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/*
* Copyright (c) 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.
*/
#include <string.h>
#include "aom_dsp/buf_ans.h"
#include "aom_mem/aom_mem.h"
#include "aom/internal/aom_codec_internal.h"
void aom_buf_ans_alloc(struct BufAnsCoder *c,
struct aom_internal_error_info *error, int size) {
c->error = error;
c->size = size;
assert(c->size > 1);
AOM_CHECK_MEM_ERROR(error, c->buf, aom_malloc(c->size * sizeof(*c->buf)));
// Initialize to overfull to trigger the assert in write.
c->offset = c->size + 1;
}
void aom_buf_ans_free(struct BufAnsCoder *c) {
aom_free(c->buf);
c->buf = NULL;
c->size = 0;
}
#if !ANS_MAX_SYMBOLS
void aom_buf_ans_grow(struct BufAnsCoder *c) {
struct buffered_ans_symbol *new_buf = NULL;
int new_size = c->size * 2;
AOM_CHECK_MEM_ERROR(c->error, new_buf,
aom_malloc(new_size * sizeof(*new_buf)));
memcpy(new_buf, c->buf, c->size * sizeof(*c->buf));
aom_free(c->buf);
c->buf = new_buf;
c->size = new_size;
}
#endif
void aom_buf_ans_flush(struct BufAnsCoder *const c) {
int offset;
#if ANS_MAX_SYMBOLS
if (c->offset == 0) return;
#endif
assert(c->offset > 0);
offset = c->offset - 1;
// Code the first symbol such that it brings the state to the smallest normal
// state from an initial state that would have been a subnormal/refill state.
if (c->buf[offset].method == ANS_METHOD_RANS) {
c->ans.state += c->buf[offset].val_start;
} else {
c->ans.state += c->buf[offset].val_start ? c->buf[offset].prob : 0;
}
for (offset = offset - 1; offset >= 0; --offset) {
if (c->buf[offset].method == ANS_METHOD_RANS) {
rans_write(&c->ans, c->buf[offset].val_start, c->buf[offset].prob);
} else {
rabs_write(&c->ans, (uint8_t)c->buf[offset].val_start,
(AnsP8)c->buf[offset].prob);
}
}
c->offset = 0;
c->output_bytes += ans_write_end(&c->ans);
}
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