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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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    const AVClass *av_class; ///< information for av_log(). Set by url_open().
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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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    int (*url_check)(URLContext *h, int mask);
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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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/**
274
 * @defgroup old_url_f_funcs Old url_f* functions
275
 * @deprecated use the avio_ -prefixed functions instead.
276
 * @{
277
 */
278
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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/**
302
 * @deprecated use AVIOContext.eof_reached
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 */
304
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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{
327
    return !s->seekable;
328
}
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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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/**
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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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 * @deprecated Use avio_check instead.
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 */
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attribute_deprecated int url_exist(const char *url);
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#endif // FF_API_OLD_AVIO
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/**
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 * Return AVIO_* access flags corresponding to the access permissions
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 * of the resource in url, or a negative value corresponding to an
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 * AVERROR code in case of failure. The returned access flags are
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 * masked by the value in flags.
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 *
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 * @note This function is intrinsically unsafe, in the sense that the
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 * checked resource may change its existence or permission status from
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 * one call to another. Thus you should not trust the returned value,
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 * unless you are sure that no other processes are accessing the
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 * checked resource.
360
 */
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int avio_check(const char *url, int flags);
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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
366
 * in this case by the interrupted function. 'NULL' means no interrupt
367
 * callback is given.
368
 */
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void avio_set_interrupt_cb(int (*interrupt_cb)(void));
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/**
372
 * Allocate and initialize an AVIOContext for buffered I/O. It must be later
373
 * freed with av_free().
374
 *
375
 * @param buffer Memory block for input/output operations via AVIOContext.
376
 * @param buffer_size The buffer size is very important for performance.
377
 *        For protocols with fixed blocksize it should be set to this blocksize.
378
 *        For others a typical size is a cache page, e.g. 4kb.
379
 * @param write_flag Set to 1 if the buffer should be writable, 0 otherwise.
380
 * @param opaque An opaque pointer to user-specific data.
381
 * @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.
384
 *
385
 * @return Allocated AVIOContext or NULL on failure.
386
 */
387
AVIOContext *avio_alloc_context(
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                  unsigned char *buffer,
389
                  int buffer_size,
390
                  int write_flag,
391
                  void *opaque,
392
                  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),
394
                  int64_t (*seek)(void *opaque, int64_t offset, int whence));
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void avio_w8(AVIOContext *s, int b);
397
void avio_write(AVIOContext *s, const unsigned char *buf, int size);
398
void avio_wl64(AVIOContext *s, uint64_t val);
399
void avio_wb64(AVIOContext *s, uint64_t val);
400
void avio_wl32(AVIOContext *s, unsigned int val);
401
void avio_wb32(AVIOContext *s, unsigned int val);
402
void avio_wl24(AVIOContext *s, unsigned int val);
403
void avio_wb24(AVIOContext *s, unsigned int val);
404
void avio_wl16(AVIOContext *s, unsigned int val);
405
void avio_wb16(AVIOContext *s, unsigned int val);
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407
/**
408
 * Write a NULL-terminated string.
409
 * @return number of bytes written.
410
 */
411
int avio_put_str(AVIOContext *s, const char *str);
412

    
413
/**
414
 * Convert an UTF-8 string to UTF-16LE and write it.
415
 * @return number of bytes written.
416
 */
417
int avio_put_str16le(AVIOContext *s, const char *str);
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419
/**
420
 * Passing this as the "whence" parameter to a seek function causes it to
421
 * return the filesize without seeking anywhere. Supporting this is optional.
422
 * If it is not supported then the seek function will return <0.
423
 */
424
#define AVSEEK_SIZE 0x10000
425

    
426
/**
427
 * Oring this flag as into the "whence" parameter to a seek function causes it to
428
 * seek by any means (like reopening and linear reading) or other normally unreasonble
429
 * means that can be extreemly slow.
430
 * This may be ignored by the seek code.
431
 */
432
#define AVSEEK_FORCE 0x20000
433

    
434
/**
435
 * fseek() equivalent for AVIOContext.
436
 * @return new position or AVERROR.
437
 */
438
int64_t avio_seek(AVIOContext *s, int64_t offset, int whence);
439

    
440
/**
441
 * Skip given number of bytes forward
442
 * @return new position or AVERROR.
443
 */
444
static av_always_inline int64_t avio_skip(AVIOContext *s, int64_t offset)
445
{
446
    return avio_seek(s, offset, SEEK_CUR);
447
}
448

    
449
/**
450
 * ftell() equivalent for AVIOContext.
451
 * @return position or AVERROR.
452
 */
453
static av_always_inline int64_t avio_tell(AVIOContext *s)
454
{
455
    return avio_seek(s, 0, SEEK_CUR);
456
}
457

    
458
/**
459
 * Get the filesize.
460
 * @return filesize or AVERROR
461
 */
462
int64_t avio_size(AVIOContext *s);
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464
/** @warning currently size is limited */
465
#ifdef __GNUC__
466
int avio_printf(AVIOContext *s, const char *fmt, ...) __attribute__ ((__format__ (__printf__, 2, 3)));
467
#else
468
int avio_printf(AVIOContext *s, const char *fmt, ...);
469
#endif
470

    
471
void avio_flush(AVIOContext *s);
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473

    
474
/**
475
 * Read size bytes from AVIOContext into buf.
476
 * @return number of bytes read or AVERROR
477
 */
478
int avio_read(AVIOContext *s, unsigned char *buf, int size);
479

    
480
/**
481
 * @defgroup avio_read Functions for reading from AVIOContext.
482
 * @{
483
 *
484
 * @note return 0 if EOF, so you cannot use it if EOF handling is
485
 *       necessary
486
 */
487
int          avio_r8  (AVIOContext *s);
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unsigned int avio_rl16(AVIOContext *s);
489
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);
495
uint64_t     avio_rb64(AVIOContext *s);
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/**
497
 * @}
498
 */
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500
/**
501
 * Read a string from pb into buf. The reading will terminate when either
502
 * a NULL character was encountered, maxlen bytes have been read, or nothing
503
 * more can be read from pb. The result is guaranteed to be NULL-terminated, it
504
 * will be truncated if buf is too small.
505
 * Note that the string is not interpreted or validated in any way, it
506
 * might get truncated in the middle of a sequence for multi-byte encodings.
507
 *
508
 * @return number of bytes read (is always <= maxlen).
509
 * If reading ends on EOF or error, the return value will be one more than
510
 * bytes actually read.
511
 */
512
int avio_get_str(AVIOContext *pb, int maxlen, char *buf, int buflen);
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514
/**
515
 * 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
517
 * encountered or maxlen bytes have been read.
518
 * @return number of bytes read (is always <= maxlen)
519
 */
520
int avio_get_str16le(AVIOContext *pb, int maxlen, char *buf, int buflen);
521
int avio_get_str16be(AVIOContext *pb, int maxlen, char *buf, int buflen);
522

    
523

    
524
/**
525
 * @defgroup open_modes URL open modes
526
 * The flags argument to avio_open must be one of the following
527
 * constants, optionally ORed with other flags.
528
 * @{
529
 */
530
#define AVIO_RDONLY 1  /**< read-only */
531
#define AVIO_WRONLY 2  /**< write-only */
532
#define AVIO_RDWR   4  /**< read-write */
533
/**
534
 * @}
535
 */
536

    
537
/**
538
 * Use non-blocking mode.
539
 * If this flag is set, operations on the context will return
540
 * AVERROR(EAGAIN) if they can not be performed immediately.
541
 * If this flag is not set, operations on the context will never return
542
 * AVERROR(EAGAIN).
543
 * Note that this flag does not affect the opening/connecting of the
544
 * context. Connecting a protocol will always block if necessary (e.g. on
545
 * network protocols) but never hang (e.g. on busy devices).
546
 * Warning: non-blocking protocols is work-in-progress; this flag may be
547
 * silently ignored.
548
 */
549
#define AVIO_FLAG_NONBLOCK 8
550

    
551
/**
552
 * Create and initialize a AVIOContext for accessing the
553
 * resource indicated by url.
554
 * @note When the resource indicated by url has been opened in
555
 * read+write mode, the AVIOContext can be used only for writing.
556
 *
557
 * @param s Used to return the pointer to the created AVIOContext.
558
 * In case of failure the pointed to value is set to NULL.
559
 * @param flags flags which control how the resource indicated by url
560
 * is to be opened
561
 * @return 0 in case of success, a negative value corresponding to an
562
 * AVERROR code in case of failure
563
 */
564
int avio_open(AVIOContext **s, const char *url, int flags);
565

    
566
/**
567
 * Close the resource accessed by the AVIOContext s and free it.
568
 * This function can only be used if s was opened by avio_open().
569
 *
570
 * @return 0 on success, an AVERROR < 0 on error.
571
 */
572
int avio_close(AVIOContext *s);
573

    
574
/**
575
 * Open a write only memory stream.
576
 *
577
 * @param s new IO context
578
 * @return zero if no error.
579
 */
580
int avio_open_dyn_buf(AVIOContext **s);
581

    
582
/**
583
 * Return the written size and a pointer to the buffer. The buffer
584
 * must be freed with av_free().
585
 * Padding of FF_INPUT_BUFFER_PADDING_SIZE is added to the buffer.
586
 *
587
 * @param s IO context
588
 * @param pbuffer pointer to a byte buffer
589
 * @return the length of the byte buffer
590
 */
591
int avio_close_dyn_buf(AVIOContext *s, uint8_t **pbuffer);
592

    
593
/**
594
 * Iterate through names of available protocols.
595
 *
596
 * @param opaque A private pointer representing current protocol.
597
 *        It must be a pointer to NULL on first iteration and will
598
 *        be updated by successive calls to avio_enum_protocols.
599
 * @param output If set to 1, iterate over output protocols,
600
 *               otherwise over input protocols.
601
 *
602
 * @return A static string containing the name of current protocol or NULL
603
 */
604
const char *avio_enum_protocols(void **opaque, int output);
605

    
606
/**
607
 * Pause and resume playing - only meaningful if using a network streaming
608
 * protocol (e.g. MMS).
609
 * @param pause 1 for pause, 0 for resume
610
 */
611
int     avio_pause(AVIOContext *h, int pause);
612

    
613
/**
614
 * Seek to a given timestamp relative to some component stream.
615
 * Only meaningful if using a network streaming protocol (e.g. MMS.).
616
 * @param stream_index The stream index that the timestamp is relative to.
617
 *        If stream_index is (-1) the timestamp should be in AV_TIME_BASE
618
 *        units from the beginning of the presentation.
619
 *        If a stream_index >= 0 is used and the protocol does not support
620
 *        seeking based on component streams, the call will fail with ENOTSUP.
621
 * @param timestamp timestamp in AVStream.time_base units
622
 *        or if there is no stream specified then in AV_TIME_BASE units.
623
 * @param flags Optional combination of AVSEEK_FLAG_BACKWARD, AVSEEK_FLAG_BYTE
624
 *        and AVSEEK_FLAG_ANY. The protocol may silently ignore
625
 *        AVSEEK_FLAG_BACKWARD and AVSEEK_FLAG_ANY, but AVSEEK_FLAG_BYTE will
626
 *        fail with ENOTSUP if used and not supported.
627
 * @return >= 0 on success
628
 * @see AVInputFormat::read_seek
629
 */
630
int64_t avio_seek_time(AVIOContext *h, int stream_index,
631
                       int64_t timestamp, int flags);
632

    
633
#endif /* AVFORMAT_AVIO_H */