Delphi-OpenCV/include/ffmpeg/libavformat/avio.pas

unit avio;

{$include ffmpeg.inc}

interface

uses
  log, ctypes;

(*
  // * 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 "libavformat/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.
*)

Type
  TAVIOInterruptCB = record
    callback: function(param: Pointer): integer; cdecl;
    opaque: Pointer;
  end;

  (*
    // * 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()
  *)

  pAVIOContext = ^TAVIOContext;

  TAVIOContext = { packed } record
    (*
      * 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.
    *)
    av_class: pAVClass;
    buffer: pByte; // **< Start of the buffer. */
    buffer_size: integer; // **< Maximum buffer size */
    buf_ptr: pByte; // **< Current position in the buffer */
    buf_end: pByte; // **< 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. */
    opaque: Pointer; // **< A private pointer, passed to the read/write/seek/...
    // functions. */
    // int (*read_packet)(void *opaque, uint8_t *buf, int buf_size);
    read_packet: function(opaque: Pointer; buf: pByte; buf_size: integer): integer; cdecl;
    // int (*write_packet)(void *opaque, uint8_t *buf, int buf_size);
    write_packet: function(opaque: Pointer; buf: pByte; buf_size: integer): integer; cdecl;
    // int64_t (*seek)(void *opaque, int64_t offset, int whence);
    seek: function(opaque: Pointer; offset: int64_t; whence: integer): int64_t; cdecl;
    pos: int64_t; // **< position in the file of the current buffer */
    must_flush: integer; // **< true if the next seek should flush */
    eof_reached: integer; // **< true if eof reached */
    write_flag: integer; // **< true if open for writing */
    max_packet_size: integer;
    checksum: culong;
    checksum_ptr: pByte;
    // unsigned long (*update_checksum)(unsigned long checksum, const uint8_t *buf, unsigned int size);
    update_checksum: function(checksum: culong; const buf: pByte; size: Cardinal): Cardinal; cdecl;
    error: integer; // **< 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);
    read_pause: function(opaque: Pointer; pause: cint): cint; cdecl;
    (*
      * 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);
    read_seek: function(opaque: Pointer; stream_index: cint; timestamp: cint64; flags: cint): cint64; cdecl;
    (*
      * A combination of AVIO_SEEKABLE_ flags or 0 when the stream is not seekable.
    *)
    seekable: integer;
    (*
      * max filesize, used to limit allocations
      * This field is internal to libavformat and access from outside is not allowed.
    *)
    maxsize: int64_t;
    (*
      * 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.
    *)
    direct: integer;
    (*
      * Bytes read statistic
      * This field is internal to libavformat and access from outside is not allowed.
    *)
    bytes_read: int64_t;
    (*
      * seek statistic
      * This field is internal to libavformat and access from outside is not allowed.
    *)
    seek_count: integer;
    (*
      * writeout statistic
      * This field is internal to libavformat and access from outside is not allowed.
    *)
    writeout_count: integer;
  end;

  /// * 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.
  *)
const
  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.
  *)
  AVIO_FLAG_DIRECT = $8000;

  (*
    // * 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);

implementation

end.