2 * Copyright (C) 2006 Aurelien Jacobs <aurel@gnuage.org>
4 * This file is part of Libav.
6 * Libav 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.
11 * Libav 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.
16 * You should have received a copy of the GNU Lesser General Public
17 * License along with Libav; if not, write to the Free Software
18 * Foundation, Inc., 51 Franklin Street, Fifth Floor, Boston, MA 02110-1301 USA
23 * VP6 compatible video decoder
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
41 #define VP6_MAX_HUFF_SIZE 12
43 static void vp6_parse_coeff(VP56Context *s);
44 static void vp6_parse_coeff_huffman(VP56Context *s);
46 static int vp6_parse_header(VP56Context *s, const uint8_t *buf, int buf_size,
49 VP56RangeCoder *c = &s->c;
50 int parse_filter_info = 0;
56 int separated_coeff = buf[0] & 1;
58 s->framep[VP56_FRAME_CURRENT]->key_frame = !(buf[0] & 0x80);
59 ff_vp56_init_dequant(s, (buf[0] >> 1) & 0x3F);
61 if (s->framep[VP56_FRAME_CURRENT]->key_frame) {
62 sub_version = buf[1] >> 3;
65 s->filter_header = buf[1] & 0x06;
67 av_log(s->avctx, AV_LOG_ERROR, "interlacing not supported\n");
70 if (separated_coeff || !s->filter_header) {
71 coeff_offset = AV_RB16(buf+2) - 2;
76 rows = buf[2]; /* number of stored macroblock rows */
77 cols = buf[3]; /* number of stored macroblock cols */
78 /* buf[4] is number of displayed macroblock rows */
79 /* buf[5] is number of displayed macroblock cols */
81 if (!s->macroblocks || /* first frame */
82 16*cols != s->avctx->coded_width ||
83 16*rows != s->avctx->coded_height) {
84 avcodec_set_dimensions(s->avctx, 16*cols, 16*rows);
85 if (s->avctx->extradata_size == 1) {
86 s->avctx->width -= s->avctx->extradata[0] >> 4;
87 s->avctx->height -= s->avctx->extradata[0] & 0x0F;
92 ff_vp56_init_range_decoder(c, buf+6, buf_size-6);
95 parse_filter_info = s->filter_header;
98 s->sub_version = sub_version;
103 if (separated_coeff || !s->filter_header) {
104 coeff_offset = AV_RB16(buf+1) - 2;
108 ff_vp56_init_range_decoder(c, buf+1, buf_size-1);
110 *golden_frame = vp56_rac_get(c);
111 if (s->filter_header) {
112 s->deblock_filtering = vp56_rac_get(c);
113 if (s->deblock_filtering)
115 if (s->sub_version > 7)
116 parse_filter_info = vp56_rac_get(c);
120 if (parse_filter_info) {
121 if (vp56_rac_get(c)) {
123 s->sample_variance_threshold = vp56_rac_gets(c, 5) << vrt_shift;
124 s->max_vector_length = 2 << vp56_rac_gets(c, 3);
125 } else if (vp56_rac_get(c)) {
130 if (s->sub_version > 7)
131 s->filter_selection = vp56_rac_gets(c, 4);
133 s->filter_selection = 16;
136 s->use_huffman = vp56_rac_get(c);
138 s->parse_coeff = vp6_parse_coeff;
141 buf_size -= coeff_offset;
143 if (s->framep[VP56_FRAME_CURRENT]->key_frame)
144 avcodec_set_dimensions(s->avctx, 0, 0);
147 if (s->use_huffman) {
148 s->parse_coeff = vp6_parse_coeff_huffman;
149 init_get_bits(&s->gb, buf, buf_size<<3);
151 ff_vp56_init_range_decoder(&s->cc, buf, buf_size);
161 static void vp6_coeff_order_table_init(VP56Context *s)
165 s->modelp->coeff_index_to_pos[0] = 0;
167 for (pos=1; pos<64; pos++)
168 if (s->modelp->coeff_reorder[pos] == i)
169 s->modelp->coeff_index_to_pos[idx++] = pos;
172 static void vp6_default_models_init(VP56Context *s)
174 VP56Model *model = s->modelp;
176 model->vector_dct[0] = 0xA2;
177 model->vector_dct[1] = 0xA4;
178 model->vector_sig[0] = 0x80;
179 model->vector_sig[1] = 0x80;
181 memcpy(model->mb_types_stats, vp56_def_mb_types_stats, sizeof(model->mb_types_stats));
182 memcpy(model->vector_fdv, vp6_def_fdv_vector_model, sizeof(model->vector_fdv));
183 memcpy(model->vector_pdv, vp6_def_pdv_vector_model, sizeof(model->vector_pdv));
184 memcpy(model->coeff_runv, vp6_def_runv_coeff_model, sizeof(model->coeff_runv));
185 memcpy(model->coeff_reorder, vp6_def_coeff_reorder, sizeof(model->coeff_reorder));
187 vp6_coeff_order_table_init(s);
190 static void vp6_parse_vector_models(VP56Context *s)
192 VP56RangeCoder *c = &s->c;
193 VP56Model *model = s->modelp;
196 for (comp=0; comp<2; comp++) {
197 if (vp56_rac_get_prob(c, vp6_sig_dct_pct[comp][0]))
198 model->vector_dct[comp] = vp56_rac_gets_nn(c, 7);
199 if (vp56_rac_get_prob(c, vp6_sig_dct_pct[comp][1]))
200 model->vector_sig[comp] = vp56_rac_gets_nn(c, 7);
203 for (comp=0; comp<2; comp++)
204 for (node=0; node<7; node++)
205 if (vp56_rac_get_prob(c, vp6_pdv_pct[comp][node]))
206 model->vector_pdv[comp][node] = vp56_rac_gets_nn(c, 7);
208 for (comp=0; comp<2; comp++)
209 for (node=0; node<8; node++)
210 if (vp56_rac_get_prob(c, vp6_fdv_pct[comp][node]))
211 model->vector_fdv[comp][node] = vp56_rac_gets_nn(c, 7);
214 /* nodes must ascend by count, but with descending symbol order */
215 static int vp6_huff_cmp(const void *va, const void *vb)
217 const Node *a = va, *b = vb;
218 return (a->count - b->count)*16 + (b->sym - a->sym);
221 static int vp6_build_huff_tree(VP56Context *s, uint8_t coeff_model[],
222 const uint8_t *map, unsigned size, VLC *vlc)
224 Node nodes[2*VP6_MAX_HUFF_SIZE], *tmp = &nodes[size];
227 /* first compute probabilities from model */
229 for (i=0; i<size-1; i++) {
230 a = tmp[i].count * coeff_model[i] >> 8;
231 b = tmp[i].count * (255 - coeff_model[i]) >> 8;
232 nodes[map[2*i ]].count = a + !a;
233 nodes[map[2*i+1]].count = b + !b;
237 /* then build the huffman tree according to probabilities */
238 return ff_huff_build_tree(s->avctx, vlc, size, nodes, vp6_huff_cmp,
239 FF_HUFFMAN_FLAG_HNODE_FIRST);
242 static int vp6_parse_coeff_models(VP56Context *s)
244 VP56RangeCoder *c = &s->c;
245 VP56Model *model = s->modelp;
247 int node, cg, ctx, pos;
248 int ct; /* code type */
249 int pt; /* plane type (0 for Y, 1 for U or V) */
251 memset(def_prob, 0x80, sizeof(def_prob));
253 for (pt=0; pt<2; pt++)
254 for (node=0; node<11; node++)
255 if (vp56_rac_get_prob(c, vp6_dccv_pct[pt][node])) {
256 def_prob[node] = vp56_rac_gets_nn(c, 7);
257 model->coeff_dccv[pt][node] = def_prob[node];
258 } else if (s->framep[VP56_FRAME_CURRENT]->key_frame) {
259 model->coeff_dccv[pt][node] = def_prob[node];
262 if (vp56_rac_get(c)) {
263 for (pos=1; pos<64; pos++)
264 if (vp56_rac_get_prob(c, vp6_coeff_reorder_pct[pos]))
265 model->coeff_reorder[pos] = vp56_rac_gets(c, 4);
266 vp6_coeff_order_table_init(s);
269 for (cg=0; cg<2; cg++)
270 for (node=0; node<14; node++)
271 if (vp56_rac_get_prob(c, vp6_runv_pct[cg][node]))
272 model->coeff_runv[cg][node] = vp56_rac_gets_nn(c, 7);
274 for (ct=0; ct<3; ct++)
275 for (pt=0; pt<2; pt++)
276 for (cg=0; cg<6; cg++)
277 for (node=0; node<11; node++)
278 if (vp56_rac_get_prob(c, vp6_ract_pct[ct][pt][cg][node])) {
279 def_prob[node] = vp56_rac_gets_nn(c, 7);
280 model->coeff_ract[pt][ct][cg][node] = def_prob[node];
281 } else if (s->framep[VP56_FRAME_CURRENT]->key_frame) {
282 model->coeff_ract[pt][ct][cg][node] = def_prob[node];
285 if (s->use_huffman) {
286 for (pt=0; pt<2; pt++) {
287 if (vp6_build_huff_tree(s, model->coeff_dccv[pt],
288 vp6_huff_coeff_map, 12, &s->dccv_vlc[pt]))
290 if (vp6_build_huff_tree(s, model->coeff_runv[pt],
291 vp6_huff_run_map, 9, &s->runv_vlc[pt]))
293 for (ct=0; ct<3; ct++)
294 for (cg = 0; cg < 6; cg++)
295 if (vp6_build_huff_tree(s, model->coeff_ract[pt][ct][cg],
296 vp6_huff_coeff_map, 12,
297 &s->ract_vlc[pt][ct][cg]))
300 memset(s->nb_null, 0, sizeof(s->nb_null));
302 /* coeff_dcct is a linear combination of coeff_dccv */
303 for (pt=0; pt<2; pt++)
304 for (ctx=0; ctx<3; ctx++)
305 for (node=0; node<5; node++)
306 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);
311 static void vp6_parse_vector_adjustment(VP56Context *s, VP56mv *vect)
313 VP56RangeCoder *c = &s->c;
314 VP56Model *model = s->modelp;
317 *vect = (VP56mv) {0,0};
318 if (s->vector_candidate_pos < 2)
319 *vect = s->vector_candidate[0];
321 for (comp=0; comp<2; comp++) {
324 if (vp56_rac_get_prob(c, model->vector_dct[comp])) {
325 static const uint8_t prob_order[] = {0, 1, 2, 7, 6, 5, 4};
326 for (i=0; i<sizeof(prob_order); i++) {
327 int j = prob_order[i];
328 delta |= vp56_rac_get_prob(c, model->vector_fdv[comp][j])<<j;
331 delta |= vp56_rac_get_prob(c, model->vector_fdv[comp][3])<<3;
335 delta = vp56_rac_get_tree(c, vp56_pva_tree,
336 model->vector_pdv[comp]);
339 if (delta && vp56_rac_get_prob(c, model->vector_sig[comp]))
350 * Read number of consecutive blocks with null DC or AC.
351 * This value is < 74.
353 static unsigned vp6_get_nb_null(VP56Context *s)
355 unsigned val = get_bits(&s->gb, 2);
357 val += get_bits(&s->gb, 2);
359 val = get_bits1(&s->gb) << 2;
360 val = 6+val + get_bits(&s->gb, 2+val);
365 static void vp6_parse_coeff_huffman(VP56Context *s)
367 VP56Model *model = s->modelp;
368 uint8_t *permute = s->scantable.permutated;
370 int coeff, sign, coeff_idx;
372 int pt = 0; /* plane type (0 for Y, 1 for U or V) */
374 for (b=0; b<6; b++) {
375 int ct = 0; /* code type */
377 vlc_coeff = &s->dccv_vlc[pt];
379 for (coeff_idx = 0;;) {
381 if (coeff_idx<2 && s->nb_null[coeff_idx][pt]) {
382 s->nb_null[coeff_idx][pt]--;
386 if (get_bits_count(&s->gb) >= s->gb.size_in_bits)
388 coeff = get_vlc2(&s->gb, vlc_coeff->table, 9, 3);
391 int pt = (coeff_idx >= 6);
392 run += get_vlc2(&s->gb, s->runv_vlc[pt].table, 9, 3);
394 run += get_bits(&s->gb, 6);
396 s->nb_null[0][pt] = vp6_get_nb_null(s);
398 } else if (coeff == 11) { /* end of block */
399 if (coeff_idx == 1) /* first AC coeff ? */
400 s->nb_null[1][pt] = vp6_get_nb_null(s);
403 int coeff2 = vp56_coeff_bias[coeff];
405 coeff2 += get_bits(&s->gb, coeff <= 9 ? coeff - 4 : 11);
406 ct = 1 + (coeff2 > 1);
407 sign = get_bits1(&s->gb);
408 coeff2 = (coeff2 ^ -sign) + sign;
410 coeff2 *= s->dequant_ac;
411 idx = model->coeff_index_to_pos[coeff_idx];
412 s->block_coeff[b][permute[idx]] = coeff2;
418 cg = FFMIN(vp6_coeff_groups[coeff_idx], 3);
419 vlc_coeff = &s->ract_vlc[pt][ct][cg];
424 static void vp6_parse_coeff(VP56Context *s)
426 VP56RangeCoder *c = s->ccp;
427 VP56Model *model = s->modelp;
428 uint8_t *permute = s->scantable.permutated;
429 uint8_t *model1, *model2, *model3;
430 int coeff, sign, coeff_idx;
431 int b, i, cg, idx, ctx;
432 int pt = 0; /* plane type (0 for Y, 1 for U or V) */
434 for (b=0; b<6; b++) {
435 int ct = 1; /* code type */
440 ctx = s->left_block[vp56_b6to4[b]].not_null_dc
441 + s->above_blocks[s->above_block_idx[b]].not_null_dc;
442 model1 = model->coeff_dccv[pt];
443 model2 = model->coeff_dcct[pt][ctx];
447 if ((coeff_idx>1 && ct==0) || vp56_rac_get_prob(c, model2[0])) {
449 if (vp56_rac_get_prob(c, model2[2])) {
450 if (vp56_rac_get_prob(c, model2[3])) {
451 idx = vp56_rac_get_tree(c, vp56_pc_tree, model1);
452 coeff = vp56_coeff_bias[idx+5];
453 for (i=vp56_coeff_bit_length[idx]; i>=0; i--)
454 coeff += vp56_rac_get_prob(c, vp56_coeff_parse_table[idx][i]) << i;
456 if (vp56_rac_get_prob(c, model2[4]))
457 coeff = 3 + vp56_rac_get_prob(c, model1[5]);
466 sign = vp56_rac_get(c);
467 coeff = (coeff ^ -sign) + sign;
469 coeff *= s->dequant_ac;
470 idx = model->coeff_index_to_pos[coeff_idx];
471 s->block_coeff[b][permute[idx]] = coeff;
477 if (!vp56_rac_get_prob(c, model2[1]))
480 model3 = model->coeff_runv[coeff_idx >= 6];
481 run = vp56_rac_get_tree(c, vp6_pcr_tree, model3);
483 for (run=9, i=0; i<6; i++)
484 run += vp56_rac_get_prob(c, model3[i+8]) << i;
490 cg = vp6_coeff_groups[coeff_idx];
491 model1 = model2 = model->coeff_ract[pt][ct][cg];
494 s->left_block[vp56_b6to4[b]].not_null_dc =
495 s->above_blocks[s->above_block_idx[b]].not_null_dc = !!s->block_coeff[b][0];
499 static int vp6_block_variance(uint8_t *src, int stride)
501 int sum = 0, square_sum = 0;
504 for (y=0; y<8; y+=2) {
505 for (x=0; x<8; x+=2) {
507 square_sum += src[x]*src[x];
511 return (16*square_sum - sum*sum) >> 8;
514 static void vp6_filter_hv4(uint8_t *dst, uint8_t *src, int stride,
515 int delta, const int16_t *weights)
519 for (y=0; y<8; y++) {
520 for (x=0; x<8; x++) {
521 dst[x] = av_clip_uint8(( src[x-delta ] * weights[0]
522 + src[x ] * weights[1]
523 + src[x+delta ] * weights[2]
524 + src[x+2*delta] * weights[3] + 64) >> 7);
531 static void vp6_filter_diag2(VP56Context *s, uint8_t *dst, uint8_t *src,
532 int stride, int h_weight, int v_weight)
534 uint8_t *tmp = s->edge_emu_buffer+16;
535 s->dsp.put_h264_chroma_pixels_tab[0](tmp, src, stride, 9, h_weight, 0);
536 s->dsp.put_h264_chroma_pixels_tab[0](dst, tmp, stride, 8, 0, v_weight);
539 static void vp6_filter(VP56Context *s, uint8_t *dst, uint8_t *src,
540 int offset1, int offset2, int stride,
541 VP56mv mv, int mask, int select, int luma)
544 int x8 = mv.x & mask;
545 int y8 = mv.y & mask;
550 filter4 = s->filter_mode;
552 if (s->max_vector_length &&
553 (FFABS(mv.x) > s->max_vector_length ||
554 FFABS(mv.y) > s->max_vector_length)) {
556 } else if (s->sample_variance_threshold
557 && (vp6_block_variance(src+offset1, stride)
558 < s->sample_variance_threshold)) {
564 if ((y8 && (offset2-offset1)*s->flip<0) || (!y8 && offset1 > offset2)) {
569 if (!y8) { /* left or right combine */
570 vp6_filter_hv4(dst, src+offset1, stride, 1,
571 vp6_block_copy_filter[select][x8]);
572 } else if (!x8) { /* above or below combine */
573 vp6_filter_hv4(dst, src+offset1, stride, stride,
574 vp6_block_copy_filter[select][y8]);
576 s->vp56dsp.vp6_filter_diag4(dst, src+offset1+((mv.x^mv.y)>>31), stride,
577 vp6_block_copy_filter[select][x8],
578 vp6_block_copy_filter[select][y8]);
582 s->dsp.put_h264_chroma_pixels_tab[0](dst, src+offset1, stride, 8, x8, y8);
584 vp6_filter_diag2(s, dst, src+offset1 + ((mv.x^mv.y)>>31), stride, x8, y8);
589 static av_cold int vp6_decode_init(AVCodecContext *avctx)
591 VP56Context *s = avctx->priv_data;
593 ff_vp56_init(avctx, avctx->codec->id == CODEC_ID_VP6,
594 avctx->codec->id == CODEC_ID_VP6A);
595 s->vp56_coord_div = vp6_coord_div;
596 s->parse_vector_adjustment = vp6_parse_vector_adjustment;
597 s->filter = vp6_filter;
598 s->default_models_init = vp6_default_models_init;
599 s->parse_vector_models = vp6_parse_vector_models;
600 s->parse_coeff_models = vp6_parse_coeff_models;
601 s->parse_header = vp6_parse_header;
606 static av_cold int vp6_decode_free(AVCodecContext *avctx)
608 VP56Context *s = avctx->priv_data;
613 for (pt=0; pt<2; pt++) {
614 free_vlc(&s->dccv_vlc[pt]);
615 free_vlc(&s->runv_vlc[pt]);
616 for (ct=0; ct<3; ct++)
617 for (cg=0; cg<6; cg++)
618 free_vlc(&s->ract_vlc[pt][ct][cg]);
623 AVCodec ff_vp6_decoder = {
625 .type = AVMEDIA_TYPE_VIDEO,
627 .priv_data_size = sizeof(VP56Context),
628 .init = vp6_decode_init,
629 .close = vp6_decode_free,
630 .decode = ff_vp56_decode_frame,
631 .capabilities = CODEC_CAP_DR1,
632 .long_name = NULL_IF_CONFIG_SMALL("On2 VP6"),
635 /* flash version, not flipped upside-down */
636 AVCodec ff_vp6f_decoder = {
638 .type = AVMEDIA_TYPE_VIDEO,
640 .priv_data_size = sizeof(VP56Context),
641 .init = vp6_decode_init,
642 .close = vp6_decode_free,
643 .decode = ff_vp56_decode_frame,
644 .capabilities = CODEC_CAP_DR1,
645 .long_name = NULL_IF_CONFIG_SMALL("On2 VP6 (Flash version)"),
648 /* flash version, not flipped upside-down, with alpha channel */
649 AVCodec ff_vp6a_decoder = {
651 .type = AVMEDIA_TYPE_VIDEO,
653 .priv_data_size = sizeof(VP56Context),
654 .init = vp6_decode_init,
655 .close = vp6_decode_free,
656 .decode = ff_vp56_decode_frame,
657 .capabilities = CODEC_CAP_DR1,
658 .long_name = NULL_IF_CONFIG_SMALL("On2 VP6 (Flash version, with alpha channel)"),