--- /dev/null	Thu Jan 01 00:00:00 1970 +0000
+++ b/lib/libavformat/avio.h	Tue Dec 31 14:52:14 2013 +0000
@@ -0,0 +1,481 @@
+/*
+ * 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 */