uvg266/src/cabac.c
2021-11-23 08:46:06 +02:00

430 lines
12 KiB
C

/*****************************************************************************
* This file is part of uvg266 VVC encoder.
*
* Copyright (c) 2021, Tampere University, ITU/ISO/IEC, project contributors
* All rights reserved.
*
* Redistribution and use in source and binary forms, with or without modification,
* are permitted provided that the following conditions are met:
*
* * Redistributions of source code must retain the above copyright notice, this
* list of conditions and the following disclaimer.
*
* * Redistributions in binary form must reproduce the above copyright notice, this
* list of conditions and the following disclaimer in the documentation and/or
* other materials provided with the distribution.
*
* * Neither the name of the Tampere University or ITU/ISO/IEC nor the names of its
* contributors may be used to endorse or promote products derived from
* this software without specific prior written permission.
*
* THIS SOFTWARE IS PROVIDED BY THE COPYRIGHT HOLDERS AND CONTRIBUTORS "AS IS" AND
* ANY EXPRESS OR IMPLIED WARRANTIES, INCLUDING, BUT NOT LIMITED TO, THE IMPLIED
* WARRANTIES OF MERCHANTABILITY AND FITNESS FOR A PARTICULAR PURPOSE ARE
* DISCLAIMED. IN NO EVENT SHALL THE COPYRIGHT HOLDER OR CONTRIBUTORS BE LIABLE FOR
* ANY DIRECT, INDIRECT, INCIDENTAL, SPECIAL, EXEMPLARY, OR CONSEQUENTIAL DAMAGES
* INCLUDING, BUT NOT LIMITED TO, PROCUREMENT OF SUBSTITUTE GOODS OR SERVICES;
* LOSS OF USE, DATA, OR PROFITS; OR BUSINESS INTERRUPTION HOWEVER CAUSED AND ON
* ANY THEORY OF LIABILITY, WHETHER IN CONTRACT, STRICT LIABILITY, OR TORT
* SOFTWARE, EVEN IF ADVISED OF THE POSSIBILITY OF SUCH DAMAGE.
* INCLUDING NEGLIGENCE OR OTHERWISE ARISING IN ANY WAY OUT OF THE USE OF THIS
****************************************************************************/
#include "cabac.h"
#include "encoder.h"
#include "encoderstate.h"
#include "kvazaar.h"
#ifdef KVZ_DEBUG_PRINT_CABAC
uint32_t kvz_cabac_bins_count = 0;
bool kvz_cabac_bins_verbose = true;
#endif
const uint8_t kvz_g_auc_renorm_table[32] =
{
6, 5, 4, 4, 3, 3, 3, 3, 2, 2, 2, 2, 2, 2, 2, 2,
1, 1, 1, 1, 1, 1, 1, 1, 1, 1, 1, 1, 1, 1, 1, 1
};
static const uint8_t kvz_tb_max[257] = { 0, 0, 1, 1, 2, 2, 2, 2, 3, 3, 3, 3, 3, 3, 3, 3, 4, 4, 4, 4, 4, 4, 4, 4, 4, 4,
4, 4, 4, 4, 4, 4, 5, 5, 5, 5, 5, 5, 5, 5, 5, 5, 5, 5, 5, 5, 5, 5, 5, 5, 5, 5,
5, 5, 5, 5, 5, 5, 5, 5, 5, 5, 5, 5, 6, 6, 6, 6, 6, 6, 6, 6, 6, 6, 6, 6, 6, 6,
6, 6, 6, 6, 6, 6, 6, 6, 6, 6, 6, 6, 6, 6, 6, 6, 6, 6, 6, 6, 6, 6, 6, 6, 6, 6,
6, 6, 6, 6, 6, 6, 6, 6, 6, 6, 6, 6, 6, 6, 6, 6, 6, 6, 6, 6, 6, 6, 6, 6, 7, 7,
7, 7, 7, 7, 7, 7, 7, 7, 7, 7, 7, 7, 7, 7, 7, 7, 7, 7, 7, 7, 7, 7, 7, 7, 7, 7,
7, 7, 7, 7, 7, 7, 7, 7, 7, 7, 7, 7, 7, 7, 7, 7, 7, 7, 7, 7, 7, 7, 7, 7, 7, 7,
7, 7, 7, 7, 7, 7, 7, 7, 7, 7, 7, 7, 7, 7, 7, 7, 7, 7, 7, 7, 7, 7, 7, 7, 7, 7,
7, 7, 7, 7, 7, 7, 7, 7, 7, 7, 7, 7, 7, 7, 7, 7, 7, 7, 7, 7, 7, 7, 7, 7, 7, 7,
7, 7, 7, 7, 7, 7, 7, 7, 7, 7, 7, 7, 7, 7, 7, 7, 7, 7, 7, 7, 7, 7, 8 };
/**
* \brief Initialize struct cabac_data.
*/
void kvz_cabac_start(cabac_data_t * const data)
{
data->low = 0;
data->range = 510;
data->bits_left = 23;
data->num_buffered_bytes = 0;
data->buffered_byte = 0xff;
data->only_count = 0; // By default, write bits out
}
/**
* \brief
*/
void kvz_cabac_encode_bin(cabac_data_t * const data, const uint32_t bin_value)
{
uint32_t lps = CTX_LPS(data->cur_ctx, data->range);
data->range -= lps;
// Not the Most Probable Symbol?
if ((bin_value ? 1 : 0) != CTX_MPS(data->cur_ctx)) {
int num_bits = kvz_g_auc_renorm_table[lps >> 3];
data->low = (data->low + data->range) << num_bits;
data->range = lps << num_bits;
data->bits_left -= num_bits;
if (data->bits_left < 12) {
kvz_cabac_write(data);
}
} else {
if (data->range < 256) {
data->low <<= 1;
data->range <<= 1;
data->bits_left--;
if (data->bits_left < 12) {
kvz_cabac_write(data);
}
}
}
CTX_UPDATE(data->cur_ctx, bin_value);
}
/**
* \brief
*/
void kvz_cabac_write(cabac_data_t * const data)
{
uint32_t lead_byte = data->low >> (24 - data->bits_left);
data->bits_left += 8;
data->low &= 0xffffffffu >> data->bits_left;
// Binary counter mode
if(data->only_count) {
data->num_buffered_bytes++;
return;
}
if (lead_byte == 0xff) {
data->num_buffered_bytes++;
} else {
if (data->num_buffered_bytes > 0) {
uint32_t carry = lead_byte >> 8;
uint32_t byte = data->buffered_byte + carry;
data->buffered_byte = lead_byte & 0xff;
kvz_bitstream_put_byte(data->stream, byte);
byte = (0xff + carry) & 0xff;
while (data->num_buffered_bytes > 1) {
kvz_bitstream_put_byte(data->stream, byte);
data->num_buffered_bytes--;
}
} else {
data->num_buffered_bytes = 1;
data->buffered_byte = lead_byte;
}
}
}
/**
* \brief
*/
void kvz_cabac_finish(cabac_data_t * const data)
{
assert(data->bits_left <= 32);
if (data->low >> (32 - data->bits_left)) {
kvz_bitstream_put_byte(data->stream, data->buffered_byte + 1);
while (data->num_buffered_bytes > 1) {
kvz_bitstream_put_byte(data->stream, 0);
data->num_buffered_bytes--;
}
data->low -= 1 << (32 - data->bits_left);
} else {
if (data->num_buffered_bytes > 0) {
kvz_bitstream_put_byte(data->stream, data->buffered_byte);
}
while (data->num_buffered_bytes > 1) {
kvz_bitstream_put_byte(data->stream, 0xff);
data->num_buffered_bytes--;
}
}
{
uint8_t bits = (uint8_t)(24 - data->bits_left);
kvz_bitstream_put(data->stream, data->low >> 8, bits);
}
}
/*!
\brief Encode terminating bin
\param binValue bin value
*/
void kvz_cabac_encode_bin_trm(cabac_data_t * const data, const uint8_t bin_value)
{
data->range -= 2;
if(bin_value) {
data->low += data->range;
data->low <<= 7;
data->range = 2 << 7;
data->bits_left -= 7;
} else if (data->range >= 256) {
return;
} else {
data->low <<= 1;
data->range <<= 1;
data->bits_left--;
}
if (data->bits_left < 12) {
kvz_cabac_write(data);
}
}
/**
* \brief encode truncated binary code
*/
void kvz_cabac_encode_trunc_bin(cabac_data_t * const data, const uint32_t bin_value, const uint32_t max_value) {
int thresh;
int symbol = bin_value;
if (max_value > 256) {
int threshVal = 1 << 8;
thresh = 8;
while (threshVal <= max_value) {
thresh++;
threshVal <<= 1;
}
thresh--;
} else {
thresh = kvz_tb_max[max_value];
}
int val = 1 << thresh;
int b = max_value - val;
if (symbol < val - b) {
CABAC_BINS_EP(data, symbol, thresh, "TruncSymbols");
} else {
symbol += val - b;
CABAC_BINS_EP(data, symbol, thresh + 1, "TruncSymbols");
}
}
/**
* \brief
*/
void kvz_cabac_encode_bin_ep(cabac_data_t * const data, const uint32_t bin_value)
{
data->low <<= 1;
if (bin_value) {
data->low += data->range;
}
data->bits_left--;
if (data->bits_left < 12) {
kvz_cabac_write(data);
}
}
// Import from VTM 4.0
void kvz_cabac_encode_aligned_bins_ep(cabac_data_t * const data, uint32_t bin_values, int num_bins)
{
uint32_t rem_bins = num_bins;
while (rem_bins > 0) {
//The process of encoding an EP bin is the same as that of coding a normal
//bin where the symbol ranges for 1 and 0 are both half the range:
//
// low = (low + range/2) << 1 (to encode a 1)
// low = low << 1 (to encode a 0)
//
// i.e.
// low = (low + (bin * range/2)) << 1
//
// which is equivalent to:
//
// low = (low << 1) + (bin * range)
//
// this can be generalised for multiple bins, producing the following expression:
//
unsigned bins_to_code = MIN(rem_bins, 8); //code bytes if able to take advantage of the system's byte-write function
unsigned bin_mask = (1 << bins_to_code) - 1;
unsigned new_bins = (bin_values >> (rem_bins - bins_to_code)) & bin_mask;
data->low = (data->low << bins_to_code) + (new_bins << 8); //range is known to be 256
rem_bins -= bins_to_code;
data->bits_left -= bins_to_code;
if (data->bits_left < 12) {
kvz_cabac_write(data);
}
}
}
/**
* \brief
*/
void kvz_cabac_encode_bins_ep(cabac_data_t * const data, uint32_t bin_values, int num_bins)
{
uint32_t pattern;
if (data->range == 256) {
kvz_cabac_encode_aligned_bins_ep(data, bin_values, num_bins);
return;
}
while (num_bins > 8) {
num_bins -= 8;
pattern = bin_values >> num_bins;
data->low <<= 8;
data->low += data->range * pattern;
bin_values -= pattern << num_bins;
data->bits_left -= 8;
if(data->bits_left < 12) {
kvz_cabac_write(data);
}
}
data->low <<= num_bins;
data->low += data->range * bin_values;
data->bits_left -= num_bins;
if (data->bits_left < 12) {
kvz_cabac_write(data);
}
}
/**
* \brief Coding of remainder abs coeff value.
* \param remainder Value of remaining abs coeff
* \param rice_param Reference to Rice parameter.
*/
void kvz_cabac_write_coeff_remain(cabac_data_t * const cabac, const uint32_t remainder, const uint32_t rice_param, const unsigned int cutoff)
{
const unsigned threshold = cutoff << rice_param;
uint32_t bins = remainder;
if (bins < threshold) {
uint32_t length = (bins >> rice_param) + 1;
CABAC_BINS_EP(cabac, ((1 << (length)) - 2) , length, "coeff_abs_level_remaining");
CABAC_BINS_EP(cabac, bins & ((1 << rice_param) - 1), rice_param, "coeff_abs_level_remaining");
} else {
const unsigned max_prefix_length = 32 - cutoff - 15/*max_log2_tr_dynamic_range*/;
unsigned prefix_length = 0;
unsigned code_value = (bins >> rice_param) - cutoff;
unsigned suffix_length;
if (code_value >= ((1 << max_prefix_length) - 1)) {
prefix_length = max_prefix_length;
suffix_length = 15 /*max_log2_tr_dynamic_range*/;
} else {
while (code_value > ((2 << prefix_length) - 2)) {
prefix_length++;
}
suffix_length = prefix_length + rice_param + 1;
}
const unsigned total_prefix_length = prefix_length + cutoff;
const unsigned bit_mask = (1 << rice_param) - 1;
const unsigned prefix = (1 << total_prefix_length) - 1;
const unsigned suffix = ((code_value - ((1 << prefix_length) - 1)) << rice_param) | (bins & bit_mask);
CABAC_BINS_EP(cabac, prefix, total_prefix_length, "coeff_abs_level_remaining");
CABAC_BINS_EP(cabac, suffix, suffix_length, "coeff_abs_level_remaining");
}
}
/**
* \brief
*/
void kvz_cabac_write_unary_max_symbol(cabac_data_t * const data, cabac_ctx_t * const ctx, uint32_t symbol, const int32_t offset, const uint32_t max_symbol)
{
int8_t code_last = max_symbol > symbol;
assert(symbol <= max_symbol);
if (!max_symbol) return;
data->cur_ctx = ctx;
CABAC_BIN(data, symbol, "ums");
if (!symbol) return;
while (--symbol) {
//data->cur_ctx = &ctx[offset];
CABAC_BIN(data, 1, "ums");
}
if (code_last) {
//data->cur_ctx = &ctx[offset];
CABAC_BIN(data, 0, "ums");
}
}
/**
* This can be used for Truncated Rice binarization with cRiceParam=0.
*/
void kvz_cabac_write_unary_max_symbol_ep(cabac_data_t * const data, unsigned int symbol, const unsigned int max_symbol)
{
/*if (symbol == 0) {
CABAC_BIN_EP(data, 0, "ums_ep");
} else {
// Make a bit-string of (symbol) times 1 and a single 0, except when
// symbol == max_symbol.
unsigned bins = ((1 << symbol) - 1) << (symbol < max_symbol);
CABAC_BINS_EP(data, bins, symbol + (symbol < max_symbol), "ums_ep");
}*/
int8_t code_last = max_symbol > symbol;
assert(symbol <= max_symbol);
CABAC_BIN_EP(data, symbol ? 1 : 0, "ums_ep");
if (!symbol) return;
while (--symbol) {
CABAC_BIN_EP(data, 1, "ums_ep");
}
if (code_last) {
CABAC_BIN_EP(data, 0, "ums_ep");
}
}
/**
* \brief
*/
void kvz_cabac_write_ep_ex_golomb(encoder_state_t * const state,
cabac_data_t * const data,
uint32_t symbol,
uint32_t count)
{
uint32_t bins = 0;
int32_t num_bins = 0;
while (symbol >= (uint32_t)(1 << count)) {
bins = 2 * bins + 1;
++num_bins;
symbol -= 1 << count;
++count;
}
bins = 2 * bins;
++num_bins;
bins = (bins << count) | symbol;
num_bins += count;
CABAC_BINS_EP(data, bins, num_bins, "ep_ex_golomb");
}