aom/aom_dsp/dkboolwriter.h

105 строки
2.5 KiB
C

/*
* 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.
*/
#ifndef AOM_DSP_DKBOOLWRITER_H_
#define AOM_DSP_DKBOOLWRITER_H_
#include "./aom_config.h"
#if CONFIG_BITSTREAM_DEBUG
#include <stdio.h>
#include "aom_util/debug_util.h"
#endif // CONFIG_BITSTREAM_DEBUG
#include "aom_dsp/prob.h"
#include "aom_ports/mem.h"
#ifdef __cplusplus
extern "C" {
#endif
typedef struct aom_dk_writer {
unsigned int lowvalue;
unsigned int range;
int count;
unsigned int pos;
uint8_t *buffer;
} aom_dk_writer;
void aom_dk_start_encode(aom_dk_writer *bc, uint8_t *buffer);
void aom_dk_stop_encode(aom_dk_writer *bc);
static INLINE void aom_dk_write(aom_dk_writer *br, int bit, int probability) {
unsigned int split;
int count = br->count;
unsigned int range = br->range;
unsigned int lowvalue = br->lowvalue;
register int shift;
#if CONFIG_BITSTREAM_DEBUG
// int queue_r = 0;
// int frame_idx_r = 0;
// int queue_w = bitstream_queue_get_write();
// int frame_idx_w = bitstream_queue_get_frame_write();
// if (frame_idx_w == frame_idx_r && queue_w == queue_r) {
// fprintf(stderr, "\n *** bitstream queue at frame_idx_w %d queue_w %d\n",
// frame_idx_w, queue_w);
// }
bitstream_queue_push(bit, probability);
#endif // CONFIG_BITSTREAM_DEBUG
split = 1 + (((range - 1) * probability) >> 8);
range = split;
if (bit) {
lowvalue += split;
range = br->range - split;
}
shift = aom_norm[range];
range <<= shift;
count += shift;
if (count >= 0) {
int offset = shift - count;
if ((lowvalue << (offset - 1)) & 0x80000000) {
int x = br->pos - 1;
while (x >= 0 && br->buffer[x] == 0xff) {
br->buffer[x] = 0;
x--;
}
br->buffer[x] += 1;
}
br->buffer[br->pos++] = (lowvalue >> (24 - offset));
lowvalue <<= offset;
shift = count;
lowvalue &= 0xffffff;
count -= 8;
}
lowvalue <<= shift;
br->count = count;
br->lowvalue = lowvalue;
br->range = range;
}
#ifdef __cplusplus
} // extern "C"
#endif
#endif // AOM_DSP_DKBOOLWRITER_H_