vpx/vp9/common/vp9_entropy.h
Jim Bankoski d6667dd54f scan order table lookup same for encoder and decoder
Change-Id: I473947b5ca70b7a81151926284bff86f8555492a
2013-11-19 15:31:43 -08:00

205 lines
7.5 KiB
C

/*
* Copyright (c) 2010 The WebM project authors. All Rights Reserved.
*
* Use of this source code is governed by a BSD-style license
* that can be found in the LICENSE file in the root of the source
* tree. An additional intellectual property rights grant can be found
* in the file PATENTS. All contributing project authors may
* be found in the AUTHORS file in the root of the source tree.
*/
#ifndef VP9_COMMON_VP9_ENTROPY_H_
#define VP9_COMMON_VP9_ENTROPY_H_
#include "vpx/vpx_integer.h"
#include "vp9/common/vp9_blockd.h"
#include "vp9/common/vp9_common.h"
#include "vp9/common/vp9_scan.h"
#include "vp9/common/vp9_treecoder.h"
#include "vp9/common/vp9_entropymode.h"
#define DIFF_UPDATE_PROB 252
/* Coefficient token alphabet */
#define ZERO_TOKEN 0 /* 0 Extra Bits 0+0 */
#define ONE_TOKEN 1 /* 1 Extra Bits 0+1 */
#define TWO_TOKEN 2 /* 2 Extra Bits 0+1 */
#define THREE_TOKEN 3 /* 3 Extra Bits 0+1 */
#define FOUR_TOKEN 4 /* 4 Extra Bits 0+1 */
#define DCT_VAL_CATEGORY1 5 /* 5-6 Extra Bits 1+1 */
#define DCT_VAL_CATEGORY2 6 /* 7-10 Extra Bits 2+1 */
#define DCT_VAL_CATEGORY3 7 /* 11-18 Extra Bits 3+1 */
#define DCT_VAL_CATEGORY4 8 /* 19-34 Extra Bits 4+1 */
#define DCT_VAL_CATEGORY5 9 /* 35-66 Extra Bits 5+1 */
#define DCT_VAL_CATEGORY6 10 /* 67+ Extra Bits 14+1 */
#define DCT_EOB_TOKEN 11 /* EOB Extra Bits 0+0 */
#define MAX_ENTROPY_TOKENS 12
#define ENTROPY_NODES 11
#define EOSB_TOKEN 127 /* Not signalled, encoder only */
#define INTER_MODE_CONTEXTS 7
extern DECLARE_ALIGNED(16, const uint8_t,
vp9_pt_energy_class[MAX_ENTROPY_TOKENS]);
extern const vp9_tree_index vp9_coef_tree[TREE_SIZE(MAX_ENTROPY_TOKENS)];
#define DCT_EOB_MODEL_TOKEN 3 /* EOB Extra Bits 0+0 */
extern const vp9_tree_index vp9_coefmodel_tree[];
extern struct vp9_token vp9_coef_encodings[MAX_ENTROPY_TOKENS];
typedef struct {
const vp9_tree_index *tree;
const vp9_prob *prob;
int len;
int base_val;
} vp9_extra_bit;
// indexed by token value
extern const vp9_extra_bit vp9_extra_bits[MAX_ENTROPY_TOKENS];
#define MAX_PROB 255
#define DCT_MAX_VALUE 16384
/* Coefficients are predicted via a 3-dimensional probability table. */
/* Outside dimension. 0 = Y with DC, 1 = UV */
#define BLOCK_TYPES 2
#define REF_TYPES 2 // intra=0, inter=1
/* Middle dimension reflects the coefficient position within the transform. */
#define COEF_BANDS 6
/* Inside dimension is measure of nearby complexity, that reflects the energy
of nearby coefficients are nonzero. For the first coefficient (DC, unless
block type is 0), we look at the (already encoded) blocks above and to the
left of the current block. The context index is then the number (0,1,or 2)
of these blocks having nonzero coefficients.
After decoding a coefficient, the measure is determined by the size of the
most recently decoded coefficient.
Note that the intuitive meaning of this measure changes as coefficients
are decoded, e.g., prior to the first token, a zero means that my neighbors
are empty while, after the first token, because of the use of end-of-block,
a zero means we just decoded a zero and hence guarantees that a non-zero
coefficient will appear later in this block. However, this shift
in meaning is perfectly OK because our context depends also on the
coefficient band (and since zigzag positions 0, 1, and 2 are in
distinct bands). */
#define PREV_COEF_CONTEXTS 6
// #define ENTROPY_STATS
typedef unsigned int vp9_coeff_count[REF_TYPES][COEF_BANDS][PREV_COEF_CONTEXTS]
[MAX_ENTROPY_TOKENS];
typedef unsigned int vp9_coeff_stats[REF_TYPES][COEF_BANDS][PREV_COEF_CONTEXTS]
[ENTROPY_NODES][2];
#define SUBEXP_PARAM 4 /* Subexponential code parameter */
#define MODULUS_PARAM 13 /* Modulus parameter */
struct VP9Common;
void vp9_default_coef_probs(struct VP9Common *cm);
void vp9_coef_tree_initialize();
void vp9_adapt_coef_probs(struct VP9Common *cm);
static INLINE void reset_skip_context(MACROBLOCKD *xd, BLOCK_SIZE bsize) {
int i;
for (i = 0; i < MAX_MB_PLANE; i++) {
struct macroblockd_plane *const pd = &xd->plane[i];
const BLOCK_SIZE plane_bsize = get_plane_block_size(bsize, pd);
vpx_memset(pd->above_context, 0, sizeof(ENTROPY_CONTEXT) *
num_4x4_blocks_wide_lookup[plane_bsize]);
vpx_memset(pd->left_context, 0, sizeof(ENTROPY_CONTEXT) *
num_4x4_blocks_high_lookup[plane_bsize]);
}
}
// This is the index in the scan order beyond which all coefficients for
// 8x8 transform and above are in the top band.
// This macro is currently unused but may be used by certain implementations
#define MAXBAND_INDEX 21
extern const uint8_t vp9_coefband_trans_8x8plus[1024];
extern const uint8_t vp9_coefband_trans_4x4[16];
static const uint8_t *get_band_translate(TX_SIZE tx_size) {
return tx_size == TX_4X4 ? vp9_coefband_trans_4x4
: vp9_coefband_trans_8x8plus;
}
// 128 lists of probabilities are stored for the following ONE node probs:
// 1, 3, 5, 7, ..., 253, 255
// In between probabilities are interpolated linearly
#define COEFPROB_MODELS 128
#define UNCONSTRAINED_NODES 3
#define PIVOT_NODE 2 // which node is pivot
#define MODEL_NODES (ENTROPY_NODES - UNCONSTRAINED_NODES)
extern const vp9_prob vp9_pareto8_full[255][MODEL_NODES];
typedef vp9_prob vp9_coeff_probs_model[REF_TYPES][COEF_BANDS]
[PREV_COEF_CONTEXTS]
[UNCONSTRAINED_NODES];
typedef unsigned int vp9_coeff_count_model[REF_TYPES][COEF_BANDS]
[PREV_COEF_CONTEXTS]
[UNCONSTRAINED_NODES + 1];
void vp9_model_to_full_probs(const vp9_prob *model, vp9_prob *full);
static int get_entropy_context(TX_SIZE tx_size, const ENTROPY_CONTEXT *a,
const ENTROPY_CONTEXT *l) {
ENTROPY_CONTEXT above_ec = 0, left_ec = 0;
switch (tx_size) {
case TX_4X4:
above_ec = a[0] != 0;
left_ec = l[0] != 0;
break;
case TX_8X8:
above_ec = !!*(const uint16_t *)a;
left_ec = !!*(const uint16_t *)l;
break;
case TX_16X16:
above_ec = !!*(const uint32_t *)a;
left_ec = !!*(const uint32_t *)l;
break;
case TX_32X32:
above_ec = !!*(const uint64_t *)a;
left_ec = !!*(const uint64_t *)l;
break;
default:
assert(!"Invalid transform size.");
}
return combine_entropy_contexts(above_ec, left_ec);
}
static void get_scan(const MACROBLOCKD *xd, TX_SIZE tx_size,
PLANE_TYPE type, int block_idx,
const int16_t **scan, const int16_t **scan_nb) {
const MODE_INFO *const mi = xd->mi_8x8[0];
const MB_MODE_INFO *const mbmi = &mi->mbmi;
const scan_order *so;
if (is_inter_block(mbmi) || type != PLANE_TYPE_Y_WITH_DC || xd->lossless) {
so = &inter_scan_orders[tx_size];
} else {
const MB_PREDICTION_MODE mode =
mbmi->sb_type < BLOCK_8X8 ? mi->bmi[block_idx].as_mode : mbmi->mode;
so = &intra_scan_orders[tx_size][mode];
}
*scan = so->scan;
*scan_nb = so->neighbors;
}
#endif // VP9_COMMON_VP9_ENTROPY_H_