/* * copyright (c) 2001 Fabrice Bellard * * 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 */ #ifndef AVFORMAT_AVIO_H #define AVFORMAT_AVIO_H /** * @file * Buffered I/O operations */ #include <stdint.h> #include "libavutil/common.h" #include "libavutil/log.h" #include "libavformat/version.h" #define AVIO_SEEKABLE_NORMAL 0x0001 /**< Seeking works like for a local file */ /** * 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(AVIOContext) must not be used outside libav*. * * @note None of the function pointers in AVIOContext should be called * directly, they should only be set by the client application * when implementing custom I/O. Normally these are set to the * function pointers specified in avio_alloc_context() */ typedef struct { unsigned char *buffer; /**< Start of the buffer. */ int buffer_size; /**< Maximum buffer size */ unsigned char *buf_ptr; /**< Current position in the buffer */ unsigned char *buf_end; /**< End of the data, may be less than buffer+buffer_size if the read function returned less data than requested, e.g. for streams where no more data has been received yet. */ void *opaque; /**< A private pointer, passed to the read/write/seek/... functions. */ 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 */ #if FF_API_OLD_AVIO attribute_deprecated int is_streamed; #endif 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 */ /** * Pause or resume playback for network streaming protocols - e.g. MMS. */ int (*read_pause)(void *opaque, int pause); /** * Seek to a given timestamp in stream with the specified stream_index. * Needed for some network streaming protocols which don't support seeking * to byte position. */ int64_t (*read_seek)(void *opaque, int stream_index, int64_t timestamp, int flags); /** * A combination of AVIO_SEEKABLE_ flags or 0 when the stream is not seekable. */ int seekable; } AVIOContext; /* unbuffered I/O */ #if FF_API_OLD_AVIO /** * 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*. * @deprecated This struct will be made private */ typedef struct URLContext { const AVClass *av_class; ///< information for av_log(). Set by url_open(). 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; #define URL_PROTOCOL_FLAG_NESTED_SCHEME 1 /*< The protocol name can be the first part of a nested protocol scheme */ /** * @deprecated This struct is to be made private. Use the higher-level * AVIOContext-based API instead. */ 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; int flags; int (*url_check)(URLContext *h, int mask); } URLProtocol; typedef struct URLPollEntry { URLContext *handle; int events; int revents; } URLPollEntry; /* not implemented */ attribute_deprecated int url_poll(URLPollEntry *poll_table, int n, int timeout); /** * @name URL open modes * The flags argument to url_open and cosins must be one of the following * constants, optionally ORed with other flags. * @{ */ #define URL_RDONLY 1 /**< read-only */ #define URL_WRONLY 2 /**< write-only */ #define URL_RDWR (URL_RDONLY|URL_WRONLY) /**< read-write */ /** * @} */ /** * Use non-blocking mode. * If this flag is set, operations on the context will return * AVERROR(EAGAIN) if they can not be performed immediately. * If this flag is not set, operations on the context will never return * AVERROR(EAGAIN). * Note that this flag does not affect the opening/connecting of the * context. Connecting a protocol will always block if necessary (e.g. on * network protocols) but never hang (e.g. on busy devices). * Warning: non-blocking protocols is work-in-progress; this flag may be * silently ignored. */ #define URL_FLAG_NONBLOCK 4 typedef int URLInterruptCB(void); extern URLInterruptCB *url_interrupt_cb; /** * @defgroup old_url_funcs Old url_* functions * The following functions are deprecated. Use the buffered API based on #AVIOContext instead. * @{ */ attribute_deprecated int url_open_protocol (URLContext **puc, struct URLProtocol *up, const char *url, int flags); attribute_deprecated int url_alloc(URLContext **h, const char *url, int flags); attribute_deprecated int url_connect(URLContext *h); attribute_deprecated int url_open(URLContext **h, const char *url, int flags); attribute_deprecated int url_read(URLContext *h, unsigned char *buf, int size); attribute_deprecated int url_read_complete(URLContext *h, unsigned char *buf, int size); attribute_deprecated int url_write(URLContext *h, const unsigned char *buf, int size); attribute_deprecated int64_t url_seek(URLContext *h, int64_t pos, int whence); attribute_deprecated int url_close(URLContext *h); attribute_deprecated int64_t url_filesize(URLContext *h); attribute_deprecated int url_get_file_handle(URLContext *h); attribute_deprecated int url_get_max_packet_size(URLContext *h); attribute_deprecated void url_get_filename(URLContext *h, char *buf, int buf_size); attribute_deprecated int av_url_read_pause(URLContext *h, int pause); attribute_deprecated int64_t av_url_read_seek(URLContext *h, int stream_index, int64_t timestamp, int flags); attribute_deprecated void url_set_interrupt_cb(int (*interrupt_cb)(void)); /** * 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. */ attribute_deprecated URLProtocol *av_protocol_next(URLProtocol *p); /** * Register the URLProtocol protocol. * * @param size the size of the URLProtocol struct referenced */ attribute_deprecated int av_register_protocol2(URLProtocol *protocol, int size); /** * @} */ typedef attribute_deprecated AVIOContext ByteIOContext; attribute_deprecated int init_put_byte(AVIOContext *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)); attribute_deprecated AVIOContext *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)); /** * @defgroup old_avio_funcs Old put_/get_*() functions * The following functions are deprecated. Use the "avio_"-prefixed functions instead. * @{ */ attribute_deprecated int get_buffer(AVIOContext *s, unsigned char *buf, int size); attribute_deprecated int get_partial_buffer(AVIOContext *s, unsigned char *buf, int size); attribute_deprecated int get_byte(AVIOContext *s); attribute_deprecated unsigned int get_le16(AVIOContext *s); attribute_deprecated unsigned int get_le24(AVIOContext *s); attribute_deprecated unsigned int get_le32(AVIOContext *s); attribute_deprecated uint64_t get_le64(AVIOContext *s); attribute_deprecated unsigned int get_be16(AVIOContext *s); attribute_deprecated unsigned int get_be24(AVIOContext *s); attribute_deprecated unsigned int get_be32(AVIOContext *s); attribute_deprecated uint64_t get_be64(AVIOContext *s); attribute_deprecated void put_byte(AVIOContext *s, int b); attribute_deprecated void put_nbyte(AVIOContext *s, int b, int count); attribute_deprecated void put_buffer(AVIOContext *s, const unsigned char *buf, int size); attribute_deprecated void put_le64(AVIOContext *s, uint64_t val); attribute_deprecated void put_be64(AVIOContext *s, uint64_t val); attribute_deprecated void put_le32(AVIOContext *s, unsigned int val); attribute_deprecated void put_be32(AVIOContext *s, unsigned int val); attribute_deprecated void put_le24(AVIOContext *s, unsigned int val); attribute_deprecated void put_be24(AVIOContext *s, unsigned int val); attribute_deprecated void put_le16(AVIOContext *s, unsigned int val); attribute_deprecated void put_be16(AVIOContext *s, unsigned int val); attribute_deprecated void put_tag(AVIOContext *s, const char *tag); /** * @} */ attribute_deprecated int av_url_read_fpause(AVIOContext *h, int pause); attribute_deprecated int64_t av_url_read_fseek (AVIOContext *h, int stream_index, int64_t timestamp, int flags); /** * @defgroup old_url_f_funcs Old url_f* functions * The following functions are deprecated, use the "avio_"-prefixed functions instead. * @{ */ attribute_deprecated int url_fopen( AVIOContext **s, const char *url, int flags); attribute_deprecated int url_fclose(AVIOContext *s); attribute_deprecated int64_t url_fseek(AVIOContext *s, int64_t offset, int whence); attribute_deprecated int url_fskip(AVIOContext *s, int64_t offset); attribute_deprecated int64_t url_ftell(AVIOContext *s); attribute_deprecated int64_t url_fsize(AVIOContext *s); #define URL_EOF (-1) attribute_deprecated int url_fgetc(AVIOContext *s); attribute_deprecated int url_setbufsize(AVIOContext *s, int buf_size); attribute_deprecated int url_fprintf(AVIOContext *s, const char *fmt, ...) av_printf_format(2, 3); attribute_deprecated void put_flush_packet(AVIOContext *s); attribute_deprecated int url_open_dyn_buf(AVIOContext **s); attribute_deprecated int url_open_dyn_packet_buf(AVIOContext **s, int max_packet_size); attribute_deprecated int url_close_dyn_buf(AVIOContext *s, uint8_t **pbuffer); attribute_deprecated int url_fdopen(AVIOContext **s, URLContext *h); /** * @} */ /** * @deprecated use AVIOContext.eof_reached */ attribute_deprecated int url_feof(AVIOContext *s); attribute_deprecated int url_ferror(AVIOContext *s); attribute_deprecated int udp_set_remote_url(URLContext *h, const char *uri); attribute_deprecated int udp_get_local_port(URLContext *h); attribute_deprecated void init_checksum(AVIOContext *s, unsigned long (*update_checksum)(unsigned long c, const uint8_t *p, unsigned int len), unsigned long checksum); attribute_deprecated unsigned long get_checksum(AVIOContext *s); attribute_deprecated void put_strz(AVIOContext *s, const char *buf); /** @note unlike fgets, the EOL character is not returned and a whole line is parsed. return NULL if first char read was EOF */ attribute_deprecated char *url_fgets(AVIOContext *s, char *buf, int buf_size); /** * @deprecated use avio_get_str instead */ attribute_deprecated char *get_strz(AVIOContext *s, char *buf, int maxlen); /** * @deprecated Use AVIOContext.seekable field directly. */ attribute_deprecated static inline int url_is_streamed(AVIOContext *s) { return !s->seekable; } attribute_deprecated URLContext *url_fileno(AVIOContext *s); /** * @deprecated use AVIOContext.max_packet_size directly. */ attribute_deprecated int url_fget_max_packet_size(AVIOContext *s); attribute_deprecated int url_open_buf(AVIOContext **s, uint8_t *buf, int buf_size, int flags); /** return the written or read size */ attribute_deprecated int url_close_buf(AVIOContext *s); /** * Return a non-zero value if the resource indicated by url * exists, 0 otherwise. * @deprecated Use avio_check instead. */ attribute_deprecated int url_exist(const char *url); #endif // FF_API_OLD_AVIO /** * Return AVIO_FLAG_* access flags corresponding to the access permissions * of the resource in url, or a negative value corresponding to an * AVERROR code in case of failure. The returned access flags are * masked by the value in flags. * * @note This function is intrinsically unsafe, in the sense that the * checked resource may change its existence or permission status from * one call to another. Thus you should not trust the returned value, * unless you are sure that no other processes are accessing the * checked resource. */ int avio_check(const char *url, int flags); /** * The callback is called in blocking functions to test regulary if * asynchronous interruption is needed. AVERROR_EXIT is returned * in this case by the interrupted function. 'NULL' means no interrupt * callback is given. */ void avio_set_interrupt_cb(int (*interrupt_cb)(void)); /** * Allocate and initialize an AVIOContext for buffered I/O. It must be later * freed with av_free(). * * @param buffer Memory block for input/output operations via AVIOContext. * The buffer must be allocated with av_malloc() and friends. * @param buffer_size The buffer size is very important for performance. * For protocols with fixed blocksize it should be set to this blocksize. * For others a typical size is a cache page, e.g. 4kb. * @param write_flag Set to 1 if the buffer should be writable, 0 otherwise. * @param opaque An opaque pointer to user-specific data. * @param read_packet A function for refilling the buffer, may be NULL. * @param write_packet A function for writing the buffer contents, may be NULL. * @param seek A function for seeking to specified byte position, may be NULL. * * @return Allocated AVIOContext or NULL on failure. */ AVIOContext *avio_alloc_context( 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 avio_w8(AVIOContext *s, int b); void avio_write(AVIOContext *s, const unsigned char *buf, int size); void avio_wl64(AVIOContext *s, uint64_t val); void avio_wb64(AVIOContext *s, uint64_t val); void avio_wl32(AVIOContext *s, unsigned int val); void avio_wb32(AVIOContext *s, unsigned int val); void avio_wl24(AVIOContext *s, unsigned int val); void avio_wb24(AVIOContext *s, unsigned int val); void avio_wl16(AVIOContext *s, unsigned int val); void avio_wb16(AVIOContext *s, unsigned int val); /** * Write a NULL-terminated string. * @return number of bytes written. */ int avio_put_str(AVIOContext *s, const char *str); /** * Convert an UTF-8 string to UTF-16LE and write it. * @return number of bytes written. */ int avio_put_str16le(AVIOContext *s, const char *str); /** * 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 /** * fseek() equivalent for AVIOContext. * @return new position or AVERROR. */ int64_t avio_seek(AVIOContext *s, int64_t offset, int whence); /** * Skip given number of bytes forward * @return new position or AVERROR. */ static av_always_inline int64_t avio_skip(AVIOContext *s, int64_t offset) { return avio_seek(s, offset, SEEK_CUR); } /** * ftell() equivalent for AVIOContext. * @return position or AVERROR. */ static av_always_inline int64_t avio_tell(AVIOContext *s) { return avio_seek(s, 0, SEEK_CUR); } /** * Get the filesize. * @return filesize or AVERROR */ int64_t avio_size(AVIOContext *s); /** @warning currently size is limited */ int avio_printf(AVIOContext *s, const char *fmt, ...) av_printf_format(2, 3); void avio_flush(AVIOContext *s); /** * Read size bytes from AVIOContext into buf. * @return number of bytes read or AVERROR */ int avio_read(AVIOContext *s, unsigned char *buf, int size); /** * @name Functions for reading from AVIOContext * @{ * * @note return 0 if EOF, so you cannot use it if EOF handling is * necessary */ int avio_r8 (AVIOContext *s); unsigned int avio_rl16(AVIOContext *s); unsigned int avio_rl24(AVIOContext *s); unsigned int avio_rl32(AVIOContext *s); uint64_t avio_rl64(AVIOContext *s); unsigned int avio_rb16(AVIOContext *s); unsigned int avio_rb24(AVIOContext *s); unsigned int avio_rb32(AVIOContext *s); uint64_t avio_rb64(AVIOContext *s); /** * @} */ /** * Read a string from pb into buf. The reading will terminate when either * a NULL character was encountered, maxlen bytes have been read, or nothing * more can be read from pb. The result is guaranteed to be NULL-terminated, it * will be truncated if buf is too small. * Note that the string is not interpreted or validated in any way, it * might get truncated in the middle of a sequence for multi-byte encodings. * * @return number of bytes read (is always <= maxlen). * If reading ends on EOF or error, the return value will be one more than * bytes actually read. */ int avio_get_str(AVIOContext *pb, int maxlen, char *buf, int buflen); /** * Read a UTF-16 string from pb and convert it to UTF-8. * The reading will terminate when either a null or invalid character was * encountered or maxlen bytes have been read. * @return number of bytes read (is always <= maxlen) */ int avio_get_str16le(AVIOContext *pb, int maxlen, char *buf, int buflen); int avio_get_str16be(AVIOContext *pb, int maxlen, char *buf, int buflen); /** * @name URL open modes * The flags argument to avio_open must be one of the following * constants, optionally ORed with other flags. * @{ */ #define AVIO_FLAG_READ 1 /**< read-only */ #define AVIO_FLAG_WRITE 2 /**< write-only */ #define AVIO_FLAG_READ_WRITE (AVIO_FLAG_READ|AVIO_FLAG_WRITE) /**< read-write pseudo flag */ /** * @} */ /** * Use non-blocking mode. * If this flag is set, operations on the context will return * AVERROR(EAGAIN) if they can not be performed immediately. * If this flag is not set, operations on the context will never return * AVERROR(EAGAIN). * Note that this flag does not affect the opening/connecting of the * context. Connecting a protocol will always block if necessary (e.g. on * network protocols) but never hang (e.g. on busy devices). * Warning: non-blocking protocols is work-in-progress; this flag may be * silently ignored. */ #define AVIO_FLAG_NONBLOCK 8 /** * Create and initialize a AVIOContext for accessing the * resource indicated by url. * @note When the resource indicated by url has been opened in * read+write mode, the AVIOContext can be used only for writing. * * @param s Used to return the pointer to the created AVIOContext. * 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 avio_open(AVIOContext **s, const char *url, int flags); /** * Close the resource accessed by the AVIOContext s and free it. * This function can only be used if s was opened by avio_open(). * * @return 0 on success, an AVERROR < 0 on error. */ int avio_close(AVIOContext *s); /** * Open a write only memory stream. * * @param s new IO context * @return zero if no error. */ int avio_open_dyn_buf(AVIOContext **s); /** * Return the written size and a pointer to the buffer. The buffer * must be freed with av_free(). * Padding of FF_INPUT_BUFFER_PADDING_SIZE is added to the buffer. * * @param s IO context * @param pbuffer pointer to a byte buffer * @return the length of the byte buffer */ int avio_close_dyn_buf(AVIOContext *s, uint8_t **pbuffer); /** * Iterate through names of available protocols. * * @param opaque A private pointer representing current protocol. * It must be a pointer to NULL on first iteration and will * be updated by successive calls to avio_enum_protocols. * @param output If set to 1, iterate over output protocols, * otherwise over input protocols. * * @return A static string containing the name of current protocol or NULL */ const char *avio_enum_protocols(void **opaque, int output); /** * Pause and resume playing - only meaningful if using a network streaming * protocol (e.g. MMS). * @param pause 1 for pause, 0 for resume */ int avio_pause(AVIOContext *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 avio_seek_time(AVIOContext *h, int stream_index, int64_t timestamp, int flags); #endif /* AVFORMAT_AVIO_H */