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/*
* Bytestream functions
* copyright (c) 2006 Baptiste Coudurier <baptiste.coudurier@free.fr>
*
* 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
*/
#ifndef AVCODEC_BYTESTREAM_H
#define AVCODEC_BYTESTREAM_H
#include <string.h>
#include "libavutil/common.h"
#include "libavutil/intreadwrite.h"
typedef struct {
const uint8_t *buffer, *buffer_end, *buffer_start;
} GetByteContext;
#define DEF_T(type, name, bytes, read, write) \
static av_always_inline type bytestream_get_ ## name(const uint8_t **b){\
(*b) += bytes;\
return read(*b - bytes);\
}\
static av_always_inline void bytestream_put_ ##name(uint8_t **b, const type value){\
write(*b, value);\
(*b) += bytes;\
}\
static av_always_inline type bytestream2_get_ ## name ## u(GetByteContext *g)\
{\
return bytestream_get_ ## name(&g->buffer);\
}\
static av_always_inline type bytestream2_get_ ## name(GetByteContext *g)\
{\
if (g->buffer_end - g->buffer < bytes)\
return 0;\
return bytestream2_get_ ## name ## u(g);\
}\
static av_always_inline type bytestream2_peek_ ## name(GetByteContext *g)\
{\
if (g->buffer_end - g->buffer < bytes)\
return 0;\
return read(g->buffer);\
}
#define DEF(name, bytes, read, write) \
DEF_T(unsigned int, name, bytes, read, write)
#define DEF64(name, bytes, read, write) \
DEF_T(uint64_t, name, bytes, read, write)
DEF64(le64, 8, AV_RL64, AV_WL64)
DEF (le32, 4, AV_RL32, AV_WL32)
DEF (le24, 3, AV_RL24, AV_WL24)
DEF (le16, 2, AV_RL16, AV_WL16)
DEF64(be64, 8, AV_RB64, AV_WB64)
DEF (be32, 4, AV_RB32, AV_WB32)
DEF (be24, 3, AV_RB24, AV_WB24)
DEF (be16, 2, AV_RB16, AV_WB16)
DEF (byte, 1, AV_RB8 , AV_WB8 )
#undef DEF
#undef DEF64
#undef DEF_T
static av_always_inline void bytestream2_init(GetByteContext *g,
const uint8_t *buf, int buf_size)
{
g->buffer = buf;
g->buffer_start = buf;
g->buffer_end = buf + buf_size;
}
static av_always_inline unsigned int bytestream2_get_bytes_left(GetByteContext *g)
{
return g->buffer_end - g->buffer;
}
static av_always_inline void bytestream2_skip(GetByteContext *g,
unsigned int size)
{
g->buffer += FFMIN(g->buffer_end - g->buffer, size);
}
static av_always_inline int bytestream2_tell(GetByteContext *g)
{
return (int)(g->buffer - g->buffer_start);
}
static av_always_inline int bytestream2_seek(GetByteContext *g, int offset,
int whence)
{
switch (whence) {
case SEEK_CUR:
offset = av_clip(offset, -(g->buffer - g->buffer_start),
g->buffer_end - g->buffer);
g->buffer += offset;
break;
case SEEK_END:
offset = av_clip(offset, -(g->buffer_end - g->buffer_start), 0);
g->buffer = g->buffer_end + offset;
break;
case SEEK_SET:
offset = av_clip(offset, 0, g->buffer_end - g->buffer_start);
g->buffer = g->buffer_start + offset;
break;
default:
return AVERROR(EINVAL);
}
return bytestream2_tell(g);
}
static av_always_inline unsigned int bytestream2_get_buffer(GetByteContext *g,
uint8_t *dst,
unsigned int size)
{
int size2 = FFMIN(g->buffer_end - g->buffer, size);
memcpy(dst, g->buffer, size2);
g->buffer += size2;
return size2;
}
static av_always_inline unsigned int bytestream_get_buffer(const uint8_t **b, uint8_t *dst, unsigned int size)
{
memcpy(dst, *b, size);
(*b) += size;
return size;
}
static av_always_inline void bytestream_put_buffer(uint8_t **b, const uint8_t *src, unsigned int size)
{
memcpy(*b, src, size);
(*b) += size;
}
#endif /* AVCODEC_BYTESTREAM_H */
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