    VP56RangeCoder *c = &s->c;
139    VP56Model *model = s->modelp;
140    uint8_t def_prob[11];
141    int node, cg, ctx;
142    int ct;    /* code type */
143    int pt;    /* plane type (0 for Y, 1 for U or V) */
144
145    memset(def_prob, 0x80, sizeof(def_prob));
146
147    for (pt=0; pt<2; pt++)
148        for (node=0; node<11; node++)
149            if (vp56_rac_get_prob(c, vp5_dccv_pct[pt][node])) {
150                def_prob[node] = vp56_rac_gets_nn(c, 7);
151                model->coeff_dccv[pt][node] = def_prob[node];
152            } else if (s->framep[VP56_FRAME_CURRENT]->key_frame) {
153                model->coeff_dccv[pt][node] = def_prob[node];
154            }
155
156    for (ct=0; ct<3; ct++)
157        for (pt=0; pt<2; pt++)
158            for (cg=0; cg<6; cg++)
159                for (node=0; node<11; node++)
160                    if (vp56_rac_get_prob(c, vp5_ract_pct[ct][pt][cg][node])) {
161                        def_prob[node] = vp56_rac_gets_nn(c, 7);
162                        model->coeff_ract[pt][ct][cg][node] = def_prob[node];
163                    } else if (s->framep[VP56_FRAME_CURRENT]->key_frame) {
164                        model->coeff_ract[pt][ct][cg][node] = def_prob[node];
165                    }
166
167    /* coeff_dcct is a linear combination of coeff_dccv */
168    for (pt=0; pt<2; pt++)
169        for (ctx=0; ctx<36; ctx++)
170            for (node=0; node<5; node++)
171                model->coeff_dcct[pt][ctx][node] = av_clip(((model->coeff_dccv[pt][node] * vp5_dccv_lc[node][ctx][0] + 128) >> 8) + vp5_dccv_lc[node][ctx][1], 1, 254);
172
173    /* coeff_acct is a linear combination of coeff_ract */
174    for (ct=0; ct<3; ct++)
175        for (pt=0; pt<2; pt++)
176            for (cg=0; cg<3; cg++)
177                for (ctx=0; ctx<6; ctx++)
178                    for (node=0; node<5; node++)
179                        model->coeff_acct[pt][ct][cg][ctx][node] = av_clip(((model->coeff_ract[pt][ct][cg][node] * vp5_ract_lc[ct][cg][node][ctx][0] + 128) >> 8) + vp5_ract_lc[ct][cg][node][ctx][1], 1, 254);
180}
181
182static void vp5_parse_coeff(VP56Context *s)
183{
184    VP56RangeCoder *c = &s->c;
185    VP56Model *model = s->modelp;
186    uint8_t *permute = s->scantable.permutated;
187    uint8_t *model1, *model2;
188    int coeff, sign, coeff_idx;
189    int b, i, cg, idx, ctx, ctx_last;
190    int pt = 0;    /* plane type (0 for Y, 1 for U or V) */
191
192    for (b=0; b<6; b++) {
193        int ct = 1;    /* code type */
194
195        if (b > 3) pt = 1;
196
197        ctx = 6*s->coeff_ctx[vp56_b6to4[b]][0]
198              + s->above_blocks[s->above_block_idx[b]].not_null_dc;
199        model1 = model->coeff_dccv[pt];
200        model2 = model->coeff_dcct[pt][ctx];
201
202        for (coeff_idx=0; coeff_idx<64; ) {
203            if (vp56_rac_get_prob(c, model2[0])) {
204                if (vp56_rac_get_prob(c, model2[2])) {
205                    if (vp56_rac_get_prob(c, model2[3])) {
206                        s->coeff_ctx[vp56_b6to4[b]][coeff_idx] = 4;
207                        idx = vp56_rac_get_tree(c, vp56_pc_tree, model1);
208                        sign = vp56_rac_get(c);
209                        coeff = vp56_coeff_bias[idx+5];
210                        for (i=vp56_coeff_bit_length[idx]; i>=0; i--)
211                            coeff += vp56_rac_get_prob(c, vp56_coeff_parse_table[idx][i]) << i;
212                    } else {
213                        if (vp56_rac_get_prob(c, model2[4])) {
214                            coeff = 3 + vp56_rac_get_prob(c, model1[5]);
215                            s->coeff_ctx[vp56_b6to4[b]][coeff_idx] = 3;
216                        } else {
217                            coeff = 2;
218                            s->coeff_ctx[vp56_b6to4[b]][coeff_idx] = 2;
219                        }
220                        sign = vp56_rac_get(c);
221                    }
222                    ct = 2;
223                } else {
224                    ct = 1;
225                    s->coeff_ctx[vp56_b6to4[b]][coeff_idx] = 1;
226                    sign = vp56_rac_get(c);
227                    coeff = 1;
228                }
229                coeff = (coeff ^ -sign) + sign;
230                if (coeff_idx)
231                    coeff *= s->dequant_ac;
232                s->block_coeff[b][permute[coeff_idx]] = coeff;
233            } else {
234                if (ct && !vp56_rac_get_prob(c, model2[1]))
235                    break;
236                ct = 0;
237                s->coeff_ctx[vp56_b6to4[b]][coeff_idx] = 0;
238            }
239
240            cg = vp5_coeff_groups[++coeff_idx];
241            ctx = s->coeff_ctx[vp56_b6to4[b]][coeff_idx];
242            model1 = model->coeff_ract[pt][ct][cg];
243            model2 = cg > 2 ? model1 : model->coeff_acct[pt][ct][cg][ctx];
244        }
245
246        ctx_last = FFMIN(s->coeff_ctx_last[vp56_b6to4[b]], 24);
247        s->coeff_ctx_last[vp56_b6to4[b]] = coeff_idx;
248        if (coeff_idx < ctx_last)
249            for (i=coeff_idx; i<=ctx_last; i++)
250                s->coeff_ctx[vp56_b6to4[b]][i] = 5;
251        s->above_blocks[s->above_block_idx[b]].not_null_dc = s->coeff_ctx[vp56_b6to4[b]][0];
252    }
253}
254
255static void vp5_default_models_init(VP56Context *s)
256{
257    VP56Model *model = s->modelp;
258    int i;
259
260    for (i=0; i<2; i++) {
261        model->vector_sig[i] = 0x80;
262        model->vector_dct[i] = 0x80;
263        model->vector_pdi[i][0] = 0x55;
264        model->vector_pdi[i][1] = 0x80;
265    }
266    memcpy(model->mb_types_stats, vp56_def_mb_types_stats, sizeof(model->mb_types_stats));
267    memset(model->vector_pdv, 0x80, sizeof(model->vector_pdv));
268}
269
270static av_cold int vp5_decode_init(AVCodecContext *avctx)
271{
272    VP56Context *s = avctx->priv_data;
273
274    vp56_init(avctx, 1, 0);
275    s->vp56_coord_div = vp5_coord_div;
276    s->parse_vector_adjustment = vp5_parse_vector_adjustment;
277    s->adjust = vp5_adjust;
278    s->parse_coeff = vp5_parse_coeff;
279    s->default_models_init = vp5_default_models_init;
280    s->parse_vector_models = vp5_parse_vector_models;
281    s->parse_coeff_models = vp5_parse_coeff_models;
282    s->parse_header = vp5_parse_header;
283
284    return 0;
285}
286
287AVCodec vp5_decoder = {
288    "vp5",
289    CODEC_TYPE_VIDEO,
290    CODEC_ID_VP5,
291    sizeof(VP56Context),
292    vp5_decode_init,
293    NULL,
294    vp56_free,
295    vp56_decode_frame,
296    CODEC_CAP_DR1,
297    .long_name = NULL_IF_CONFIG_SMALL("On2 VP5"),
298};
299