// Copyright 2011 Google Inc. // // This code is licensed under the same terms as WebM: // Software License Agreement: http://www.webmproject.org/license/software/ // Additional IP Rights Grant: http://www.webmproject.org/license/additional/ // ----------------------------------------------------------------------------- // // Bit writing and boolean coder // // Author: Skal (pascal.massimino@gmail.com) #ifndef WEBP_ENC_BIT_WRITER_H_ #define WEBP_ENC_BIT_WRITER_H_ #include "vp8enci.h" #if defined(__cplusplus) || defined(c_plusplus) extern "C" { #endif //----------------------------------------------------------------------------- // Bit-writing typedef struct VP8BitWriter VP8BitWriter; struct VP8BitWriter { int32_t range_; // range-1 int32_t value_; int run_; // number of outstanding bits int nb_bits_; // number of pending bits uint8_t* buf_; size_t pos_; size_t max_pos_; int error_; // true in case of error }; int VP8BitWriterInit(VP8BitWriter* const bw, size_t expected_size); uint8_t* VP8BitWriterFinish(VP8BitWriter* const bw); int VP8PutBit(VP8BitWriter* const bw, int bit, int prob); int VP8PutBitUniform(VP8BitWriter* const bw, int bit); void VP8PutValue(VP8BitWriter* const bw, int value, int nb_bits); void VP8PutSignedValue(VP8BitWriter* const bw, int value, int nb_bits); int VP8BitWriterAppend(VP8BitWriter* const bw, const uint8_t* data, size_t size); // return approximate write position (in bits) static inline uint64_t VP8BitWriterPos(const VP8BitWriter* const bw) { return (uint64_t)(bw->pos_ + bw->run_) * 8 + 8 + bw->nb_bits_; } static inline uint8_t* VP8BitWriterBuf(const VP8BitWriter* const bw) { return bw->buf_; } static inline size_t VP8BitWriterSize(const VP8BitWriter* const bw) { return bw->pos_; } //----------------------------------------------------------------------------- #if defined(__cplusplus) || defined(c_plusplus) } // extern "C" #endif #endif // WEBP_ENC_BIT_WRITER_H_