src/audio/SDL_wave.h
author Sam Lantinga <slouken@libsdl.org>
Tue, 09 May 2006 08:52:54 +0000
changeset 1794 5605a9820134
parent 1402 d910939febfa
child 1659 14717b52abc0
permissions -rw-r--r--
Fixed bug #137 If SDL_OpenAudio() is passed zero for the desired format fields, the following environment variables will be used to fill them in: SDL_AUDIO_FREQUENCY SDL_AUDIO_FORMAT SDL_AUDIO_CHANNELS SDL_AUDIO_SAMPLES If an environment variable is not specified, it will be set to a reasonable default value.

/*
    SDL - Simple DirectMedia Layer
    Copyright (C) 1997-2006 Sam Lantinga

    This library is SDL_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.

    This library 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 this library; if not, write to the Free Software
    Foundation, Inc., 51 Franklin St, Fifth Floor, Boston, MA  02110-1301  USA

    Sam Lantinga
    slouken@libsdl.org
*/
#include "SDL_config.h"

/* WAVE files are little-endian */

/*******************************************/
/* Define values for Microsoft WAVE format */
/*******************************************/
#define RIFF		0x46464952		/* "RIFF" */
#define WAVE		0x45564157		/* "WAVE" */
#define FACT		0x74636166		/* "fact" */
#define LIST		0x5453494c		/* "LIST" */
#define FMT		0x20746D66		/* "fmt " */
#define DATA		0x61746164		/* "data" */
#define PCM_CODE	0x0001
#define MS_ADPCM_CODE	0x0002
#define IMA_ADPCM_CODE	0x0011
#define WAVE_MONO	1
#define WAVE_STEREO	2

/* Normally, these three chunks come consecutively in a WAVE file */
typedef struct WaveFMT {
/* Not saved in the chunk we read:
	Uint32	FMTchunk;
	Uint32	fmtlen;
*/
	Uint16	encoding;	
	Uint16	channels;		/* 1 = mono, 2 = stereo */
	Uint32	frequency;		/* One of 11025, 22050, or 44100 Hz */
	Uint32	byterate;		/* Average bytes per second */
	Uint16	blockalign;		/* Bytes per sample block */
	Uint16	bitspersample;		/* One of 8, 12, 16, or 4 for ADPCM */
} WaveFMT;

/* The general chunk found in the WAVE file */
typedef struct Chunk {
	Uint32 magic;
	Uint32 length;
	Uint8 *data;
} Chunk;