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
39 #define VP6_MAX_HUFF_SIZE 12
41 static void vp6_parse_coeff(VP56Context *s);
42 static void vp6_parse_coeff_huffman(VP56Context *s);
44 static int vp6_parse_header(VP56Context *s, const uint8_t *buf, int buf_size,
47 VP56RangeCoder *c = &s->c;
48 int parse_filter_info = 0;
54 int separated_coeff = buf[0] & 1;
56 s->framep[VP56_FRAME_CURRENT]->key_frame = !(buf[0] & 0x80);
57 ff_vp56_init_dequant(s, (buf[0] >> 1) & 0x3F);
59 if (s->framep[VP56_FRAME_CURRENT]->key_frame) {
60 sub_version = buf[1] >> 3;
63 s->filter_header = buf[1] & 0x06;
65 av_log(s->avctx, AV_LOG_ERROR, "interlacing not supported\n");
68 if (separated_coeff || !s->filter_header) {
69 coeff_offset = AV_RB16(buf+2) - 2;
74 rows = buf[2]; /* number of stored macroblock rows */
75 cols = buf[3]; /* number of stored macroblock cols */
76 /* buf[4] is number of displayed macroblock rows */
77 /* buf[5] is number of displayed macroblock cols */
79 if (!s->macroblocks || /* first frame */
80 16*cols != s->avctx->coded_width ||
81 16*rows != s->avctx->coded_height) {
82 avcodec_set_dimensions(s->avctx, 16*cols, 16*rows);
83 if (s->avctx->extradata_size == 1) {
84 s->avctx->width -= s->avctx->extradata[0] >> 4;
85 s->avctx->height -= s->avctx->extradata[0] & 0x0F;
90 vp56_init_range_decoder(c, buf+6, buf_size-6);
93 parse_filter_info = s->filter_header;
96 s->sub_version = sub_version;
101 if (separated_coeff || !s->filter_header) {
102 coeff_offset = AV_RB16(buf+1) - 2;
106 vp56_init_range_decoder(c, buf+1, buf_size-1);
108 *golden_frame = vp56_rac_get(c);
109 if (s->filter_header) {
110 s->deblock_filtering = vp56_rac_get(c);
111 if (s->deblock_filtering)
113 if (s->sub_version > 7)
114 parse_filter_info = vp56_rac_get(c);
118 if (parse_filter_info) {
119 if (vp56_rac_get(c)) {
121 s->sample_variance_threshold = vp56_rac_gets(c, 5) << vrt_shift;
122 s->max_vector_length = 2 << vp56_rac_gets(c, 3);
123 } else if (vp56_rac_get(c)) {
128 if (s->sub_version > 7)
129 s->filter_selection = vp56_rac_gets(c, 4);
131 s->filter_selection = 16;
134 s->use_huffman = vp56_rac_get(c);
136 s->parse_coeff = vp6_parse_coeff;
139 buf_size -= coeff_offset;
142 if (s->use_huffman) {
143 s->parse_coeff = vp6_parse_coeff_huffman;
144 init_get_bits(&s->gb, buf, buf_size<<3);
146 vp56_init_range_decoder(&s->cc, buf, buf_size);
156 static void vp6_coeff_order_table_init(VP56Context *s)
160 s->modelp->coeff_index_to_pos[0] = 0;
162 for (pos=1; pos<64; pos++)
163 if (s->modelp->coeff_reorder[pos] == i)
164 s->modelp->coeff_index_to_pos[idx++] = pos;
167 static void vp6_default_models_init(VP56Context *s)
169 VP56Model *model = s->modelp;
171 model->vector_dct[0] = 0xA2;
172 model->vector_dct[1] = 0xA4;
173 model->vector_sig[0] = 0x80;
174 model->vector_sig[1] = 0x80;
176 memcpy(model->mb_types_stats, vp56_def_mb_types_stats, sizeof(model->mb_types_stats));
177 memcpy(model->vector_fdv, vp6_def_fdv_vector_model, sizeof(model->vector_fdv));
178 memcpy(model->vector_pdv, vp6_def_pdv_vector_model, sizeof(model->vector_pdv));
179 memcpy(model->coeff_runv, vp6_def_runv_coeff_model, sizeof(model->coeff_runv));
180 memcpy(model->coeff_reorder, vp6_def_coeff_reorder, sizeof(model->coeff_reorder));
182 vp6_coeff_order_table_init(s);
185 static void vp6_parse_vector_models(VP56Context *s)
187 VP56RangeCoder *c = &s->c;
188 VP56Model *model = s->modelp;
191 for (comp=0; comp<2; comp++) {
192 if (vp56_rac_get_prob(c, vp6_sig_dct_pct[comp][0]))
193 model->vector_dct[comp] = vp56_rac_gets_nn(c, 7);
194 if (vp56_rac_get_prob(c, vp6_sig_dct_pct[comp][1]))
195 model->vector_sig[comp] = vp56_rac_gets_nn(c, 7);
198 for (comp=0; comp<2; comp++)
199 for (node=0; node<7; node++)
200 if (vp56_rac_get_prob(c, vp6_pdv_pct[comp][node]))
201 model->vector_pdv[comp][node] = vp56_rac_gets_nn(c, 7);
203 for (comp=0; comp<2; comp++)
204 for (node=0; node<8; node++)
205 if (vp56_rac_get_prob(c, vp6_fdv_pct[comp][node]))
206 model->vector_fdv[comp][node] = vp56_rac_gets_nn(c, 7);
209 /* nodes must ascend by count, but with descending symbol order */
210 static int vp6_huff_cmp(const void *va, const void *vb)
212 const Node *a = va, *b = vb;
213 return (a->count - b->count)*16 + (b->sym - a->sym);
216 static void vp6_build_huff_tree(VP56Context *s, uint8_t coeff_model[],
217 const uint8_t *map, unsigned size, VLC *vlc)
219 Node nodes[2*VP6_MAX_HUFF_SIZE], *tmp = &nodes[size];
222 /* first compute probabilities from model */
224 for (i=0; i<size-1; i++) {
225 a = tmp[i].count * coeff_model[i] >> 8;
226 b = tmp[i].count * (255 - coeff_model[i]) >> 8;
227 nodes[map[2*i ]].count = a + !a;
228 nodes[map[2*i+1]].count = b + !b;
232 /* then build the huffman tree accodring to probabilities */
233 ff_huff_build_tree(s->avctx, vlc, size, nodes, vp6_huff_cmp,
234 FF_HUFFMAN_FLAG_HNODE_FIRST);
237 static void vp6_parse_coeff_models(VP56Context *s)
239 VP56RangeCoder *c = &s->c;
240 VP56Model *model = s->modelp;
242 int node, cg, ctx, pos;
243 int ct; /* code type */
244 int pt; /* plane type (0 for Y, 1 for U or V) */
246 memset(def_prob, 0x80, sizeof(def_prob));
248 for (pt=0; pt<2; pt++)
249 for (node=0; node<11; node++)
250 if (vp56_rac_get_prob(c, vp6_dccv_pct[pt][node])) {
251 def_prob[node] = vp56_rac_gets_nn(c, 7);
252 model->coeff_dccv[pt][node] = def_prob[node];
253 } else if (s->framep[VP56_FRAME_CURRENT]->key_frame) {
254 model->coeff_dccv[pt][node] = def_prob[node];
257 if (vp56_rac_get(c)) {
258 for (pos=1; pos<64; pos++)
259 if (vp56_rac_get_prob(c, vp6_coeff_reorder_pct[pos]))
260 model->coeff_reorder[pos] = vp56_rac_gets(c, 4);
261 vp6_coeff_order_table_init(s);
264 for (cg=0; cg<2; cg++)
265 for (node=0; node<14; node++)
266 if (vp56_rac_get_prob(c, vp6_runv_pct[cg][node]))
267 model->coeff_runv[cg][node] = vp56_rac_gets_nn(c, 7);
269 for (ct=0; ct<3; ct++)
270 for (pt=0; pt<2; pt++)
271 for (cg=0; cg<6; cg++)
272 for (node=0; node<11; node++)
273 if (vp56_rac_get_prob(c, vp6_ract_pct[ct][pt][cg][node])) {
274 def_prob[node] = vp56_rac_gets_nn(c, 7);
275 model->coeff_ract[pt][ct][cg][node] = def_prob[node];
276 } else if (s->framep[VP56_FRAME_CURRENT]->key_frame) {
277 model->coeff_ract[pt][ct][cg][node] = def_prob[node];
280 if (s->use_huffman) {
281 for (pt=0; pt<2; pt++) {
282 vp6_build_huff_tree(s, model->coeff_dccv[pt],
283 vp6_huff_coeff_map, 12, &s->dccv_vlc[pt]);
284 vp6_build_huff_tree(s, model->coeff_runv[pt],
285 vp6_huff_run_map, 9, &s->runv_vlc[pt]);
286 for (ct=0; ct<3; ct++)
287 for (cg = 0; cg < 6; cg++)
288 vp6_build_huff_tree(s, model->coeff_ract[pt][ct][cg],
289 vp6_huff_coeff_map, 12,
290 &s->ract_vlc[pt][ct][cg]);
292 memset(s->nb_null, 0, sizeof(s->nb_null));
294 /* coeff_dcct is a linear combination of coeff_dccv */
295 for (pt=0; pt<2; pt++)
296 for (ctx=0; ctx<3; ctx++)
297 for (node=0; node<5; node++)
298 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);
302 static void vp6_parse_vector_adjustment(VP56Context *s, VP56mv *vect)
304 VP56RangeCoder *c = &s->c;
305 VP56Model *model = s->modelp;
308 *vect = (VP56mv) {0,0};
309 if (s->vector_candidate_pos < 2)
310 *vect = s->vector_candidate[0];
312 for (comp=0; comp<2; comp++) {
315 if (vp56_rac_get_prob(c, model->vector_dct[comp])) {
316 static const uint8_t prob_order[] = {0, 1, 2, 7, 6, 5, 4};
317 for (i=0; i<sizeof(prob_order); i++) {
318 int j = prob_order[i];
319 delta |= vp56_rac_get_prob(c, model->vector_fdv[comp][j])<<j;
322 delta |= vp56_rac_get_prob(c, model->vector_fdv[comp][3])<<3;
326 delta = vp56_rac_get_tree(c, vp56_pva_tree,
327 model->vector_pdv[comp]);
330 if (delta && vp56_rac_get_prob(c, model->vector_sig[comp]))
341 * Read number of consecutive blocks with null DC or AC.
342 * This value is < 74.
344 static unsigned vp6_get_nb_null(VP56Context *s)
346 unsigned val = get_bits(&s->gb, 2);
348 val += get_bits(&s->gb, 2);
350 val = get_bits1(&s->gb) << 2;
351 val = 6+val + get_bits(&s->gb, 2+val);
356 static void vp6_parse_coeff_huffman(VP56Context *s)
358 VP56Model *model = s->modelp;
359 uint8_t *permute = s->scantable.permutated;
361 int coeff, sign, coeff_idx;
363 int pt = 0; /* plane type (0 for Y, 1 for U or V) */
365 for (b=0; b<6; b++) {
366 int ct = 0; /* code type */
368 vlc_coeff = &s->dccv_vlc[pt];
370 for (coeff_idx=0; coeff_idx<64; ) {
372 if (coeff_idx<2 && s->nb_null[coeff_idx][pt]) {
373 s->nb_null[coeff_idx][pt]--;
377 if (get_bits_count(&s->gb) >= s->gb.size_in_bits)
379 coeff = get_vlc2(&s->gb, vlc_coeff->table, 9, 3);
382 int pt = (coeff_idx >= 6);
383 run += get_vlc2(&s->gb, s->runv_vlc[pt].table, 9, 3);
385 run += get_bits(&s->gb, 6);
387 s->nb_null[0][pt] = vp6_get_nb_null(s);
389 } else if (coeff == 11) { /* end of block */
390 if (coeff_idx == 1) /* first AC coeff ? */
391 s->nb_null[1][pt] = vp6_get_nb_null(s);
394 int coeff2 = vp56_coeff_bias[coeff];
396 coeff2 += get_bits(&s->gb, coeff <= 9 ? coeff - 4 : 11);
397 ct = 1 + (coeff2 > 1);
398 sign = get_bits1(&s->gb);
399 coeff2 = (coeff2 ^ -sign) + sign;
401 coeff2 *= s->dequant_ac;
402 idx = model->coeff_index_to_pos[coeff_idx];
403 s->block_coeff[b][permute[idx]] = coeff2;
407 cg = FFMIN(vp6_coeff_groups[coeff_idx], 3);
408 vlc_coeff = &s->ract_vlc[pt][ct][cg];
413 static void vp6_parse_coeff(VP56Context *s)
415 VP56RangeCoder *c = s->ccp;
416 VP56Model *model = s->modelp;
417 uint8_t *permute = s->scantable.permutated;
418 uint8_t *model1, *model2, *model3;
419 int coeff, sign, coeff_idx;
420 int b, i, cg, idx, ctx;
421 int pt = 0; /* plane type (0 for Y, 1 for U or V) */
423 for (b=0; b<6; b++) {
424 int ct = 1; /* code type */
429 ctx = s->left_block[vp56_b6to4[b]].not_null_dc
430 + s->above_blocks[s->above_block_idx[b]].not_null_dc;
431 model1 = model->coeff_dccv[pt];
432 model2 = model->coeff_dcct[pt][ctx];
434 for (coeff_idx=0; coeff_idx<64; ) {
435 if ((coeff_idx>1 && ct==0) || vp56_rac_get_prob(c, model2[0])) {
437 if (vp56_rac_get_prob(c, model2[2])) {
438 if (vp56_rac_get_prob(c, model2[3])) {
439 idx = vp56_rac_get_tree(c, vp56_pc_tree, model1);
440 coeff = vp56_coeff_bias[idx+5];
441 for (i=vp56_coeff_bit_length[idx]; i>=0; i--)
442 coeff += vp56_rac_get_prob(c, vp56_coeff_parse_table[idx][i]) << i;
444 if (vp56_rac_get_prob(c, model2[4]))
445 coeff = 3 + vp56_rac_get_prob(c, model1[5]);
454 sign = vp56_rac_get(c);
455 coeff = (coeff ^ -sign) + sign;
457 coeff *= s->dequant_ac;
458 idx = model->coeff_index_to_pos[coeff_idx];
459 s->block_coeff[b][permute[idx]] = coeff;
465 if (!vp56_rac_get_prob(c, model2[1]))
468 model3 = model->coeff_runv[coeff_idx >= 6];
469 run = vp56_rac_get_tree(c, vp6_pcr_tree, model3);
471 for (run=9, i=0; i<6; i++)
472 run += vp56_rac_get_prob(c, model3[i+8]) << i;
476 cg = vp6_coeff_groups[coeff_idx+=run];
477 model1 = model2 = model->coeff_ract[pt][ct][cg];
480 s->left_block[vp56_b6to4[b]].not_null_dc =
481 s->above_blocks[s->above_block_idx[b]].not_null_dc = !!s->block_coeff[b][0];
485 static int vp6_block_variance(uint8_t *src, int stride)
487 int sum = 0, square_sum = 0;
490 for (y=0; y<8; y+=2) {
491 for (x=0; x<8; x+=2) {
493 square_sum += src[x]*src[x];
497 return (16*square_sum - sum*sum) >> 8;
500 static void vp6_filter_hv4(uint8_t *dst, uint8_t *src, int stride,
501 int delta, const int16_t *weights)
505 for (y=0; y<8; y++) {
506 for (x=0; x<8; x++) {
507 dst[x] = av_clip_uint8(( src[x-delta ] * weights[0]
508 + src[x ] * weights[1]
509 + src[x+delta ] * weights[2]
510 + src[x+2*delta] * weights[3] + 64) >> 7);
517 static void vp6_filter_diag2(VP56Context *s, uint8_t *dst, uint8_t *src,
518 int stride, int h_weight, int v_weight)
520 uint8_t *tmp = s->edge_emu_buffer+16;
521 s->dsp.put_h264_chroma_pixels_tab[0](tmp, src, stride, 9, h_weight, 0);
522 s->dsp.put_h264_chroma_pixels_tab[0](dst, tmp, stride, 8, 0, v_weight);
525 static void vp6_filter(VP56Context *s, uint8_t *dst, uint8_t *src,
526 int offset1, int offset2, int stride,
527 VP56mv mv, int mask, int select, int luma)
530 int x8 = mv.x & mask;
531 int y8 = mv.y & mask;
536 filter4 = s->filter_mode;
538 if (s->max_vector_length &&
539 (FFABS(mv.x) > s->max_vector_length ||
540 FFABS(mv.y) > s->max_vector_length)) {
542 } else if (s->sample_variance_threshold
543 && (vp6_block_variance(src+offset1, stride)
544 < s->sample_variance_threshold)) {
550 if ((y8 && (offset2-offset1)*s->flip<0) || (!y8 && offset1 > offset2)) {
555 if (!y8) { /* left or right combine */
556 vp6_filter_hv4(dst, src+offset1, stride, 1,
557 vp6_block_copy_filter[select][x8]);
558 } else if (!x8) { /* above or below combine */
559 vp6_filter_hv4(dst, src+offset1, stride, stride,
560 vp6_block_copy_filter[select][y8]);
562 s->dsp.vp6_filter_diag4(dst, src+offset1+((mv.x^mv.y)>>31), stride,
563 vp6_block_copy_filter[select][x8],
564 vp6_block_copy_filter[select][y8]);
568 s->dsp.put_h264_chroma_pixels_tab[0](dst, src+offset1, stride, 8, x8, y8);
570 vp6_filter_diag2(s, dst, src+offset1 + ((mv.x^mv.y)>>31), stride, x8, y8);
575 static av_cold int vp6_decode_init(AVCodecContext *avctx)
577 VP56Context *s = avctx->priv_data;
579 ff_vp56_init(avctx, avctx->codec->id == CODEC_ID_VP6,
580 avctx->codec->id == CODEC_ID_VP6A);
581 s->vp56_coord_div = vp6_coord_div;
582 s->parse_vector_adjustment = vp6_parse_vector_adjustment;
583 s->filter = vp6_filter;
584 s->default_models_init = vp6_default_models_init;
585 s->parse_vector_models = vp6_parse_vector_models;
586 s->parse_coeff_models = vp6_parse_coeff_models;
587 s->parse_header = vp6_parse_header;
592 static av_cold int vp6_decode_free(AVCodecContext *avctx)
594 VP56Context *s = avctx->priv_data;
599 for (pt=0; pt<2; pt++) {
600 free_vlc(&s->dccv_vlc[pt]);
601 free_vlc(&s->runv_vlc[pt]);
602 for (ct=0; ct<3; ct++)
603 for (cg=0; cg<6; cg++)
604 free_vlc(&s->ract_vlc[pt][ct][cg]);
609 AVCodec vp6_decoder = {
617 ff_vp56_decode_frame,
619 .long_name = NULL_IF_CONFIG_SMALL("On2 VP6"),
622 /* flash version, not flipped upside-down */
623 AVCodec vp6f_decoder = {
631 ff_vp56_decode_frame,
633 .long_name = NULL_IF_CONFIG_SMALL("On2 VP6 (Flash version)"),
636 /* flash version, not flipped upside-down, with alpha channel */
637 AVCodec vp6a_decoder = {
645 ff_vp56_decode_frame,
647 .long_name = NULL_IF_CONFIG_SMALL("On2 VP6 (Flash version, with alpha channel)"),