From 1612ba63ab66b2f875fe6aca70e5fabea6b578ca Mon Sep 17 00:00:00 2001 From: Ray Date: Wed, 30 Mar 2022 20:13:02 +0200 Subject: [PATCH] ADDED: Audio stream processors support -WIP- #2212 This feature is still under consideration/testing and it doesn't work properly, at least the Delay Effect processor. --- examples/audio/audio_music_stream.c | 65 +++++++++++++++++++++++++++ src/raudio.c | 70 +++++++++++++++++++++++++++++ src/raylib.h | 5 +++ 3 files changed, 140 insertions(+) diff --git a/examples/audio/audio_music_stream.c b/examples/audio/audio_music_stream.c index 22db3dd8..30a13c0d 100644 --- a/examples/audio/audio_music_stream.c +++ b/examples/audio/audio_music_stream.c @@ -11,6 +11,47 @@ #include "raylib.h" +// Audio effect: lowpass filter +static void AudioProcessEffectLPF(float *buffer, unsigned int frames) +{ + static float low[2] = { 0.0f, 0.0f }; + static const float cutoff = 70.0f / 44100.0f; // 70 Hz lowpass filter + const float k = cutoff / (cutoff + 0.1591549431f); // RC filter formula + + for (unsigned int i = 0; i < frames*2; i += 2) + { + float l = buffer[i], r = buffer[i + 1]; + low[0] += k * (l - low[0]); + low[1] += k * (r - low[1]); + buffer[i] = low[0]; + buffer[i + 1] = low[1]; + } +} + +static float *delayBuffer = NULL; +static unsigned int delayBufferSize = 0; +static unsigned int delayReadIndex = 2; +static unsigned int delayWriteIndex = 0; + +// Audio effect: delay +static void AudioProcessEffectDelay(float *buffer, unsigned int frames) +{ + for (unsigned int i = 0; i < frames*2; i += 2) + { + float leftDelay = delayBuffer[delayReadIndex++]; // ERROR: Reading buffer -> WHY??? Maybe thread related??? + float rightDelay = delayBuffer[delayReadIndex++]; + + if (delayReadIndex == delayBufferSize) delayReadIndex = 0; + + buffer[i] = 0.5f*buffer[i] + 0.5f*leftDelay; + buffer[i + 1] = 0.5f*buffer[i + 1] + 0.5f*rightDelay; + + delayBuffer[delayWriteIndex++] = buffer[i]; + delayBuffer[delayWriteIndex++] = buffer[i + 1]; + if (delayWriteIndex == delayBufferSize) delayWriteIndex = 0; + } +} + int main(void) { // Initialization @@ -24,11 +65,17 @@ int main(void) Music music = LoadMusicStream("resources/country.mp3"); + // Allocate buffer for the delay effect + delayBuffer = (float *)RL_CALLOC(48000*2, sizeof(float)); // 1 second delay (device sampleRate*channels) + PlayMusicStream(music); float timePlayed = 0.0f; bool pause = false; + bool hasFilter = false; + bool hasDelay = false; + SetTargetFPS(60); // Set our game to run at 60 frames-per-second //-------------------------------------------------------------------------------------- @@ -55,6 +102,22 @@ int main(void) else ResumeMusicStream(music); } + // Add/Remove effect: lowpass filter + if (IsKeyPressed(KEY_F)) + { + hasFilter = !hasFilter; + if (hasFilter) AttachAudioStreamProcessor(music.stream, AudioProcessEffectLPF); + else DetachAudioStreamProcessor(music.stream, AudioProcessEffectLPF); + } + + // Add/Remove effect: delay + if (IsKeyPressed(KEY_D)) + { + hasDelay = !hasDelay; + if (hasDelay) AttachAudioStreamProcessor(music.stream, AudioProcessEffectDelay); + else DetachAudioStreamProcessor(music.stream, AudioProcessEffectDelay); + } + // Get timePlayed scaled to bar dimensions (400 pixels) timePlayed = GetMusicTimePlayed(music)/GetMusicTimeLength(music)*400; @@ -86,6 +149,8 @@ int main(void) CloseAudioDevice(); // Close audio device (music streaming is automatically stopped) + RL_FREE(delayBuffer); // Free delay buffer + CloseWindow(); // Close window and OpenGL context //-------------------------------------------------------------------------------------- diff --git a/src/raudio.c b/src/raudio.c index f25de079..9b83afd7 100644 --- a/src/raudio.c +++ b/src/raudio.c @@ -316,6 +316,7 @@ struct rAudioBuffer { ma_data_converter converter; // Audio data converter AudioCallback callback; // Audio buffer callback for buffer filling on audio threads + rAudioProcessor *processor; // Audio processor float volume; // Audio buffer volume float pitch; // Audio buffer pitch @@ -337,6 +338,14 @@ struct rAudioBuffer { rAudioBuffer *prev; // Previous audio buffer on the list }; +// Audio processor struct +// NOTE: Useful to apply effects to an AudioBuffer +struct rAudioProcessor { + AudioCallback process; // Processor callback function + rAudioProcessor *next; // Next audio processor on the list + rAudioProcessor *prev; // Previous audio processor on the list +}; + #define AudioBuffer rAudioBuffer // HACK: To avoid CoreAudio (macOS) symbol collision // Audio data context @@ -559,6 +568,7 @@ AudioBuffer *LoadAudioBuffer(ma_format format, ma_uint32 channels, ma_uint32 sam audioBuffer->pan = 0.5f; audioBuffer->callback = NULL; + audioBuffer->processor = NULL; audioBuffer->playing = false; audioBuffer->paused = false; @@ -2039,6 +2049,58 @@ void SetAudioStreamCallback(AudioStream stream, AudioCallback callback) if (stream.buffer != NULL) stream.buffer->callback = callback; } +// Add processor to audio stream. Contrary to buffers, the order of processors is important. +// The new processor must be added at the end. As there aren't supposed to be a lot of processors attached to +// a given stream, we iterate through the list to find the end. That way we don't need a pointer to the last element. +void AttachAudioStreamProcessor(AudioStream stream, AudioCallback process) +{ + ma_mutex_lock(&AUDIO.System.lock); + + rAudioProcessor *processor = (rAudioProcessor *)RL_CALLOC(1, sizeof(rAudioProcessor)); + processor->process = process; + + rAudioProcessor *last = stream.buffer->processor; + + while (last && last->next) + { + last = last->next; + } + if (last) + { + processor->prev = last; + last->next = processor; + } + else stream.buffer->processor = processor; + + ma_mutex_unlock(&AUDIO.System.lock); +} + +void DetachAudioStreamProcessor(AudioStream stream, AudioCallback process) +{ + ma_mutex_lock(&AUDIO.System.lock); + + rAudioProcessor *processor = stream.buffer->processor; + + while (processor) + { + rAudioProcessor *next = processor->next; + rAudioProcessor *prev = processor->prev; + + if (processor->process == process) + { + if (stream.buffer->processor == processor) stream.buffer->processor = next; + if (prev) prev->next = next; + if (next) next->prev = prev; + + RL_FREE(processor); + } + + processor = next; + } + + ma_mutex_unlock(&AUDIO.System.lock); +} + //---------------------------------------------------------------------------------- // Module specific Functions Definition //---------------------------------------------------------------------------------- @@ -2235,6 +2297,14 @@ static void OnSendAudioDataToDevice(ma_device *pDevice, void *pFramesOut, const float *framesOut = (float *)pFramesOut + (framesRead*AUDIO.System.device.playback.channels); float *framesIn = tempBuffer; + // Apply processors chain if defined + rAudioProcessor *processor = audioBuffer->processor; + while (processor) + { + processor->process(framesIn, framesJustRead); + processor = processor->next; + } + MixAudioFrames(framesOut, framesIn, framesJustRead, audioBuffer); framesToRead -= framesJustRead; diff --git a/src/raylib.h b/src/raylib.h index 1add734b..7cb19927 100644 --- a/src/raylib.h +++ b/src/raylib.h @@ -428,10 +428,12 @@ typedef struct Wave { // Opaque structs declaration // NOTE: Actual structs are defined internally in raudio module typedef struct rAudioBuffer rAudioBuffer; +typedef struct rAudioProcessor rAudioProcessor; // AudioStream, custom audio stream typedef struct AudioStream { rAudioBuffer *buffer; // Pointer to internal data used by the audio system + rAudioProcessor *processor; // Pointer to internal data processor, useful for audio effects unsigned int sampleRate; // Frequency (samples per second) unsigned int sampleSize; // Bit depth (bits per sample): 8, 16, 32 (24 not supported) @@ -1543,6 +1545,9 @@ RLAPI void SetAudioStreamPan(AudioStream stream, float pan); // Set pan RLAPI void SetAudioStreamBufferSizeDefault(int size); // Default size for new audio streams RLAPI void SetAudioStreamCallback(AudioStream stream, AudioCallback callback); // Audio thread callback to request new data +RLAPI void AttachAudioStreamProcessor(AudioStream stream, AudioCallback processor); +RLAPI void DetachAudioStreamProcessor(AudioStream stream, AudioCallback processor); + #if defined(__cplusplus) } #endif