ffmpeg/libavformat/avio.h
2011-04-08 15:59:26 +02:00

604 lines
21 KiB
C

/*
* 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
* 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"
#include "libavutil/log.h"
#include "libavformat/version.h"
/* 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 {
#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;
/**
* @defgroup open_modes 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 0 /**< read-only */
#define URL_WRONLY 1 /**< write-only */
#define URL_RDWR 2 /**< 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);
/**
* @defgroup old_url_funcs Old url_* functions
* @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));
#endif
/**
* Return a non-zero value if the resource indicated by url
* exists, 0 otherwise.
*/
int url_exist(const char *url);
/**
* 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));
#if FF_API_OLD_AVIO
/* not implemented */
attribute_deprecated int url_poll(URLPollEntry *poll_table, int n, int timeout);
#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;
} URLProtocol;
#endif
#if FF_API_REGISTER_PROTOCOL
extern URLProtocol *first_protocol;
#endif
#if FF_API_OLD_AVIO
extern URLInterruptCB *url_interrupt_cb;
#endif
/**
* 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
#if FF_API_OLD_AVIO
/**
* Register the URLProtocol protocol.
*
* @param size the size of the URLProtocol struct referenced
*/
attribute_deprecated int av_register_protocol2(URLProtocol *protocol, int size);
#endif
#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*.
*/
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 */
#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
int (*read_pause)(void *opaque, int pause);
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;
#if FF_API_OLD_AVIO
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
* @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
* @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);
#ifdef __GNUC__
attribute_deprecated int url_fprintf(AVIOContext *s, const char *fmt, ...) __attribute__ ((__format__ (__printf__, 2, 3)));
#else
attribute_deprecated int url_fprintf(AVIOContext *s, const char *fmt, ...);
#endif
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);
#endif
/**
* 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.
* @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);
#if FF_API_OLD_AVIO
attribute_deprecated void put_strz(AVIOContext *s, const char *buf);
#endif
/**
* 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 */
#ifdef __GNUC__
int avio_printf(AVIOContext *s, const char *fmt, ...) __attribute__ ((__format__ (__printf__, 2, 3)));
#else
int avio_printf(AVIOContext *s, const char *fmt, ...);
#endif
#if FF_API_OLD_AVIO
/** @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);
#endif
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);
/** @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);
/**
* 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);
#if FF_API_OLD_AVIO
/**
* @deprecated use avio_get_str instead
*/
attribute_deprecated char *get_strz(AVIOContext *s, char *buf, int maxlen);
#endif
unsigned int avio_rb16(AVIOContext *s);
unsigned int avio_rb24(AVIOContext *s);
unsigned int avio_rb32(AVIOContext *s);
uint64_t avio_rb64(AVIOContext *s);
#if FF_API_OLD_AVIO
/**
* @deprecated Use AVIOContext.seekable field directly.
*/
attribute_deprecated static inline int url_is_streamed(AVIOContext *s)
{
return !s->seekable;
}
#endif
#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(AVIOContext *s, int flags);
#endif
/**
* @defgroup open_modes URL open modes
* The flags argument to avio_open must be one of the following
* constants, optionally ORed with other flags.
* @{
*/
#define AVIO_RDONLY 0 /**< read-only */
#define AVIO_WRONLY 1 /**< write-only */
#define AVIO_RDWR 2 /**< 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 AVIO_FLAG_NONBLOCK 4
/**
* 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);
int avio_close(AVIOContext *s);
#if FF_API_OLD_AVIO
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);
#endif
/**
* 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);
#if FF_API_UDP_GET_FILE
int udp_get_file_handle(URLContext *h);
#endif
#endif /* AVFORMAT_AVIO_H */