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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 FFmpeg.
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 *
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 * FFmpeg 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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 * FFmpeg 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 FFmpeg; 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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 * unbuffered I/O operations
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 *
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 * @warning This file has to be considered an internal but installed
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 * header, so it should not be directly included in your projects.
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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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/* unbuffered I/O */
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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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 */
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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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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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#define URL_RDONLY 0
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#define URL_WRONLY 1
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#define URL_RDWR   2
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typedef int URLInterruptCB(void);
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/**
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 * Create a URLContext for accessing to the resource indicated by
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 * url, and open it using the URLProtocol up.
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 *
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 * @param puc pointer to the location where, in case of success, the
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 * function puts the pointer to the created URLContext
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 * @param flags flags which control how the resource indicated by url
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 * is to be opened
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 * @return 0 in case of success, a negative value corresponding to an
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 * AVERROR code in case of failure
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 */
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int url_open_protocol (URLContext **puc, struct URLProtocol *up,
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                       const char *url, int flags);
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/**
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 * Create a URLContext for accessing to the resource indicated by
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 * url, but do not initiate the connection yet.
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 *
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 * @param puc pointer to the location where, in case of success, the
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 * function puts the pointer to the created URLContext
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 * @param flags flags which control how the resource indicated by url
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 * is to be opened
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 * @return 0 in case of success, a negative value corresponding to an
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 * AVERROR code in case of failure
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 */
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int url_alloc(URLContext **h, const char *url, int flags);
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/**
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 * Connect an URLContext that has been allocated by url_alloc
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 */
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int url_connect(URLContext *h);
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/**
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 * Create an URLContext for accessing to the resource indicated by
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 * url, and open it.
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 *
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 * @param puc pointer to the location where, in case of success, the
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 * function puts the pointer to the created URLContext
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 * @param flags flags which control how the resource indicated by url
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 * is to be opened
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 * @return 0 in case of success, a negative value corresponding to an
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 * AVERROR code in case of failure
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 */
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int url_open(URLContext **h, const char *url, int flags);
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/**
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 * Read up to size bytes from the resource accessed by h, and store
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 * the read bytes in buf.
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 *
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 * @return The number of bytes actually read, or a negative value
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 * corresponding to an AVERROR code in case of error. A value of zero
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 * indicates that it is not possible to read more from the accessed
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 * resource (except if the value of the size argument is also zero).
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 */
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int url_read(URLContext *h, unsigned char *buf, int size);
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/**
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 * Read as many bytes as possible (up to size), calling the
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 * read function multiple times if necessary.
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 * Will also retry if the read function returns AVERROR(EAGAIN).
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 * This makes special short-read handling in applications
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 * unnecessary, if the return value is < size then it is
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 * certain there was either an error or the end of file was reached.
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 */
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int url_read_complete(URLContext *h, unsigned char *buf, int size);
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/**
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 * Write size bytes from buf to the resource accessed by h.
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 *
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 * @return the number of bytes actually written, or a negative value
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 * corresponding to an AVERROR code in case of failure
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 */
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int url_write(URLContext *h, const unsigned char *buf, int size);
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/**
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 * Passing this as the "whence" parameter to a seek function causes it to
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 * return the filesize without seeking anywhere. Supporting this is optional.
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 * If it is not supported then the seek function will return <0.
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 */
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#define AVSEEK_SIZE 0x10000
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/**
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 * Change the position that will be used by the next read/write
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 * operation on the resource accessed by h.
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 *
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 * @param pos specifies the new position to set
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 * @param whence specifies how pos should be interpreted, it must be
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 * one of SEEK_SET (seek from the beginning), SEEK_CUR (seek from the
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 * current position), SEEK_END (seek from the end), or AVSEEK_SIZE
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 * (return the filesize of the requested resource, pos is ignored).
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 * @return a negative value corresponding to an AVERROR code in case
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 * of failure, or the resulting file position, measured in bytes from
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 * the beginning of the file. You can use this feature together with
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 * SEEK_CUR to read the current file position.
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 */
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int64_t url_seek(URLContext *h, int64_t pos, int whence);
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/**
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 * Close the resource accessed by the URLContext h, and free the
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 * memory used by it.
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 *
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 * @return a negative value if an error condition occurred, 0
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 * otherwise
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 */
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int url_close(URLContext *h);
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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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 * Return the filesize of the resource accessed by h, AVERROR(ENOSYS)
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 * if the operation is not supported by h, or another negative value
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 * corresponding to an AVERROR error code in case of failure.
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 */
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int64_t url_filesize(URLContext *h);
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/**
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 * Return the file descriptor associated with this URL. For RTP, this
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 * will return only the RTP file descriptor, not the RTCP file descriptor.
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 *
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 * @return the file descriptor associated with this URL, or <0 on error.
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 */
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int url_get_file_handle(URLContext *h);
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/**
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 * Return the maximum packet size associated to packetized file
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 * handle. If the file is not packetized (stream like HTTP or file on
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 * disk), then 0 is returned.
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 *
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 * @param h file handle
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 * @return maximum packet size in bytes
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 */
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int url_get_max_packet_size(URLContext *h);
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/**
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 * Copy the filename of the resource accessed by h to buf.
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 *
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 * @param buf_size size in bytes of buf
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 */
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void url_get_filename(URLContext *h, char *buf, int buf_size);
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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(EINTR) 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 url_set_interrupt_cb(URLInterruptCB *interrupt_cb);
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/* not implemented */
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int url_poll(URLPollEntry *poll_table, int n, int timeout);
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/**
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 * Pause and resume playing - only meaningful if using a network streaming
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 * protocol (e.g. MMS).
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 * @param pause 1 for pause, 0 for resume
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 */
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int av_url_read_pause(URLContext *h, int pause);
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/**
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 * Seek to a given timestamp relative to some component stream.
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 * Only meaningful if using a network streaming protocol (e.g. MMS.).
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 * @param stream_index The stream index that the timestamp is relative to.
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 *        If stream_index is (-1) the timestamp should be in AV_TIME_BASE
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 *        units from the beginning of the presentation.
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 *        If a stream_index >= 0 is used and the protocol does not support
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 *        seeking based on component streams, the call will fail with ENOTSUP.
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 * @param timestamp timestamp in AVStream.time_base units
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 *        or if there is no stream specified then in AV_TIME_BASE units.
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 * @param flags Optional combination of AVSEEK_FLAG_BACKWARD, AVSEEK_FLAG_BYTE
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 *        and AVSEEK_FLAG_ANY. The protocol may silently ignore
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 *        AVSEEK_FLAG_BACKWARD and AVSEEK_FLAG_ANY, but AVSEEK_FLAG_BYTE will
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 *        fail with ENOTSUP if used and not supported.
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 * @return >= 0 on success
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 * @see AVInputFormat::read_seek
250
 */
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int64_t av_url_read_seek(URLContext *h, int stream_index,
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                         int64_t timestamp, int flags);
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/**
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 * Oring this flag as into the "whence" parameter to a seek function causes it to
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 * seek by any means (like reopening and linear reading) or other normally unreasonble
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 * means that can be extreemly slow.
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 * This may be ignored by the seek code.
259
 */
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#define AVSEEK_FORCE 0x20000
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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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} URLProtocol;
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#if FF_API_REGISTER_PROTOCOL
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extern URLProtocol *first_protocol;
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#endif
281

    
282
extern URLInterruptCB *url_interrupt_cb;
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284
/**
285
 * 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,
287
 * or NULL if protocol is the last one.
288
 */
289
URLProtocol *av_protocol_next(URLProtocol *p);
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291
#if FF_API_REGISTER_PROTOCOL
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/**
293
 * @deprecated Use av_register_protocol() instead.
294
 */
295
attribute_deprecated int register_protocol(URLProtocol *protocol);
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297
/**
298
 * @deprecated Use av_register_protocol2() instead.
299
 */
300
attribute_deprecated int av_register_protocol(URLProtocol *protocol);
301
#endif
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/**
304
 * Register the URLProtocol protocol.
305
 *
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 * @param size the size of the URLProtocol struct referenced
307
 */
308
int av_register_protocol2(URLProtocol *protocol, int size);
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/**
311
 * Bytestream IO Context.
312
 * New fields can be added to the end with minor version bumps.
313
 * Removal, reordering and changes to existing fields require a major
314
 * version bump.
315
 * sizeof(ByteIOContext) must not be used outside libav*.
316
 */
317
typedef struct {
318
    unsigned char *buffer;
319
    int buffer_size;
320
    unsigned char *buf_ptr, *buf_end;
321
    void *opaque;
322
    int (*read_packet)(void *opaque, uint8_t *buf, int buf_size);
323
    int (*write_packet)(void *opaque, uint8_t *buf, int buf_size);
324
    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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    int is_streamed;
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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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    int (*read_pause)(void *opaque, int pause);
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    int64_t (*read_seek)(void *opaque, int stream_index,
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                         int64_t timestamp, int flags);
338
} ByteIOContext;
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int init_put_byte(ByteIOContext *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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ByteIOContext *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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void put_byte(ByteIOContext *s, int b);
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void put_nbyte(ByteIOContext *s, int b, int count);
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void put_buffer(ByteIOContext *s, const unsigned char *buf, int size);
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void put_le64(ByteIOContext *s, uint64_t val);
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void put_be64(ByteIOContext *s, uint64_t val);
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void put_le32(ByteIOContext *s, unsigned int val);
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void put_be32(ByteIOContext *s, unsigned int val);
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void put_le24(ByteIOContext *s, unsigned int val);
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void put_be24(ByteIOContext *s, unsigned int val);
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void put_le16(ByteIOContext *s, unsigned int val);
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void put_be16(ByteIOContext *s, unsigned int val);
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void put_tag(ByteIOContext *s, const char *tag);
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void put_strz(ByteIOContext *s, const char *buf);
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/**
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 * fseek() equivalent for ByteIOContext.
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 * @return new position or AVERROR.
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 */
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int64_t url_fseek(ByteIOContext *s, int64_t offset, int whence);
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/**
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 * Skip given number of bytes forward.
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 * @param offset number of bytes
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 * @return 0 on success, <0 on error
382
 */
383
int url_fskip(ByteIOContext *s, int64_t offset);
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/**
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 * ftell() equivalent for ByteIOContext.
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 * @return position or AVERROR.
388
 */
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int64_t url_ftell(ByteIOContext *s);
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/**
392
 * Get the filesize.
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 * @return filesize or AVERROR
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 */
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int64_t url_fsize(ByteIOContext *s);
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/**
398
 * feof() equivalent for ByteIOContext.
399
 * @return non zero if and only if end of file
400
 */
401
int url_feof(ByteIOContext *s);
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403
int url_ferror(ByteIOContext *s);
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int av_url_read_fpause(ByteIOContext *h, int pause);
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int64_t av_url_read_fseek(ByteIOContext *h, int stream_index,
407
                          int64_t timestamp, int flags);
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#define URL_EOF (-1)
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/** @note return URL_EOF (-1) if EOF */
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int url_fgetc(ByteIOContext *s);
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/** @warning currently size is limited */
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#ifdef __GNUC__
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int url_fprintf(ByteIOContext *s, const char *fmt, ...) __attribute__ ((__format__ (__printf__, 2, 3)));
416
#else
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int url_fprintf(ByteIOContext *s, const char *fmt, ...);
418
#endif
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/** @note unlike fgets, the EOL character is not returned and a whole
421
    line is parsed. return NULL if first char read was EOF */
422
char *url_fgets(ByteIOContext *s, char *buf, int buf_size);
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void put_flush_packet(ByteIOContext *s);
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/**
428
 * Read size bytes from ByteIOContext into buf.
429
 * @return number of bytes read or AVERROR
430
 */
431
int get_buffer(ByteIOContext *s, unsigned char *buf, int size);
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433
/**
434
 * Read size bytes from ByteIOContext into buf.
435
 * This reads at most 1 packet. If that is not enough fewer bytes will be
436
 * returned.
437
 * @return number of bytes read or AVERROR
438
 */
439
int get_partial_buffer(ByteIOContext *s, unsigned char *buf, int size);
440

    
441
/** @note return 0 if EOF, so you cannot use it if EOF handling is
442
    necessary */
443
int get_byte(ByteIOContext *s);
444
unsigned int get_le24(ByteIOContext *s);
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unsigned int get_le32(ByteIOContext *s);
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uint64_t get_le64(ByteIOContext *s);
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unsigned int get_le16(ByteIOContext *s);
448

    
449
char *get_strz(ByteIOContext *s, char *buf, int maxlen);
450
unsigned int get_be16(ByteIOContext *s);
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unsigned int get_be24(ByteIOContext *s);
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unsigned int get_be32(ByteIOContext *s);
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uint64_t get_be64(ByteIOContext *s);
454

    
455
uint64_t ff_get_v(ByteIOContext *bc);
456

    
457
static inline int url_is_streamed(ByteIOContext *s)
458
{
459
    return s->is_streamed;
460
}
461

    
462
/**
463
 * Create and initialize a ByteIOContext for accessing the
464
 * resource referenced by the URLContext h.
465
 * @note When the URLContext h has been opened in read+write mode, the
466
 * ByteIOContext can be used only for writing.
467
 *
468
 * @param s Used to return the pointer to the created ByteIOContext.
469
 * In case of failure the pointed to value is set to NULL.
470
 * @return 0 in case of success, a negative value corresponding to an
471
 * AVERROR code in case of failure
472
 */
473
int url_fdopen(ByteIOContext **s, URLContext *h);
474

    
475
/** @warning must be called before any I/O */
476
int url_setbufsize(ByteIOContext *s, int buf_size);
477
#if FF_API_URL_RESETBUF
478
/** Reset the buffer for reading or writing.
479
 * @note Will drop any data currently in the buffer without transmitting it.
480
 * @param flags URL_RDONLY to set up the buffer for reading, or URL_WRONLY
481
 *        to set up the buffer for writing. */
482
int url_resetbuf(ByteIOContext *s, int flags);
483
#endif
484

    
485
/**
486
 * Rewind the ByteIOContext using the specified buffer containing the first buf_size bytes of the file.
487
 * Used after probing to avoid seeking.
488
 * Joins buf and s->buffer, taking any overlap into consideration.
489
 * @note s->buffer must overlap with buf or they can't be joined and the function fails
490
 * @note This function is NOT part of the public API
491
 *
492
 * @param s The read-only ByteIOContext to rewind
493
 * @param buf The probe buffer containing the first buf_size bytes of the file
494
 * @param buf_size The size of buf
495
 * @return 0 in case of success, a negative value corresponding to an
496
 * AVERROR code in case of failure
497
 */
498
int ff_rewind_with_probe_data(ByteIOContext *s, unsigned char *buf, int buf_size);
499

    
500
/**
501
 * Create and initialize a ByteIOContext for accessing the
502
 * resource indicated by url.
503
 * @note When the resource indicated by url has been opened in
504
 * read+write mode, the ByteIOContext can be used only for writing.
505
 *
506
 * @param s Used to return the pointer to the created ByteIOContext.
507
 * In case of failure the pointed to value is set to NULL.
508
 * @param flags flags which control how the resource indicated by url
509
 * is to be opened
510
 * @return 0 in case of success, a negative value corresponding to an
511
 * AVERROR code in case of failure
512
 */
513
int url_fopen(ByteIOContext **s, const char *url, int flags);
514

    
515
int url_fclose(ByteIOContext *s);
516
URLContext *url_fileno(ByteIOContext *s);
517

    
518
/**
519
 * Return the maximum packet size associated to packetized buffered file
520
 * handle. If the file is not packetized (stream like http or file on
521
 * disk), then 0 is returned.
522
 *
523
 * @param s buffered file handle
524
 * @return maximum packet size in bytes
525
 */
526
int url_fget_max_packet_size(ByteIOContext *s);
527

    
528
int url_open_buf(ByteIOContext **s, uint8_t *buf, int buf_size, int flags);
529

    
530
/** return the written or read size */
531
int url_close_buf(ByteIOContext *s);
532

    
533
/**
534
 * Open a write only memory stream.
535
 *
536
 * @param s new IO context
537
 * @return zero if no error.
538
 */
539
int url_open_dyn_buf(ByteIOContext **s);
540

    
541
/**
542
 * Open a write only packetized memory stream with a maximum packet
543
 * size of 'max_packet_size'.  The stream is stored in a memory buffer
544
 * with a big endian 4 byte header giving the packet size in bytes.
545
 *
546
 * @param s new IO context
547
 * @param max_packet_size maximum packet size (must be > 0)
548
 * @return zero if no error.
549
 */
550
int url_open_dyn_packet_buf(ByteIOContext **s, int max_packet_size);
551

    
552
/**
553
 * Return the written size and a pointer to the buffer. The buffer
554
 * must be freed with av_free(). If the buffer is opened with
555
 * url_open_dyn_buf, then padding of FF_INPUT_BUFFER_PADDING_SIZE is
556
 * added; if opened with url_open_dyn_packet_buf, no padding is added.
557
 *
558
 * @param s IO context
559
 * @param pbuffer pointer to a byte buffer
560
 * @return the length of the byte buffer
561
 */
562
int url_close_dyn_buf(ByteIOContext *s, uint8_t **pbuffer);
563

    
564
unsigned long ff_crc04C11DB7_update(unsigned long checksum, const uint8_t *buf,
565
                                    unsigned int len);
566
unsigned long get_checksum(ByteIOContext *s);
567
void init_checksum(ByteIOContext *s,
568
                   unsigned long (*update_checksum)(unsigned long c, const uint8_t *p, unsigned int len),
569
                   unsigned long checksum);
570

    
571
/* udp.c */
572
int udp_set_remote_url(URLContext *h, const char *uri);
573
int udp_get_local_port(URLContext *h);
574
#if FF_API_UDP_GET_FILE
575
int udp_get_file_handle(URLContext *h);
576
#endif
577

    
578
#endif /* AVFORMAT_AVIO_H */