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/*
* Copyright (c) 2013 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_ENCODER_VP9_WRITE_BIT_BUFFER_H_
#define VP9_ENCODER_VP9_WRITE_BIT_BUFFER_H_
#include <limits.h>
#include "vpx/vpx_integer.h"
#ifdef __cplusplus
extern "C" {
#endif
struct vp9_write_bit_buffer {
uint8_t *bit_buffer;
size_t bit_offset;
};
static size_t vp9_rb_bytes_written(struct vp9_write_bit_buffer *wb) {
return wb->bit_offset / CHAR_BIT + (wb->bit_offset % CHAR_BIT > 0);
}
static void vp9_wb_write_bit(struct vp9_write_bit_buffer *wb, int bit) {
const int off = (int)wb->bit_offset;
const int p = off / CHAR_BIT;
const int q = CHAR_BIT - 1 - off % CHAR_BIT;
if (q == CHAR_BIT -1) {
wb->bit_buffer[p] = bit << q;
} else {
wb->bit_buffer[p] &= ~(1 << q);
wb->bit_buffer[p] |= bit << q;
}
wb->bit_offset = off + 1;
}
static void vp9_wb_write_literal(struct vp9_write_bit_buffer *wb,
int data, int bits) {
int bit;
for (bit = bits - 1; bit >= 0; bit--)
vp9_wb_write_bit(wb, (data >> bit) & 1);
}
#ifdef __cplusplus
} // extern "C"
#endif
#endif // VP9_ENCODER_VP9_WRITE_BIT_BUFFER_H_
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