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new silence generator

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This commit is contained in:
Joshua Reisenauer 2016-05-01 18:53:40 -07:00
parent fa3112b40e
commit a2a3d3aeb6
3 changed files with 60 additions and 28 deletions
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74
src/audio.c
View File

@ -37,6 +37,7 @@
#include "AL/al.h" // OpenAL basic header
#include "AL/alc.h" // OpenAL context header (like OpenGL, OpenAL requires a context to work)
#include "AL/alext.h" // extensions for other format types
#include <stdlib.h> // Declares malloc() and free() for memory management
#include <string.h> // Required for strcmp()
@ -93,12 +94,10 @@ typedef struct Music {
// Audio Context, used to create custom audio streams that are not bound to a sound file. There can be
// no more than 4 concurrent audio contexts in use. This is due to each active context being tied to
// a dedicated mix channel.
// a dedicated mix channel. All audio is 32bit floating point in stereo.
typedef struct AudioContext_t {
unsigned short sampleRate; // default is 48000
unsigned char bitsPerSample; // 16 is default
unsigned char mixChannel; // 0-3 or mixA-mixD, each mix channel can receive up to one dedicated audio stream
unsigned char channels; // 1=mono, 2=stereo
ALenum alFormat; // openAL format specifier
ALuint alSource; // openAL source
ALuint alBuffer[2]; // openAL sample buffer
@ -126,6 +125,9 @@ 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);
#if defined(AUDIO_STANDALONE)
const char *GetExtension(const char *fileName); // Get the extension for a filename
void TraceLog(int msgType, const char *text, ...); // Outputs a trace log message (INFO, ERROR, WARNING)
@ -197,8 +199,9 @@ 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, 16, 0, 2); // stereo, mixchannel 1, 16bit, 48khz
AudioContext InitAudioContext(unsigned short sampleRate, unsigned char bitsPerSample, unsigned char mixChannel, unsigned char channels)
// 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)
{
if(mixChannel > MAX_AUDIO_CONTEXTS) return NULL;
if(!IsAudioDeviceReady()) InitAudioDevice();
@ -207,22 +210,11 @@ AudioContext InitAudioContext(unsigned short sampleRate, unsigned char bitsPerSa
if(!mixChannelsActive_g[mixChannel]){
AudioContext_t *ac = malloc(sizeof(AudioContext_t));
ac->sampleRate = sampleRate;
ac->bitsPerSample = bitsPerSample;
ac->mixChannel = mixChannel;
ac->channels = channels;
mixChannelsActive_g[mixChannel] = ac;
// setup openAL format
if (channels == 1)
{
if (bitsPerSample == 8 ) ac->alFormat = AL_FORMAT_MONO8;
else if (bitsPerSample == 16) ac->alFormat = AL_FORMAT_MONO16;
}
else if (channels == 2)
{
if (bitsPerSample == 8 ) ac->alFormat = AL_FORMAT_STEREO8;
else if (bitsPerSample == 16) ac->alFormat = AL_FORMAT_STEREO16;
}
ac->alFormat = AL_FORMAT_STEREO_FLOAT32;
// Create an audio source
alGenSources(1, &ac->alSource);
@ -232,7 +224,14 @@ AudioContext InitAudioContext(unsigned short sampleRate, unsigned char bitsPerSa
alSource3f(ac->alSource, AL_VELOCITY, 0, 0, 0);
// Create Buffer
alGenBuffers(2, &ac->alBuffer);
alGenBuffers(2, ac->alBuffer);
//fill buffers
FillAlBufferWithSilence(ac, ac->alBuffer[0]);
FillAlBufferWithSilence(ac, ac->alBuffer[1]);
alSourceQueueBuffers(ac->alSource, 2, ac->alBuffer);
alSourcei(ac->alSource, AL_LOOPING, AL_FALSE); // this could cause errors
alSourcePlay(ac->alSource);
return ac;
@ -245,8 +244,20 @@ void CloseAudioContext(AudioContext ctx)
{
AudioContext_t *context = (AudioContext_t*)ctx;
if(context){
alSourceStop(context->alSource);
//flush out all queued buffers
ALuint buffer = 0;
int queued = 0;
alGetSourcei(context->alSource, AL_BUFFERS_QUEUED, &queued);
while (queued > 0)
{
alSourceUnqueueBuffers(context->alSource, 1, &buffer);
queued--;
}
alDeleteSources(1, &context->alSource);
alDeleteBuffers(2, &context->alBuffer);
alDeleteBuffers(2, context->alBuffer);
mixChannelsActive_g[context->mixChannel] = NULL;
free(context);
ctx = NULL;
@ -254,15 +265,34 @@ void CloseAudioContext(AudioContext ctx)
}
// Pushes more audio data into context mix channel, if none are ever pushed then zeros are fed in
void UpdateAudioContext(AudioContext ctx, void *data, unsigned short *dataLength)
// Call "UpdateAudioContext(ctx, NULL, 0)" every game tick if you want to pause the audio
void UpdateAudioContext(AudioContext ctx, float *data, unsigned short dataLength)
{
AudioContext_t *context = (AudioContext_t*)ctx;
if(!musicEnabled && context && mixChannelsActive_g[context->mixChannel] == context)
if (context && mixChannelsActive_g[context->mixChannel] == context)
{
;
ALint processed = 0;
ALuint buffer = 0;
alGetSourcei(context->alSource, AL_BUFFERS_PROCESSED, &processed); // Get the number of already processed buffers (if any)
if (!data || !dataLength)// play silence
while (processed > 0)
{
alSourceUnqueueBuffers(context->alSource, 1, &buffer);
FillAlBufferWithSilence(context, buffer);
alSourceQueueBuffers(context->alSource, 1, &buffer);
processed--;
}
}
}
// fill buffer with zeros
static void FillAlBufferWithSilence(AudioContext_t *ac, ALuint buffer)
{
float pcm[MUSIC_BUFFER_SIZE] = {0.f};
alBufferData(buffer, ac->alFormat, pcm, MUSIC_BUFFER_SIZE*sizeof(float), ac->sampleRate);
}
//----------------------------------------------------------------------------------

7
src/audio.h
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@ -84,10 +84,11 @@ 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, 16, 0, 2); // stereo, mixchannel 1, 16bit, 48khz
AudioContext InitAudioContext(unsigned short sampleRate, unsigned char bitsPerSample, unsigned char mixChannel, unsigned char channels);
// 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);
void CloseAudioContext(AudioContext ctx); // Frees audio context
void UpdateAudioContext(AudioContext ctx, void *data, unsigned short *dataLength); // Pushes more audio data into context mix channel, if none are ever pushed then zeros are fed in
void 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
Sound LoadSound(char *fileName); // Load sound to memory
Sound LoadSoundFromWave(Wave wave); // Load sound to memory from wave data

7
src/raylib.h
View File

@ -872,10 +872,11 @@ 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, 16, 0, 2); // stereo, mixchannel 1, 16bit, 48khz
AudioContext InitAudioContext(unsigned short sampleRate, unsigned char bitsPerSample, unsigned char mixChannel, unsigned char channels);
// 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);
void CloseAudioContext(AudioContext ctx); // Frees audio context
void UpdateAudioContext(AudioContext ctx, void *data, unsigned short *dataLength); // Pushes more audio data into context mix channel, if none are ever pushed then zeros are fed in
void 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
Sound LoadSound(char *fileName); // Load sound to memory
Sound LoadSoundFromWave(Wave wave); // Load sound to memory from wave data