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/*
* Copyright (c) 2001-2016, Alliance for Open Media. All rights reserved.
*
* This source code is subject to the terms of the BSD 2 Clause License and
* the Alliance for Open Media Patent License 1.0. If the BSD 2 Clause License
* was not distributed with this source code in the LICENSE file, you can
* obtain it at www.aomedia.org/license/software. If the Alliance for Open
* Media Patent License 1.0 was not distributed with this source code in the
* PATENTS file, you can obtain it at www.aomedia.org/license/patent.
*/
#ifndef AOM_AOM_DSP_ENTENC_H_
#define AOM_AOM_DSP_ENTENC_H_
#include <stddef.h>
#include "aom_dsp/entcode.h"
#include "aom_util/endian_inl.h"
#ifdef __cplusplus
extern "C" {
#endif
typedef uint64_t od_ec_enc_window;
typedef struct od_ec_enc od_ec_enc;
#define OD_MEASURE_EC_OVERHEAD (0)
/*The entropy encoder context.*/
struct od_ec_enc {
/*Buffered output.
This contains only the raw bits until the final call to od_ec_enc_done(),
where all the arithmetic-coded data gets prepended to it.*/
unsigned char *buf;
/*The size of the buffer.*/
uint32_t storage;
/*The offset at which the next entropy-coded byte will be written.*/
uint32_t offs;
/*The low end of the current range.*/
od_ec_enc_window low;
/*The number of values in the current range.*/
uint16_t rng;
/*The number of bits of data in the current value.*/
int16_t cnt;
/*Nonzero if an error occurred.*/
int error;
#if OD_MEASURE_EC_OVERHEAD
double entropy;
int nb_symbols;
#endif
};
/*See entenc.c for further documentation.*/
void od_ec_enc_init(od_ec_enc *enc, uint32_t size) OD_ARG_NONNULL(1);
void od_ec_enc_reset(od_ec_enc *enc) OD_ARG_NONNULL(1);
void od_ec_enc_clear(od_ec_enc *enc) OD_ARG_NONNULL(1);
void od_ec_encode_bool_q15(od_ec_enc *enc, int val, unsigned f_q15)
OD_ARG_NONNULL(1);
void od_ec_encode_cdf_q15(od_ec_enc *enc, int s, const uint16_t *cdf, int nsyms)
OD_ARG_NONNULL(1) OD_ARG_NONNULL(3);
void od_ec_enc_bits(od_ec_enc *enc, uint32_t fl, unsigned ftb)
OD_ARG_NONNULL(1);
void od_ec_enc_patch_initial_bits(od_ec_enc *enc, unsigned val, int nbits)
OD_ARG_NONNULL(1);
OD_WARN_UNUSED_RESULT unsigned char *od_ec_enc_done(od_ec_enc *enc,
uint32_t *nbytes)
OD_ARG_NONNULL(1) OD_ARG_NONNULL(2);
OD_WARN_UNUSED_RESULT int od_ec_enc_tell(const od_ec_enc *enc)
OD_ARG_NONNULL(1);
OD_WARN_UNUSED_RESULT uint32_t od_ec_enc_tell_frac(const od_ec_enc *enc)
OD_ARG_NONNULL(1);
// buf is the frame bitbuffer, offs is where carry to be added
static inline void propagate_carry_bwd(unsigned char *buf, uint32_t offs) {
uint16_t sum, carry = 1;
do {
sum = (uint16_t)buf[offs] + 1;
buf[offs--] = (unsigned char)sum;
carry = sum >> 8;
} while (carry);
}
// Convert to big-endian byte order and write data to buffer adding the
// carry-bit
static inline void write_enc_data_to_out_buf(unsigned char *out, uint32_t offs,
uint64_t output, uint64_t carry,
uint32_t *enc_offs,
uint8_t num_bytes_ready) {
const uint64_t reg = HToBE64(output << ((8 - num_bytes_ready) << 3));
memcpy(&out[offs], &reg, 8);
// Propagate carry backwards if exists
if (carry) {
assert(offs > 0);
propagate_carry_bwd(out, offs - 1);
}
*enc_offs = offs + num_bytes_ready;
}
#ifdef __cplusplus
} // extern "C"
#endif
#endif // AOM_AOM_DSP_ENTENC_H_