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ffmpeg/libavcodec/vp6.c

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/**
* @file libavcodec/vp6.c
* VP6 compatible video decoder
*
* Copyright (C) 2006 Aurelien Jacobs <aurel@gnuage.org>
*
* The VP6F decoder accepts an optional 1 byte extradata. It is composed of:
* - upper 4bits: difference between encoded width and visible width
* - lower 4bits: difference between encoded height and visible height
*
* This file is part of FFmpeg.
*
* FFmpeg is free software; you can redistribute it and/or
* modify it under the terms of the GNU Lesser General Public
* License as published by the Free Software Foundation; either
* version 2.1 of the License, or (at your option) any later version.
*
* FFmpeg is distributed in the hope that it will be useful,
* but WITHOUT ANY WARRANTY; without even the implied warranty of
* MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE. See the GNU
* Lesser General Public License for more details.
*
* You should have received a copy of the GNU Lesser General Public
* License along with FFmpeg; if not, write to the Free Software
* Foundation, Inc., 51 Franklin Street, Fifth Floor, Boston, MA 02110-1301 USA
*/
#include <stdlib.h>
#include "avcodec.h"
#include "dsputil.h"
#include "get_bits.h"
#include "huffman.h"
#include "vp56.h"
#include "vp56data.h"
#include "vp6data.h"
static void vp6_parse_coeff(VP56Context *s);
static void vp6_parse_coeff_huffman(VP56Context *s);
static int vp6_parse_header(VP56Context *s, const uint8_t *buf, int buf_size,
int *golden_frame)
{
VP56RangeCoder *c = &s->c;
int parse_filter_info = 0;
int coeff_offset = 0;
int vrt_shift = 0;
int sub_version;
int rows, cols;
int res = 1;
int separated_coeff = buf[0] & 1;
s->framep[VP56_FRAME_CURRENT]->key_frame = !(buf[0] & 0x80);
vp56_init_dequant(s, (buf[0] >> 1) & 0x3F);
if (s->framep[VP56_FRAME_CURRENT]->key_frame) {
sub_version = buf[1] >> 3;
if (sub_version > 8)
return 0;
s->filter_header = buf[1] & 0x06;
if (buf[1] & 1) {
av_log(s->avctx, AV_LOG_ERROR, "interlacing not supported\n");
return 0;
}
if (separated_coeff || !s->filter_header) {
coeff_offset = AV_RB16(buf+2) - 2;
buf += 2;
buf_size -= 2;
}
rows = buf[2]; /* number of stored macroblock rows */
cols = buf[3]; /* number of stored macroblock cols */
/* buf[4] is number of displayed macroblock rows */
/* buf[5] is number of displayed macroblock cols */
if (!s->macroblocks || /* first frame */
16*cols != s->avctx->coded_width ||
16*rows != s->avctx->coded_height) {
avcodec_set_dimensions(s->avctx, 16*cols, 16*rows);
if (s->avctx->extradata_size == 1) {
s->avctx->width -= s->avctx->extradata[0] >> 4;
s->avctx->height -= s->avctx->extradata[0] & 0x0F;
}
res = 2;
}
vp56_init_range_decoder(c, buf+6, buf_size-6);
vp56_rac_gets(c, 2);
parse_filter_info = s->filter_header;
if (sub_version < 8)
vrt_shift = 5;
s->sub_version = sub_version;
} else {
if (!s->sub_version)
return 0;
if (separated_coeff || !s->filter_header) {
coeff_offset = AV_RB16(buf+1) - 2;
buf += 2;
buf_size -= 2;
}
vp56_init_range_decoder(c, buf+1, buf_size-1);
*golden_frame = vp56_rac_get(c);
if (s->filter_header) {
s->deblock_filtering = vp56_rac_get(c);
if (s->deblock_filtering)
vp56_rac_get(c);
if (s->sub_version > 7)
parse_filter_info = vp56_rac_get(c);
}
}
if (parse_filter_info) {
if (vp56_rac_get(c)) {
s->filter_mode = 2;
s->sample_variance_threshold = vp56_rac_gets(c, 5) << vrt_shift;
s->max_vector_length = 2 << vp56_rac_gets(c, 3);
} else if (vp56_rac_get(c)) {
s->filter_mode = 1;
} else {
s->filter_mode = 0;
}
if (s->sub_version > 7)
s->filter_selection = vp56_rac_gets(c, 4);
else
s->filter_selection = 16;
}
s->use_huffman = vp56_rac_get(c);
s->parse_coeff = vp6_parse_coeff;
if (coeff_offset) {
buf += coeff_offset;
buf_size -= coeff_offset;
if (buf_size < 0)
return 0;
if (s->use_huffman) {
s->parse_coeff = vp6_parse_coeff_huffman;
init_get_bits(&s->gb, buf, buf_size<<3);
} else {
vp56_init_range_decoder(&s->cc, buf, buf_size);
s->ccp = &s->cc;
}
} else {
s->ccp = &s->c;
}
return res;
}
static void vp6_coeff_order_table_init(VP56Context *s)
{
int i, pos, idx = 1;
s->modelp->coeff_index_to_pos[0] = 0;
for (i=0; i<16; i++)
for (pos=1; pos<64; pos++)
if (s->modelp->coeff_reorder[pos] == i)
s->modelp->coeff_index_to_pos[idx++] = pos;
}
static void vp6_default_models_init(VP56Context *s)
{
VP56Model *model = s->modelp;
model->vector_dct[0] = 0xA2;
model->vector_dct[1] = 0xA4;
model->vector_sig[0] = 0x80;
model->vector_sig[1] = 0x80;
memcpy(model->mb_types_stats, vp56_def_mb_types_stats, sizeof(model->mb_types_stats));
memcpy(model->vector_fdv, vp6_def_fdv_vector_model, sizeof(model->vector_fdv));
memcpy(model->vector_pdv, vp6_def_pdv_vector_model, sizeof(model->vector_pdv));
memcpy(model->coeff_runv, vp6_def_runv_coeff_model, sizeof(model->coeff_runv));
memcpy(model->coeff_reorder, vp6_def_coeff_reorder, sizeof(model->coeff_reorder));
vp6_coeff_order_table_init(s);
}
static void vp6_parse_vector_models(VP56Context *s)
{
VP56RangeCoder *c = &s->c;
VP56Model *model = s->modelp;
int comp, node;
for (comp=0; comp<2; comp++) {
if (vp56_rac_get_prob(c, vp6_sig_dct_pct[comp][0]))
model->vector_dct[comp] = vp56_rac_gets_nn(c, 7);
if (vp56_rac_get_prob(c, vp6_sig_dct_pct[comp][1]))
model->vector_sig[comp] = vp56_rac_gets_nn(c, 7);
}
for (comp=0; comp<2; comp++)
for (node=0; node<7; node++)
if (vp56_rac_get_prob(c, vp6_pdv_pct[comp][node]))
model->vector_pdv[comp][node] = vp56_rac_gets_nn(c, 7);
for (comp=0; comp<2; comp++)
for (node=0; node<8; node++)
if (vp56_rac_get_prob(c, vp6_fdv_pct[comp][node]))
model->vector_fdv[comp][node] = vp56_rac_gets_nn(c, 7);
}
/* nodes must ascend by count, but with descending symbol order */
static int vp6_huff_cmp(const void *va, const void *vb)
{
const Node *a = va, *b = vb;
return (a->count - b->count)*16 + (b->sym - a->sym);
}
static void vp6_build_huff_tree(VP56Context *s, uint8_t coeff_model[],
const uint8_t *map, unsigned size, VLC *vlc)
{
Node nodes[2*size], *tmp = &nodes[size];
int a, b, i;
/* first compute probabilities from model */
tmp[0].count = 256;
for (i=0; i<size-1; i++) {
a = tmp[i].count * coeff_model[i] >> 8;
b = tmp[i].count * (255 - coeff_model[i]) >> 8;
nodes[map[2*i ]].count = a + !a;
nodes[map[2*i+1]].count = b + !b;
}
free_vlc(vlc);
/* then build the huffman tree accodring to probabilities */
ff_huff_build_tree(s->avctx, vlc, size, nodes, vp6_huff_cmp,
FF_HUFFMAN_FLAG_HNODE_FIRST);
}
static void vp6_parse_coeff_models(VP56Context *s)
{
VP56RangeCoder *c = &s->c;
VP56Model *model = s->modelp;
int def_prob[11];
int node, cg, ctx, pos;
int ct; /* code type */
int pt; /* plane type (0 for Y, 1 for U or V) */
memset(def_prob, 0x80, sizeof(def_prob));
for (pt=0; pt<2; pt++)
for (node=0; node<11; node++)
if (vp56_rac_get_prob(c, vp6_dccv_pct[pt][node])) {
def_prob[node] = vp56_rac_gets_nn(c, 7);
model->coeff_dccv[pt][node] = def_prob[node];
} else if (s->framep[VP56_FRAME_CURRENT]->key_frame) {
model->coeff_dccv[pt][node] = def_prob[node];
}
if (vp56_rac_get(c)) {
for (pos=1; pos<64; pos++)
if (vp56_rac_get_prob(c, vp6_coeff_reorder_pct[pos]))
model->coeff_reorder[pos] = vp56_rac_gets(c, 4);
vp6_coeff_order_table_init(s);
}
for (cg=0; cg<2; cg++)
for (node=0; node<14; node++)
if (vp56_rac_get_prob(c, vp6_runv_pct[cg][node]))
model->coeff_runv[cg][node] = vp56_rac_gets_nn(c, 7);
for (ct=0; ct<3; ct++)
for (pt=0; pt<2; pt++)
for (cg=0; cg<6; cg++)
for (node=0; node<11; node++)
if (vp56_rac_get_prob(c, vp6_ract_pct[ct][pt][cg][node])) {
def_prob[node] = vp56_rac_gets_nn(c, 7);
model->coeff_ract[pt][ct][cg][node] = def_prob[node];
} else if (s->framep[VP56_FRAME_CURRENT]->key_frame) {
model->coeff_ract[pt][ct][cg][node] = def_prob[node];
}
if (s->use_huffman) {
for (pt=0; pt<2; pt++) {
vp6_build_huff_tree(s, model->coeff_dccv[pt],
vp6_huff_coeff_map, 12, &s->dccv_vlc[pt]);
vp6_build_huff_tree(s, model->coeff_runv[pt],
vp6_huff_run_map, 9, &s->runv_vlc[pt]);
for (ct=0; ct<3; ct++)
for (cg = 0; cg < 6; cg++)
vp6_build_huff_tree(s, model->coeff_ract[pt][ct][cg],
vp6_huff_coeff_map, 12,
&s->ract_vlc[pt][ct][cg]);
}
memset(s->nb_null, 0, sizeof(s->nb_null));
} else {
/* coeff_dcct is a linear combination of coeff_dccv */
for (pt=0; pt<2; pt++)
for (ctx=0; ctx<3; ctx++)
for (node=0; node<5; node++)
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);
}
}
static void vp6_parse_vector_adjustment(VP56Context *s, VP56mv *vect)
{
VP56RangeCoder *c = &s->c;
VP56Model *model = s->modelp;
int comp;
*vect = (VP56mv) {0,0};
if (s->vector_candidate_pos < 2)
*vect = s->vector_candidate[0];
for (comp=0; comp<2; comp++) {
int i, delta = 0;
if (vp56_rac_get_prob(c, model->vector_dct[comp])) {
static const uint8_t prob_order[] = {0, 1, 2, 7, 6, 5, 4};
for (i=0; i<sizeof(prob_order); i++) {
int j = prob_order[i];
delta |= vp56_rac_get_prob(c, model->vector_fdv[comp][j])<<j;
}
if (delta & 0xF0)
delta |= vp56_rac_get_prob(c, model->vector_fdv[comp][3])<<3;
else
delta |= 8;
} else {
delta = vp56_rac_get_tree(c, vp56_pva_tree,
model->vector_pdv[comp]);
}
if (delta && vp56_rac_get_prob(c, model->vector_sig[comp]))
delta = -delta;
if (!comp)
vect->x += delta;
else
vect->y += delta;
}
}
/**
* Read number of consecutive blocks with null DC or AC.
* This value is < 74.
*/
static unsigned vp6_get_nb_null(VP56Context *s)
{
unsigned val = get_bits(&s->gb, 2);
if (val == 2)
val += get_bits(&s->gb, 2);
else if (val == 3) {
val = get_bits1(&s->gb) << 2;
val = 6+val + get_bits(&s->gb, 2+val);
}
return val;
}
static void vp6_parse_coeff_huffman(VP56Context *s)
{
VP56Model *model = s->modelp;
uint8_t *permute = s->scantable.permutated;
VLC *vlc_coeff;
int coeff, sign, coeff_idx;
int b, cg, idx;
int pt = 0; /* plane type (0 for Y, 1 for U or V) */
for (b=0; b<6; b++) {
int ct = 0; /* code type */
if (b > 3) pt = 1;
vlc_coeff = &s->dccv_vlc[pt];
for (coeff_idx=0; coeff_idx<64; ) {
int run = 1;
if (coeff_idx<2 && s->nb_null[coeff_idx][pt]) {
s->nb_null[coeff_idx][pt]--;
if (coeff_idx)
break;
} else {
if (get_bits_count(&s->gb) >= s->gb.size_in_bits)
return;
coeff = get_vlc2(&s->gb, vlc_coeff->table, 9, 3);
if (coeff == 0) {
if (coeff_idx) {
int pt = (coeff_idx >= 6);
run += get_vlc2(&s->gb, s->runv_vlc[pt].table, 9, 3);
if (run >= 9)
run += get_bits(&s->gb, 6);
} else
s->nb_null[0][pt] = vp6_get_nb_null(s);
ct = 0;
} else if (coeff == 11) { /* end of block */
if (coeff_idx == 1) /* first AC coeff ? */
s->nb_null[1][pt] = vp6_get_nb_null(s);
break;
} else {
int coeff2 = vp56_coeff_bias[coeff];
if (coeff > 4)
coeff2 += get_bits(&s->gb, coeff <= 9 ? coeff - 4 : 11);
ct = 1 + (coeff2 > 1);
sign = get_bits1(&s->gb);
coeff2 = (coeff2 ^ -sign) + sign;
if (coeff_idx)
coeff2 *= s->dequant_ac;
idx = model->coeff_index_to_pos[coeff_idx];
s->block_coeff[b][permute[idx]] = coeff2;
}
}
coeff_idx+=run;
cg = FFMIN(vp6_coeff_groups[coeff_idx], 3);
vlc_coeff = &s->ract_vlc[pt][ct][cg];
}
}
}
static void vp6_parse_coeff(VP56Context *s)
{
VP56RangeCoder *c = s->ccp;
VP56Model *model = s->modelp;
uint8_t *permute = s->scantable.permutated;
uint8_t *model1, *model2, *model3;
int coeff, sign, coeff_idx;
int b, i, cg, idx, ctx;
int pt = 0; /* plane type (0 for Y, 1 for U or V) */
for (b=0; b<6; b++) {
int ct = 1; /* code type */
int run = 1;
if (b > 3) pt = 1;
ctx = s->left_block[vp56_b6to4[b]].not_null_dc
+ s->above_blocks[s->above_block_idx[b]].not_null_dc;
model1 = model->coeff_dccv[pt];
model2 = model->coeff_dcct[pt][ctx];
for (coeff_idx=0; coeff_idx<64; ) {
if ((coeff_idx>1 && ct==0) || vp56_rac_get_prob(c, model2[0])) {
/* parse a coeff */
if (vp56_rac_get_prob(c, model2[2])) {
if (vp56_rac_get_prob(c, model2[3])) {
idx = vp56_rac_get_tree(c, vp56_pc_tree, model1);
coeff = vp56_coeff_bias[idx+5];
for (i=vp56_coeff_bit_length[idx]; i>=0; i--)
coeff += vp56_rac_get_prob(c, vp56_coeff_parse_table[idx][i]) << i;
} else {
if (vp56_rac_get_prob(c, model2[4]))
coeff = 3 + vp56_rac_get_prob(c, model1[5]);
else
coeff = 2;
}
ct = 2;
} else {
ct = 1;
coeff = 1;
}
sign = vp56_rac_get(c);
coeff = (coeff ^ -sign) + sign;
if (coeff_idx)
coeff *= s->dequant_ac;
idx = model->coeff_index_to_pos[coeff_idx];
s->block_coeff[b][permute[idx]] = coeff;
run = 1;
} else {
/* parse a run */
ct = 0;
if (coeff_idx > 0) {
if (!vp56_rac_get_prob(c, model2[1]))
break;
model3 = model->coeff_runv[coeff_idx >= 6];
run = vp56_rac_get_tree(c, vp6_pcr_tree, model3);
if (!run)
for (run=9, i=0; i<6; i++)
run += vp56_rac_get_prob(c, model3[i+8]) << i;
}
}
cg = vp6_coeff_groups[coeff_idx+=run];
model1 = model2 = model->coeff_ract[pt][ct][cg];
}
s->left_block[vp56_b6to4[b]].not_null_dc =
s->above_blocks[s->above_block_idx[b]].not_null_dc = !!s->block_coeff[b][0];
}
}
static int vp6_adjust(int v, int t)
{
int V = v, s = v >> 31;
V ^= s;
V -= s;
if (V-t-1 >= (unsigned)(t-1))
return v;
V = 2*t - V;
V += s;
V ^= s;
return V;
}
static int vp6_block_variance(uint8_t *src, int stride)
{
int sum = 0, square_sum = 0;
int y, x;
for (y=0; y<8; y+=2) {
for (x=0; x<8; x+=2) {
sum += src[x];
square_sum += src[x]*src[x];
}
src += 2*stride;
}
return (16*square_sum - sum*sum) >> 8;
}
static void vp6_filter_hv4(uint8_t *dst, uint8_t *src, int stride,
int delta, const int16_t *weights)
{
int x, y;
for (y=0; y<8; y++) {
for (x=0; x<8; x++) {
dst[x] = av_clip_uint8(( src[x-delta ] * weights[0]
+ src[x ] * weights[1]
+ src[x+delta ] * weights[2]
+ src[x+2*delta] * weights[3] + 64) >> 7);
}
src += stride;
dst += stride;
}
}
static void vp6_filter_diag2(VP56Context *s, uint8_t *dst, uint8_t *src,
int stride, int h_weight, int v_weight)
{
uint8_t *tmp = s->edge_emu_buffer+16;
s->dsp.put_h264_chroma_pixels_tab[0](tmp, src, stride, 9, h_weight, 0);
s->dsp.put_h264_chroma_pixels_tab[0](dst, tmp, stride, 8, 0, v_weight);
}
static void vp6_filter(VP56Context *s, uint8_t *dst, uint8_t *src,
int offset1, int offset2, int stride,
VP56mv mv, int mask, int select, int luma)
{
int filter4 = 0;
int x8 = mv.x & mask;
int y8 = mv.y & mask;
if (luma) {
x8 *= 2;
y8 *= 2;
filter4 = s->filter_mode;
if (filter4 == 2) {
if (s->max_vector_length &&
(FFABS(mv.x) > s->max_vector_length ||
FFABS(mv.y) > s->max_vector_length)) {
filter4 = 0;
} else if (s->sample_variance_threshold
&& (vp6_block_variance(src+offset1, stride)
< s->sample_variance_threshold)) {
filter4 = 0;
}
}
}
if ((y8 && (offset2-offset1)*s->flip<0) || (!y8 && offset1 > offset2)) {
offset1 = offset2;
}
if (filter4) {
if (!y8) { /* left or right combine */
vp6_filter_hv4(dst, src+offset1, stride, 1,
vp6_block_copy_filter[select][x8]);
} else if (!x8) { /* above or below combine */
vp6_filter_hv4(dst, src+offset1, stride, stride,
vp6_block_copy_filter[select][y8]);
} else {
s->dsp.vp6_filter_diag4(dst, src+offset1+((mv.x^mv.y)>>31), stride,
vp6_block_copy_filter[select][x8],
vp6_block_copy_filter[select][y8]);
}
} else {
if (!x8 || !y8) {
s->dsp.put_h264_chroma_pixels_tab[0](dst, src+offset1, stride, 8, x8, y8);
} else {
vp6_filter_diag2(s, dst, src+offset1 + ((mv.x^mv.y)>>31), stride, x8, y8);
}
}
}
static av_cold int vp6_decode_init(AVCodecContext *avctx)
{
VP56Context *s = avctx->priv_data;
vp56_init(avctx, avctx->codec->id == CODEC_ID_VP6,
avctx->codec->id == CODEC_ID_VP6A);
s->vp56_coord_div = vp6_coord_div;
s->parse_vector_adjustment = vp6_parse_vector_adjustment;
s->adjust = vp6_adjust;
s->filter = vp6_filter;
s->default_models_init = vp6_default_models_init;
s->parse_vector_models = vp6_parse_vector_models;
s->parse_coeff_models = vp6_parse_coeff_models;
s->parse_header = vp6_parse_header;
return 0;
}
static av_cold int vp6_decode_free(AVCodecContext *avctx)
{
VP56Context *s = avctx->priv_data;
int pt, ct, cg;
vp56_free(avctx);
for (pt=0; pt<2; pt++) {
free_vlc(&s->dccv_vlc[pt]);
free_vlc(&s->runv_vlc[pt]);
for (ct=0; ct<3; ct++)
for (cg=0; cg<6; cg++)
free_vlc(&s->ract_vlc[pt][ct][cg]);
}
return 0;
}
AVCodec vp6_decoder = {
"vp6",
AVMEDIA_TYPE_VIDEO,
CODEC_ID_VP6,
sizeof(VP56Context),
vp6_decode_init,
NULL,
vp6_decode_free,
vp56_decode_frame,
CODEC_CAP_DR1,
.long_name = NULL_IF_CONFIG_SMALL("On2 VP6"),
};
/* flash version, not flipped upside-down */
AVCodec vp6f_decoder = {
"vp6f",
AVMEDIA_TYPE_VIDEO,
CODEC_ID_VP6F,
sizeof(VP56Context),
vp6_decode_init,
NULL,
vp6_decode_free,
vp56_decode_frame,
CODEC_CAP_DR1,
.long_name = NULL_IF_CONFIG_SMALL("On2 VP6 (Flash version)"),
};
/* flash version, not flipped upside-down, with alpha channel */
AVCodec vp6a_decoder = {
"vp6a",
AVMEDIA_TYPE_VIDEO,
CODEC_ID_VP6A,
sizeof(VP56Context),
vp6_decode_init,
NULL,
vp6_decode_free,
vp56_decode_frame,
CODEC_CAP_DR1,
.long_name = NULL_IF_CONFIG_SMALL("On2 VP6 (Flash version, with alpha channel)"),
};
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