src/audio/avfile.h

   1 /** @file avfile.h
   2  *  Prototypes for audio/video input plugins.
   3  *  An input plugin provides at least provisions for reading source data from
   4  *  the VFS, decoding it into one or more raw formats, and rewinding to the
   5  *  beginning.  Optional features include audio-video interleaving or seeking.
   6  */
   7 /*  2ooM: The Master of Orion II Reverse Engineering Project
   8  *  Copyright (C) 2006 Nick Bowler
   9  *
  10  *  This program is free software; you can redistribute it and/or modify
  11  *  it under the terms of the GNU General Public License as published by
  12  *  the Free Software Foundation; either version 2 of the License, or
  13  *  (at your option) any later version.
  14  *
  15  *  This program is distributed in the hope that it will be useful,
  16  *  but WITHOUT ANY WARRANTY; without even the implied warranty of
  17  *  MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE.  See the
  18  *  GNU General Public License for more details.
  19  *
  20  *  You should have received a copy of the GNU General Public License
  21  *  along with this program; if not, write to the Free Software
  22  *  Foundation, Inc., 59 Temple Place, Suite 330, Boston, MA  02111-1307 USA
  23  **
  24  * $HeadURL$
  25  * $Date$
  26  * $Revision$
  27  * $Author$
  28  */
  29
  30 #ifndef _AVFILE_H
  31 #define _AVFILE_H
  32
  33 #include "audio.h"
  34
  35 struct video_format;
  36
  37 #define AV_INPUT_AUDIO 1
  38 #define AV_INPUT_VIDEO 2
  39
  40 #define AV_MODULENAME "AV"
  41 #define AV_PLUGIN_SERVICE "AVPLUGIN"
  42 #define AV_ACCESS_SERVICE "AVACCESS"
  43
  44 struct av_accessor {
  45         int  (*open)(const char *, int, const struct audio_format *,
  46                      const struct video_format *);
  47         void (*close)(int);
  48         int  (*read_audio)(int, void *, int);
  49         int  (*rewind)(int);
  50         struct av_accessor *next;
  51 };
  52
  53 int av_init(void);
  54
  55 /** Attempt to open the specified VFS resource as media.
  56  * The specified resource will be opened by each input plugin in turn, until
  57  * one accepts the input or there are none left.  If it is accepted by a plugin,
  58  * the returned identifier can be used for accessing raw media data in the
  59  * specified formats.
  60  *
  61  * @see av_close
  62  * @param resource VFS resource to open.
  63  * @param type One or more AV_INPUT_* values, bitwise OR'd together.
  64  * @param afmt Audio format for raw data, if audio was requested.
  65  * @param vfmt Video format for raw data, if video was requested.
  66  * @return Identifier for use with further calls, or -1 on failure.
  67  */
  68 int av_open(const char *resource, int type,
  69             const struct audio_format *afmt,
  70             const struct video_format *vfmt);
  71
  72 /** Free all resources associated with the provided identifier.
  73  *
  74  * @see av_open
  75  * @param id Identifier as returned by av_open()
  76  */
  77 void av_close(int id);
  78
  79 /** Read up to len bytes of decoded audio data into buffer.
  80  * Decode audio data into the raw format associated with the provided
  81  * identifier, and store at most len bytes of complete samples into the buffer
  82  * pointed to by buf.
  83  *
  84  * @see av_open
  85  * @param id Identifier as returned by av_open().
  86  * @param buf Pointer to buffer of at least len bytes.
  87  * @param len Maximum number of bytes to write.
  88  * @return Number of bytes written, or -1 on failure.
  89  */
  90 int av_read_audio(int id, void *buf, int len);
  91
  92 /** Rewind the media to the beginning.
  93  *
  94  * @param id Identifier as returned by av_open().
  95  * @return 0 on success, -1 on failure.
  96  */
  97 int av_rewind(int id);
  98
  99 #endif