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Diffstat (limited to 'include/libavformat/avio.h')
-rw-r--r-- | include/libavformat/avio.h | 525 |
1 files changed, 525 insertions, 0 deletions
diff --git a/include/libavformat/avio.h b/include/libavformat/avio.h new file mode 100644 index 00000000..9ffe9356 --- /dev/null +++ b/include/libavformat/avio.h @@ -0,0 +1,525 @@ +/* + * 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 <stdint.h> + +#include "libavutil/common.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 LIBAVFORMAT_VERSION_MAJOR >= 53 + 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 */ +} 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); + +/** + * Creates an URLContext for accessing to the resource indicated by + * url, and opens 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); + +/** + * Creates an URLContext for accessing to the resource indicated by + * url, and opens 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); + +/** + * Reads up to size bytes from the resource accessed by h, and stores + * 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, unsigned char *buf, int size); + +/** + * Changes 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); + +/** + * Closes the resource accessed by the URLContext h, and frees the + * memory used by it. + * + * @return a negative value if an error condition occurred, 0 + * otherwise + */ +int url_close(URLContext *h); + +/** + * Returns a non-zero value if the resource indicated by url + * exists, 0 otherwise. + */ +int url_exist(const char *url); + +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); +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, 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); +} URLProtocol; + +#if LIBAVFORMAT_VERSION_MAJOR < 53 +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 LIBAVFORMAT_VERSION_MAJOR < 53 +/** + * @deprecated Use av_register_protocol() instead. + */ +attribute_deprecated int register_protocol(URLProtocol *protocol); +#endif + +/** + * Registers the URLProtocol protocol. + */ +int av_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); + 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 + */ +void url_fskip(ByteIOContext *s, int64_t offset); + +/** + * ftell() equivalent for ByteIOContext. + * @return position or AVERROR. + */ +int64_t url_ftell(ByteIOContext *s); + +/** + * Gets 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); + + +/** + * Reads size bytes from ByteIOContext into buf. + * @return number of bytes read or AVERROR + */ +int get_buffer(ByteIOContext *s, unsigned char *buf, int size); + +/** + * Reads 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; +} + +/** + * Creates and initializes 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 LIBAVFORMAT_VERSION_MAJOR < 53 +/** 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 + +/** + * Rewinds 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); + +/** + * Creates and initializes 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(). + * @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 */ |