ffmpeg / libavformat / avio.h @ d3058be6
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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
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*/
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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.
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*/
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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
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extern URLInterruptCB *url_interrupt_cb;
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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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URLProtocol *av_protocol_next(URLProtocol *p); |
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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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* 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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int av_register_protocol2(URLProtocol *protocol, int size); |
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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(ByteIOContext) must not be used outside libav*.
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*/
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typedef struct { |
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unsigned char *buffer; |
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int buffer_size;
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unsigned char *buf_ptr, *buf_end; |
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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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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);
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} 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
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*/
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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.
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*/
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int64_t url_ftell(ByteIOContext *s); |
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/**
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* 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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/**
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* feof() equivalent for ByteIOContext.
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* @return non zero if and only if end of file
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*/
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int url_feof(ByteIOContext *s);
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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,
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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))); |
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#else
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int url_fprintf(ByteIOContext *s, const char *fmt, ...); |
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#endif
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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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char *url_fgets(ByteIOContext *s, char *buf, int buf_size); |
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void put_flush_packet(ByteIOContext *s);
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/**
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* Read size bytes from ByteIOContext into buf.
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* @return number of bytes read or AVERROR
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*/
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int get_buffer(ByteIOContext *s, unsigned char *buf, int size); |
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/**
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* Read size bytes from ByteIOContext into buf.
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* This reads at most 1 packet. If that is not enough fewer bytes will be
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* returned.
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* @return number of bytes read or AVERROR
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*/
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int get_partial_buffer(ByteIOContext *s, unsigned char *buf, int size); |
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/** @note return 0 if EOF, so you cannot use it if EOF handling is
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necessary */
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int get_byte(ByteIOContext *s);
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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); |
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char *get_strz(ByteIOContext *s, char *buf, int maxlen); |
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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); |
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uint64_t ff_get_v(ByteIOContext *bc); |
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static inline int url_is_streamed(ByteIOContext *s) |
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{ |
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return s->is_streamed;
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} |
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/**
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* Create and initialize a ByteIOContext for accessing the
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* resource referenced by the URLContext h.
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* @note When the URLContext h has been opened in read+write mode, the
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* ByteIOContext can be used only for writing.
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*
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* @param s Used to return the pointer to the created ByteIOContext.
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* In case of failure the pointed to value is set to NULL.
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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_fdopen(ByteIOContext **s, URLContext *h);
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/** @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 */ |