1 /* 2 * Copyright (c) 2013 The WebM project authors. All Rights Reserved. 3 * 4 * Use of this source code is governed by a BSD-style license 5 * that can be found in the LICENSE file in the root of the source 6 * tree. An additional intellectual property rights grant can be found 7 * in the file PATENTS. All contributing project authors may 8 * be found in the AUTHORS file in the root of the source tree. 9 */ 10 11 #ifndef VPX_VPX_DSP_BITWRITER_BUFFER_H_ 12 #define VPX_VPX_DSP_BITWRITER_BUFFER_H_ 13 14 #include "vpx/vpx_integer.h" 15 16 #ifdef __cplusplus 17 extern "C" { 18 #endif 19 20 struct vpx_write_bit_buffer { 21 // Whether there has been an error. 22 int error; 23 // We maintain the invariant that bit_offset <= size * CHAR_BIT, i.e., we 24 // never write beyond the end of bit_buffer. If bit_offset would be 25 // incremented to be greater than size * CHAR_BIT, leave bit_offset unchanged 26 // and set error to 1. 27 size_t bit_offset; 28 // Size of bit_buffer in bytes. 29 size_t size; 30 uint8_t *bit_buffer; 31 }; 32 33 void vpx_wb_init(struct vpx_write_bit_buffer *wb, uint8_t *bit_buffer, 34 size_t size); 35 36 int vpx_wb_has_error(const struct vpx_write_bit_buffer *wb); 37 38 // Must not be called if vpx_wb_has_error(wb) returns true. 39 size_t vpx_wb_bytes_written(const struct vpx_write_bit_buffer *wb); 40 41 void vpx_wb_write_bit(struct vpx_write_bit_buffer *wb, int bit); 42 43 void vpx_wb_write_literal(struct vpx_write_bit_buffer *wb, int data, int bits); 44 45 void vpx_wb_write_inv_signed_literal(struct vpx_write_bit_buffer *wb, int data, 46 int bits); 47 48 #ifdef __cplusplus 49 } // extern "C" 50 #endif 51 52 #endif // VPX_VPX_DSP_BITWRITER_BUFFER_H_ 53