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/*
*
* 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 AVFORMAT_AVIO_INTERNAL_H
#define AVFORMAT_AVIO_INTERNAL_H
#include "avio.h"
#include "url.h"
#include "libavutil/log.h"
extern const AVClass ffio_url_class;
int ffio_init_context(AVIOContext *s,
unsigned char *buffer,
int buffer_size,
int write_flag,
void *opaque,
int (*read_packet)(void *opaque, uint8_t *buf, int buf_size),
int (*write_packet)(void *opaque, uint8_t *buf, int buf_size),
int64_t (*seek)(void *opaque, int64_t offset, int whence));
/**
* Read size bytes from AVIOContext, returning a pointer.
* Note that the data pointed at by the returned pointer is only
* valid until the next call that references the same IO context.
* @param s IO context
* @param buf pointer to buffer into which to assemble the requested
* data if it is not available in contiguous addresses in the
* underlying buffer
* @param size number of bytes requested
* @param data address at which to store pointer: this will be a
* a direct pointer into the underlying buffer if the requested
* number of bytes are available at contiguous addresses, otherwise
* will be a copy of buf
* @return number of bytes read or AVERROR
*/
int ffio_read_indirect(AVIOContext *s, unsigned char *buf, int size, const unsigned char **data);
/**
* Read size bytes from AVIOContext into buf.
* This reads at most 1 packet. If that is not enough fewer bytes will be
* returned.
* @return number of bytes read or AVERROR
*/
int ffio_read_partial(AVIOContext *s, unsigned char *buf, int size);
void ffio_fill(AVIOContext *s, int b, int count);
static av_always_inline void ffio_wfourcc(AVIOContext *pb, const uint8_t *s)
{
avio_wl32(pb, MKTAG(s[0], s[1], s[2], s[3]));
}
/**
* Rewind the AVIOContext using the specified buffer containing the first buf_size bytes of the file.
* Used after probing to avoid seeking.
* Joins buf and s->buffer, taking any overlap into consideration.
* @note s->buffer must overlap with buf or they can't be joined and the function fails
*
* @param s The read-only AVIOContext to rewind
* @param buf The probe buffer containing the first buf_size bytes of the file
* @param buf_size The size of buf
* @return >= 0 in case of success, a negative value corresponding to an
* AVERROR code in case of failure
*/
int ffio_rewind_with_probe_data(AVIOContext *s, unsigned char **buf, int buf_size);
uint64_t ffio_read_varlen(AVIOContext *bc);
/** @warning must be called before any I/O */
int ffio_set_buf_size(AVIOContext *s, int buf_size);
/**
* Ensures that the requested seekback buffer size will be available
*
* Will ensure that when reading sequentially up to buf_size, seeking
* within the current pos and pos+buf_size is possible.
* Once the stream position moves outside this window this gurantee is lost.
*/
int ffio_ensure_seekback(AVIOContext *s, int buf_size);
int ffio_limit(AVIOContext *s, int size);
void ffio_init_checksum(AVIOContext *s,
unsigned long (*update_checksum)(unsigned long c, const uint8_t *p, unsigned int len),
unsigned long checksum);
unsigned long ffio_get_checksum(AVIOContext *s);
unsigned long ff_crc04C11DB7_update(unsigned long checksum, const uint8_t *buf,
unsigned int len);
/**
* Open a write only packetized memory stream with a maximum packet
* size of 'max_packet_size'. The stream is stored in a memory buffer
* with a big-endian 4 byte header giving the packet size in bytes.
*
* @param s new IO context
* @param max_packet_size maximum packet size (must be > 0)
* @return zero if no error.
*/
int ffio_open_dyn_packet_buf(AVIOContext **s, int max_packet_size);
/**
* Create and initialize a AVIOContext for accessing the
* resource referenced by the URLContext h.
* @note When the URLContext h has been opened in read+write mode, the
* AVIOContext can be used only for writing.
*
* @param s Used to return the pointer to the created AVIOContext.
* In case of failure the pointed to value is set to NULL.
* @return >= 0 in case of success, a negative value corresponding to an
* AVERROR code in case of failure
*/
int ffio_fdopen(AVIOContext **s, URLContext *h);
/**
* Open a write-only fake memory stream. The written data is not stored
* anywhere - this is only used for measuring the amount of data
* written.
*
* @param s new IO context
* @return zero if no error.
*/
int ffio_open_null_buf(AVIOContext **s);
/**
* Close a null buffer.
*
* @param s an IO context opened by ffio_open_null_buf
* @return the number of bytes written to the null buffer
*/
int ffio_close_null_buf(AVIOContext *s);
#endif /* AVFORMAT_AVIO_INTERNAL_H */
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