mm7: lib/libavformat/avio.h comparison

comparison lib/libavformat/avio.h @ 2134:992d2e6f907d

preparation for libavcodec

author	zipi
date	Tue, 31 Dec 2013 14:52:14 +0000
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-:e378232bfd36
+:992d2e6f907d
+/*
+* 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
+* @ingroup lavf_io
+* Buffered I/O operations
+*/
+#include <stdint.h>
+#include "../libavutil/common.h"
+#include "../libavutil/dict.h"
+#include "../libavutil/log.h"
+#include "version.h"
+#define AVIO_SEEKABLE_NORMAL 0x0001 /**< Seeking works like for a local file */
+/**
+* Callback for checking whether to abort blocking functions.
+* AVERROR_EXIT is returned in this case by the interrupted
+* function. During blocking operations, callback is called with
+* opaque as parameter. If the callback returns 1, the
+* blocking operation will be aborted.
+*
+* No members can be added to this struct without a major bump, if
+* new elements have been added after this struct in AVFormatContext
+* or AVIOContext.
+*/
+typedef struct AVIOInterruptCB {
+int (*callback)(void*);
+void *opaque;
+} AVIOInterruptCB;
+/**
+* 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 AVIOContext {
+/**
+* A class for private options.
+*
+* If this AVIOContext is created by avio_open2(), av_class is set and
+* passes the options down to protocols.
+*
+* If this AVIOContext is manually allocated, then av_class may be set by
+* the caller.
+*
+* warning -- this field can be NULL, be sure to not pass this AVIOContext
+* to any av_opt_* functions in that case.
+*/
+const AVClass *av_class;
+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 */
+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;
+/**
+* max filesize, used to limit allocations
+* This field is internal to libavformat and access from outside is not allowed.
+*/
+int64_t maxsize;
+/**
+* avio_read and avio_write should if possible be satisfied directly
+* instead of going through a buffer, and avio_seek will always
+* call the underlying seek function directly.
+*/
+int direct;
+/**
+* Bytes read statistic
+* This field is internal to libavformat and access from outside is not allowed.
+*/
+int64_t bytes_read;
+/**
+* seek statistic
+* This field is internal to libavformat and access from outside is not allowed.
+*/
+int seek_count;
+/**
+* writeout statistic
+* This field is internal to libavformat and access from outside is not allowed.
+*/
+int writeout_count;
+} AVIOContext;
+/* unbuffered I/O */
+/**
+* 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);
+/**
+* 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.
+*        The function may not change the input buffers content.
+* @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 unreasonable
+* means that can be extremely 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.
+*/
+int64_t avio_skip(AVIOContext *s, int64_t offset);
+/**
+* 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);
+/**
+* feof() equivalent for AVIOContext.
+* @return non zero if and only if end of file
+*/
+int url_feof(AVIOContext *s);
+/** @warning currently size is limited */
+int avio_printf(AVIOContext *s, const char *fmt, ...) av_printf_format(2, 3);
+/**
+* Force flushing of buffered data to the output s.
+*
+* Force the buffered data to be immediately written to the output,
+* without to wait to fill the internal buffer.
+*/
+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
+/**
+* Use direct mode.
+* avio_read and avio_write should if possible be satisfied directly
+* instead of going through a buffer, and avio_seek will always
+* call the underlying seek function directly.
+*/
+#define AVIO_FLAG_DIRECT 0x8000
+/**
+* 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);
+/**
+* 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
+* @param int_cb an interrupt callback to be used at the protocols level
+* @param options  A dictionary filled with protocol-private options. On return
+* this parameter will be destroyed and replaced with a dict containing options
+* that were not found. May be NULL.
+* @return 0 in case of success, a negative value corresponding to an
+* AVERROR code in case of failure
+*/
+int avio_open2(AVIOContext **s, const char *url, int flags,
+const AVIOInterruptCB *int_cb, AVDictionary **options);
+/**
+* Close the resource accessed by the AVIOContext s and free it.
+* This function can only be used if s was opened by avio_open().
+*
+* The internal buffer is automatically flushed before closing the
+* resource.
+*
+* @return 0 on success, an AVERROR < 0 on error.
+* @see avio_closep
+*/
+int avio_close(AVIOContext *s);
+/**
+* Close the resource accessed by the AVIOContext *s, free it
+* and set the pointer pointing to it to NULL.
+* This function can only be used if s was opened by avio_open().
+*
+* The internal buffer is automatically flushed before closing the
+* resource.
+*
+* @return 0 on success, an AVERROR < 0 on error.
+* @see avio_close
+*/
+int avio_closep(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.
+* @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 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 */

Mercurial > mm7

comparison lib/libavformat/avio.h @ 2134:992d2e6f907d