/*
* OpenAL Helpers
*
* Copyright (c) 2011 by Chris Robinson <chris.kcat@gmail.com>
*
* Permission is hereby granted, free of charge, to any person obtaining a copy
* of this software and associated documentation files (the "Software"), to deal
* in the Software without restriction, including without limitation the rights
* to use, copy, modify, merge, publish, distribute, sublicense, and/or sell
* copies of the Software, and to permit persons to whom the Software is
* furnished to do so, subject to the following conditions:
*
* The above copyright notice and this permission notice shall be included in
* all copies or substantial portions of the Software.
*
* THE SOFTWARE IS PROVIDED "AS IS", WITHOUT WARRANTY OF ANY KIND, EXPRESS OR
* IMPLIED, INCLUDING BUT NOT LIMITED TO THE WARRANTIES OF MERCHANTABILITY,
* FITNESS FOR A PARTICULAR PURPOSE AND NONINFRINGEMENT. IN NO EVENT SHALL THE
* AUTHORS OR COPYRIGHT HOLDERS BE LIABLE FOR ANY CLAIM, DAMAGES OR OTHER
* LIABILITY, WHETHER IN AN ACTION OF CONTRACT, TORT OR OTHERWISE, ARISING FROM,
* OUT OF OR IN CONNECTION WITH THE SOFTWARE OR THE USE OR OTHER DEALINGS IN
* THE SOFTWARE.
*/
/* This file contains routines to help with some menial OpenAL-related tasks,
* such as opening a device and setting up a context, closing the device and
* destroying its context, converting between frame counts and byte lengths,
* finding an appropriate buffer format, and getting readable strings for
* channel configs and sample types. */
#include <stdio.h>
#include "AL/al.h"
#include "AL/alc.h"
#include "AL/alext.h"
#include "alhelpers.h"
const char *ChannelsName(ALenum chans)
{
switch(chans)
{
case AL_MONO: return "Mono";
case AL_STEREO: return "Stereo";
case AL_REAR: return "Rear";
case AL_QUAD: return "Quadraphonic";
case AL_5POINT1: return "5.1 Surround";
case AL_6POINT1: return "6.1 Surround";
case AL_7POINT1: return "7.1 Surround";
}
return "Unknown Channels";
}
const char *TypeName(ALenum type)
{
switch(type)
{
case AL_BYTE: return "S8";
case AL_UNSIGNED_BYTE: return "U8";
case AL_SHORT: return "S16";
case AL_UNSIGNED_SHORT: return "U16";
case AL_INT: return "S32";
case AL_UNSIGNED_INT: return "U32";
case AL_FLOAT: return "Float32";
case AL_DOUBLE: return "Float64";
}
return "Unknown Type";
}
ALsizei FramesToBytes(ALsizei size, ALenum channels, ALenum type)
{
switch(channels)
{
case AL_MONO: size *= 1; break;
case AL_STEREO: size *= 2; break;
case AL_REAR: size *= 2; break;
case AL_QUAD: size *= 4; break;
case AL_5POINT1: size *= 6; break;
case AL_6POINT1: size *= 7; break;
case AL_7POINT1: size *= 8; break;
}
switch(type)
{
case AL_BYTE: size *= sizeof(ALbyte); break;
case AL_UNSIGNED_BYTE: size *= sizeof(ALubyte); break;
case AL_SHORT: size *= sizeof(ALshort); break;
case AL_UNSIGNED_SHORT: size *= sizeof(ALushort); break;
case AL_INT: size *= sizeof(ALint); break;
case AL_UNSIGNED_INT: size *= sizeof(ALuint); break;
case AL_FLOAT: size *= sizeof(ALfloat); break;
case AL_DOUBLE: size *= sizeof(ALdouble); break;
}
return size;
}
ALsizei BytesToFrames(ALsizei size, ALenum channels, ALenum type)
{
return size / FramesToBytes(1, channels, type);
}
ALenum GetFormat(ALenum channels, ALenum type)
{
ALenum format = 0;
/* We use the AL_EXT_MCFORMATS extension to provide output of Quad, 5.1,
* and 7.1 channel configs, AL_EXT_FLOAT32 for 32-bit float samples, and
* AL_EXT_DOUBLE for 64-bit float samples. */
if(type == AL_UNSIGNED_BYTE)
{
if(channels == AL_MONO)
format = AL_FORMAT_MONO8;
else if(channels == AL_STEREO)
format = AL_FORMAT_STEREO8;
else if(alIsExtensionPresent("AL_EXT_MCFORMATS"))
{
if(channels == AL_QUAD)
format = alGetEnumValue("AL_FORMAT_QUAD8");
else if(channels == AL_5POINT1)
format = alGetEnumValue("AL_FORMAT_51CHN8");
else if(channels == AL_6POINT1)
format = alGetEnumValue("AL_FORMAT_61CHN8");
else if(channels == AL_7POINT1)
format = alGetEnumValue("AL_FORMAT_71CHN8");
}
}
else if(type == AL_SHORT)
{
if(channels == AL_MONO)
format = AL_FORMAT_MONO16;
else if(channels == AL_STEREO)
format = AL_FORMAT_STEREO16;
else if(alIsExtensionPresent("AL_EXT_MCFORMATS"))
{
if(channels == AL_QUAD)
format = alGetEnumValue("AL_FORMAT_QUAD16");
else if(channels == AL_5POINT1)
format = alGetEnumValue("AL_FORMAT_51CHN16");
else if(channels == AL_6POINT1)
format = alGetEnumValue("AL_FORMAT_61CHN16");
else if(channels == AL_7POINT1)
format = alGetEnumValue("AL_FORMAT_71CHN16");
}
}
else if(type == AL_FLOAT && alIsExtensionPresent("AL_EXT_FLOAT32"))
{
if(channels == AL_MONO)
format = alGetEnumValue("AL_FORMAT_MONO_FLOAT32");
else if(channels == AL_STEREO)
format = alGetEnumValue("AL_FORMAT_STEREO_FLOAT32");
else if(alIsExtensionPresent("AL_EXT_MCFORMATS"))
{
if(channels == AL_QUAD)
format = alGetEnumValue("AL_FORMAT_QUAD32");
else if(channels == AL_5POINT1)
format = alGetEnumValue("AL_FORMAT_51CHN32");
else if(channels == AL_6POINT1)
format = alGetEnumValue("AL_FORMAT_61CHN32");
else if(channels == AL_7POINT1)
format = alGetEnumValue("AL_FORMAT_71CHN32");
}
}
else if(type == AL_DOUBLE && alIsExtensionPresent("AL_EXT_DOUBLE"))
{
if(channels == AL_MONO)
format = alGetEnumValue("AL_FORMAT_MONO_DOUBLE");
else if(channels == AL_STEREO)
format = alGetEnumValue("AL_FORMAT_STEREO_DOUBLE");
}
/* NOTE: It seems OSX returns -1 from alGetEnumValue for unknown enums, as
* opposed to 0. Correct it. */
if(format == -1)
format = 0;
return format;
}
int InitAL(void)
{
ALCdevice *device;
ALCcontext *ctx;
/* Open and initialize a device with default settings */
device = alcOpenDevice(NULL);
if(!device)
{
fprintf(stderr, "Could not open a device!\n");
return 1;
}
ctx = alcCreateContext(device, NULL);
if(ctx == NULL || alcMakeContextCurrent(ctx) == ALC_FALSE)
{
if(ctx != NULL)
alcDestroyContext(ctx);
alcCloseDevice(device);
fprintf(stderr, "Could not set a context!\n");
return 1;
}
return 0;
}
void CloseAL(void)
{
ALCdevice *device;
ALCcontext *ctx;
/* Close the device belonging to the current context, and destroy the
* context. */
ctx = alcGetCurrentContext();
if(ctx == NULL)
return;
device = alcGetContextsDevice(ctx);
alcMakeContextCurrent(NULL);
alcDestroyContext(ctx);
alcCloseDevice(device);
}