3 * VP6 compatible video decoder
5 * Copyright (C) 2006 Aurelien Jacobs <aurel@gnuage.org>
7 * The VP6F decoder accepts an optional 1 byte extradata. It is composed of:
8 * - upper 4bits: difference between encoded width and visible width
9 * - lower 4bits: difference between encoded height and visible height
11 * This file is part of FFmpeg.
13 * FFmpeg is free software; you can redistribute it and/or
14 * modify it under the terms of the GNU Lesser General Public
15 * License as published by the Free Software Foundation; either
16 * version 2.1 of the License, or (at your option) any later version.
18 * FFmpeg is distributed in the hope that it will be useful,
19 * but WITHOUT ANY WARRANTY; without even the implied warranty of
20 * MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE. See the GNU
21 * Lesser General Public License for more details.
23 * You should have received a copy of the GNU Lesser General Public
24 * License along with FFmpeg; if not, write to the Free Software
25 * Foundation, Inc., 51 Franklin Street, Fifth Floor, Boston, MA 02110-1301 USA
40 static void vp6_parse_coeff(VP56Context *s);
41 static void vp6_parse_coeff_huffman(VP56Context *s);
43 static int vp6_parse_header(VP56Context *s, const uint8_t *buf, int buf_size,
46 VP56RangeCoder *c = &s->c;
47 int parse_filter_info = 0;
53 int separated_coeff = buf[0] & 1;
55 s->framep[VP56_FRAME_CURRENT]->key_frame = !(buf[0] & 0x80);
56 vp56_init_dequant(s, (buf[0] >> 1) & 0x3F);
58 if (s->framep[VP56_FRAME_CURRENT]->key_frame) {
59 sub_version = buf[1] >> 3;
62 s->filter_header = buf[1] & 0x06;
64 av_log(s->avctx, AV_LOG_ERROR, "interlacing not supported\n");
67 if (separated_coeff || !s->filter_header) {
68 coeff_offset = AV_RB16(buf+2) - 2;
73 rows = buf[2]; /* number of stored macroblock rows */
74 cols = buf[3]; /* number of stored macroblock cols */
75 /* buf[4] is number of displayed macroblock rows */
76 /* buf[5] is number of displayed macroblock cols */
78 if (!s->macroblocks || /* first frame */
79 16*cols != s->avctx->coded_width ||
80 16*rows != s->avctx->coded_height) {
81 avcodec_set_dimensions(s->avctx, 16*cols, 16*rows);
82 if (s->avctx->extradata_size == 1) {
83 s->avctx->width -= s->avctx->extradata[0] >> 4;
84 s->avctx->height -= s->avctx->extradata[0] & 0x0F;
89 vp56_init_range_decoder(c, buf+6, buf_size-6);
92 parse_filter_info = s->filter_header;
95 s->sub_version = sub_version;
100 if (separated_coeff || !s->filter_header) {
101 coeff_offset = AV_RB16(buf+1) - 2;
105 vp56_init_range_decoder(c, buf+1, buf_size-1);
107 *golden_frame = vp56_rac_get(c);
108 if (s->filter_header) {
109 s->deblock_filtering = vp56_rac_get(c);
110 if (s->deblock_filtering)
112 if (s->sub_version > 7)
113 parse_filter_info = vp56_rac_get(c);
117 if (parse_filter_info) {
118 if (vp56_rac_get(c)) {
120 s->sample_variance_threshold = vp56_rac_gets(c, 5) << vrt_shift;
121 s->max_vector_length = 2 << vp56_rac_gets(c, 3);
122 } else if (vp56_rac_get(c)) {
127 if (s->sub_version > 7)
128 s->filter_selection = vp56_rac_gets(c, 4);
130 s->filter_selection = 16;
133 s->use_huffman = vp56_rac_get(c);
135 s->parse_coeff = vp6_parse_coeff;
138 buf_size -= coeff_offset;
141 if (s->use_huffman) {
142 s->parse_coeff = vp6_parse_coeff_huffman;
143 init_get_bits(&s->gb, buf, buf_size<<3);
145 vp56_init_range_decoder(&s->cc, buf, buf_size);
155 static void vp6_coeff_order_table_init(VP56Context *s)
159 s->modelp->coeff_index_to_pos[0] = 0;
161 for (pos=1; pos<64; pos++)
162 if (s->modelp->coeff_reorder[pos] == i)
163 s->modelp->coeff_index_to_pos[idx++] = pos;
166 static void vp6_default_models_init(VP56Context *s)
168 VP56Model *model = s->modelp;
170 model->vector_dct[0] = 0xA2;
171 model->vector_dct[1] = 0xA4;
172 model->vector_sig[0] = 0x80;
173 model->vector_sig[1] = 0x80;
175 memcpy(model->mb_types_stats, vp56_def_mb_types_stats, sizeof(model->mb_types_stats));
176 memcpy(model->vector_fdv, vp6_def_fdv_vector_model, sizeof(model->vector_fdv));
177 memcpy(model->vector_pdv, vp6_def_pdv_vector_model, sizeof(model->vector_pdv));
178 memcpy(model->coeff_runv, vp6_def_runv_coeff_model, sizeof(model->coeff_runv));
179 memcpy(model->coeff_reorder, vp6_def_coeff_reorder, sizeof(model->coeff_reorder));
181 vp6_coeff_order_table_init(s);
184 static void vp6_parse_vector_models(VP56Context *s)
186 VP56RangeCoder *c = &s->c;
187 VP56Model *model = s->modelp;
190 for (comp=0; comp<2; comp++) {
191 if (vp56_rac_get_prob(c, vp6_sig_dct_pct[comp][0]))
192 model->vector_dct[comp] = vp56_rac_gets_nn(c, 7);
193 if (vp56_rac_get_prob(c, vp6_sig_dct_pct[comp][1]))
194 model->vector_sig[comp] = vp56_rac_gets_nn(c, 7);
197 for (comp=0; comp<2; comp++)
198 for (node=0; node<7; node++)
199 if (vp56_rac_get_prob(c, vp6_pdv_pct[comp][node]))
200 model->vector_pdv[comp][node] = vp56_rac_gets_nn(c, 7);
202 for (comp=0; comp<2; comp++)
203 for (node=0; node<8; node++)
204 if (vp56_rac_get_prob(c, vp6_fdv_pct[comp][node]))
205 model->vector_fdv[comp][node] = vp56_rac_gets_nn(c, 7);
208 /* nodes must ascend by count, but with descending symbol order */
209 static int vp6_huff_cmp(const void *va, const void *vb)
211 const Node *a = va, *b = vb;
212 return (a->count - b->count)*16 + (b->sym - a->sym);
215 static void vp6_build_huff_tree(VP56Context *s, uint8_t coeff_model[],
216 const uint8_t *map, unsigned size, VLC *vlc)
218 Node nodes[2*size], *tmp = &nodes[size];
221 /* first compute probabilities from model */
223 for (i=0; i<size-1; i++) {
224 a = tmp[i].count * coeff_model[i] >> 8;
225 b = tmp[i].count * (255 - coeff_model[i]) >> 8;
226 nodes[map[2*i ]].count = a + !a;
227 nodes[map[2*i+1]].count = b + !b;
231 /* then build the huffman tree accodring to probabilities */
232 ff_huff_build_tree(s->avctx, vlc, size, nodes, vp6_huff_cmp,
233 FF_HUFFMAN_FLAG_HNODE_FIRST);
236 static void vp6_parse_coeff_models(VP56Context *s)
238 VP56RangeCoder *c = &s->c;
239 VP56Model *model = s->modelp;
241 int node, cg, ctx, pos;
242 int ct; /* code type */
243 int pt; /* plane type (0 for Y, 1 for U or V) */
245 memset(def_prob, 0x80, sizeof(def_prob));
247 for (pt=0; pt<2; pt++)
248 for (node=0; node<11; node++)
249 if (vp56_rac_get_prob(c, vp6_dccv_pct[pt][node])) {
250 def_prob[node] = vp56_rac_gets_nn(c, 7);
251 model->coeff_dccv[pt][node] = def_prob[node];
252 } else if (s->framep[VP56_FRAME_CURRENT]->key_frame) {
253 model->coeff_dccv[pt][node] = def_prob[node];
256 if (vp56_rac_get(c)) {
257 for (pos=1; pos<64; pos++)
258 if (vp56_rac_get_prob(c, vp6_coeff_reorder_pct[pos]))
259 model->coeff_reorder[pos] = vp56_rac_gets(c, 4);
260 vp6_coeff_order_table_init(s);
263 for (cg=0; cg<2; cg++)
264 for (node=0; node<14; node++)
265 if (vp56_rac_get_prob(c, vp6_runv_pct[cg][node]))
266 model->coeff_runv[cg][node] = vp56_rac_gets_nn(c, 7);
268 for (ct=0; ct<3; ct++)
269 for (pt=0; pt<2; pt++)
270 for (cg=0; cg<6; cg++)
271 for (node=0; node<11; node++)
272 if (vp56_rac_get_prob(c, vp6_ract_pct[ct][pt][cg][node])) {
273 def_prob[node] = vp56_rac_gets_nn(c, 7);
274 model->coeff_ract[pt][ct][cg][node] = def_prob[node];
275 } else if (s->framep[VP56_FRAME_CURRENT]->key_frame) {
276 model->coeff_ract[pt][ct][cg][node] = def_prob[node];
279 if (s->use_huffman) {
280 for (pt=0; pt<2; pt++) {
281 vp6_build_huff_tree(s, model->coeff_dccv[pt],
282 vp6_huff_coeff_map, 12, &s->dccv_vlc[pt]);
283 vp6_build_huff_tree(s, model->coeff_runv[pt],
284 vp6_huff_run_map, 9, &s->runv_vlc[pt]);
285 for (ct=0; ct<3; ct++)
286 for (cg = 0; cg < 6; cg++)
287 vp6_build_huff_tree(s, model->coeff_ract[pt][ct][cg],
288 vp6_huff_coeff_map, 12,
289 &s->ract_vlc[pt][ct][cg]);
291 memset(s->nb_null, 0, sizeof(s->nb_null));
293 /* coeff_dcct is a linear combination of coeff_dccv */
294 for (pt=0; pt<2; pt++)
295 for (ctx=0; ctx<3; ctx++)
296 for (node=0; node<5; node++)
297 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);
301 static void vp6_parse_vector_adjustment(VP56Context *s, VP56mv *vect)
303 VP56RangeCoder *c = &s->c;
304 VP56Model *model = s->modelp;
307 *vect = (VP56mv) {0,0};
308 if (s->vector_candidate_pos < 2)
309 *vect = s->vector_candidate[0];
311 for (comp=0; comp<2; comp++) {
314 if (vp56_rac_get_prob(c, model->vector_dct[comp])) {
315 static const uint8_t prob_order[] = {0, 1, 2, 7, 6, 5, 4};
316 for (i=0; i<sizeof(prob_order); i++) {
317 int j = prob_order[i];
318 delta |= vp56_rac_get_prob(c, model->vector_fdv[comp][j])<<j;
321 delta |= vp56_rac_get_prob(c, model->vector_fdv[comp][3])<<3;
325 delta = vp56_rac_get_tree(c, vp56_pva_tree,
326 model->vector_pdv[comp]);
329 if (delta && vp56_rac_get_prob(c, model->vector_sig[comp]))
340 * Read number of consecutive blocks with null DC or AC.
341 * This value is < 74.
343 static unsigned vp6_get_nb_null(VP56Context *s)
345 unsigned val = get_bits(&s->gb, 2);
347 val += get_bits(&s->gb, 2);
349 val = get_bits1(&s->gb) << 2;
350 val = 6+val + get_bits(&s->gb, 2+val);
355 static void vp6_parse_coeff_huffman(VP56Context *s)
357 VP56Model *model = s->modelp;
358 uint8_t *permute = s->scantable.permutated;
360 int coeff, sign, coeff_idx;
362 int pt = 0; /* plane type (0 for Y, 1 for U or V) */
364 for (b=0; b<6; b++) {
365 int ct = 0; /* code type */
367 vlc_coeff = &s->dccv_vlc[pt];
369 for (coeff_idx=0; coeff_idx<64; ) {
371 if (coeff_idx<2 && s->nb_null[coeff_idx][pt]) {
372 s->nb_null[coeff_idx][pt]--;
376 if (get_bits_count(&s->gb) >= s->gb.size_in_bits)
378 coeff = get_vlc2(&s->gb, vlc_coeff->table, 9, 3);
381 int pt = (coeff_idx >= 6);
382 run += get_vlc2(&s->gb, s->runv_vlc[pt].table, 9, 3);
384 run += get_bits(&s->gb, 6);
386 s->nb_null[0][pt] = vp6_get_nb_null(s);
388 } else if (coeff == 11) { /* end of block */
389 if (coeff_idx == 1) /* first AC coeff ? */
390 s->nb_null[1][pt] = vp6_get_nb_null(s);
393 int coeff2 = vp56_coeff_bias[coeff];
395 coeff2 += get_bits(&s->gb, coeff <= 9 ? coeff - 4 : 11);
396 ct = 1 + (coeff2 > 1);
397 sign = get_bits1(&s->gb);
398 coeff2 = (coeff2 ^ -sign) + sign;
400 coeff2 *= s->dequant_ac;
401 idx = model->coeff_index_to_pos[coeff_idx];
402 s->block_coeff[b][permute[idx]] = coeff2;
406 cg = FFMIN(vp6_coeff_groups[coeff_idx], 3);
407 vlc_coeff = &s->ract_vlc[pt][ct][cg];
412 static void vp6_parse_coeff(VP56Context *s)
414 VP56RangeCoder *c = s->ccp;
415 VP56Model *model = s->modelp;
416 uint8_t *permute = s->scantable.permutated;
417 uint8_t *model1, *model2, *model3;
418 int coeff, sign, coeff_idx;
419 int b, i, cg, idx, ctx;
420 int pt = 0; /* plane type (0 for Y, 1 for U or V) */
422 for (b=0; b<6; b++) {
423 int ct = 1; /* code type */
428 ctx = s->left_block[vp56_b6to4[b]].not_null_dc
429 + s->above_blocks[s->above_block_idx[b]].not_null_dc;
430 model1 = model->coeff_dccv[pt];
431 model2 = model->coeff_dcct[pt][ctx];
433 for (coeff_idx=0; coeff_idx<64; ) {
434 if ((coeff_idx>1 && ct==0) || vp56_rac_get_prob(c, model2[0])) {
436 if (vp56_rac_get_prob(c, model2[2])) {
437 if (vp56_rac_get_prob(c, model2[3])) {
438 idx = vp56_rac_get_tree(c, vp56_pc_tree, model1);
439 coeff = vp56_coeff_bias[idx+5];
440 for (i=vp56_coeff_bit_length[idx]; i>=0; i--)
441 coeff += vp56_rac_get_prob(c, vp56_coeff_parse_table[idx][i]) << i;
443 if (vp56_rac_get_prob(c, model2[4]))
444 coeff = 3 + vp56_rac_get_prob(c, model1[5]);
453 sign = vp56_rac_get(c);
454 coeff = (coeff ^ -sign) + sign;
456 coeff *= s->dequant_ac;
457 idx = model->coeff_index_to_pos[coeff_idx];
458 s->block_coeff[b][permute[idx]] = coeff;
464 if (!vp56_rac_get_prob(c, model2[1]))
467 model3 = model->coeff_runv[coeff_idx >= 6];
468 run = vp56_rac_get_tree(c, vp6_pcr_tree, model3);
470 for (run=9, i=0; i<6; i++)
471 run += vp56_rac_get_prob(c, model3[i+8]) << i;
475 cg = vp6_coeff_groups[coeff_idx+=run];
476 model1 = model2 = model->coeff_ract[pt][ct][cg];
479 s->left_block[vp56_b6to4[b]].not_null_dc =
480 s->above_blocks[s->above_block_idx[b]].not_null_dc = !!s->block_coeff[b][0];
484 static int vp6_block_variance(uint8_t *src, int stride)
486 int sum = 0, square_sum = 0;
489 for (y=0; y<8; y+=2) {
490 for (x=0; x<8; x+=2) {
492 square_sum += src[x]*src[x];
496 return (16*square_sum - sum*sum) >> 8;
499 static void vp6_filter_hv4(uint8_t *dst, uint8_t *src, int stride,
500 int delta, const int16_t *weights)
504 for (y=0; y<8; y++) {
505 for (x=0; x<8; x++) {
506 dst[x] = av_clip_uint8(( src[x-delta ] * weights[0]
507 + src[x ] * weights[1]
508 + src[x+delta ] * weights[2]
509 + src[x+2*delta] * weights[3] + 64) >> 7);
516 static void vp6_filter_diag2(VP56Context *s, uint8_t *dst, uint8_t *src,
517 int stride, int h_weight, int v_weight)
519 uint8_t *tmp = s->edge_emu_buffer+16;
520 s->dsp.put_h264_chroma_pixels_tab[0](tmp, src, stride, 9, h_weight, 0);
521 s->dsp.put_h264_chroma_pixels_tab[0](dst, tmp, stride, 8, 0, v_weight);
524 static void vp6_filter(VP56Context *s, uint8_t *dst, uint8_t *src,
525 int offset1, int offset2, int stride,
526 VP56mv mv, int mask, int select, int luma)
529 int x8 = mv.x & mask;
530 int y8 = mv.y & mask;
535 filter4 = s->filter_mode;
537 if (s->max_vector_length &&
538 (FFABS(mv.x) > s->max_vector_length ||
539 FFABS(mv.y) > s->max_vector_length)) {
541 } else if (s->sample_variance_threshold
542 && (vp6_block_variance(src+offset1, stride)
543 < s->sample_variance_threshold)) {
549 if ((y8 && (offset2-offset1)*s->flip<0) || (!y8 && offset1 > offset2)) {
554 if (!y8) { /* left or right combine */
555 vp6_filter_hv4(dst, src+offset1, stride, 1,
556 vp6_block_copy_filter[select][x8]);
557 } else if (!x8) { /* above or below combine */
558 vp6_filter_hv4(dst, src+offset1, stride, stride,
559 vp6_block_copy_filter[select][y8]);
561 s->dsp.vp6_filter_diag4(dst, src+offset1+((mv.x^mv.y)>>31), stride,
562 vp6_block_copy_filter[select][x8],
563 vp6_block_copy_filter[select][y8]);
567 s->dsp.put_h264_chroma_pixels_tab[0](dst, src+offset1, stride, 8, x8, y8);
569 vp6_filter_diag2(s, dst, src+offset1 + ((mv.x^mv.y)>>31), stride, x8, y8);
574 static av_cold int vp6_decode_init(AVCodecContext *avctx)
576 VP56Context *s = avctx->priv_data;
578 vp56_init(avctx, avctx->codec->id == CODEC_ID_VP6,
579 avctx->codec->id == CODEC_ID_VP6A);
580 s->vp56_coord_div = vp6_coord_div;
581 s->parse_vector_adjustment = vp6_parse_vector_adjustment;
582 s->filter = vp6_filter;
583 s->default_models_init = vp6_default_models_init;
584 s->parse_vector_models = vp6_parse_vector_models;
585 s->parse_coeff_models = vp6_parse_coeff_models;
586 s->parse_header = vp6_parse_header;
591 static av_cold int vp6_decode_free(AVCodecContext *avctx)
593 VP56Context *s = avctx->priv_data;
598 for (pt=0; pt<2; pt++) {
599 free_vlc(&s->dccv_vlc[pt]);
600 free_vlc(&s->runv_vlc[pt]);
601 for (ct=0; ct<3; ct++)
602 for (cg=0; cg<6; cg++)
603 free_vlc(&s->ract_vlc[pt][ct][cg]);
608 AVCodec vp6_decoder = {
618 .long_name = NULL_IF_CONFIG_SMALL("On2 VP6"),
621 /* flash version, not flipped upside-down */
622 AVCodec vp6f_decoder = {
632 .long_name = NULL_IF_CONFIG_SMALL("On2 VP6 (Flash version)"),
635 /* flash version, not flipped upside-down, with alpha channel */
636 AVCodec vp6a_decoder = {
646 .long_name = NULL_IF_CONFIG_SMALL("On2 VP6 (Flash version, with alpha channel)"),