/* * copyright (c) 2001 Fabrice Bellard * * This file is part of FFmpeg. * * FFmpeg 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. * * FFmpeg 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 FFmpeg; if not, write to the Free Software * Foundation, Inc., 51 Franklin Street, Fifth Floor, Boston, MA 02110-1301 USA */ #ifndef AVFORMAT_AVIO_H #define AVFORMAT_AVIO_H /** * @file * unbuffered I/O operations * * @warning This file has to be considered an internal but installed * header, so it should not be directly included in your projects. */ #include #include "libavutil/common.h" #include "libavutil/log.h" /* unbuffered I/O */ /** * URL Context. * New fields can be added to the end with minor version bumps. * Removal, reordering and changes to existing fields require a major * version bump. * sizeof(URLContext) must not be used outside libav*. */ typedef struct URLContext { #if FF_API_URL_CLASS const AVClass *av_class; ///< information for av_log(). Set by url_open(). #endif struct URLProtocol *prot; int flags; int is_streamed; /**< true if streamed (no seek possible), default = false */ int max_packet_size; /**< if non zero, the stream is packetized with this max packet size */ void *priv_data; char *filename; /**< specified URL */ int is_connected; } URLContext; typedef struct URLPollEntry { URLContext *handle; int events; int revents; } URLPollEntry; #define URL_RDONLY 0 #define URL_WRONLY 1 #define URL_RDWR 2 typedef int URLInterruptCB(void); /** * Create a URLContext for accessing to the resource indicated by * url, and open it using the URLProtocol up. * * @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 * @return 0 in case of success, a negative value corresponding to an * AVERROR code in case of failure */ int url_open_protocol (URLContext **puc, struct URLProtocol *up, const char *url, int flags); /** * 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 * @return 0 in case of success, a negative value corresponding to an * AVERROR code in case of failure */ int url_alloc(URLContext **h, const char *url, int flags); /** * Connect an URLContext that has been allocated by url_alloc */ int url_connect(URLContext *h); /** * 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 * @return 0 in case of success, a negative value corresponding to an * AVERROR code in case of failure */ int url_open(URLContext **h, const char *url, int flags); /** * 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 url_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. * Will also retry if the read function returns AVERROR(EAGAIN). * 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 url_read_complete(URLContext *h, unsigned char *buf, int size); int url_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 url_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 url_close(URLContext *h); /** * Return a non-zero value if the resource indicated by url * exists, 0 otherwise. */ int url_exist(const char *url); /** * 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 url_filesize(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. * To get both, use rtp_get_file_handles(). * * @return the file descriptor associated with this URL, or <0 on error. */ int url_get_file_handle(URLContext *h); /** * Return the maximum packet size associated to packetized file * handle. If the file is not packetized (stream like HTTP or file on * disk), then 0 is returned. * * @param h file handle * @return maximum packet size in bytes */ int url_get_max_packet_size(URLContext *h); /** * Copy the filename of the resource accessed by h to buf. * * @param buf_size size in bytes of buf */ void url_get_filename(URLContext *h, char *buf, int buf_size); /** * The callback is called in blocking functions to test regulary if * asynchronous interruption is needed. AVERROR(EINTR) is returned * in this case by the interrupted function. 'NULL' means no interrupt * callback is given. */ void url_set_interrupt_cb(URLInterruptCB *interrupt_cb); /* not implemented */ int url_poll(URLPollEntry *poll_table, int n, int timeout); /** * Pause and resume playing - only meaningful if using a network streaming * protocol (e.g. MMS). * @param pause 1 for pause, 0 for resume */ int av_url_read_pause(URLContext *h, int pause); /** * Seek to a given timestamp relative to some component stream. * Only meaningful if using a network streaming protocol (e.g. MMS.). * @param stream_index The stream index that the timestamp is relative to. * If stream_index is (-1) the timestamp should be in AV_TIME_BASE * units from the beginning of the presentation. * If a stream_index >= 0 is used and the protocol does not support * seeking based on component streams, the call will fail with ENOTSUP. * @param timestamp timestamp in AVStream.time_base units * or if there is no stream specified then in AV_TIME_BASE units. * @param flags Optional combination of AVSEEK_FLAG_BACKWARD, AVSEEK_FLAG_BYTE * and AVSEEK_FLAG_ANY. The protocol may silently ignore * AVSEEK_FLAG_BACKWARD and AVSEEK_FLAG_ANY, but AVSEEK_FLAG_BYTE will * fail with ENOTSUP if used and not supported. * @return >= 0 on success * @see AVInputFormat::read_seek */ int64_t av_url_read_seek(URLContext *h, int stream_index, int64_t timestamp, int flags); /** * Passing this as the "whence" parameter to a seek function causes it to * return the filesize without seeking anywhere. Supporting this is optional. * If it is not supported then the seek function will return <0. */ #define AVSEEK_SIZE 0x10000 /** * Oring this flag as into the "whence" parameter to a seek function causes it to * seek by any means (like reopening and linear reading) or other normally unreasonble * means that can be extreemly slow. * This may be ignored by the seek code. */ #define AVSEEK_FORCE 0x20000 typedef struct URLProtocol { const char *name; int (*url_open)(URLContext *h, const char *url, int flags); 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); struct URLProtocol *next; 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 priv_data_size; const AVClass *priv_data_class; } URLProtocol; #if FF_API_REGISTER_PROTOCOL extern URLProtocol *first_protocol; #endif extern URLInterruptCB *url_interrupt_cb; /** * If protocol is NULL, returns the first registered protocol, * if protocol is non-NULL, returns the next registered protocol after protocol, * or NULL if protocol is the last one. */ URLProtocol *av_protocol_next(URLProtocol *p); #if FF_API_REGISTER_PROTOCOL /** * @deprecated Use av_register_protocol() instead. */ attribute_deprecated int register_protocol(URLProtocol *protocol); /** * @deprecated Use av_register_protocol2() instead. */ attribute_deprecated int av_register_protocol(URLProtocol *protocol); #endif /** * Register the URLProtocol protocol. * * @param size the size of the URLProtocol struct referenced */ int av_register_protocol2(URLProtocol *protocol, int size); /** * Bytestream IO Context. * New fields can be added to the end with minor version bumps. * Removal, reordering and changes to existing fields require a major * version bump. * sizeof(ByteIOContext) must not be used outside libav*. */ typedef struct { unsigned char *buffer; int buffer_size; unsigned char *buf_ptr, *buf_end; void *opaque; int (*read_packet)(void *opaque, uint8_t *buf, int buf_size); int (*write_packet)(void *opaque, uint8_t *buf, int buf_size); int64_t (*seek)(void *opaque, int64_t offset, int whence); int64_t pos; /**< position in the file of the current buffer */ int must_flush; /**< true if the next seek should flush */ int eof_reached; /**< true if eof reached */ int write_flag; /**< true if open for writing */ int is_streamed; int max_packet_size; unsigned long checksum; unsigned char *checksum_ptr; unsigned long (*update_checksum)(unsigned long checksum, const uint8_t *buf, unsigned int size); int error; ///< contains the error code or 0 if no error happened int (*read_pause)(void *opaque, int pause); int64_t (*read_seek)(void *opaque, int stream_index, int64_t timestamp, int flags); } ByteIOContext; int init_put_byte(ByteIOContext *s, unsigned char *buffer, int buffer_size, int write_flag, void *opaque, int (*read_packet)(void *opaque, uint8_t *buf, int buf_size), int (*write_packet)(void *opaque, uint8_t *buf, int buf_size), int64_t (*seek)(void *opaque, int64_t offset, int whence)); ByteIOContext *av_alloc_put_byte( unsigned char *buffer, int buffer_size, int write_flag, void *opaque, int (*read_packet)(void *opaque, uint8_t *buf, int buf_size), int (*write_packet)(void *opaque, uint8_t *buf, int buf_size), int64_t (*seek)(void *opaque, int64_t offset, int whence)); void put_byte(ByteIOContext *s, int b); void put_buffer(ByteIOContext *s, const unsigned char *buf, int size); void put_le64(ByteIOContext *s, uint64_t val); void put_be64(ByteIOContext *s, uint64_t val); void put_le32(ByteIOContext *s, unsigned int val); void put_be32(ByteIOContext *s, unsigned int val); void put_le24(ByteIOContext *s, unsigned int val); void put_be24(ByteIOContext *s, unsigned int val); void put_le16(ByteIOContext *s, unsigned int val); void put_be16(ByteIOContext *s, unsigned int val); void put_tag(ByteIOContext *s, const char *tag); void put_strz(ByteIOContext *s, const char *buf); /** * fseek() equivalent for ByteIOContext. * @return new position or AVERROR. */ int64_t url_fseek(ByteIOContext *s, int64_t offset, int whence); /** * Skip given number of bytes forward. * @param offset number of bytes * @return 0 on success, <0 on error */ int url_fskip(ByteIOContext *s, int64_t offset); /** * ftell() equivalent for ByteIOContext. * @return position or AVERROR. */ int64_t url_ftell(ByteIOContext *s); /** * Get the filesize. * @return filesize or AVERROR */ int64_t url_fsize(ByteIOContext *s); /** * feof() equivalent for ByteIOContext. * @return non zero if and only if end of file */ int url_feof(ByteIOContext *s); int url_ferror(ByteIOContext *s); int av_url_read_fpause(ByteIOContext *h, int pause); int64_t av_url_read_fseek(ByteIOContext *h, int stream_index, int64_t timestamp, int flags); #define URL_EOF (-1) /** @note return URL_EOF (-1) if EOF */ int url_fgetc(ByteIOContext *s); /** @warning currently size is limited */ #ifdef __GNUC__ int url_fprintf(ByteIOContext *s, const char *fmt, ...) __attribute__ ((__format__ (__printf__, 2, 3))); #else int url_fprintf(ByteIOContext *s, const char *fmt, ...); #endif /** @note unlike fgets, the EOL character is not returned and a whole line is parsed. return NULL if first char read was EOF */ char *url_fgets(ByteIOContext *s, char *buf, int buf_size); void put_flush_packet(ByteIOContext *s); /** * Read size bytes from ByteIOContext into buf. * @return number of bytes read or AVERROR */ int get_buffer(ByteIOContext *s, unsigned char *buf, int size); /** * Read size bytes from ByteIOContext into buf. * This reads at most 1 packet. If that is not enough fewer bytes will be * returned. * @return number of bytes read or AVERROR */ int get_partial_buffer(ByteIOContext *s, unsigned char *buf, int size); /** @note return 0 if EOF, so you cannot use it if EOF handling is necessary */ int get_byte(ByteIOContext *s); unsigned int get_le24(ByteIOContext *s); unsigned int get_le32(ByteIOContext *s); uint64_t get_le64(ByteIOContext *s); unsigned int get_le16(ByteIOContext *s); char *get_strz(ByteIOContext *s, char *buf, int maxlen); unsigned int get_be16(ByteIOContext *s); unsigned int get_be24(ByteIOContext *s); unsigned int get_be32(ByteIOContext *s); uint64_t get_be64(ByteIOContext *s); uint64_t ff_get_v(ByteIOContext *bc); static inline int url_is_streamed(ByteIOContext *s) { return s->is_streamed; } /** * Create and initialize a ByteIOContext for accessing the * resource referenced by the URLContext h. * @note When the URLContext h has been opened in read+write mode, the * ByteIOContext can be used only for writing. * * @param s Used to return the pointer to the created ByteIOContext. * In case of failure the pointed to value is set to NULL. * @return 0 in case of success, a negative value corresponding to an * AVERROR code in case of failure */ int url_fdopen(ByteIOContext **s, URLContext *h); /** @warning must be called before any I/O */ int url_setbufsize(ByteIOContext *s, int buf_size); #if FF_API_URL_RESETBUF /** Reset the buffer for reading or writing. * @note Will drop any data currently in the buffer without transmitting it. * @param flags URL_RDONLY to set up the buffer for reading, or URL_WRONLY * to set up the buffer for writing. */ int url_resetbuf(ByteIOContext *s, int flags); #endif /** * Rewind the ByteIOContext using the specified buffer containing the first buf_size bytes of the file. * Used after probing to avoid seeking. * Joins buf and s->buffer, taking any overlap into consideration. * @note s->buffer must overlap with buf or they can't be joined and the function fails * @note This function is NOT part of the public API * * @param s The read-only ByteIOContext to rewind * @param buf The probe buffer containing the first buf_size bytes of the file * @param buf_size The size of buf * @return 0 in case of success, a negative value corresponding to an * AVERROR code in case of failure */ int ff_rewind_with_probe_data(ByteIOContext *s, unsigned char *buf, int buf_size); /** * Create and initialize a ByteIOContext for accessing the * resource indicated by url. * @note When the resource indicated by url has been opened in * read+write mode, the ByteIOContext can be used only for writing. * * @param s Used to return the pointer to the created ByteIOContext. * In case of failure the pointed to value is set to NULL. * @param flags flags which control how the resource indicated by url * is to be opened * @return 0 in case of success, a negative value corresponding to an * AVERROR code in case of failure */ int url_fopen(ByteIOContext **s, const char *url, int flags); int url_fclose(ByteIOContext *s); URLContext *url_fileno(ByteIOContext *s); /** * Return the maximum packet size associated to packetized buffered file * handle. If the file is not packetized (stream like http or file on * disk), then 0 is returned. * * @param s buffered file handle * @return maximum packet size in bytes */ int url_fget_max_packet_size(ByteIOContext *s); int url_open_buf(ByteIOContext **s, uint8_t *buf, int buf_size, int flags); /** return the written or read size */ int url_close_buf(ByteIOContext *s); /** * Open a write only memory stream. * * @param s new IO context * @return zero if no error. */ int url_open_dyn_buf(ByteIOContext **s); /** * Open a write only packetized memory stream with a maximum packet * size of 'max_packet_size'. The stream is stored in a memory buffer * with a big endian 4 byte header giving the packet size in bytes. * * @param s new IO context * @param max_packet_size maximum packet size (must be > 0) * @return zero if no error. */ int url_open_dyn_packet_buf(ByteIOContext **s, int max_packet_size); /** * Return the written size and a pointer to the buffer. The buffer * must be freed with av_free(). If the buffer is opened with * url_open_dyn_buf, then padding of FF_INPUT_BUFFER_PADDING_SIZE is * added; if opened with url_open_dyn_packet_buf, no padding is added. * * @param s IO context * @param pbuffer pointer to a byte buffer * @return the length of the byte buffer */ int url_close_dyn_buf(ByteIOContext *s, uint8_t **pbuffer); unsigned long ff_crc04C11DB7_update(unsigned long checksum, const uint8_t *buf, unsigned int len); unsigned long get_checksum(ByteIOContext *s); void init_checksum(ByteIOContext *s, unsigned long (*update_checksum)(unsigned long c, const uint8_t *p, unsigned int len), unsigned long checksum); /* udp.c */ int udp_set_remote_url(URLContext *h, const char *uri); int udp_get_local_port(URLContext *h); #if (LIBAVFORMAT_VERSION_MAJOR <= 52) int udp_get_file_handle(URLContext *h); #endif #endif /* AVFORMAT_AVIO_H */