chromium/third_party/ffmpeg/libavcodec/put_bits.h

/*
 * copyright (c) 2004 Michael Niedermayer <[email protected]>
 *
 * This file is part of FFmpeg.
 *
 * FFmpeg is free software; you can redistribute it and/or
 * modify it under the terms of the GNU Lesser General Public
 * License as published by the Free Software Foundation; either
 * version 2.1 of the License, or (at your option) any later version.
 *
 * FFmpeg is distributed in the hope that it will be useful,
 * but WITHOUT ANY WARRANTY; without even the implied warranty of
 * MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE.  See the GNU
 * Lesser General Public License for more details.
 *
 * You should have received a copy of the GNU Lesser General Public
 * License along with FFmpeg; if not, write to the Free Software
 * Foundation, Inc., 51 Franklin Street, Fifth Floor, Boston, MA 02110-1301 USA
 */

/**
 * @file
 * bitstream writer API
 */

#ifndef AVCODEC_PUT_BITS_H
#define AVCODEC_PUT_BITS_H

#include <stdint.h>
#include <stddef.h>

#include "config.h"
#include "libavutil/intreadwrite.h"
#include "libavutil/avassert.h"
#include "libavutil/common.h"

#if ARCH_X86_64
// TODO: Benchmark and optionally enable on other 64-bit architectures.
BitBuf;
#define AV_WBBUF …
#define AV_WLBUF …
#else
typedef uint32_t BitBuf;
#define AV_WBBUF …
#define AV_WLBUF …
#endif

static const int BUF_BITS = …;

PutBitContext;

/**
 * Initialize the PutBitContext s.
 *
 * @param buffer the buffer where to put bits
 * @param buffer_size the size in bytes of buffer
 */
static inline void init_put_bits(PutBitContext *s, uint8_t *buffer,
                                 int buffer_size)
{ … }

/**
 * @return the total number of bits written to the bitstream.
 */
static inline int put_bits_count(PutBitContext *s)
{ … }

/**
 * @return the number of bytes output so far; may only be called
 *         when the PutBitContext is freshly initialized or flushed.
 */
static inline int put_bytes_output(const PutBitContext *s)
{ … }

/**
 * @param  round_up  When set, the number of bits written so far will be
 *                   rounded up to the next byte.
 * @return the number of bytes output so far.
 */
static inline int put_bytes_count(const PutBitContext *s, int round_up)
{ … }

/**
 * Rebase the bit writer onto a reallocated buffer.
 *
 * @param buffer the buffer where to put bits
 * @param buffer_size the size in bytes of buffer,
 *                    must be large enough to hold everything written so far
 */
static inline void rebase_put_bits(PutBitContext *s, uint8_t *buffer,
                                   int buffer_size)
{ … }

/**
 * @return the number of bits available in the bitstream.
 */
static inline int put_bits_left(PutBitContext* s)
{ … }

/**
 * @param  round_up  When set, the number of bits written will be
 *                   rounded up to the next byte.
 * @return the number of bytes left.
 */
static inline int put_bytes_left(const PutBitContext *s, int round_up)
{ … }

/**
 * Pad the end of the output stream with zeros.
 */
static inline void flush_put_bits(PutBitContext *s)
{ … }

static inline void flush_put_bits_le(PutBitContext *s)
{ … }

#ifdef BITSTREAM_WRITER_LE
#define ff_put_string …
#define ff_copy_bits …
#else

/**
 * Put the string string in the bitstream.
 *
 * @param terminate_string 0-terminates the written string if value is 1
 */
void ff_put_string(PutBitContext *pb, const char *string,
                       int terminate_string);

/**
 * Copy the content of src to the bitstream.
 *
 * @param length the number of bits of src to copy
 */
void ff_copy_bits(PutBitContext *pb, const uint8_t *src, int length);
#endif

static inline void put_bits_no_assert(PutBitContext *s, int n, BitBuf value)
{ … }

/**
 * Write up to 31 bits into a bitstream.
 * Use put_bits32 to write 32 bits.
 */
static inline void put_bits(PutBitContext *s, int n, BitBuf value)
{ … }

static inline void put_bits_le(PutBitContext *s, int n, BitBuf value)
{ … }

static inline void put_sbits(PutBitContext *pb, int n, int32_t value)
{ … }

/**
 * Write exactly 32 bits into a bitstream.
 */
static void av_unused put_bits32(PutBitContext *s, uint32_t value)
{ … }

/**
 * Write up to 64 bits into a bitstream.
 */
static inline void put_bits64(PutBitContext *s, int n, uint64_t value)
{ … }

static inline void put_sbits63(PutBitContext *pb, int n, int64_t value)
{ … }

/**
 * Return the pointer to the byte where the bitstream writer will put
 * the next bit.
 */
static inline uint8_t *put_bits_ptr(PutBitContext *s)
{ … }

/**
 * Skip the given number of bytes.
 * PutBitContext must be flushed & aligned to a byte boundary before calling this.
 */
static inline void skip_put_bytes(PutBitContext *s, int n)
{ … }

/**
 * Skip the given number of bits.
 * Must only be used if the actual values in the bitstream do not matter.
 * If n is < 0 the behavior is undefined.
 */
static inline void skip_put_bits(PutBitContext *s, int n)
{ … }

/**
 * Change the end of the buffer.
 *
 * @param size the new size in bytes of the buffer where to put bits
 */
static inline void set_put_bits_buffer_size(PutBitContext *s, int size)
{ … }

/**
 * Pad the bitstream with zeros up to the next byte boundary.
 */
static inline void align_put_bits(PutBitContext *s)
{ … }

#undef AV_WBBUF
#undef AV_WLBUF

#endif /* AVCODEC_PUT_BITS_H */