www.pudn.com > ffmpeg-Sdk.rar > avio.h
/* * unbuffered io for ffmpeg system * 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 FFMPEG_AVIO_H #define FFMPEG_AVIO_H #include/* output byte stream handling */ typedef int64_t offset_t; /* 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*. */ struct URLContext { 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 filename */ }; typedef struct URLContext 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); int url_open(URLContext **h, const char *filename, int flags); int url_read(URLContext *h, unsigned char *buf, int size); int url_write(URLContext *h, unsigned char *buf, int size); offset_t url_seek(URLContext *h, offset_t pos, int whence); int url_close(URLContext *h); int url_exist(const char *filename); offset_t url_filesize(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); 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 */ offset_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 typedef struct URLProtocol { const char *name; int (*url_open)(URLContext *h, const char *filename, int flags); int (*url_read)(URLContext *h, unsigned char *buf, int size); int (*url_write)(URLContext *h, unsigned char *buf, int size); offset_t (*url_seek)(URLContext *h, offset_t pos, int whence); int (*url_close)(URLContext *h); struct URLProtocol *next; int (*url_read_pause)(URLContext *h, int pause); offset_t (*url_read_seek)(URLContext *h, int stream_index, int64_t timestamp, int flags); } URLProtocol; extern URLProtocol *first_protocol; extern URLInterruptCB *url_interrupt_cb; URLProtocol *av_protocol_next(URLProtocol *p); int register_protocol(URLProtocol *protocol); /** * 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); offset_t (*seek)(void *opaque, offset_t offset, int whence); offset_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); offset_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), offset_t (*seek)(void *opaque, offset_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), offset_t (*seek)(void *opaque, offset_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); offset_t url_fseek(ByteIOContext *s, offset_t offset, int whence); void url_fskip(ByteIOContext *s, offset_t offset); offset_t url_ftell(ByteIOContext *s); offset_t url_fsize(ByteIOContext *s); int url_feof(ByteIOContext *s); int url_ferror(ByteIOContext *s); int av_url_read_fpause(ByteIOContext *h, int pause); offset_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); int get_buffer(ByteIOContext *s, unsigned char *buf, int size); 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; } /** @note when opened as read/write, the buffers are only used for writing */ int url_fdopen(ByteIOContext **s, URLContext *h); /** @warning must be called before any I/O */ int url_setbufsize(ByteIOContext *s, int buf_size); /** 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); /** @note when opened as read/write, the buffers are only used for writing */ int url_fopen(ByteIOContext **s, const char *filename, 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(). * @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); int udp_get_file_handle(URLContext *h); #endif /* FFMPEG_AVIO_H */