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resamples added

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Ease of use considered in api and channels are more convenient as
unsigned char type.
This commit is contained in:
Joshua Reisenauer 2016-05-02 01:24:24 -07:00
parent 790bc72806
commit 9ef0240e99
3 changed files with 49 additions and 12 deletions
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49
src/audio.c
View file

@ -97,6 +97,7 @@ typedef struct Music {
// a dedicated mix channel. All audio is 32bit floating point in stereo.
typedef struct AudioContext_t {
unsigned short sampleRate; // default is 48000
unsigned char channels; // 1=mono,2=stereo
unsigned char mixChannel; // 0-3 or mixA-mixD, each mix channel can receive up to one dedicated audio stream
ALenum alFormat; // openAL format specifier
ALuint alSource; // openAL source
@ -125,8 +126,9 @@ static void UnloadWave(Wave wave); // Unload wave data
static bool BufferMusicStream(ALuint buffer); // Fill music buffers with data
static void EmptyMusicStream(void); // Empty music buffers
// fill buffer with zeros
static void FillAlBufferWithSilence(AudioContext_t *ac, ALuint buffer);
static void FillAlBufferWithSilence(AudioContext_t *ac, ALuint buffer);// fill buffer with zeros
static void ResampleShortToFloat(short *shorts, float *floats, unsigned short len); // pass two arrays of the same legnth in
static void ResampleByteToFloat(char *chars, float *floats, unsigned short len); // pass two arrays of same length in
#if defined(AUDIO_STANDALONE)
const char *GetExtension(const char *fileName); // Get the extension for a filename
@ -199,9 +201,9 @@ bool IsAudioDeviceReady(void)
// Audio contexts are for outputing custom audio waveforms, This will shut down any other sound sources currently playing
// The mixChannel is what mix channel you want to operate on, 0-3 are the ones available. Each mix channel can only be used one at a time.
// exmple usage is InitAudioContext(48000, 0); // mixchannel 1, 48khz
// all samples are floating point stereo by default
AudioContext InitAudioContext(unsigned short sampleRate, unsigned char mixChannel)
// exmple usage is InitAudioContext(48000, 0, 2); // mixchannel 1, 48khz, stereo
// all samples are floating point by default
AudioContext InitAudioContext(unsigned short sampleRate, unsigned char mixChannel, unsigned char channels)
{
if(mixChannel > MAX_AUDIO_CONTEXTS) return NULL;
if(!IsAudioDeviceReady()) InitAudioDevice();
@ -210,11 +212,15 @@ AudioContext InitAudioContext(unsigned short sampleRate, unsigned char mixChanne
if(!mixChannelsActive_g[mixChannel]){
AudioContext_t *ac = malloc(sizeof(AudioContext_t));
ac->sampleRate = sampleRate;
ac->channels = channels;
ac->mixChannel = mixChannel;
mixChannelsActive_g[mixChannel] = ac;
// setup openAL format
ac->alFormat = AL_FORMAT_STEREO_FLOAT32;
if(channels == 1)
ac->alFormat = AL_FORMAT_MONO_FLOAT32;
else
ac->alFormat = AL_FORMAT_STEREO_FLOAT32;
// Create an audio source
alGenSources(1, &ac->alSource);
@ -289,6 +295,7 @@ bool UpdateAudioContext(AudioContext ctx, float *data, unsigned short dataLength
}
return true;
}
return false;
}
// fill buffer with zeros
@ -298,6 +305,36 @@ static void FillAlBufferWithSilence(AudioContext_t *ac, ALuint buffer)
alBufferData(buffer, ac->alFormat, pcm, MUSIC_BUFFER_SIZE*sizeof(float), ac->sampleRate);
}
// example usage:
// short sh[3] = {1,2,3};float fl[3];
// ResampleShortToFloat(sh,fl,3);
static void ResampleShortToFloat(short *shorts, float *floats, unsigned short len)
{
int x;
for(x=0;x<len;x++)
{
if(shorts[x] < 0)
floats[x] = (float)shorts[x] / 32766.f;
else
floats[x] = (float)shorts[x] / 32767.f;
}
}
// example usage:
// char ch[3] = {1,2,3};float fl[3];
// ResampleShortToFloat(ch,fl,3);
static void ResampleByteToFloat(char *chars, float *floats, unsigned short len)
{
int x;
for(x=0;x<len;x++)
{
if(chars[x] < 0)
floats[x] = (float)chars[x] / 127.f;
else
floats[x] = (float)chars[x] / 128.f;
}
}
//----------------------------------------------------------------------------------

6
src/audio.h
View file

@ -84,9 +84,9 @@ bool IsAudioDeviceReady(void); // True if call
// Audio contexts are for outputing custom audio waveforms, This will shut down any other sound sources currently playing
// The mixChannel is what mix channel you want to operate on, 0-3 are the ones available. Each mix channel can only be used one at a time.
// exmple usage is InitAudioContext(48000, 0); // mixchannel 1, 48khz
// all samples are floating point stereo by default
AudioContext InitAudioContext(unsigned short sampleRate, unsigned char mixChannel);
// exmple usage is InitAudioContext(48000, 0, 2); // mixchannel 1, 48khz, stereo
// all samples are floating point by default
AudioContext InitAudioContext(unsigned short sampleRate, unsigned char mixChannel, unsigned char channels);
void CloseAudioContext(AudioContext ctx); // Frees audio context
bool UpdateAudioContext(AudioContext ctx, float *data, unsigned short dataLength); // Pushes more audio data into context mix channel, if NULL is passed to data then zeros are played

6
src/raylib.h
View file

@ -870,9 +870,9 @@ bool IsAudioDeviceReady(void); // True if call
// Audio contexts are for outputing custom audio waveforms, This will shut down any other sound sources currently playing
// The mixChannel is what mix channel you want to operate on, 0-3 are the ones available. Each mix channel can only be used one at a time.
// exmple usage is InitAudioContext(48000, 0); // mixchannel 1, 48khz
// all samples are floating point stereo by default
AudioContext InitAudioContext(unsigned short sampleRate, unsigned char mixChannel);
// exmple usage is InitAudioContext(48000, 0, 2); // mixchannel 1, 48khz, stereo
// all samples are floating point by default
AudioContext InitAudioContext(unsigned short sampleRate, unsigned char mixChannel, unsigned char channels);
void CloseAudioContext(AudioContext ctx); // Frees audio context
bool UpdateAudioContext(AudioContext ctx, float *data, unsigned short dataLength); // Pushes more audio data into context mix channel, if NULL is passed to data then zeros are played