FFmpeg/libavcodec/vp56.h
2012-01-07 22:13:12 +01:00

374 lines
10 KiB
C

/*
* Copyright (C) 2006 Aurelien Jacobs <aurel@gnuage.org>
*
* This file is part of Libav.
*
* Libav 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.
*
* Libav 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 Libav; if not, write to the Free Software
* Foundation, Inc., 51 Franklin Street, Fifth Floor, Boston, MA 02110-1301 USA
*/
/**
* @file
* VP5 and VP6 compatible video decoder (common features)
*/
#ifndef AVCODEC_VP56_H
#define AVCODEC_VP56_H
#include "vp56data.h"
#include "dsputil.h"
#include "get_bits.h"
#include "bytestream.h"
#include "vp56dsp.h"
typedef struct vp56_context VP56Context;
typedef struct {
int16_t x;
int16_t y;
} DECLARE_ALIGNED(4, , VP56mv);
typedef void (*VP56ParseVectorAdjustment)(VP56Context *s,
VP56mv *vect);
typedef void (*VP56Filter)(VP56Context *s, uint8_t *dst, uint8_t *src,
int offset1, int offset2, int stride,
VP56mv mv, int mask, int select, int luma);
typedef void (*VP56ParseCoeff)(VP56Context *s);
typedef void (*VP56DefaultModelsInit)(VP56Context *s);
typedef void (*VP56ParseVectorModels)(VP56Context *s);
typedef int (*VP56ParseCoeffModels)(VP56Context *s);
typedef int (*VP56ParseHeader)(VP56Context *s, const uint8_t *buf,
int buf_size, int *golden_frame);
typedef struct {
int high;
int bits; /* stored negated (i.e. negative "bits" is a positive number of
bits left) in order to eliminate a negate in cache refilling */
const uint8_t *buffer;
const uint8_t *end;
unsigned int code_word;
} VP56RangeCoder;
typedef struct {
uint8_t not_null_dc;
VP56Frame ref_frame;
DCTELEM dc_coeff;
} VP56RefDc;
typedef struct {
uint8_t type;
VP56mv mv;
} VP56Macroblock;
typedef struct {
uint8_t coeff_reorder[64]; /* used in vp6 only */
uint8_t coeff_index_to_pos[64]; /* used in vp6 only */
uint8_t vector_sig[2]; /* delta sign */
uint8_t vector_dct[2]; /* delta coding types */
uint8_t vector_pdi[2][2]; /* predefined delta init */
uint8_t vector_pdv[2][7]; /* predefined delta values */
uint8_t vector_fdv[2][8]; /* 8 bit delta value definition */
uint8_t coeff_dccv[2][11]; /* DC coeff value */
uint8_t coeff_ract[2][3][6][11]; /* Run/AC coding type and AC coeff value */
uint8_t coeff_acct[2][3][3][6][5];/* vp5 only AC coding type for coding group < 3 */
uint8_t coeff_dcct[2][36][5]; /* DC coeff coding type */
uint8_t coeff_runv[2][14]; /* run value (vp6 only) */
uint8_t mb_type[3][10][10]; /* model for decoding MB type */
uint8_t mb_types_stats[3][10][2];/* contextual, next MB type stats */
} VP56Model;
struct vp56_context {
AVCodecContext *avctx;
DSPContext dsp;
VP56DSPContext vp56dsp;
ScanTable scantable;
AVFrame frames[4];
AVFrame *framep[6];
uint8_t *edge_emu_buffer_alloc;
uint8_t *edge_emu_buffer;
VP56RangeCoder c;
VP56RangeCoder cc;
VP56RangeCoder *ccp;
int sub_version;
/* frame info */
int plane_width[4];
int plane_height[4];
int mb_width; /* number of horizontal MB */
int mb_height; /* number of vertical MB */
int block_offset[6];
int quantizer;
uint16_t dequant_dc;
uint16_t dequant_ac;
int8_t *qscale_table;
/* DC predictors management */
VP56RefDc *above_blocks;
VP56RefDc left_block[4];
int above_block_idx[6];
DCTELEM prev_dc[3][3]; /* [plan][ref_frame] */
/* blocks / macroblock */
VP56mb mb_type;
VP56Macroblock *macroblocks;
DECLARE_ALIGNED(16, DCTELEM, block_coeff)[6][64];
/* motion vectors */
VP56mv mv[6]; /* vectors for each block in MB */
VP56mv vector_candidate[2];
int vector_candidate_pos;
/* filtering hints */
int filter_header; /* used in vp6 only */
int deblock_filtering;
int filter_selection;
int filter_mode;
int max_vector_length;
int sample_variance_threshold;
uint8_t coeff_ctx[4][64]; /* used in vp5 only */
uint8_t coeff_ctx_last[4]; /* used in vp5 only */
int has_alpha;
/* upside-down flipping hints */
int flip; /* are we flipping ? */
int frbi; /* first row block index in MB */
int srbi; /* second row block index in MB */
int stride[4]; /* stride for each plan */
const uint8_t *vp56_coord_div;
VP56ParseVectorAdjustment parse_vector_adjustment;
VP56Filter filter;
VP56ParseCoeff parse_coeff;
VP56DefaultModelsInit default_models_init;
VP56ParseVectorModels parse_vector_models;
VP56ParseCoeffModels parse_coeff_models;
VP56ParseHeader parse_header;
VP56Model *modelp;
VP56Model models[2];
/* huffman decoding */
int use_huffman;
GetBitContext gb;
VLC dccv_vlc[2];
VLC runv_vlc[2];
VLC ract_vlc[2][3][6];
unsigned int nb_null[2][2]; /* number of consecutive NULL DC/AC */
};
void ff_vp56_init(AVCodecContext *avctx, int flip, int has_alpha);
int ff_vp56_free(AVCodecContext *avctx);
void ff_vp56_init_dequant(VP56Context *s, int quantizer);
int ff_vp56_decode_frame(AVCodecContext *avctx, void *data, int *data_size,
AVPacket *avpkt);
/**
* vp56 specific range coder implementation
*/
extern const uint8_t ff_vp56_norm_shift[256];
void ff_vp56_init_range_decoder(VP56RangeCoder *c, const uint8_t *buf, int buf_size);
static av_always_inline unsigned int vp56_rac_renorm(VP56RangeCoder *c)
{
int shift = ff_vp56_norm_shift[c->high];
int bits = c->bits;
unsigned int code_word = c->code_word;
c->high <<= shift;
code_word <<= shift;
bits += shift;
if(bits >= 0 && c->buffer < c->end) {
code_word |= bytestream_get_be16(&c->buffer) << bits;
bits -= 16;
}
c->bits = bits;
return code_word;
}
#if ARCH_ARM
#include "arm/vp56_arith.h"
#elif ARCH_X86
#include "x86/vp56_arith.h"
#endif
#ifndef vp56_rac_get_prob
#define vp56_rac_get_prob vp56_rac_get_prob
static av_always_inline int vp56_rac_get_prob(VP56RangeCoder *c, uint8_t prob)
{
unsigned int code_word = vp56_rac_renorm(c);
unsigned int low = 1 + (((c->high - 1) * prob) >> 8);
unsigned int low_shift = low << 16;
int bit = code_word >= low_shift;
c->high = bit ? c->high - low : low;
c->code_word = bit ? code_word - low_shift : code_word;
return bit;
}
#endif
#ifndef vp56_rac_get_prob_branchy
// branchy variant, to be used where there's a branch based on the bit decoded
static av_always_inline int vp56_rac_get_prob_branchy(VP56RangeCoder *c, int prob)
{
unsigned long code_word = vp56_rac_renorm(c);
unsigned low = 1 + (((c->high - 1) * prob) >> 8);
unsigned low_shift = low << 16;
if (code_word >= low_shift) {
c->high -= low;
c->code_word = code_word - low_shift;
return 1;
}
c->high = low;
c->code_word = code_word;
return 0;
}
#endif
static av_always_inline int vp56_rac_get(VP56RangeCoder *c)
{
unsigned int code_word = vp56_rac_renorm(c);
/* equiprobable */
int low = (c->high + 1) >> 1;
unsigned int low_shift = low << 16;
int bit = code_word >= low_shift;
if (bit) {
c->high -= low;
code_word -= low_shift;
} else {
c->high = low;
}
c->code_word = code_word;
return bit;
}
// rounding is different than vp56_rac_get, is vp56_rac_get wrong?
static av_always_inline int vp8_rac_get(VP56RangeCoder *c)
{
return vp56_rac_get_prob(c, 128);
}
static av_unused int vp56_rac_gets(VP56RangeCoder *c, int bits)
{
int value = 0;
while (bits--) {
value = (value << 1) | vp56_rac_get(c);
}
return value;
}
static av_unused int vp8_rac_get_uint(VP56RangeCoder *c, int bits)
{
int value = 0;
while (bits--) {
value = (value << 1) | vp8_rac_get(c);
}
return value;
}
// fixme: add 1 bit to all the calls to this?
static av_unused int vp8_rac_get_sint(VP56RangeCoder *c, int bits)
{
int v;
if (!vp8_rac_get(c))
return 0;
v = vp8_rac_get_uint(c, bits);
if (vp8_rac_get(c))
v = -v;
return v;
}
// P(7)
static av_unused int vp56_rac_gets_nn(VP56RangeCoder *c, int bits)
{
int v = vp56_rac_gets(c, 7) << 1;
return v + !v;
}
static av_unused int vp8_rac_get_nn(VP56RangeCoder *c)
{
int v = vp8_rac_get_uint(c, 7) << 1;
return v + !v;
}
static av_always_inline
int vp56_rac_get_tree(VP56RangeCoder *c,
const VP56Tree *tree,
const uint8_t *probs)
{
while (tree->val > 0) {
if (vp56_rac_get_prob(c, probs[tree->prob_idx]))
tree += tree->val;
else
tree++;
}
return -tree->val;
}
/**
* This is identical to vp8_rac_get_tree except for the possibility of starting
* on a node other than the root node, needed for coeff decode where this is
* used to save a bit after a 0 token (by disallowing EOB to immediately follow.)
*/
static av_always_inline
int vp8_rac_get_tree_with_offset(VP56RangeCoder *c, const int8_t (*tree)[2],
const uint8_t *probs, int i)
{
do {
i = tree[i][vp56_rac_get_prob(c, probs[i])];
} while (i > 0);
return -i;
}
// how probabilities are associated with decisions is different I think
// well, the new scheme fits in the old but this way has one fewer branches per decision
static av_always_inline
int vp8_rac_get_tree(VP56RangeCoder *c, const int8_t (*tree)[2],
const uint8_t *probs)
{
return vp8_rac_get_tree_with_offset(c, tree, probs, 0);
}
// DCTextra
static av_always_inline int vp8_rac_get_coeff(VP56RangeCoder *c, const uint8_t *prob)
{
int v = 0;
do {
v = (v<<1) + vp56_rac_get_prob(c, *prob++);
} while (*prob);
return v;
}
#endif /* AVCODEC_VP56_H */