/* * This file is part of Libav. * * Libav is free software; you can redistribute it and/or * modify it under the terms of the GNU Lesser General Public * License as published by the Free Software Foundation; either * version 2.1 of the License, or (at your option) any later version. * * Libav is distributed in the hope that it will be useful, * but WITHOUT ANY WARRANTY; without even the implied warranty of * MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE. See the GNU * Lesser General Public License for more details. * * You should have received a copy of the GNU Lesser General Public * License along with Libav; if not, write to the Free Software * Foundation, Inc., 51 Franklin Street, Fifth Floor, Boston, MA 02110-1301 USA */ /** * @file * unbuffered private I/O API */ #ifndef AVFORMAT_URL_H #define AVFORMAT_URL_H #include "avio.h" #include "libavformat/version.h" #include "libavutil/dict.h" #include "libavutil/log.h" #define URL_PROTOCOL_FLAG_NESTED_SCHEME 1 /*< The protocol name can be the first part of a nested protocol scheme */ #define URL_PROTOCOL_FLAG_NETWORK 2 /*< The protocol uses network */ extern const AVClass ffurl_context_class; typedef struct URLContext { const AVClass *av_class; /**< information for av_log(). Set by url_open(). */ const struct URLProtocol *prot; void *priv_data; char *filename; /**< specified URL */ int flags; int max_packet_size; /**< if non zero, the stream is packetized with this max packet size */ int is_streamed; /**< true if streamed (no seek possible), default = false */ int is_connected; AVIOInterruptCB interrupt_callback; } URLContext; typedef struct URLProtocol { const char *name; int (*url_open)( URLContext *h, const char *url, int flags); /** * This callback is to be used by protocols which open further nested * protocols. options are then to be passed to ffurl_open()/ffurl_connect() * for those nested protocols. */ int (*url_open2)(URLContext *h, const char *url, int flags, AVDictionary **options); /** * Read data from the protocol. * If data is immediately available (even less than size), EOF is * reached or an error occurs (including EINTR), return immediately. * Otherwise: * In non-blocking mode, return AVERROR(EAGAIN) immediately. * In blocking mode, wait for data/EOF/error with a short timeout (0.1s), * and return AVERROR(EAGAIN) on timeout. * Checking interrupt_callback, looping on EINTR and EAGAIN and until * enough data has been read is left to the calling function; see * retry_transfer_wrapper in avio.c. */ int (*url_read)( URLContext *h, unsigned char *buf, int size); int (*url_write)(URLContext *h, const unsigned char *buf, int size); int64_t (*url_seek)( URLContext *h, int64_t pos, int whence); int (*url_close)(URLContext *h); int (*url_read_pause)(URLContext *h, int pause); int64_t (*url_read_seek)(URLContext *h, int stream_index, int64_t timestamp, int flags); int (*url_get_file_handle)(URLContext *h); int (*url_get_multi_file_handle)(URLContext *h, int **handles, int *numhandles); int (*url_shutdown)(URLContext *h, int flags); int priv_data_size; const AVClass *priv_data_class; int flags; int (*url_check)(URLContext *h, int mask); } URLProtocol; /** * Create a URLContext for accessing to the resource indicated by * url, but do not initiate the connection yet. * * @param puc pointer to the location where, in case of success, the * function puts the pointer to the created URLContext * @param flags flags which control how the resource indicated by url * is to be opened * @param int_cb interrupt callback to use for the URLContext, may be * NULL * @return 0 in case of success, a negative value corresponding to an * AVERROR code in case of failure */ int ffurl_alloc(URLContext **puc, const char *filename, int flags, const AVIOInterruptCB *int_cb); /** * Connect an URLContext that has been allocated by ffurl_alloc * * @param options A dictionary filled with options for nested protocols, * i.e. it will be passed to url_open2() for protocols implementing it. * This parameter will be destroyed and replaced with a dict containing options * that were not found. May be NULL. */ int ffurl_connect(URLContext *uc, AVDictionary **options); /** * Create an URLContext for accessing to the resource indicated by * url, and open it. * * @param puc pointer to the location where, in case of success, the * function puts the pointer to the created URLContext * @param flags flags which control how the resource indicated by url * is to be opened * @param int_cb interrupt callback to use for the URLContext, may be * NULL * @param options A dictionary filled with protocol-private options. On return * this parameter will be destroyed and replaced with a dict containing options * that were not found. May be NULL. * @return 0 in case of success, a negative value corresponding to an * AVERROR code in case of failure */ int ffurl_open(URLContext **puc, const char *filename, int flags, const AVIOInterruptCB *int_cb, AVDictionary **options); /** * Read up to size bytes from the resource accessed by h, and store * the read bytes in buf. * * @return The number of bytes actually read, or a negative value * corresponding to an AVERROR code in case of error. A value of zero * indicates that it is not possible to read more from the accessed * resource (except if the value of the size argument is also zero). */ int ffurl_read(URLContext *h, unsigned char *buf, int size); /** * Read as many bytes as possible (up to size), calling the * read function multiple times if necessary. * This makes special short-read handling in applications * unnecessary, if the return value is < size then it is * certain there was either an error or the end of file was reached. */ int ffurl_read_complete(URLContext *h, unsigned char *buf, int size); /** * Write size bytes from buf to the resource accessed by h. * * @return the number of bytes actually written, or a negative value * corresponding to an AVERROR code in case of failure */ int ffurl_write(URLContext *h, const unsigned char *buf, int size); /** * Change the position that will be used by the next read/write * operation on the resource accessed by h. * * @param pos specifies the new position to set * @param whence specifies how pos should be interpreted, it must be * one of SEEK_SET (seek from the beginning), SEEK_CUR (seek from the * current position), SEEK_END (seek from the end), or AVSEEK_SIZE * (return the filesize of the requested resource, pos is ignored). * @return a negative value corresponding to an AVERROR code in case * of failure, or the resulting file position, measured in bytes from * the beginning of the file. You can use this feature together with * SEEK_CUR to read the current file position. */ int64_t ffurl_seek(URLContext *h, int64_t pos, int whence); /** * Close the resource accessed by the URLContext h, and free the * memory used by it. * * @return a negative value if an error condition occurred, 0 * otherwise */ int ffurl_close(URLContext *h); /** * Return the filesize of the resource accessed by h, AVERROR(ENOSYS) * if the operation is not supported by h, or another negative value * corresponding to an AVERROR error code in case of failure. */ int64_t ffurl_size(URLContext *h); /** * Return the file descriptor associated with this URL. For RTP, this * will return only the RTP file descriptor, not the RTCP file descriptor. * * @return the file descriptor associated with this URL, or <0 on error. */ int ffurl_get_file_handle(URLContext *h); /** * Return the file descriptors associated with this URL. * * @return 0 on success or <0 on error. */ int ffurl_get_multi_file_handle(URLContext *h, int **handles, int *numhandles); /** * Signal the URLContext that we are done reading or writing the stream. * * @param h pointer to the resource * @param flags flags which control how the resource indicated by url * is to be shutdown * * @return a negative value if an error condition occurred, 0 * otherwise */ int ffurl_shutdown(URLContext *h, int flags); /** * Check if the user has requested to interrup a blocking function * associated with cb. */ int ff_check_interrupt(AVIOInterruptCB *cb); /* udp.c */ int ff_udp_set_remote_url(URLContext *h, const char *uri); int ff_udp_get_local_port(URLContext *h); /** * Assemble a URL string from components. This is the reverse operation * of av_url_split. * * Note, this requires networking to be initialized, so the caller must * ensure ff_network_init has been called. * * @see av_url_split * * @param str the buffer to fill with the url * @param size the size of the str buffer * @param proto the protocol identifier, if null, the separator * after the identifier is left out, too * @param authorization an optional authorization string, may be null. * An empty string is treated the same as a null string. * @param hostname the host name string * @param port the port number, left out from the string if negative * @param fmt a generic format string for everything to add after the * host/port, may be null * @return the number of characters written to the destination buffer */ int ff_url_join(char *str, int size, const char *proto, const char *authorization, const char *hostname, int port, const char *fmt, ...) av_printf_format(7, 8); /* * Convert a relative url into an absolute url, given a base url. * * @param buf the buffer where output absolute url is written * @param size the size of buf * @param base the base url, may be equal to buf. * @param rel the new url, which is interpreted relative to base */ void ff_make_absolute_url(char *buf, int size, const char *base, const char *rel); extern const URLProtocol *ff_url_protocols[]; #endif /* AVFORMAT_URL_H */