1 /*
2  * Copyright (C) 2006  Aurelien Jacobs <aurel@gnuage.org>
3  *
4  * This file is part of FFmpeg.
5  *
6  * FFmpeg is free software; you can redistribute it and/or
7  * modify it under the terms of the GNU Lesser General Public
8  * License as published by the Free Software Foundation; either
9  * version 2.1 of the License, or (at your option) any later version.
10  *
11  * FFmpeg is distributed in the hope that it will be useful,
12  * but WITHOUT ANY WARRANTY; without even the implied warranty of
13  * MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE.  See the GNU
14  * Lesser General Public License for more details.
15  *
16  * You should have received a copy of the GNU Lesser General Public
17  * License along with FFmpeg; if not, write to the Free Software
18  * Foundation, Inc., 51 Franklin Street, Fifth Floor, Boston, MA 02110-1301 USA
19  */
20 
21 /**
22  * @file
23  * VP6 compatible video decoder
24  *
25  * The VP6F decoder accepts an optional 1 byte extradata. It is composed of:
26  *  - upper 4 bits: difference between encoded width and visible width
27  *  - lower 4 bits: difference between encoded height and visible height
28  */
29 
30 #include <stdlib.h>
31 
32 #include "avcodec.h"
33 #include "codec_internal.h"
34 #include "get_bits.h"
35 #include "huffman.h"
36 #include "internal.h"
37 
38 #include "vp56.h"
39 #include "vp56data.h"
40 #include "vp6data.h"
41 
42 #define VP6_MAX_HUFF_SIZE 12
43 
44 static int vp6_parse_coeff(VP56Context *s);
45 static int vp6_parse_coeff_huffman(VP56Context *s);
46 
vp6_parse_header(VP56Context *s, const uint8_t *buf, int buf_size)47 static int vp6_parse_header(VP56Context *s, const uint8_t *buf, int buf_size)
48 {
49     VP56RangeCoder *c = &s->c;
50     int parse_filter_info = 0;
51     int coeff_offset = 0;
52     int vrt_shift = 0;
53     int sub_version;
54     int rows, cols;
55     int res = 0;
56     int ret;
57     int separated_coeff = buf[0] & 1;
58 
59     s->frames[VP56_FRAME_CURRENT]->key_frame = !(buf[0] & 0x80);
60     ff_vp56_init_dequant(s, (buf[0] >> 1) & 0x3F);
61 
62     if (s->frames[VP56_FRAME_CURRENT]->key_frame) {
63         sub_version = buf[1] >> 3;
64         if (sub_version > 8)
65             return AVERROR_INVALIDDATA;
66         s->filter_header = buf[1] & 0x06;
67         if (buf[1] & 1) {
68             avpriv_report_missing_feature(s->avctx, "Interlacing");
69             return AVERROR_PATCHWELCOME;
70         }
71         if (separated_coeff || !s->filter_header) {
72             coeff_offset = AV_RB16(buf+2) - 2;
73             buf += 2;
74             buf_size -= 2;
75         }
76 
77         rows = buf[2];  /* number of stored macroblock rows */
78         cols = buf[3];  /* number of stored macroblock cols */
79         /* buf[4] is number of displayed macroblock rows */
80         /* buf[5] is number of displayed macroblock cols */
81         if (!rows || !cols) {
82             av_log(s->avctx, AV_LOG_ERROR, "Invalid size %dx%d\n", cols << 4, rows << 4);
83             return AVERROR_INVALIDDATA;
84         }
85 
86         if (!s->macroblocks || /* first frame */
87             16*cols != s->avctx->coded_width ||
88             16*rows != s->avctx->coded_height) {
89             if (s->avctx->extradata_size == 0 &&
90                 FFALIGN(s->avctx->width,  16) == 16 * cols &&
91                 FFALIGN(s->avctx->height, 16) == 16 * rows) {
92                 // We assume this is properly signalled container cropping,
93                 // in an F4V file. Just set the coded_width/height, don't
94                 // touch the cropped ones.
95                 s->avctx->coded_width  = 16 * cols;
96                 s->avctx->coded_height = 16 * rows;
97             } else {
98                 ret = ff_set_dimensions(s->avctx, 16 * cols, 16 * rows);
99                 if (ret < 0)
100                     return ret;
101 
102                 if (s->avctx->extradata_size == 1) {
103                     s->avctx->width  -= s->avctx->extradata[0] >> 4;
104                     s->avctx->height -= s->avctx->extradata[0] & 0x0F;
105                 }
106             }
107             res = VP56_SIZE_CHANGE;
108         }
109 
110         ret = ff_vp56_init_range_decoder(c, buf+6, buf_size-6);
111         if (ret < 0)
112             goto fail;
113         vp56_rac_gets(c, 2);
114 
115         parse_filter_info = s->filter_header;
116         if (sub_version < 8)
117             vrt_shift = 5;
118         s->sub_version = sub_version;
119         s->golden_frame = 0;
120     } else {
121         if (!s->sub_version || !s->avctx->coded_width || !s->avctx->coded_height)
122             return AVERROR_INVALIDDATA;
123 
124         if (separated_coeff || !s->filter_header) {
125             coeff_offset = AV_RB16(buf+1) - 2;
126             buf += 2;
127             buf_size -= 2;
128         }
129         ret = ff_vp56_init_range_decoder(c, buf+1, buf_size-1);
130         if (ret < 0)
131             return ret;
132 
133         s->golden_frame = vp56_rac_get(c);
134         if (s->filter_header) {
135             s->deblock_filtering = vp56_rac_get(c);
136             if (s->deblock_filtering)
137                 vp56_rac_get(c);
138             if (s->sub_version > 7)
139                 parse_filter_info = vp56_rac_get(c);
140         }
141     }
142 
143     if (parse_filter_info) {
144         if (vp56_rac_get(c)) {
145             s->filter_mode = 2;
146             s->sample_variance_threshold = vp56_rac_gets(c, 5) << vrt_shift;
147             s->max_vector_length = 2 << vp56_rac_gets(c, 3);
148         } else if (vp56_rac_get(c)) {
149             s->filter_mode = 1;
150         } else {
151             s->filter_mode = 0;
152         }
153         if (s->sub_version > 7)
154             s->filter_selection = vp56_rac_gets(c, 4);
155         else
156             s->filter_selection = 16;
157     }
158 
159     s->use_huffman = vp56_rac_get(c);
160 
161     s->parse_coeff = vp6_parse_coeff;
162     if (coeff_offset) {
163         buf      += coeff_offset;
164         buf_size -= coeff_offset;
165         if (buf_size < 0) {
166             ret = AVERROR_INVALIDDATA;
167             goto fail;
168         }
169         if (s->use_huffman) {
170             s->parse_coeff = vp6_parse_coeff_huffman;
171             ret = init_get_bits8(&s->gb, buf, buf_size);
172             if (ret < 0)
173                 return ret;
174         } else {
175             ret = ff_vp56_init_range_decoder(&s->cc, buf, buf_size);
176             if (ret < 0)
177                 goto fail;
178             s->ccp = &s->cc;
179         }
180     } else {
181         s->ccp = &s->c;
182     }
183 
184     return res;
185 fail:
186     if (res == VP56_SIZE_CHANGE)
187         ff_set_dimensions(s->avctx, 0, 0);
188     return ret;
189 }
190 
vp6_coeff_order_table_init(VP56Context *s)191 static void vp6_coeff_order_table_init(VP56Context *s)
192 {
193     int i, pos, idx = 1;
194 
195     s->modelp->coeff_index_to_pos[0] = 0;
196     for (i=0; i<16; i++)
197         for (pos=1; pos<64; pos++)
198             if (s->modelp->coeff_reorder[pos] == i)
199                 s->modelp->coeff_index_to_pos[idx++] = pos;
200 
201     for (idx = 0; idx < 64; idx++) {
202         int max = 0;
203         for (i = 0; i <= idx; i++) {
204             int v = s->modelp->coeff_index_to_pos[i];
205             if (v > max)
206                 max = v;
207         }
208         if (s->sub_version > 6)
209             max++;
210         s->modelp->coeff_index_to_idct_selector[idx] = max;
211     }
212 }
213 
vp6_default_models_init(VP56Context *s)214 static void vp6_default_models_init(VP56Context *s)
215 {
216     VP56Model *model = s->modelp;
217 
218     model->vector_dct[0] = 0xA2;
219     model->vector_dct[1] = 0xA4;
220     model->vector_sig[0] = 0x80;
221     model->vector_sig[1] = 0x80;
222 
223     memcpy(model->mb_types_stats, ff_vp56_def_mb_types_stats, sizeof(model->mb_types_stats));
224     memcpy(model->vector_fdv, vp6_def_fdv_vector_model, sizeof(model->vector_fdv));
225     memcpy(model->vector_pdv, vp6_def_pdv_vector_model, sizeof(model->vector_pdv));
226     memcpy(model->coeff_runv, vp6_def_runv_coeff_model, sizeof(model->coeff_runv));
227     memcpy(model->coeff_reorder, vp6_def_coeff_reorder, sizeof(model->coeff_reorder));
228 
229     vp6_coeff_order_table_init(s);
230 }
231 
vp6_parse_vector_models(VP56Context *s)232 static void vp6_parse_vector_models(VP56Context *s)
233 {
234     VP56RangeCoder *c = &s->c;
235     VP56Model *model = s->modelp;
236     int comp, node;
237 
238     for (comp=0; comp<2; comp++) {
239         if (vp56_rac_get_prob_branchy(c, vp6_sig_dct_pct[comp][0]))
240             model->vector_dct[comp] = vp56_rac_gets_nn(c, 7);
241         if (vp56_rac_get_prob_branchy(c, vp6_sig_dct_pct[comp][1]))
242             model->vector_sig[comp] = vp56_rac_gets_nn(c, 7);
243     }
244 
245     for (comp=0; comp<2; comp++)
246         for (node=0; node<7; node++)
247             if (vp56_rac_get_prob_branchy(c, vp6_pdv_pct[comp][node]))
248                 model->vector_pdv[comp][node] = vp56_rac_gets_nn(c, 7);
249 
250     for (comp=0; comp<2; comp++)
251         for (node=0; node<8; node++)
252             if (vp56_rac_get_prob_branchy(c, vp6_fdv_pct[comp][node]))
253                 model->vector_fdv[comp][node] = vp56_rac_gets_nn(c, 7);
254 }
255 
256 /* nodes must ascend by count, but with descending symbol order */
vp6_huff_cmp(const void *va, const void *vb)257 static int vp6_huff_cmp(const void *va, const void *vb)
258 {
259     const Node *a = va, *b = vb;
260     return (a->count - b->count)*16 + (b->sym - a->sym);
261 }
262 
vp6_build_huff_tree(VP56Context *s, uint8_t coeff_model[], const uint8_t *map, unsigned size, VLC *vlc)263 static int vp6_build_huff_tree(VP56Context *s, uint8_t coeff_model[],
264                                const uint8_t *map, unsigned size, VLC *vlc)
265 {
266     Node nodes[2*VP6_MAX_HUFF_SIZE], *tmp = &nodes[size];
267     int a, b, i;
268 
269     /* first compute probabilities from model */
270     tmp[0].count = 256;
271     for (i=0; i<size-1; i++) {
272         a = tmp[i].count *        coeff_model[i]  >> 8;
273         b = tmp[i].count * (255 - coeff_model[i]) >> 8;
274         nodes[map[2*i  ]].count = a + !a;
275         nodes[map[2*i+1]].count = b + !b;
276     }
277 
278     ff_free_vlc(vlc);
279     /* then build the huffman tree according to probabilities */
280     return ff_huff_build_tree(s->avctx, vlc, size, FF_HUFFMAN_BITS,
281                               nodes, vp6_huff_cmp,
282                               FF_HUFFMAN_FLAG_HNODE_FIRST);
283 }
284 
vp6_parse_coeff_models(VP56Context *s)285 static int vp6_parse_coeff_models(VP56Context *s)
286 {
287     VP56RangeCoder *c = &s->c;
288     VP56Model *model = s->modelp;
289     int def_prob[11];
290     int node, cg, ctx, pos;
291     int ct;    /* code type */
292     int pt;    /* plane type (0 for Y, 1 for U or V) */
293 
294     memset(def_prob, 0x80, sizeof(def_prob));
295 
296     for (pt=0; pt<2; pt++)
297         for (node=0; node<11; node++)
298             if (vp56_rac_get_prob_branchy(c, vp6_dccv_pct[pt][node])) {
299                 def_prob[node] = vp56_rac_gets_nn(c, 7);
300                 model->coeff_dccv[pt][node] = def_prob[node];
301             } else if (s->frames[VP56_FRAME_CURRENT]->key_frame) {
302                 model->coeff_dccv[pt][node] = def_prob[node];
303             }
304 
305     if (vp56_rac_get(c)) {
306         for (pos=1; pos<64; pos++)
307             if (vp56_rac_get_prob_branchy(c, vp6_coeff_reorder_pct[pos]))
308                 model->coeff_reorder[pos] = vp56_rac_gets(c, 4);
309         vp6_coeff_order_table_init(s);
310     }
311 
312     for (cg=0; cg<2; cg++)
313         for (node=0; node<14; node++)
314             if (vp56_rac_get_prob_branchy(c, vp6_runv_pct[cg][node]))
315                 model->coeff_runv[cg][node] = vp56_rac_gets_nn(c, 7);
316 
317     for (ct=0; ct<3; ct++)
318         for (pt=0; pt<2; pt++)
319             for (cg=0; cg<6; cg++)
320                 for (node=0; node<11; node++)
321                     if (vp56_rac_get_prob_branchy(c, vp6_ract_pct[ct][pt][cg][node])) {
322                         def_prob[node] = vp56_rac_gets_nn(c, 7);
323                         model->coeff_ract[pt][ct][cg][node] = def_prob[node];
324                     } else if (s->frames[VP56_FRAME_CURRENT]->key_frame) {
325                         model->coeff_ract[pt][ct][cg][node] = def_prob[node];
326                     }
327 
328     if (s->use_huffman) {
329         for (pt=0; pt<2; pt++) {
330             if (vp6_build_huff_tree(s, model->coeff_dccv[pt],
331                                     vp6_huff_coeff_map, 12, &s->dccv_vlc[pt]))
332                 return -1;
333             if (vp6_build_huff_tree(s, model->coeff_runv[pt],
334                                     vp6_huff_run_map, 9, &s->runv_vlc[pt]))
335                 return -1;
336             for (ct=0; ct<3; ct++)
337                 for (cg = 0; cg < 6; cg++)
338                     if (vp6_build_huff_tree(s, model->coeff_ract[pt][ct][cg],
339                                             vp6_huff_coeff_map, 12,
340                                             &s->ract_vlc[pt][ct][cg]))
341                         return -1;
342         }
343         memset(s->nb_null, 0, sizeof(s->nb_null));
344     } else {
345     /* coeff_dcct is a linear combination of coeff_dccv */
346     for (pt=0; pt<2; pt++)
347         for (ctx=0; ctx<3; ctx++)
348             for (node=0; node<5; node++)
349                 model->coeff_dcct[pt][ctx][node] = av_clip(((model->coeff_dccv[pt][node] * vp6_dccv_lc[ctx][node][0] + 128) >> 8) + vp6_dccv_lc[ctx][node][1], 1, 255);
350     }
351     return 0;
352 }
353 
vp6_parse_vector_adjustment(VP56Context *s, VP56mv *vect)354 static void vp6_parse_vector_adjustment(VP56Context *s, VP56mv *vect)
355 {
356     VP56RangeCoder *c = &s->c;
357     VP56Model *model = s->modelp;
358     int comp;
359 
360     *vect = (VP56mv) {0,0};
361     if (s->vector_candidate_pos < 2)
362         *vect = s->vector_candidate[0];
363 
364     for (comp=0; comp<2; comp++) {
365         int i, delta = 0;
366 
367         if (vp56_rac_get_prob_branchy(c, model->vector_dct[comp])) {
368             static const uint8_t prob_order[] = {0, 1, 2, 7, 6, 5, 4};
369             for (i=0; i<sizeof(prob_order); i++) {
370                 int j = prob_order[i];
371                 delta |= vp56_rac_get_prob(c, model->vector_fdv[comp][j])<<j;
372             }
373             if (delta & 0xF0)
374                 delta |= vp56_rac_get_prob(c, model->vector_fdv[comp][3])<<3;
375             else
376                 delta |= 8;
377         } else {
378             delta = vp56_rac_get_tree(c, ff_vp56_pva_tree,
379                                       model->vector_pdv[comp]);
380         }
381 
382         if (delta && vp56_rac_get_prob_branchy(c, model->vector_sig[comp]))
383             delta = -delta;
384 
385         if (!comp)
386             vect->x += delta;
387         else
388             vect->y += delta;
389     }
390 }
391 
392 /**
393  * Read number of consecutive blocks with null DC or AC.
394  * This value is < 74.
395  */
vp6_get_nb_null(VP56Context *s)396 static unsigned vp6_get_nb_null(VP56Context *s)
397 {
398     unsigned val = get_bits(&s->gb, 2);
399     if (val == 2)
400         val += get_bits(&s->gb, 2);
401     else if (val == 3) {
402         val = get_bits1(&s->gb) << 2;
403         val = 6+val + get_bits(&s->gb, 2+val);
404     }
405     return val;
406 }
407 
vp6_parse_coeff_huffman(VP56Context *s)408 static int vp6_parse_coeff_huffman(VP56Context *s)
409 {
410     VP56Model *model = s->modelp;
411     uint8_t *permute = s->idct_scantable;
412     VLC *vlc_coeff;
413     int coeff, sign, coeff_idx;
414     int b, cg, idx;
415     int pt = 0;    /* plane type (0 for Y, 1 for U or V) */
416 
417     for (b=0; b<6; b++) {
418         int ct = 0;    /* code type */
419         if (b > 3) pt = 1;
420         vlc_coeff = &s->dccv_vlc[pt];
421 
422         for (coeff_idx = 0;;) {
423             int run = 1;
424             if (coeff_idx<2 && s->nb_null[coeff_idx][pt]) {
425                 s->nb_null[coeff_idx][pt]--;
426                 if (coeff_idx)
427                     break;
428             } else {
429                 if (get_bits_left(&s->gb) <= 0)
430                     return AVERROR_INVALIDDATA;
431                 coeff = get_vlc2(&s->gb, vlc_coeff->table, FF_HUFFMAN_BITS, 3);
432                 if (coeff == 0) {
433                     if (coeff_idx) {
434                         int pt = (coeff_idx >= 6);
435                         run += get_vlc2(&s->gb, s->runv_vlc[pt].table, FF_HUFFMAN_BITS, 3);
436                         if (run >= 9)
437                             run += get_bits(&s->gb, 6);
438                     } else
439                         s->nb_null[0][pt] = vp6_get_nb_null(s);
440                     ct = 0;
441                 } else if (coeff == 11) {  /* end of block */
442                     if (coeff_idx == 1)    /* first AC coeff ? */
443                         s->nb_null[1][pt] = vp6_get_nb_null(s);
444                     break;
445                 } else {
446                     int coeff2 = ff_vp56_coeff_bias[coeff];
447                     if (coeff > 4)
448                         coeff2 += get_bits(&s->gb, coeff <= 9 ? coeff - 4 : 11);
449                     ct = 1 + (coeff2 > 1);
450                     sign = get_bits1(&s->gb);
451                     coeff2 = (coeff2 ^ -sign) + sign;
452                     if (coeff_idx)
453                         coeff2 *= s->dequant_ac;
454                     idx = model->coeff_index_to_pos[coeff_idx];
455                     s->block_coeff[b][permute[idx]] = coeff2;
456                 }
457             }
458             coeff_idx+=run;
459             if (coeff_idx >= 64)
460                 break;
461             cg = FFMIN(vp6_coeff_groups[coeff_idx], 3);
462             vlc_coeff = &s->ract_vlc[pt][ct][cg];
463         }
464         s->idct_selector[b] = model->coeff_index_to_idct_selector[FFMIN(coeff_idx, 63)];
465     }
466     return 0;
467 }
468 
vp6_parse_coeff(VP56Context *s)469 static int vp6_parse_coeff(VP56Context *s)
470 {
471     VP56RangeCoder *c = s->ccp;
472     VP56Model *model = s->modelp;
473     uint8_t *permute = s->idct_scantable;
474     uint8_t *model1, *model2, *model3;
475     int coeff, sign, coeff_idx;
476     int b, i, cg, idx, ctx;
477     int pt = 0;    /* plane type (0 for Y, 1 for U or V) */
478 
479     if (vpX_rac_is_end(c)) {
480         av_log(s->avctx, AV_LOG_ERROR, "End of AC stream reached in vp6_parse_coeff\n");
481         return AVERROR_INVALIDDATA;
482     }
483 
484     for (b=0; b<6; b++) {
485         int ct = 1;    /* code type */
486         int run = 1;
487 
488         if (b > 3) pt = 1;
489 
490         ctx = s->left_block[ff_vp56_b6to4[b]].not_null_dc
491               + s->above_blocks[s->above_block_idx[b]].not_null_dc;
492         model1 = model->coeff_dccv[pt];
493         model2 = model->coeff_dcct[pt][ctx];
494 
495         coeff_idx = 0;
496         for (;;) {
497             if ((coeff_idx>1 && ct==0) || vp56_rac_get_prob_branchy(c, model2[0])) {
498                 /* parse a coeff */
499                 if (vp56_rac_get_prob_branchy(c, model2[2])) {
500                     if (vp56_rac_get_prob_branchy(c, model2[3])) {
501                         idx = vp56_rac_get_tree(c, ff_vp56_pc_tree, model1);
502                         coeff = ff_vp56_coeff_bias[idx+5];
503                         for (i=ff_vp56_coeff_bit_length[idx]; i>=0; i--)
504                             coeff += vp56_rac_get_prob(c, ff_vp56_coeff_parse_table[idx][i]) << i;
505                     } else {
506                         if (vp56_rac_get_prob_branchy(c, model2[4]))
507                             coeff = 3 + vp56_rac_get_prob(c, model1[5]);
508                         else
509                             coeff = 2;
510                     }
511                     ct = 2;
512                 } else {
513                     ct = 1;
514                     coeff = 1;
515                 }
516                 sign = vp56_rac_get(c);
517                 coeff = (coeff ^ -sign) + sign;
518                 if (coeff_idx)
519                     coeff *= s->dequant_ac;
520                 idx = model->coeff_index_to_pos[coeff_idx];
521                 s->block_coeff[b][permute[idx]] = coeff;
522                 run = 1;
523             } else {
524                 /* parse a run */
525                 ct = 0;
526                 if (coeff_idx > 0) {
527                     if (!vp56_rac_get_prob_branchy(c, model2[1]))
528                         break;
529 
530                     model3 = model->coeff_runv[coeff_idx >= 6];
531                     run = vp56_rac_get_tree(c, vp6_pcr_tree, model3);
532                     if (!run)
533                         for (run=9, i=0; i<6; i++)
534                             run += vp56_rac_get_prob(c, model3[i+8]) << i;
535                 }
536             }
537             coeff_idx += run;
538             if (coeff_idx >= 64)
539                 break;
540             cg = vp6_coeff_groups[coeff_idx];
541             model1 = model2 = model->coeff_ract[pt][ct][cg];
542         }
543 
544         s->left_block[ff_vp56_b6to4[b]].not_null_dc =
545         s->above_blocks[s->above_block_idx[b]].not_null_dc = !!s->block_coeff[b][0];
546         s->idct_selector[b] = model->coeff_index_to_idct_selector[FFMIN(coeff_idx, 63)];
547     }
548     return 0;
549 }
550 
vp6_block_variance(uint8_t *src, ptrdiff_t stride)551 static int vp6_block_variance(uint8_t *src, ptrdiff_t stride)
552 {
553     int sum = 0, square_sum = 0;
554     int y, x;
555 
556     for (y=0; y<8; y+=2) {
557         for (x=0; x<8; x+=2) {
558             sum += src[x];
559             square_sum += src[x]*src[x];
560         }
561         src += 2*stride;
562     }
563     return (16*square_sum - sum*sum) >> 8;
564 }
565 
vp6_filter_hv4(uint8_t *dst, uint8_t *src, ptrdiff_t stride, int delta, const int16_t *weights)566 static void vp6_filter_hv4(uint8_t *dst, uint8_t *src, ptrdiff_t stride,
567                            int delta, const int16_t *weights)
568 {
569     int x, y;
570 
571     for (y=0; y<8; y++) {
572         for (x=0; x<8; x++) {
573             dst[x] = av_clip_uint8((  src[x-delta  ] * weights[0]
574                                  + src[x        ] * weights[1]
575                                  + src[x+delta  ] * weights[2]
576                                  + src[x+2*delta] * weights[3] + 64) >> 7);
577         }
578         src += stride;
579         dst += stride;
580     }
581 }
582 
vp6_filter_diag2(VP56Context *s, uint8_t *dst, uint8_t *src, ptrdiff_t stride, int h_weight, int v_weight)583 static void vp6_filter_diag2(VP56Context *s, uint8_t *dst, uint8_t *src,
584                              ptrdiff_t stride, int h_weight, int v_weight)
585 {
586     uint8_t *tmp = s->edge_emu_buffer+16;
587     s->h264chroma.put_h264_chroma_pixels_tab[0](tmp, src, stride, 9, h_weight, 0);
588     s->h264chroma.put_h264_chroma_pixels_tab[0](dst, tmp, stride, 8, 0, v_weight);
589 }
590 
vp6_filter(VP56Context *s, uint8_t *dst, uint8_t *src, int offset1, int offset2, ptrdiff_t stride, VP56mv mv, int mask, int select, int luma)591 static void vp6_filter(VP56Context *s, uint8_t *dst, uint8_t *src,
592                        int offset1, int offset2, ptrdiff_t stride,
593                        VP56mv mv, int mask, int select, int luma)
594 {
595     int filter4 = 0;
596     int x8 = mv.x & mask;
597     int y8 = mv.y & mask;
598 
599     if (luma) {
600         x8 *= 2;
601         y8 *= 2;
602         filter4 = s->filter_mode;
603         if (filter4 == 2) {
604             if (s->max_vector_length &&
605                 (FFABS(mv.x) > s->max_vector_length ||
606                  FFABS(mv.y) > s->max_vector_length)) {
607                 filter4 = 0;
608             } else if (s->sample_variance_threshold
609                        && (vp6_block_variance(src+offset1, stride)
610                            < s->sample_variance_threshold)) {
611                 filter4 = 0;
612             }
613         }
614     }
615 
616     if ((y8 && (offset2-offset1)*s->flip<0) || (!y8 && offset1 > offset2)) {
617         offset1 = offset2;
618     }
619 
620     if (filter4) {
621         if (!y8) {                      /* left or right combine */
622             vp6_filter_hv4(dst, src+offset1, stride, 1,
623                            vp6_block_copy_filter[select][x8]);
624         } else if (!x8) {               /* above or below combine */
625             vp6_filter_hv4(dst, src+offset1, stride, stride,
626                            vp6_block_copy_filter[select][y8]);
627         } else {
628             s->vp56dsp.vp6_filter_diag4(dst, src+offset1+((mv.x^mv.y)>>31), stride,
629                              vp6_block_copy_filter[select][x8],
630                              vp6_block_copy_filter[select][y8]);
631         }
632     } else {
633         if (!x8 || !y8) {
634             s->h264chroma.put_h264_chroma_pixels_tab[0](dst, src + offset1, stride, 8, x8, y8);
635         } else {
636             vp6_filter_diag2(s, dst, src+offset1 + ((mv.x^mv.y)>>31), stride, x8, y8);
637         }
638     }
639 }
640 
vp6_decode_init_context(AVCodecContext *avctx, VP56Context *s, int flip, int has_alpha)641 static av_cold int vp6_decode_init_context(AVCodecContext *avctx,
642                                            VP56Context *s, int flip, int has_alpha)
643 {
644     int ret = ff_vp56_init_context(avctx, s, flip, has_alpha);
645     if (ret < 0)
646         return ret;
647 
648     ff_vp6dsp_init(&s->vp56dsp);
649 
650     s->deblock_filtering = 0;
651     s->vp56_coord_div = vp6_coord_div;
652     s->parse_vector_adjustment = vp6_parse_vector_adjustment;
653     s->filter = vp6_filter;
654     s->default_models_init = vp6_default_models_init;
655     s->parse_vector_models = vp6_parse_vector_models;
656     s->parse_coeff_models = vp6_parse_coeff_models;
657     s->parse_header = vp6_parse_header;
658 
659     return 0;
660 }
661 
vp6_decode_init(AVCodecContext *avctx)662 static av_cold int vp6_decode_init(AVCodecContext *avctx)
663 {
664     VP56Context *s = avctx->priv_data;
665     int ret;
666 
667     ret = vp6_decode_init_context(avctx, s, avctx->codec_id == AV_CODEC_ID_VP6,
668                                   avctx->codec_id == AV_CODEC_ID_VP6A);
669     if (ret < 0)
670         return ret;
671 
672     if (s->has_alpha) {
673         /* Can only happen for ff_vp6a_decoder */
674         s->alpha_context = &s[1];
675         ret = vp6_decode_init_context(avctx, s->alpha_context,
676                                       s->flip == -1, s->has_alpha);
677         if (ret < 0)
678             return ret;
679     }
680 
681     return 0;
682 }
683 
684 static av_cold void vp6_decode_free_context(VP56Context *s);
685 
vp6_decode_free(AVCodecContext *avctx)686 static av_cold int vp6_decode_free(AVCodecContext *avctx)
687 {
688     VP56Context *s = avctx->priv_data;
689 
690     vp6_decode_free_context(s);
691 
692     if (s->alpha_context) {
693         vp6_decode_free_context(s->alpha_context);
694         s->alpha_context = NULL;
695     }
696 
697     return 0;
698 }
699 
vp6_decode_free_context(VP56Context *s)700 static av_cold void vp6_decode_free_context(VP56Context *s)
701 {
702     int pt, ct, cg;
703 
704     ff_vp56_free_context(s);
705 
706     for (pt=0; pt<2; pt++) {
707         ff_free_vlc(&s->dccv_vlc[pt]);
708         ff_free_vlc(&s->runv_vlc[pt]);
709         for (ct=0; ct<3; ct++)
710             for (cg=0; cg<6; cg++)
711                 ff_free_vlc(&s->ract_vlc[pt][ct][cg]);
712     }
713 }
714 
715 const FFCodec ff_vp6_decoder = {
716     .p.name         = "vp6",
717     .p.long_name    = NULL_IF_CONFIG_SMALL("On2 VP6"),
718     .p.type         = AVMEDIA_TYPE_VIDEO,
719     .p.id           = AV_CODEC_ID_VP6,
720     .priv_data_size = sizeof(VP56Context),
721     .init           = vp6_decode_init,
722     .close          = vp6_decode_free,
723     FF_CODEC_DECODE_CB(ff_vp56_decode_frame),
724     .p.capabilities = AV_CODEC_CAP_DR1,
725     .caps_internal  = FF_CODEC_CAP_INIT_THREADSAFE | FF_CODEC_CAP_INIT_CLEANUP,
726 };
727 
728 /* flash version, not flipped upside-down */
729 const FFCodec ff_vp6f_decoder = {
730     .p.name         = "vp6f",
731     .p.long_name    = NULL_IF_CONFIG_SMALL("On2 VP6 (Flash version)"),
732     .p.type         = AVMEDIA_TYPE_VIDEO,
733     .p.id           = AV_CODEC_ID_VP6F,
734     .priv_data_size = sizeof(VP56Context),
735     .init           = vp6_decode_init,
736     .close          = vp6_decode_free,
737     FF_CODEC_DECODE_CB(ff_vp56_decode_frame),
738     .p.capabilities = AV_CODEC_CAP_DR1,
739     .caps_internal  = FF_CODEC_CAP_INIT_THREADSAFE | FF_CODEC_CAP_INIT_CLEANUP,
740 };
741 
742 /* flash version, not flipped upside-down, with alpha channel */
743 const FFCodec ff_vp6a_decoder = {
744     .p.name         = "vp6a",
745     .p.long_name    = NULL_IF_CONFIG_SMALL("On2 VP6 (Flash version, with alpha channel)"),
746     .p.type         = AVMEDIA_TYPE_VIDEO,
747     .p.id           = AV_CODEC_ID_VP6A,
748     .priv_data_size = 2 /* Main context + alpha context */ * sizeof(VP56Context),
749     .init           = vp6_decode_init,
750     .close          = vp6_decode_free,
751     FF_CODEC_DECODE_CB(ff_vp56_decode_frame),
752     .p.capabilities = AV_CODEC_CAP_DR1 | AV_CODEC_CAP_SLICE_THREADS,
753     .caps_internal  = FF_CODEC_CAP_INIT_THREADSAFE | FF_CODEC_CAP_INIT_CLEANUP,
754 };
755