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/*
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 * copyright (c) 2001 Fabrice Bellard
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 *
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 * This file is part of Libav.
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 *
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 * Libav is free software; you can redistribute it and/or
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 * modify it under the terms of the GNU Lesser General Public
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 * License as published by the Free Software Foundation; either
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 * version 2.1 of the License, or (at your option) any later version.
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 *
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 * Libav is distributed in the hope that it will be useful,
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 * but WITHOUT ANY WARRANTY; without even the implied warranty of
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 * MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE.  See the GNU
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 * Lesser General Public License for more details.
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 *
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 * You should have received a copy of the GNU Lesser General Public
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 * License along with Libav; if not, write to the Free Software
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 * Foundation, Inc., 51 Franklin Street, Fifth Floor, Boston, MA 02110-1301 USA
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 */
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#ifndef AVFORMAT_AVIO_H
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#define AVFORMAT_AVIO_H
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/**
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 * @file
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 * Buffered I/O operations
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 */
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#include <stdint.h>
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#include "libavutil/common.h"
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#include "libavutil/log.h"
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#include "libavformat/version.h"
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#define AVIO_SEEKABLE_NORMAL 0x0001 /**< Seeking works like for a local file */
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/**
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 * Bytestream IO Context.
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 * New fields can be added to the end with minor version bumps.
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 * Removal, reordering and changes to existing fields require a major
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 * version bump.
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 * sizeof(AVIOContext) must not be used outside libav*.
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 *
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 * @note None of the function pointers in AVIOContext should be called
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 *       directly, they should only be set by the client application
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 *       when implementing custom I/O. Normally these are set to the
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 *       function pointers specified in avio_alloc_context()
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 */
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typedef struct {
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    unsigned char *buffer;  /**< Start of the buffer. */
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    int buffer_size;        /**< Maximum buffer size */
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    unsigned char *buf_ptr; /**< Current position in the buffer */
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    unsigned char *buf_end; /**< End of the data, may be less than
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                                 buffer+buffer_size if the read function returned
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                                 less data than requested, e.g. for streams where
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                                 no more data has been received yet. */
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    void *opaque;           /**< A private pointer, passed to the read/write/seek/...
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                                 functions. */
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    int (*read_packet)(void *opaque, uint8_t *buf, int buf_size);
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    int (*write_packet)(void *opaque, uint8_t *buf, int buf_size);
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    int64_t (*seek)(void *opaque, int64_t offset, int whence);
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    int64_t pos;            /**< position in the file of the current buffer */
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    int must_flush;         /**< true if the next seek should flush */
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    int eof_reached;        /**< true if eof reached */
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    int write_flag;         /**< true if open for writing */
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#if FF_API_OLD_AVIO
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    attribute_deprecated int is_streamed;
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#endif
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    int max_packet_size;
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    unsigned long checksum;
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    unsigned char *checksum_ptr;
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    unsigned long (*update_checksum)(unsigned long checksum, const uint8_t *buf, unsigned int size);
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    int error;              /**< contains the error code or 0 if no error happened */
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    /**
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     * Pause or resume playback for network streaming protocols - e.g. MMS.
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     */
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    int (*read_pause)(void *opaque, int pause);
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    /**
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     * Seek to a given timestamp in stream with the specified stream_index.
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     * Needed for some network streaming protocols which don't support seeking
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     * to byte position.
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     */
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    int64_t (*read_seek)(void *opaque, int stream_index,
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                         int64_t timestamp, int flags);
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    /**
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     * A combination of AVIO_SEEKABLE_ flags or 0 when the stream is not seekable.
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     */
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    int seekable;
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} AVIOContext;
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/* unbuffered I/O */
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#if FF_API_OLD_AVIO
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/**
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 * URL Context.
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 * New fields can be added to the end with minor version bumps.
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 * Removal, reordering and changes to existing fields require a major
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 * version bump.
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 * sizeof(URLContext) must not be used outside libav*.
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 * @deprecated This struct will be made private
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 */
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typedef struct URLContext {
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#if FF_API_URL_CLASS
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    const AVClass *av_class; ///< information for av_log(). Set by url_open().
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#endif
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    struct URLProtocol *prot;
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    int flags;
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    int is_streamed;  /**< true if streamed (no seek possible), default = false */
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    int max_packet_size;  /**< if non zero, the stream is packetized with this max packet size */
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    void *priv_data;
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    char *filename; /**< specified URL */
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    int is_connected;
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} URLContext;
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#define URL_PROTOCOL_FLAG_NESTED_SCHEME 1 /*< The protocol name can be the first part of a nested protocol scheme */
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/**
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 * @deprecated This struct is to be made private. Use the higher-level
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 *             AVIOContext-based API instead.
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 */
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typedef struct URLProtocol {
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    const char *name;
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    int (*url_open)(URLContext *h, const char *url, int flags);
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    int (*url_read)(URLContext *h, unsigned char *buf, int size);
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    int (*url_write)(URLContext *h, const unsigned char *buf, int size);
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    int64_t (*url_seek)(URLContext *h, int64_t pos, int whence);
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    int (*url_close)(URLContext *h);
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    struct URLProtocol *next;
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    int (*url_read_pause)(URLContext *h, int pause);
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    int64_t (*url_read_seek)(URLContext *h, int stream_index,
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                             int64_t timestamp, int flags);
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    int (*url_get_file_handle)(URLContext *h);
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    int priv_data_size;
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    const AVClass *priv_data_class;
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    int flags;
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} URLProtocol;
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typedef struct URLPollEntry {
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    URLContext *handle;
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    int events;
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    int revents;
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} URLPollEntry;
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/* not implemented */
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attribute_deprecated int url_poll(URLPollEntry *poll_table, int n, int timeout);
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/**
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 * @defgroup open_modes URL open modes
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 * The flags argument to url_open and cosins must be one of the following
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 * constants, optionally ORed with other flags.
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 * @{
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 */
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#define URL_RDONLY 0  /**< read-only */
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#define URL_WRONLY 1  /**< write-only */
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#define URL_RDWR   2  /**< read-write */
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/**
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 * @}
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 */
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/**
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 * Use non-blocking mode.
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 * If this flag is set, operations on the context will return
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 * AVERROR(EAGAIN) if they can not be performed immediately.
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 * If this flag is not set, operations on the context will never return
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 * AVERROR(EAGAIN).
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 * Note that this flag does not affect the opening/connecting of the
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 * context. Connecting a protocol will always block if necessary (e.g. on
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 * network protocols) but never hang (e.g. on busy devices).
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 * Warning: non-blocking protocols is work-in-progress; this flag may be
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 * silently ignored.
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 */
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#define URL_FLAG_NONBLOCK 4
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typedef int URLInterruptCB(void);
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extern URLInterruptCB *url_interrupt_cb;
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/**
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 * @defgroup old_url_funcs Old url_* functions
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 * @deprecated use the buffered API based on AVIOContext instead
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 * @{
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 */
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attribute_deprecated int url_open_protocol (URLContext **puc, struct URLProtocol *up,
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                                            const char *url, int flags);
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attribute_deprecated int url_alloc(URLContext **h, const char *url, int flags);
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attribute_deprecated int url_connect(URLContext *h);
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attribute_deprecated int url_open(URLContext **h, const char *url, int flags);
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attribute_deprecated int url_read(URLContext *h, unsigned char *buf, int size);
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attribute_deprecated int url_read_complete(URLContext *h, unsigned char *buf, int size);
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attribute_deprecated int url_write(URLContext *h, const unsigned char *buf, int size);
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attribute_deprecated int64_t url_seek(URLContext *h, int64_t pos, int whence);
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attribute_deprecated int url_close(URLContext *h);
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attribute_deprecated int64_t url_filesize(URLContext *h);
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attribute_deprecated int url_get_file_handle(URLContext *h);
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attribute_deprecated int url_get_max_packet_size(URLContext *h);
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attribute_deprecated void url_get_filename(URLContext *h, char *buf, int buf_size);
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attribute_deprecated int av_url_read_pause(URLContext *h, int pause);
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attribute_deprecated int64_t av_url_read_seek(URLContext *h, int stream_index,
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                                              int64_t timestamp, int flags);
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attribute_deprecated void url_set_interrupt_cb(int (*interrupt_cb)(void));
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/**
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 * If protocol is NULL, returns the first registered protocol,
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 * if protocol is non-NULL, returns the next registered protocol after protocol,
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 * or NULL if protocol is the last one.
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 */
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attribute_deprecated URLProtocol *av_protocol_next(URLProtocol *p);
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/**
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 * Register the URLProtocol protocol.
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 *
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 * @param size the size of the URLProtocol struct referenced
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 */
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attribute_deprecated int av_register_protocol2(URLProtocol *protocol, int size);
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/**
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 * @}
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 */
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typedef attribute_deprecated AVIOContext ByteIOContext;
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attribute_deprecated int init_put_byte(AVIOContext *s,
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                  unsigned char *buffer,
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                  int buffer_size,
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                  int write_flag,
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                  void *opaque,
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                  int (*read_packet)(void *opaque, uint8_t *buf, int buf_size),
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                  int (*write_packet)(void *opaque, uint8_t *buf, int buf_size),
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                  int64_t (*seek)(void *opaque, int64_t offset, int whence));
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attribute_deprecated AVIOContext *av_alloc_put_byte(
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                  unsigned char *buffer,
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                  int buffer_size,
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                  int write_flag,
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                  void *opaque,
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                  int (*read_packet)(void *opaque, uint8_t *buf, int buf_size),
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                  int (*write_packet)(void *opaque, uint8_t *buf, int buf_size),
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                  int64_t (*seek)(void *opaque, int64_t offset, int whence));
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/**
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 * @defgroup old_avio_funcs Old put_/get_*() functions
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 * @deprecated use the avio_ -prefixed functions instead.
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 * @{
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 */
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attribute_deprecated int          get_buffer(AVIOContext *s, unsigned char *buf, int size);
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attribute_deprecated int          get_partial_buffer(AVIOContext *s, unsigned char *buf, int size);
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attribute_deprecated int          get_byte(AVIOContext *s);
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attribute_deprecated unsigned int get_le16(AVIOContext *s);
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attribute_deprecated unsigned int get_le24(AVIOContext *s);
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attribute_deprecated unsigned int get_le32(AVIOContext *s);
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attribute_deprecated uint64_t     get_le64(AVIOContext *s);
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attribute_deprecated unsigned int get_be16(AVIOContext *s);
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attribute_deprecated unsigned int get_be24(AVIOContext *s);
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attribute_deprecated unsigned int get_be32(AVIOContext *s);
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attribute_deprecated uint64_t     get_be64(AVIOContext *s);
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attribute_deprecated void         put_byte(AVIOContext *s, int b);
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attribute_deprecated void         put_nbyte(AVIOContext *s, int b, int count);
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attribute_deprecated void         put_buffer(AVIOContext *s, const unsigned char *buf, int size);
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attribute_deprecated void         put_le64(AVIOContext *s, uint64_t val);
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attribute_deprecated void         put_be64(AVIOContext *s, uint64_t val);
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attribute_deprecated void         put_le32(AVIOContext *s, unsigned int val);
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attribute_deprecated void         put_be32(AVIOContext *s, unsigned int val);
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attribute_deprecated void         put_le24(AVIOContext *s, unsigned int val);
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attribute_deprecated void         put_be24(AVIOContext *s, unsigned int val);
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attribute_deprecated void         put_le16(AVIOContext *s, unsigned int val);
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attribute_deprecated void         put_be16(AVIOContext *s, unsigned int val);
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attribute_deprecated void         put_tag(AVIOContext *s, const char *tag);
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/**
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 * @}
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 */
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attribute_deprecated int     av_url_read_fpause(AVIOContext *h,    int pause);
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attribute_deprecated int64_t av_url_read_fseek (AVIOContext *h,    int stream_index,
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                                                int64_t timestamp, int flags);
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/**
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 * @defgroup old_url_f_funcs Old url_f* functions
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 * @deprecated use the avio_ -prefixed functions instead.
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 * @{
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 */
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attribute_deprecated int url_fopen( AVIOContext **s, const char *url, int flags);
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attribute_deprecated int url_fclose(AVIOContext *s);
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attribute_deprecated int64_t url_fseek(AVIOContext *s, int64_t offset, int whence);
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attribute_deprecated int url_fskip(AVIOContext *s, int64_t offset);
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attribute_deprecated int64_t url_ftell(AVIOContext *s);
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attribute_deprecated int64_t url_fsize(AVIOContext *s);
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#define URL_EOF (-1)
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attribute_deprecated int url_fgetc(AVIOContext *s);
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attribute_deprecated int url_setbufsize(AVIOContext *s, int buf_size);
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#ifdef __GNUC__
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attribute_deprecated int url_fprintf(AVIOContext *s, const char *fmt, ...) __attribute__ ((__format__ (__printf__, 2, 3)));
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#else
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attribute_deprecated int url_fprintf(AVIOContext *s, const char *fmt, ...);
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#endif
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attribute_deprecated void put_flush_packet(AVIOContext *s);
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attribute_deprecated int url_open_dyn_buf(AVIOContext **s);
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attribute_deprecated int url_open_dyn_packet_buf(AVIOContext **s, int max_packet_size);
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attribute_deprecated int url_close_dyn_buf(AVIOContext *s, uint8_t **pbuffer);
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attribute_deprecated int url_fdopen(AVIOContext **s, URLContext *h);
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/**
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 * @}
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 */
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/**
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 * @deprecated use AVIOContext.eof_reached
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 */
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attribute_deprecated int url_feof(AVIOContext *s);
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attribute_deprecated int url_ferror(AVIOContext *s);
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attribute_deprecated int udp_set_remote_url(URLContext *h, const char *uri);
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attribute_deprecated int udp_get_local_port(URLContext *h);
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attribute_deprecated void init_checksum(AVIOContext *s,
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                   unsigned long (*update_checksum)(unsigned long c, const uint8_t *p, unsigned int len),
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                   unsigned long checksum);
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attribute_deprecated unsigned long get_checksum(AVIOContext *s);
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attribute_deprecated void put_strz(AVIOContext *s, const char *buf);
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/** @note unlike fgets, the EOL character is not returned and a whole
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    line is parsed. return NULL if first char read was EOF */
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attribute_deprecated char *url_fgets(AVIOContext *s, char *buf, int buf_size);
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/**
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 * @deprecated use avio_get_str instead
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 */
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attribute_deprecated char *get_strz(AVIOContext *s, char *buf, int maxlen);
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/**
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 * @deprecated Use AVIOContext.seekable field directly.
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 */
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attribute_deprecated static inline int url_is_streamed(AVIOContext *s)
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{
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    return !s->seekable;
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}
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attribute_deprecated URLContext *url_fileno(AVIOContext *s);
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/**
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 * @deprecated use AVIOContext.max_packet_size directly.
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 */
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attribute_deprecated int url_fget_max_packet_size(AVIOContext *s);
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attribute_deprecated int url_open_buf(AVIOContext **s, uint8_t *buf, int buf_size, int flags);
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/** return the written or read size */
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attribute_deprecated int url_close_buf(AVIOContext *s);
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#endif // FF_API_OLD_AVIO
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/**
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 * Return a non-zero value if the resource indicated by url
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 * exists, 0 otherwise.
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 */
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int url_exist(const char *url);
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/**
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 * The callback is called in blocking functions to test regulary if
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 * asynchronous interruption is needed. AVERROR_EXIT is returned
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 * in this case by the interrupted function. 'NULL' means no interrupt
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 * callback is given.
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 */
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void avio_set_interrupt_cb(int (*interrupt_cb)(void));
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#if FF_API_REGISTER_PROTOCOL
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extern URLProtocol *first_protocol;
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#endif
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#if FF_API_REGISTER_PROTOCOL
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/**
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 * @deprecated Use av_register_protocol() instead.
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 */
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attribute_deprecated int register_protocol(URLProtocol *protocol);
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/**
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 * @deprecated Use av_register_protocol2() instead.
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 */
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attribute_deprecated int av_register_protocol(URLProtocol *protocol);
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#endif
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/**
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 * Allocate and initialize an AVIOContext for buffered I/O. It must be later
375
 * freed with av_free().
376
 *
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 * @param buffer Memory block for input/output operations via AVIOContext.
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 * @param buffer_size The buffer size is very important for performance.
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 *        For protocols with fixed blocksize it should be set to this blocksize.
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 *        For others a typical size is a cache page, e.g. 4kb.
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 * @param write_flag Set to 1 if the buffer should be writable, 0 otherwise.
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 * @param opaque An opaque pointer to user-specific data.
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 * @param read_packet  A function for refilling the buffer, may be NULL.
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 * @param write_packet A function for writing the buffer contents, may be NULL.
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 * @param seek A function for seeking to specified byte position, may be NULL.
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 *
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 * @return Allocated AVIOContext or NULL on failure.
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 */
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AVIOContext *avio_alloc_context(
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                  unsigned char *buffer,
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                  int buffer_size,
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                  int write_flag,
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                  void *opaque,
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                  int (*read_packet)(void *opaque, uint8_t *buf, int buf_size),
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                  int (*write_packet)(void *opaque, uint8_t *buf, int buf_size),
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                  int64_t (*seek)(void *opaque, int64_t offset, int whence));
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void avio_w8(AVIOContext *s, int b);
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void avio_write(AVIOContext *s, const unsigned char *buf, int size);
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void avio_wl64(AVIOContext *s, uint64_t val);
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void avio_wb64(AVIOContext *s, uint64_t val);
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void avio_wl32(AVIOContext *s, unsigned int val);
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void avio_wb32(AVIOContext *s, unsigned int val);
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void avio_wl24(AVIOContext *s, unsigned int val);
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void avio_wb24(AVIOContext *s, unsigned int val);
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void avio_wl16(AVIOContext *s, unsigned int val);
407
void avio_wb16(AVIOContext *s, unsigned int val);
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/**
410
 * Write a NULL-terminated string.
411
 * @return number of bytes written.
412
 */
413
int avio_put_str(AVIOContext *s, const char *str);
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415
/**
416
 * Convert an UTF-8 string to UTF-16LE and write it.
417
 * @return number of bytes written.
418
 */
419
int avio_put_str16le(AVIOContext *s, const char *str);
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/**
422
 * Passing this as the "whence" parameter to a seek function causes it to
423
 * return the filesize without seeking anywhere. Supporting this is optional.
424
 * If it is not supported then the seek function will return <0.
425
 */
426
#define AVSEEK_SIZE 0x10000
427

    
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/**
429
 * Oring this flag as into the "whence" parameter to a seek function causes it to
430
 * seek by any means (like reopening and linear reading) or other normally unreasonble
431
 * means that can be extreemly slow.
432
 * This may be ignored by the seek code.
433
 */
434
#define AVSEEK_FORCE 0x20000
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436
/**
437
 * fseek() equivalent for AVIOContext.
438
 * @return new position or AVERROR.
439
 */
440
int64_t avio_seek(AVIOContext *s, int64_t offset, int whence);
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/**
443
 * Skip given number of bytes forward
444
 * @return new position or AVERROR.
445
 */
446
static av_always_inline int64_t avio_skip(AVIOContext *s, int64_t offset)
447
{
448
    return avio_seek(s, offset, SEEK_CUR);
449
}
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451
/**
452
 * ftell() equivalent for AVIOContext.
453
 * @return position or AVERROR.
454
 */
455
static av_always_inline int64_t avio_tell(AVIOContext *s)
456
{
457
    return avio_seek(s, 0, SEEK_CUR);
458
}
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460
/**
461
 * Get the filesize.
462
 * @return filesize or AVERROR
463
 */
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int64_t avio_size(AVIOContext *s);
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/** @warning currently size is limited */
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#ifdef __GNUC__
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int avio_printf(AVIOContext *s, const char *fmt, ...) __attribute__ ((__format__ (__printf__, 2, 3)));
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#else
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int avio_printf(AVIOContext *s, const char *fmt, ...);
471
#endif
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473
void avio_flush(AVIOContext *s);
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475

    
476
/**
477
 * Read size bytes from AVIOContext into buf.
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 * @return number of bytes read or AVERROR
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 */
480
int avio_read(AVIOContext *s, unsigned char *buf, int size);
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482
/**
483
 * @defgroup avio_read Functions for reading from AVIOContext.
484
 * @{
485
 *
486
 * @note return 0 if EOF, so you cannot use it if EOF handling is
487
 *       necessary
488
 */
489
int          avio_r8  (AVIOContext *s);
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unsigned int avio_rl16(AVIOContext *s);
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unsigned int avio_rl24(AVIOContext *s);
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unsigned int avio_rl32(AVIOContext *s);
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uint64_t     avio_rl64(AVIOContext *s);
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unsigned int avio_rb16(AVIOContext *s);
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unsigned int avio_rb24(AVIOContext *s);
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unsigned int avio_rb32(AVIOContext *s);
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uint64_t     avio_rb64(AVIOContext *s);
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/**
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 * @}
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 */
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/**
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 * Read a string from pb into buf. The reading will terminate when either
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 * a NULL character was encountered, maxlen bytes have been read, or nothing
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 * more can be read from pb. The result is guaranteed to be NULL-terminated, it
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 * will be truncated if buf is too small.
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 * Note that the string is not interpreted or validated in any way, it
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 * might get truncated in the middle of a sequence for multi-byte encodings.
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 *
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 * @return number of bytes read (is always <= maxlen).
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 * If reading ends on EOF or error, the return value will be one more than
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 * bytes actually read.
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 */
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int avio_get_str(AVIOContext *pb, int maxlen, char *buf, int buflen);
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/**
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 * Read a UTF-16 string from pb and convert it to UTF-8.
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 * The reading will terminate when either a null or invalid character was
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 * encountered or maxlen bytes have been read.
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 * @return number of bytes read (is always <= maxlen)
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 */
522
int avio_get_str16le(AVIOContext *pb, int maxlen, char *buf, int buflen);
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int avio_get_str16be(AVIOContext *pb, int maxlen, char *buf, int buflen);
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526
#if FF_API_URL_RESETBUF
527
/** Reset the buffer for reading or writing.
528
 * @note Will drop any data currently in the buffer without transmitting it.
529
 * @param flags URL_RDONLY to set up the buffer for reading, or URL_WRONLY
530
 *        to set up the buffer for writing. */
531
int url_resetbuf(AVIOContext *s, int flags);
532
#endif
533

    
534
/**
535
 * @defgroup open_modes URL open modes
536
 * The flags argument to avio_open must be one of the following
537
 * constants, optionally ORed with other flags.
538
 * @{
539
 */
540
#define AVIO_RDONLY 0  /**< read-only */
541
#define AVIO_WRONLY 1  /**< write-only */
542
#define AVIO_RDWR   2  /**< read-write */
543
/**
544
 * @}
545
 */
546

    
547
/**
548
 * Use non-blocking mode.
549
 * If this flag is set, operations on the context will return
550
 * AVERROR(EAGAIN) if they can not be performed immediately.
551
 * If this flag is not set, operations on the context will never return
552
 * AVERROR(EAGAIN).
553
 * Note that this flag does not affect the opening/connecting of the
554
 * context. Connecting a protocol will always block if necessary (e.g. on
555
 * network protocols) but never hang (e.g. on busy devices).
556
 * Warning: non-blocking protocols is work-in-progress; this flag may be
557
 * silently ignored.
558
 */
559
#define AVIO_FLAG_NONBLOCK 4
560

    
561
/**
562
 * Create and initialize a AVIOContext for accessing the
563
 * resource indicated by url.
564
 * @note When the resource indicated by url has been opened in
565
 * read+write mode, the AVIOContext can be used only for writing.
566
 *
567
 * @param s Used to return the pointer to the created AVIOContext.
568
 * In case of failure the pointed to value is set to NULL.
569
 * @param flags flags which control how the resource indicated by url
570
 * is to be opened
571
 * @return 0 in case of success, a negative value corresponding to an
572
 * AVERROR code in case of failure
573
 */
574
int avio_open(AVIOContext **s, const char *url, int flags);
575

    
576
/**
577
 * Close the resource accessed by the AVIOContext s and free it.
578
 * This function can only be used if s was opened by avio_open().
579
 *
580
 * @return 0 on success, an AVERROR < 0 on error.
581
 */
582
int avio_close(AVIOContext *s);
583

    
584
/**
585
 * Open a write only memory stream.
586
 *
587
 * @param s new IO context
588
 * @return zero if no error.
589
 */
590
int avio_open_dyn_buf(AVIOContext **s);
591

    
592
/**
593
 * Return the written size and a pointer to the buffer. The buffer
594
 * must be freed with av_free().
595
 * Padding of FF_INPUT_BUFFER_PADDING_SIZE is added to the buffer.
596
 *
597
 * @param s IO context
598
 * @param pbuffer pointer to a byte buffer
599
 * @return the length of the byte buffer
600
 */
601
int avio_close_dyn_buf(AVIOContext *s, uint8_t **pbuffer);
602

    
603
#if FF_API_UDP_GET_FILE
604
int udp_get_file_handle(URLContext *h);
605
#endif
606

    
607
/**
608
 * Iterate through names of available protocols.
609
 *
610
 * @param opaque A private pointer representing current protocol.
611
 *        It must be a pointer to NULL on first iteration and will
612
 *        be updated by successive calls to avio_enum_protocols.
613
 * @param output If set to 1, iterate over output protocols,
614
 *               otherwise over input protocols.
615
 *
616
 * @return A static string containing the name of current protocol or NULL
617
 */
618
const char *avio_enum_protocols(void **opaque, int output);
619

    
620
#endif /* AVFORMAT_AVIO_H */