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/*
* Bytestream functions
* copyright (c) 2006 Baptiste Coudurier <baptiste.coudurier@free.fr>
* Copyright (c) 2012 Aneesh Dogra (lionaneesh) <lionaneesh@gmail.com>
*
* 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;
typedef struct {
uint8_t *buffer, *buffer_end, *buffer_start;
int eof;
} PutByteContext;
#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 void bytestream2_put_ ## name ## u(PutByteContext *p, \
const type value) \
{ \
bytestream_put_ ## name(&p->buffer, value); \
} \
static av_always_inline void bytestream2_put_ ## name(PutByteContext *p, \
const type value) \
{ \
if (!p->eof && (p->buffer_end - p->buffer >= bytes)) { \
write(p->buffer, value); \
p->buffer += bytes; \
} else \
p->eof = 1; \
} \
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
#if HAVE_BIGENDIAN
# define bytestream2_get_ne16 bytestream2_get_be16
# define bytestream2_get_ne24 bytestream2_get_be24
# define bytestream2_get_ne32 bytestream2_get_be32
# define bytestream2_get_ne64 bytestream2_get_be64
# define bytestream2_get_ne16u bytestream2_get_be16u
# define bytestream2_get_ne24u bytestream2_get_be24u
# define bytestream2_get_ne32u bytestream2_get_be32u
# define bytestream2_get_ne64u bytestream2_get_be64u
# define bytestream2_put_ne16 bytestream2_put_be16
# define bytestream2_put_ne24 bytestream2_put_be24
# define bytestream2_put_ne32 bytestream2_put_be32
# define bytestream2_put_ne64 bytestream2_put_be64
# define bytestream2_peek_ne16 bytestream2_peek_be16
# define bytestream2_peek_ne24 bytestream2_peek_be24
# define bytestream2_peek_ne32 bytestream2_peek_be32
# define bytestream2_peek_ne64 bytestream2_peek_be64
#else
# define bytestream2_get_ne16 bytestream2_get_le16
# define bytestream2_get_ne24 bytestream2_get_le24
# define bytestream2_get_ne32 bytestream2_get_le32
# define bytestream2_get_ne64 bytestream2_get_le64
# define bytestream2_get_ne16u bytestream2_get_le16u
# define bytestream2_get_ne24u bytestream2_get_le24u
# define bytestream2_get_ne32u bytestream2_get_le32u
# define bytestream2_get_ne64u bytestream2_get_le64u
# define bytestream2_put_ne16 bytestream2_put_le16
# define bytestream2_put_ne24 bytestream2_put_le24
# define bytestream2_put_ne32 bytestream2_put_le32
# define bytestream2_put_ne64 bytestream2_put_le64
# define bytestream2_peek_ne16 bytestream2_peek_le16
# define bytestream2_peek_ne24 bytestream2_peek_le24
# define bytestream2_peek_ne32 bytestream2_peek_le32
# define bytestream2_peek_ne64 bytestream2_peek_le64
#endif
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 void bytestream2_init_writer(PutByteContext *p,
uint8_t *buf,
int buf_size)
{
p->buffer = buf;
p->buffer_start = buf;
p->buffer_end = buf + buf_size;
p->eof = 0;
}
static av_always_inline unsigned int bytestream2_get_bytes_left(GetByteContext *g)
{
return g->buffer_end - g->buffer;
}
static av_always_inline unsigned int bytestream2_get_bytes_left_p(PutByteContext *p)
{
return p->buffer_end - p->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 void bytestream2_skip_p(PutByteContext *p,
unsigned int size)
{
int size2;
if (p->eof)
return;
size2 = FFMIN(p->buffer_end - p->buffer, size);
if (size2 != size)
p->eof = 1;
p->buffer += size2;
}
static av_always_inline int bytestream2_tell(GetByteContext *g)
{
return (int)(g->buffer - g->buffer_start);
}
static av_always_inline int bytestream2_tell_p(PutByteContext *p)
{
return (int)(p->buffer - p->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 int bytestream2_seek_p(PutByteContext *p,
int offset,
int whence)
{
p->eof = 0;
switch (whence) {
case SEEK_CUR:
if (p->buffer_end - p->buffer < offset)
p->eof = 1;
offset = av_clip(offset, -(p->buffer - p->buffer_start),
p->buffer_end - p->buffer);
p->buffer += offset;
break;
case SEEK_END:
if (offset > 0)
p->eof = 1;
offset = av_clip(offset, -(p->buffer_end - p->buffer_start), 0);
p->buffer = p->buffer_end + offset;
break;
case SEEK_SET:
if (p->buffer_end - p->buffer_start < offset)
p->eof = 1;
offset = av_clip(offset, 0, p->buffer_end - p->buffer_start);
p->buffer = p->buffer_start + offset;
break;
default:
return AVERROR(EINVAL);
}
return bytestream2_tell_p(p);
}
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 bytestream2_put_buffer(PutByteContext *p,
const uint8_t *src,
unsigned int size)
{
int size2;
if (p->eof)
return 0;
size2 = FFMIN(p->buffer_end - p->buffer, size);
if (size2 != size)
p->eof = 1;
memcpy(p->buffer, src, size2);
p->buffer += size2;
return size2;
}
static av_always_inline void bytestream2_set_buffer(PutByteContext *p,
const uint8_t c,
unsigned int size)
{
int size2;
if (p->eof)
return;
size2 = FFMIN(p->buffer_end - p->buffer, size);
if (size2 != size)
p->eof = 1;
memset(p->buffer, c, size2);
p->buffer += size2;
}
static av_always_inline unsigned int bytestream2_get_eof(PutByteContext *p)
{
return p->eof;
}
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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