libavformat/url.h

   1 /*
   2  *
   3  * This file is part of Libav.
   4  *
   5  * Libav is free software; you can redistribute it and/or
   6  * modify it under the terms of the GNU Lesser General Public
   7  * License as published by the Free Software Foundation; either
   8  * version 2.1 of the License, or (at your option) any later version.
   9  *
  10  * Libav is distributed in the hope that it will be useful,
  11  * but WITHOUT ANY WARRANTY; without even the implied warranty of
  12  * MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE.  See the GNU
  13  * Lesser General Public License for more details.
  14  *
  15  * You should have received a copy of the GNU Lesser General Public
  16  * License along with Libav; if not, write to the Free Software
  17  * Foundation, Inc., 51 Franklin Street, Fifth Floor, Boston, MA 02110-1301 USA
  18  */
  19
  20 /**
  21  * @file
  22  * unbuffered private I/O API
  23  */
  24
  25 #ifndef AVFORMAT_URL_H
  26 #define AVFORMAT_URL_H
  27
  28 #include "avio.h"
  29 #include "libavformat/version.h"
  30
  31 #if !FF_API_OLD_AVIO
  32 #define URL_PROTOCOL_FLAG_NESTED_SCHEME 1 /*< The protocol name can be the first part of a nested protocol scheme */
  33
  34 extern int (*url_interrupt_cb)(void);
  35
  36 typedef struct URLContext {
  37     const AVClass *av_class;    /**< information for av_log(). Set by url_open(). */
  38     struct URLProtocol *prot;
  39     void *priv_data;
  40     char *filename;             /**< specified URL */
  41     int flags;
  42     int max_packet_size;        /**< if non zero, the stream is packetized with this max packet size */
  43     int is_streamed;            /**< true if streamed (no seek possible), default = false */
  44     int is_connected;
  45 } URLContext;
  46
  47 typedef struct URLProtocol {
  48     const char *name;
  49     int     (*url_open)( URLContext *h, const char *url, int flags);
  50     int     (*url_read)( URLContext *h, unsigned char *buf, int size);
  51     int     (*url_write)(URLContext *h, const unsigned char *buf, int size);
  52     int64_t (*url_seek)( URLContext *h, int64_t pos, int whence);
  53     int     (*url_close)(URLContext *h);
  54     struct URLProtocol *next;
  55     int (*url_read_pause)(URLContext *h, int pause);
  56     int64_t (*url_read_seek)(URLContext *h, int stream_index,
  57                              int64_t timestamp, int flags);
  58     int (*url_get_file_handle)(URLContext *h);
  59     int priv_data_size;
  60     const AVClass *priv_data_class;
  61     int flags;
  62     int (*url_check)(URLContext *h, int mask);
  63 } URLProtocol;
  64 #endif
  65
  66 /**
  67  * Create a URLContext for accessing to the resource indicated by
  68  * url, but do not initiate the connection yet.
  69  *
  70  * @param puc pointer to the location where, in case of success, the
  71  * function puts the pointer to the created URLContext
  72  * @param flags flags which control how the resource indicated by url
  73  * is to be opened
  74  * @return 0 in case of success, a negative value corresponding to an
  75  * AVERROR code in case of failure
  76  */
  77 int ffurl_alloc(URLContext **puc, const char *filename, int flags);
  78
  79 /**
  80  * Connect an URLContext that has been allocated by ffurl_alloc
  81  */
  82 int ffurl_connect(URLContext *uc);
  83
  84 /**
  85  * Create an URLContext for accessing to the resource indicated by
  86  * url, and open it.
  87  *
  88  * @param puc pointer to the location where, in case of success, the
  89  * function puts the pointer to the created URLContext
  90  * @param flags flags which control how the resource indicated by url
  91  * is to be opened
  92  * @return 0 in case of success, a negative value corresponding to an
  93  * AVERROR code in case of failure
  94  */
  95 int ffurl_open(URLContext **puc, const char *filename, int flags);
  96
  97 /**
  98  * Read up to size bytes from the resource accessed by h, and store
  99  * the read bytes in buf.
 100  *
 101  * @return The number of bytes actually read, or a negative value
 102  * corresponding to an AVERROR code in case of error. A value of zero
 103  * indicates that it is not possible to read more from the accessed
 104  * resource (except if the value of the size argument is also zero).
 105  */
 106 int ffurl_read(URLContext *h, unsigned char *buf, int size);
 107
 108 /**
 109  * Read as many bytes as possible (up to size), calling the
 110  * read function multiple times if necessary.
 111  * This makes special short-read handling in applications
 112  * unnecessary, if the return value is < size then it is
 113  * certain there was either an error or the end of file was reached.
 114  */
 115 int ffurl_read_complete(URLContext *h, unsigned char *buf, int size);
 116
 117 /**
 118  * Write size bytes from buf to the resource accessed by h.
 119  *
 120  * @return the number of bytes actually written, or a negative value
 121  * corresponding to an AVERROR code in case of failure
 122  */
 123 int ffurl_write(URLContext *h, const unsigned char *buf, int size);
 124
 125 /**
 126  * Change the position that will be used by the next read/write
 127  * operation on the resource accessed by h.
 128  *
 129  * @param pos specifies the new position to set
 130  * @param whence specifies how pos should be interpreted, it must be
 131  * one of SEEK_SET (seek from the beginning), SEEK_CUR (seek from the
 132  * current position), SEEK_END (seek from the end), or AVSEEK_SIZE
 133  * (return the filesize of the requested resource, pos is ignored).
 134  * @return a negative value corresponding to an AVERROR code in case
 135  * of failure, or the resulting file position, measured in bytes from
 136  * the beginning of the file. You can use this feature together with
 137  * SEEK_CUR to read the current file position.
 138  */
 139 int64_t ffurl_seek(URLContext *h, int64_t pos, int whence);
 140
 141 /**
 142  * Close the resource accessed by the URLContext h, and free the
 143  * memory used by it.
 144  *
 145  * @return a negative value if an error condition occurred, 0
 146  * otherwise
 147  */
 148 int ffurl_close(URLContext *h);
 149
 150 /**
 151  * Return the filesize of the resource accessed by h, AVERROR(ENOSYS)
 152  * if the operation is not supported by h, or another negative value
 153  * corresponding to an AVERROR error code in case of failure.
 154  */
 155 int64_t ffurl_size(URLContext *h);
 156
 157 /**
 158  * Return the file descriptor associated with this URL. For RTP, this
 159  * will return only the RTP file descriptor, not the RTCP file descriptor.
 160  *
 161  * @return the file descriptor associated with this URL, or <0 on error.
 162  */
 163 int ffurl_get_file_handle(URLContext *h);
 164
 165 /**
 166  * Register the URLProtocol protocol.
 167  *
 168  * @param size the size of the URLProtocol struct referenced
 169  */
 170 int ffurl_register_protocol(URLProtocol *protocol, int size);
 171
 172 /* udp.c */
 173 int ff_udp_set_remote_url(URLContext *h, const char *uri);
 174 int ff_udp_get_local_port(URLContext *h);
 175
 176 #endif /* AVFORMAT_URL_H */