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#include "libavutil/dict.h" 32#include "libavutil/log.h" 33 34#if !FF_API_OLD_AVIO 35#define URL_PROTOCOL_FLAG_NESTED_SCHEME 1 /*< The protocol name can be the first part of a nested protocol scheme */ 36#define URL_PROTOCOL_FLAG_NETWORK 2 /*< The protocol uses network */ 37 38extern int (*url_interrupt_cb)(void); 39 40extern const AVClass ffurl_context_class; 41 42typedef struct URLContext { 43 const AVClass *av_class; /**< information for av_log(). Set by url_open(). */ 44 struct URLProtocol *prot; 45 void *priv_data; 46 char *filename; /**< specified URL */ 47 int flags; 48 int max_packet_size; /**< if non zero, the stream is packetized with this max packet size */ 49 int is_streamed; /**< true if streamed (no seek possible), default = false */ 50 int is_connected; 51 AVIOInterruptCB interrupt_callback; 52} URLContext; 53 54typedef struct URLProtocol { 55 const char *name; 56 int (*url_open)( URLContext *h, const char *url, int flags); 57 /** 58 * This callback is to be used by protocols which open further nested 59 * protocols. options are then to be passed to ffurl_open()/ffurl_connect() 60 * for those nested protocols. 61 */ 62 int (*url_open2)(URLContext *h, const char *url, int flags, AVDictionary **options); 63 int (*url_read)( URLContext *h, unsigned char *buf, int size); 64 int (*url_write)(URLContext *h, const unsigned char *buf, int size); 65 int64_t (*url_seek)( URLContext *h, int64_t pos, int whence); 66 int (*url_close)(URLContext *h); 67 struct URLProtocol *next; 68 int (*url_read_pause)(URLContext *h, int pause); 69 int64_t (*url_read_seek)(URLContext *h, int stream_index, 70 int64_t timestamp, int flags); 71 int (*url_get_file_handle)(URLContext *h); 72 int priv_data_size; 73 const AVClass *priv_data_class; 74 int flags; 75 int (*url_check)(URLContext *h, int mask); 76} URLProtocol; 77#endif 78 79/** 80 * Create a URLContext for accessing to the resource indicated by 81 * url, but do not initiate the connection yet. 82 * 83 * @param puc pointer to the location where, in case of success, the 84 * function puts the pointer to the created URLContext 85 * @param flags flags which control how the resource indicated by url 86 * is to be opened 87 * @param int_cb interrupt callback to use for the URLContext, may be 88 * NULL 89 * @return 0 in case of success, a negative value corresponding to an 90 * AVERROR code in case of failure 91 */ 92int ffurl_alloc(URLContext **puc, const char *filename, int flags, 93 const AVIOInterruptCB *int_cb); 94 95/** 96 * Connect an URLContext that has been allocated by ffurl_alloc 97 * 98 * @param options A dictionary filled with options for nested protocols, 99 * i.e. it will be passed to url_open2() for protocols implementing it. 100 * This parameter will be destroyed and replaced with a dict containing options 101 * that were not found. May be NULL. 102 */ 103int ffurl_connect(URLContext *uc, AVDictionary **options); 104 105/** 106 * Create an URLContext for accessing to the resource indicated by 107 * url, and open it. 108 * 109 * @param puc pointer to the location where, in case of success, the 110 * function puts the pointer to the created URLContext 111 * @param flags flags which control how the resource indicated by url 112 * is to be opened 113 * @param int_cb interrupt callback to use for the URLContext, may be 114 * NULL 115 * @param options A dictionary filled with protocol-private options. On return 116 * this parameter will be destroyed and replaced with a dict containing options 117 * that were not found. May be NULL. 118 * @return 0 in case of success, a negative value corresponding to an 119 * AVERROR code in case of failure 120 */ 121int ffurl_open(URLContext **puc, const char *filename, int flags, 122 const AVIOInterruptCB *int_cb, AVDictionary **options); 123 124/** 125 * Read up to size bytes from the resource accessed by h, and store 126 * the read bytes in buf. 127 * 128 * @return The number of bytes actually read, or a negative value 129 * corresponding to an AVERROR code in case of error. A value of zero 130 * indicates that it is not possible to read more from the accessed 131 * resource (except if the value of the size argument is also zero). 132 */ 133int ffurl_read(URLContext *h, unsigned char *buf, int size); 134 135/** 136 * Read as many bytes as possible (up to size), calling the 137 * read function multiple times if necessary. 138 * This makes special short-read handling in applications 139 * unnecessary, if the return value is < size then it is 140 * certain there was either an error or the end of file was reached. 141 */ 142int ffurl_read_complete(URLContext *h, unsigned char *buf, int size); 143 144/** 145 * Write size bytes from buf to the resource accessed by h. 146 * 147 * @return the number of bytes actually written, or a negative value 148 * corresponding to an AVERROR code in case of failure 149 */ 150int ffurl_write(URLContext *h, const unsigned char *buf, int size); 151 152/** 153 * Change the position that will be used by the next read/write 154 * operation on the resource accessed by h. 155 * 156 * @param pos specifies the new position to set 157 * @param whence specifies how pos should be interpreted, it must be 158 * one of SEEK_SET (seek from the beginning), SEEK_CUR (seek from the 159 * current position), SEEK_END (seek from the end), or AVSEEK_SIZE 160 * (return the filesize of the requested resource, pos is ignored). 161 * @return a negative value corresponding to an AVERROR code in case 162 * of failure, or the resulting file position, measured in bytes from 163 * the beginning of the file. You can use this feature together with 164 * SEEK_CUR to read the current file position. 165 */ 166int64_t ffurl_seek(URLContext *h, int64_t pos, int whence); 167 168/** 169 * Close the resource accessed by the URLContext h, and free the 170 * memory used by it. 171 * 172 * @return a negative value if an error condition occurred, 0 173 * otherwise 174 */ 175int ffurl_close(URLContext *h); 176 177/** 178 * Return the filesize of the resource accessed by h, AVERROR(ENOSYS) 179 * if the operation is not supported by h, or another negative value 180 * corresponding to an AVERROR error code in case of failure. 181 */ 182int64_t ffurl_size(URLContext *h); 183 184/** 185 * Return the file descriptor associated with this URL. For RTP, this 186 * will return only the RTP file descriptor, not the RTCP file descriptor. 187 * 188 * @return the file descriptor associated with this URL, or <0 on error. 189 */ 190int ffurl_get_file_handle(URLContext *h); 191 192/** 193 * Register the URLProtocol protocol. 194 * 195 * @param size the size of the URLProtocol struct referenced 196 */ 197int ffurl_register_protocol(URLProtocol *protocol, int size); 198 199/** 200 * Check if the user has requested to interrup a blocking function 201 * associated with cb. 202 */ 203int ff_check_interrupt(AVIOInterruptCB *cb); 204 205/** 206 * Iterate over all available protocols. 207 * 208 * @param prev result of the previous call to this functions or NULL. 209 */ 210URLProtocol *ffurl_protocol_next(URLProtocol *prev); 211 212/* udp.c */ 213int ff_udp_set_remote_url(URLContext *h, const char *uri); 214int ff_udp_get_local_port(URLContext *h); 215 216#endif /* AVFORMAT_URL_H */ 217