3 * VP5 compatible video decoder
5 * Copyright (C) 2006 Aurelien Jacobs <aurel@gnuage.org>
7 * This file is part of FFmpeg.
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.
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.
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 St, Fifth Floor, Boston, MA 02110-1301 USA
29 #include "bitstream.h"
30 #include "mpegvideo.h"
37 static int vp5_parse_header(vp56_context_t *s, uint8_t *buf, int buf_size,
40 vp56_range_coder_t *c = &s->c;
43 vp56_init_range_decoder(&s->c, buf, buf_size);
44 s->frames[VP56_FRAME_CURRENT].key_frame = !vp56_rac_get(c);
46 vp56_init_dequant(s, vp56_rac_gets(c, 6));
47 if (s->frames[VP56_FRAME_CURRENT].key_frame)
50 if(vp56_rac_gets(c, 5) > 5)
53 if (vp56_rac_get(c)) {
54 av_log(s->avctx, AV_LOG_ERROR, "interlacing not supported\n");
57 rows = vp56_rac_gets(c, 8); /* number of stored macroblock rows */
58 cols = vp56_rac_gets(c, 8); /* number of stored macroblock cols */
59 vp56_rac_gets(c, 8); /* number of displayed macroblock rows */
60 vp56_rac_gets(c, 8); /* number of displayed macroblock cols */
62 if (16*cols != s->avctx->coded_width ||
63 16*rows != s->avctx->coded_height) {
64 avcodec_set_dimensions(s->avctx, 16*cols, 16*rows);
71 /* Gives very similar result than the vp6 version except in a few cases */
72 static int vp5_adjust(int v, int t)
88 static void vp5_parse_vector_adjustment(vp56_context_t *s, vp56_mv_t *vect)
90 vp56_range_coder_t *c = &s->c;
93 for (comp=0; comp<2; comp++) {
95 if (vp56_rac_get_prob(c, s->vector_model_dct[comp])) {
96 int sign = vp56_rac_get_prob(c, s->vector_model_sig[comp]);
97 di = vp56_rac_get_prob(c, s->vector_model_pdi[comp][0]);
98 di |= vp56_rac_get_prob(c, s->vector_model_pdi[comp][1]) << 1;
99 delta = vp56_rac_get_tree(c, vp56_pva_tree,
100 s->vector_model_pdv[comp]);
101 delta = di | (delta << 2);
102 delta = (delta ^ -sign) + sign;
111 static void vp5_parse_vector_models(vp56_context_t *s)
113 vp56_range_coder_t *c = &s->c;
116 for (comp=0; comp<2; comp++) {
117 if (vp56_rac_get_prob(c, vp5_vmc_pct[comp][0]))
118 s->vector_model_dct[comp] = vp56_rac_gets_nn(c, 7);
119 if (vp56_rac_get_prob(c, vp5_vmc_pct[comp][1]))
120 s->vector_model_sig[comp] = vp56_rac_gets_nn(c, 7);
121 if (vp56_rac_get_prob(c, vp5_vmc_pct[comp][2]))
122 s->vector_model_pdi[comp][0] = vp56_rac_gets_nn(c, 7);
123 if (vp56_rac_get_prob(c, vp5_vmc_pct[comp][3]))
124 s->vector_model_pdi[comp][1] = vp56_rac_gets_nn(c, 7);
127 for (comp=0; comp<2; comp++)
128 for (node=0; node<7; node++)
129 if (vp56_rac_get_prob(c, vp5_vmc_pct[comp][4 + node]))
130 s->vector_model_pdv[comp][node] = vp56_rac_gets_nn(c, 7);
133 static void vp5_parse_coeff_models(vp56_context_t *s)
135 vp56_range_coder_t *c = &s->c;
136 uint8_t def_prob[11];
138 int ct; /* code type */
139 int pt; /* plane type (0 for Y, 1 for U or V) */
141 memset(def_prob, 0x80, sizeof(def_prob));
143 for (pt=0; pt<2; pt++)
144 for (node=0; node<11; node++)
145 if (vp56_rac_get_prob(c, vp5_dccv_pct[pt][node])) {
146 def_prob[node] = vp56_rac_gets_nn(c, 7);
147 s->coeff_model_dccv[pt][node] = def_prob[node];
148 } else if (s->frames[VP56_FRAME_CURRENT].key_frame) {
149 s->coeff_model_dccv[pt][node] = def_prob[node];
152 for (ct=0; ct<3; ct++)
153 for (pt=0; pt<2; pt++)
154 for (cg=0; cg<6; cg++)
155 for (node=0; node<11; node++)
156 if (vp56_rac_get_prob(c, vp5_ract_pct[ct][pt][cg][node])) {
157 def_prob[node] = vp56_rac_gets_nn(c, 7);
158 s->coeff_model_ract[pt][ct][cg][node] = def_prob[node];
159 } else if (s->frames[VP56_FRAME_CURRENT].key_frame) {
160 s->coeff_model_ract[pt][ct][cg][node] = def_prob[node];
163 /* coeff_model_dcct is a linear combination of coeff_model_dccv */
164 for (pt=0; pt<2; pt++)
165 for (ctx=0; ctx<36; ctx++)
166 for (node=0; node<5; node++)
167 s->coeff_model_dcct[pt][ctx][node] = clip(((s->coeff_model_dccv[pt][node] * vp5_dccv_lc[node][ctx][0] + 128) >> 8) + vp5_dccv_lc[node][ctx][1], 1, 254);
169 /* coeff_model_acct is a linear combination of coeff_model_ract */
170 for (ct=0; ct<3; ct++)
171 for (pt=0; pt<2; pt++)
172 for (cg=0; cg<3; cg++)
173 for (ctx=0; ctx<6; ctx++)
174 for (node=0; node<5; node++)
175 s->coeff_model_acct[pt][ct][cg][ctx][node] = clip(((s->coeff_model_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);
178 static void vp5_parse_coeff(vp56_context_t *s)
180 vp56_range_coder_t *c = &s->c;
181 uint8_t *permute = s->scantable.permutated;
182 uint8_t *model, *model2;
183 int coeff, sign, coeff_idx;
184 int b, i, cg, idx, ctx, ctx_last;
185 int pt = 0; /* plane type (0 for Y, 1 for U or V) */
187 for (b=0; b<6; b++) {
188 int ct = 1; /* code type */
192 ctx = 6*s->coeff_ctx[vp56_b6to4[b]][0]
193 + s->above_blocks[s->above_block_idx[b]].not_null_dc;
194 model = s->coeff_model_dccv[pt];
195 model2 = s->coeff_model_dcct[pt][ctx];
197 for (coeff_idx=0; coeff_idx<64; ) {
198 if (vp56_rac_get_prob(c, model2[0])) {
199 if (vp56_rac_get_prob(c, model2[2])) {
200 if (vp56_rac_get_prob(c, model2[3])) {
201 s->coeff_ctx[vp56_b6to4[b]][coeff_idx] = 4;
202 idx = vp56_rac_get_tree(c, vp56_pc_tree, model);
203 sign = vp56_rac_get(c);
204 coeff = vp56_coeff_bias[idx];
205 for (i=vp56_coeff_bit_length[idx]; i>=0; i--)
206 coeff += vp56_rac_get_prob(c, vp56_coeff_parse_table[idx][i]) << i;
208 if (vp56_rac_get_prob(c, model2[4])) {
209 coeff = 3 + vp56_rac_get_prob(c, model[5]);
210 s->coeff_ctx[vp56_b6to4[b]][coeff_idx] = 3;
213 s->coeff_ctx[vp56_b6to4[b]][coeff_idx] = 2;
215 sign = vp56_rac_get(c);
220 s->coeff_ctx[vp56_b6to4[b]][coeff_idx] = 1;
221 sign = vp56_rac_get(c);
224 coeff = (coeff ^ -sign) + sign;
226 coeff *= s->dequant_ac;
227 s->block_coeff[b][permute[coeff_idx]] = coeff;
229 if (ct && !vp56_rac_get_prob(c, model2[1]))
232 s->coeff_ctx[vp56_b6to4[b]][coeff_idx] = 0;
235 cg = vp5_coeff_groups[++coeff_idx];
236 ctx = s->coeff_ctx[vp56_b6to4[b]][coeff_idx];
237 model = s->coeff_model_ract[pt][ct][cg];
238 model2 = cg > 2 ? model : s->coeff_model_acct[pt][ct][cg][ctx];
241 ctx_last = FFMIN(s->coeff_ctx_last[vp56_b6to4[b]], 24);
242 s->coeff_ctx_last[vp56_b6to4[b]] = coeff_idx;
243 if (coeff_idx < ctx_last)
244 for (i=coeff_idx; i<=ctx_last; i++)
245 s->coeff_ctx[vp56_b6to4[b]][i] = 5;
246 s->above_blocks[s->above_block_idx[b]].not_null_dc = s->coeff_ctx[vp56_b6to4[b]][0];
250 static void vp5_default_models_init(vp56_context_t *s)
254 for (i=0; i<2; i++) {
255 s->vector_model_sig[i] = 0x80;
256 s->vector_model_dct[i] = 0x80;
257 s->vector_model_pdi[i][0] = 0x55;
258 s->vector_model_pdi[i][1] = 0x80;
260 memcpy(s->mb_types_stats, vp56_def_mb_types_stats, sizeof(s->mb_types_stats));
261 memset(s->vector_model_pdv, 0x80, sizeof(s->vector_model_pdv));
264 static int vp5_decode_init(AVCodecContext *avctx)
266 vp56_context_t *s = avctx->priv_data;
268 vp56_init(s, avctx, 1);
269 s->vp56_coord_div = vp5_coord_div;
270 s->parse_vector_adjustment = vp5_parse_vector_adjustment;
271 s->adjust = vp5_adjust;
272 s->parse_coeff = vp5_parse_coeff;
273 s->default_models_init = vp5_default_models_init;
274 s->parse_vector_models = vp5_parse_vector_models;
275 s->parse_coeff_models = vp5_parse_coeff_models;
276 s->parse_header = vp5_parse_header;
281 AVCodec vp5_decoder = {
285 sizeof(vp56_context_t),