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FFmpeg/libavcodec/vp5.c

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/**
* @file vp5.c
* VP5 compatible video decoder
*
* Copyright (C) 2006 Aurelien Jacobs <aurel@gnuage.org>
*
* 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 St, Fifth Floor, Boston, MA 02110-1301 USA
*/
#include <stdlib.h>
#include <string.h>
#include "avcodec.h"
#include "dsputil.h"
#include "bitstream.h"
#include "mpegvideo.h"
#include "vp56.h"
#include "vp56data.h"
#include "vp5data.h"
static int vp5_parse_header(vp56_context_t *s, uint8_t *buf, int buf_size,
int *golden_frame)
{
vp56_range_coder_t *c = &s->c;
int rows, cols;
vp56_init_range_decoder(&s->c, buf, buf_size);
s->frames[VP56_FRAME_CURRENT].key_frame = !vp56_rac_get(c);
vp56_rac_get(c);
vp56_init_dequant(s, vp56_rac_gets(c, 6));
if (s->frames[VP56_FRAME_CURRENT].key_frame)
{
vp56_rac_gets(c, 8);
if(vp56_rac_gets(c, 5) > 5)
return 0;
vp56_rac_gets(c, 2);
if (vp56_rac_get(c)) {
av_log(s->avctx, AV_LOG_ERROR, "interlacing not supported\n");
return 0;
}
rows = vp56_rac_gets(c, 8); /* number of stored macroblock rows */
cols = vp56_rac_gets(c, 8); /* number of stored macroblock cols */
vp56_rac_gets(c, 8); /* number of displayed macroblock rows */
vp56_rac_gets(c, 8); /* number of displayed macroblock cols */
vp56_rac_gets(c, 2);
if (16*cols != s->avctx->coded_width ||
16*rows != s->avctx->coded_height) {
avcodec_set_dimensions(s->avctx, 16*cols, 16*rows);
return 2;
}
}
return 1;
}
/* Gives very similar result than the vp6 version except in a few cases */
static int vp5_adjust(int v, int t)
{
int s2, s1 = v >> 31;
v ^= s1;
v -= s1;
v *= v < 2*t;
v -= t;
s2 = v >> 31;
v ^= s2;
v -= s2;
v = t - v;
v += s1;
v ^= s1;
return v;
}
static void vp5_parse_vector_adjustment(vp56_context_t *s, vp56_mv_t *vect)
{
vp56_range_coder_t *c = &s->c;
int comp, di;
for (comp=0; comp<2; comp++) {
int delta = 0;
if (vp56_rac_get_prob(c, s->vector_model_dct[comp])) {
int sign = vp56_rac_get_prob(c, s->vector_model_sig[comp]);
di = vp56_rac_get_prob(c, s->vector_model_pdi[comp][0]);
di |= vp56_rac_get_prob(c, s->vector_model_pdi[comp][1]) << 1;
delta = vp56_rac_get_tree(c, vp56_pva_tree,
s->vector_model_pdv[comp]);
delta = di | (delta << 2);
delta = (delta ^ -sign) + sign;
}
if (!comp)
vect->x = delta;
else
vect->y = delta;
}
}
static void vp5_parse_vector_models(vp56_context_t *s)
{
vp56_range_coder_t *c = &s->c;
int comp, node;
for (comp=0; comp<2; comp++) {
if (vp56_rac_get_prob(c, vp5_vmc_pct[comp][0]))
s->vector_model_dct[comp] = vp56_rac_gets_nn(c, 7);
if (vp56_rac_get_prob(c, vp5_vmc_pct[comp][1]))
s->vector_model_sig[comp] = vp56_rac_gets_nn(c, 7);
if (vp56_rac_get_prob(c, vp5_vmc_pct[comp][2]))
s->vector_model_pdi[comp][0] = vp56_rac_gets_nn(c, 7);
if (vp56_rac_get_prob(c, vp5_vmc_pct[comp][3]))
s->vector_model_pdi[comp][1] = vp56_rac_gets_nn(c, 7);
}
for (comp=0; comp<2; comp++)
for (node=0; node<7; node++)
if (vp56_rac_get_prob(c, vp5_vmc_pct[comp][4 + node]))
s->vector_model_pdv[comp][node] = vp56_rac_gets_nn(c, 7);
}
static void vp5_parse_coeff_models(vp56_context_t *s)
{
vp56_range_coder_t *c = &s->c;
uint8_t def_prob[11];
int node, cg, ctx;
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, vp5_dccv_pct[pt][node])) {
def_prob[node] = vp56_rac_gets_nn(c, 7);
s->coeff_model_dccv[pt][node] = def_prob[node];
} else if (s->frames[VP56_FRAME_CURRENT].key_frame) {
s->coeff_model_dccv[pt][node] = def_prob[node];
}
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, vp5_ract_pct[ct][pt][cg][node])) {
def_prob[node] = vp56_rac_gets_nn(c, 7);
s->coeff_model_ract[pt][ct][cg][node] = def_prob[node];
} else if (s->frames[VP56_FRAME_CURRENT].key_frame) {
s->coeff_model_ract[pt][ct][cg][node] = def_prob[node];
}
/* coeff_model_dcct is a linear combination of coeff_model_dccv */
for (pt=0; pt<2; pt++)
for (ctx=0; ctx<36; ctx++)
for (node=0; node<5; node++)
s->coeff_model_dcct[pt][ctx][node] = clip(((s->coeff_model_dccv[pt][node] * vp5_dccv_lc[node][ctx][0] + 128) >> 8) + vp5_dccv_lc[node][ctx][1], 1, 254);
/* coeff_model_acct is a linear combination of coeff_model_ract */
for (ct=0; ct<3; ct++)
for (pt=0; pt<2; pt++)
for (cg=0; cg<3; cg++)
for (ctx=0; ctx<6; ctx++)
for (node=0; node<5; node++)
s->coeff_model_acct[pt][ct][cg][ctx][node] = clip(((s->coeff_model_ract[pt][ct][cg][node] * vp5_ract_lc[ct][cg][node][ctx][0] + 128) >> 8) + vp5_ract_lc[ct][cg][node][ctx][1], 1, 254);
}
static void vp5_parse_coeff(vp56_context_t *s)
{
vp56_range_coder_t *c = &s->c;
uint8_t *permute = s->scantable.permutated;
uint8_t *model, *model2;
int coeff, sign, coeff_idx;
int b, i, cg, idx, ctx, ctx_last;
int pt = 0; /* plane type (0 for Y, 1 for U or V) */
for (b=0; b<6; b++) {
int ct = 1; /* code type */
if (b > 3) pt = 1;
ctx = 6*s->coeff_ctx[vp56_b6to4[b]][0]
+ s->above_blocks[s->above_block_idx[b]].not_null_dc;
model = s->coeff_model_dccv[pt];
model2 = s->coeff_model_dcct[pt][ctx];
for (coeff_idx=0; coeff_idx<64; ) {
if (vp56_rac_get_prob(c, model2[0])) {
if (vp56_rac_get_prob(c, model2[2])) {
if (vp56_rac_get_prob(c, model2[3])) {
s->coeff_ctx[vp56_b6to4[b]][coeff_idx] = 4;
idx = vp56_rac_get_tree(c, vp56_pc_tree, model);
sign = vp56_rac_get(c);
coeff = vp56_coeff_bias[idx];
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, model[5]);
s->coeff_ctx[vp56_b6to4[b]][coeff_idx] = 3;
} else {
coeff = 2;
s->coeff_ctx[vp56_b6to4[b]][coeff_idx] = 2;
}
sign = vp56_rac_get(c);
}
ct = 2;
} else {
ct = 1;
s->coeff_ctx[vp56_b6to4[b]][coeff_idx] = 1;
sign = vp56_rac_get(c);
coeff = 1;
}
coeff = (coeff ^ -sign) + sign;
if (coeff_idx)
coeff *= s->dequant_ac;
s->block_coeff[b][permute[coeff_idx]] = coeff;
} else {
if (ct && !vp56_rac_get_prob(c, model2[1]))
break;
ct = 0;
s->coeff_ctx[vp56_b6to4[b]][coeff_idx] = 0;
}
cg = vp5_coeff_groups[++coeff_idx];
ctx = s->coeff_ctx[vp56_b6to4[b]][coeff_idx];
model = s->coeff_model_ract[pt][ct][cg];
model2 = cg > 2 ? model : s->coeff_model_acct[pt][ct][cg][ctx];
}
ctx_last = FFMIN(s->coeff_ctx_last[vp56_b6to4[b]], 24);
s->coeff_ctx_last[vp56_b6to4[b]] = coeff_idx;
if (coeff_idx < ctx_last)
for (i=coeff_idx; i<=ctx_last; i++)
s->coeff_ctx[vp56_b6to4[b]][i] = 5;
s->above_blocks[s->above_block_idx[b]].not_null_dc = s->coeff_ctx[vp56_b6to4[b]][0];
}
}
static void vp5_default_models_init(vp56_context_t *s)
{
int i;
for (i=0; i<2; i++) {
s->vector_model_sig[i] = 0x80;
s->vector_model_dct[i] = 0x80;
s->vector_model_pdi[i][0] = 0x55;
s->vector_model_pdi[i][1] = 0x80;
}
memcpy(s->mb_types_stats, vp56_def_mb_types_stats, sizeof(s->mb_types_stats));
memset(s->vector_model_pdv, 0x80, sizeof(s->vector_model_pdv));
}
static int vp5_decode_init(AVCodecContext *avctx)
{
vp56_context_t *s = avctx->priv_data;
vp56_init(s, avctx, 1);
s->vp56_coord_div = vp5_coord_div;
s->parse_vector_adjustment = vp5_parse_vector_adjustment;
s->adjust = vp5_adjust;
s->parse_coeff = vp5_parse_coeff;
s->default_models_init = vp5_default_models_init;
s->parse_vector_models = vp5_parse_vector_models;
s->parse_coeff_models = vp5_parse_coeff_models;
s->parse_header = vp5_parse_header;
return 0;
}
AVCodec vp5_decoder = {
"vp5",
CODEC_TYPE_VIDEO,
CODEC_ID_VP5,
sizeof(vp56_context_t),
vp5_decode_init,
NULL,
vp56_free,
vp56_decode_frame,
};