diff options
Diffstat (limited to 'src/main/jni/libwebp/utils/bit_writer.h')
-rw-r--r-- | src/main/jni/libwebp/utils/bit_writer.h | 120 |
1 files changed, 120 insertions, 0 deletions
diff --git a/src/main/jni/libwebp/utils/bit_writer.h b/src/main/jni/libwebp/utils/bit_writer.h new file mode 100644 index 000000000..c80d22ae9 --- /dev/null +++ b/src/main/jni/libwebp/utils/bit_writer.h @@ -0,0 +1,120 @@ +// Copyright 2011 Google Inc. All Rights Reserved. +// +// Use of this source code is governed by a BSD-style license +// that can be found in the COPYING 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. +// ----------------------------------------------------------------------------- +// +// Bit writing and boolean coder +// +// Author: Skal (pascal.massimino@gmail.com) + +#ifndef WEBP_UTILS_BIT_WRITER_H_ +#define WEBP_UTILS_BIT_WRITER_H_ + +#include "../webp/types.h" + +#ifdef __cplusplus +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_; // internal buffer. Re-allocated regularly. Not owned. + size_t pos_; + size_t max_pos_; + int error_; // true in case of error +}; + +// Initialize the object. Allocates some initial memory based on expected_size. +int VP8BitWriterInit(VP8BitWriter* const bw, size_t expected_size); +// Finalize the bitstream coding. Returns a pointer to the internal buffer. +uint8_t* VP8BitWriterFinish(VP8BitWriter* const bw); +// Release any pending memory and zeroes the object. Not a mandatory call. +// Only useful in case of error, when the internal buffer hasn't been grabbed! +void VP8BitWriterWipeOut(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); + +// Appends some bytes to the internal buffer. Data is copied. +int VP8BitWriterAppend(VP8BitWriter* const bw, + const uint8_t* data, size_t size); + +// return approximate write position (in bits) +static WEBP_INLINE uint64_t VP8BitWriterPos(const VP8BitWriter* const bw) { + return (uint64_t)(bw->pos_ + bw->run_) * 8 + 8 + bw->nb_bits_; +} + +// Returns a pointer to the internal buffer. +static WEBP_INLINE uint8_t* VP8BitWriterBuf(const VP8BitWriter* const bw) { + return bw->buf_; +} +// Returns the size of the internal buffer. +static WEBP_INLINE size_t VP8BitWriterSize(const VP8BitWriter* const bw) { + return bw->pos_; +} + +//------------------------------------------------------------------------------ +// VP8LBitWriter + +#if defined(__x86_64__) || defined(_M_X64) // 64bit +typedef uint64_t vp8l_atype_t; // accumulator type +typedef uint32_t vp8l_wtype_t; // writing type +#define WSWAP HToLE32 +#else +typedef uint32_t vp8l_atype_t; +typedef uint16_t vp8l_wtype_t; +#define WSWAP HToLE16 +#endif + +typedef struct { + vp8l_atype_t bits_; // bit accumulator + int used_; // number of bits used in accumulator + uint8_t* buf_; // start of buffer + uint8_t* cur_; // current write position + uint8_t* end_; // end of buffer + + // After all bits are written (VP8LBitWriterFinish()), the caller must observe + // the state of error_. A value of 1 indicates that a memory allocation + // failure has happened during bit writing. A value of 0 indicates successful + // writing of bits. + int error_; +} VP8LBitWriter; + +static WEBP_INLINE size_t VP8LBitWriterNumBytes(VP8LBitWriter* const bw) { + return (bw->cur_ - bw->buf_) + ((bw->used_ + 7) >> 3); +} + +uint8_t* VP8LBitWriterFinish(VP8LBitWriter* const bw); + +// Returns 0 in case of memory allocation error. +int VP8LBitWriterInit(VP8LBitWriter* const bw, size_t expected_size); + +void VP8LBitWriterDestroy(VP8LBitWriter* const bw); + +// This function writes bits into bytes in increasing addresses (little endian), +// and within a byte least-significant-bit first. +// This function can write up to 32 bits in one go, but VP8LBitReader can only +// read 24 bits max (VP8L_MAX_NUM_BIT_READ). +// VP8LBitWriter's error_ flag is set in case of memory allocation error. +void VP8LWriteBits(VP8LBitWriter* const bw, int n_bits, uint32_t bits); + +//------------------------------------------------------------------------------ + +#ifdef __cplusplus +} // extern "C" +#endif + +#endif /* WEBP_UTILS_BIT_WRITER_H_ */ |