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Siren audio engine in progress - Implementing Impulse-Response based reverb

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Kearwood Gilbert
2013-02-15 23:27:04 -08:00
parent 91aca18620
commit fac1df2f6a
2 changed files with 50 additions and 31 deletions
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68
KREngine/kraken/KRAudioManager.cpp
View File

@@ -65,6 +65,7 @@ KRAudioManager::KRAudioManager(KRContext &context) : KRContextObject(context)
m_reverb_input_next_sample = 0;
m_reverb_workspace_data = NULL;
m_reverb_sequence = 0;
for(int i=0; i < KRENGINE_MAX_REVERB_IMPULSE_MIX; i++) {
m_reverb_impulse_responses[i] = NULL;
@@ -141,47 +142,62 @@ float *KRAudioManager::getBlockAddress(int block_offset)
return m_output_accumulation + (m_output_accumulation_block_start + block_offset * KRENGINE_AUDIO_BLOCK_LENGTH * KRENGINE_MAX_OUTPUT_CHANNELS) % (KRENGINE_REVERB_MAX_SAMPLES * KRENGINE_MAX_OUTPUT_CHANNELS);
}
void KRAudioManager::renderReverbImpulseResponse(KRAudioSample *impulse_response, int impulse_response_block)
void KRAudioManager::renderReverbImpulseResponse(KRAudioSample *impulse_response, int impulse_response_offset, int frame_count_log_2)
{
int frame_count = 1 << frame_count_log_2;
int fft_size = frame_count * 2;
int fft_size_log_2 = frame_count_log_2 + 1;
DSPSplitComplex reverb_sample_data_complex = m_reverb_workspace[0];
DSPSplitComplex impulse_block_data_complex = m_reverb_workspace[1];
DSPSplitComplex conv_data_complex = m_reverb_workspace[2];
float *block_data = getBlockAddress(0);
float *next_block = getBlockAddress(1);
float impulse_block_start_index = impulse_response_block * KRENGINE_AUDIO_BLOCK_LENGTH;
int reverb_block_start_index = (m_reverb_input_next_sample - KRENGINE_AUDIO_BLOCK_LENGTH * (impulse_response_block + 1));
if(reverb_block_start_index < 0) {
reverb_block_start_index += KRENGINE_REVERB_MAX_SAMPLES;
int reverb_offset = (m_reverb_input_next_sample + KRENGINE_AUDIO_BLOCK_LENGTH - impulse_response_offset);
if(reverb_offset < 0) {
reverb_offset += KRENGINE_REVERB_MAX_SAMPLES;
} else {
reverb_block_start_index = reverb_block_start_index % KRENGINE_REVERB_MAX_SAMPLES;
reverb_offset = reverb_offset % KRENGINE_REVERB_MAX_SAMPLES;
}
int frames_left = frame_count;
while(frames_left) {
int frames_to_process = KRENGINE_REVERB_MAX_SAMPLES - reverb_offset;
if(frames_to_process > frames_left) frames_to_process = frames_left;
memcpy(reverb_sample_data_complex.realp + frame_count - frames_left, m_reverb_input_samples + reverb_offset, frames_to_process * sizeof(float));
memcpy(reverb_sample_data_complex.realp, m_reverb_input_samples + reverb_block_start_index, KRENGINE_AUDIO_BLOCK_LENGTH * sizeof(float));
memset(reverb_sample_data_complex.realp + KRENGINE_AUDIO_BLOCK_LENGTH, 0, KRENGINE_AUDIO_BLOCK_LENGTH * sizeof(float));
memset(reverb_sample_data_complex.imagp, 0, KRENGINE_AUDIO_BLOCK_LENGTH * 2 * sizeof(float));
frames_left -= frames_to_process;
reverb_offset = (reverb_offset + frames_to_process) % KRENGINE_REVERB_MAX_SAMPLES;
}
memset(reverb_sample_data_complex.realp + frame_count, 0, frame_count * sizeof(float));
memset(reverb_sample_data_complex.imagp, 0, fft_size * sizeof(float));
vDSP_fft_zip(m_fft_setup, &reverb_sample_data_complex, 1, fft_size_log_2, kFFTDirection_Forward);
vDSP_fft_zip(m_fft_setup, &reverb_sample_data_complex, 1, KRENGINE_AUDIO_BLOCK_LOG2N + 1, kFFTDirection_Forward);
float scale = 1.0f / (2 * KRENGINE_AUDIO_BLOCK_LENGTH);
float scale = 1.0f / fft_size;
int impulse_response_channels = 2;
for(int channel=0; channel < impulse_response_channels; channel++) {
impulse_response->sample(impulse_block_start_index, KRENGINE_AUDIO_BLOCK_LENGTH, channel, impulse_block_data_complex.realp, 1.0f);
memset(impulse_block_data_complex.realp + KRENGINE_AUDIO_BLOCK_LENGTH, 0, KRENGINE_AUDIO_BLOCK_LENGTH * sizeof(float));
memset(impulse_block_data_complex.imagp, 0, KRENGINE_AUDIO_BLOCK_LENGTH * 2 * sizeof(float));
impulse_response->sample(impulse_response_offset, frame_count, channel, impulse_block_data_complex.realp, 1.0f);
memset(impulse_block_data_complex.realp + frame_count, 0, KRENGINE_AUDIO_BLOCK_LENGTH * sizeof(float));
memset(impulse_block_data_complex.imagp, 0, fft_size * sizeof(float));
vDSP_fft_zip(m_fft_setup, &impulse_block_data_complex, 1, KRENGINE_AUDIO_BLOCK_LOG2N + 1, kFFTDirection_Forward);
vDSP_zvmul(&reverb_sample_data_complex, 1, &impulse_block_data_complex, 1, &conv_data_complex, 1, KRENGINE_AUDIO_BLOCK_LENGTH * 2, 1);
vDSP_fft_zip(m_fft_setup, &conv_data_complex, 1, KRENGINE_AUDIO_BLOCK_LOG2N + 1, kFFTDirection_Inverse);
vDSP_vsmul(conv_data_complex.realp, 1, &scale, conv_data_complex.realp, 1, KRENGINE_AUDIO_BLOCK_LENGTH * 2);
vDSP_vadd(block_data + channel, impulse_response_channels, conv_data_complex.realp, 1, block_data + channel, impulse_response_channels, KRENGINE_AUDIO_BLOCK_LENGTH);
vDSP_vadd(next_block + channel, impulse_response_channels, conv_data_complex.realp + KRENGINE_AUDIO_BLOCK_LENGTH, 1, next_block + channel, impulse_response_channels, KRENGINE_AUDIO_BLOCK_LENGTH);
vDSP_fft_zip(m_fft_setup, &impulse_block_data_complex, 1, fft_size_log_2, kFFTDirection_Forward);
vDSP_zvmul(&reverb_sample_data_complex, 1, &impulse_block_data_complex, 1, &conv_data_complex, 1, fft_size, 1);
vDSP_fft_zip(m_fft_setup, &conv_data_complex, 1, fft_size_log_2, kFFTDirection_Inverse);
vDSP_vsmul(conv_data_complex.realp, 1, &scale, conv_data_complex.realp, 1, fft_size);
int output_offset = m_output_accumulation_block_start;
frames_left = fft_size;
while(frames_left) {
int frames_to_process = (KRENGINE_REVERB_MAX_SAMPLES * KRENGINE_MAX_OUTPUT_CHANNELS - m_output_accumulation_block_start) / 2;
if(frames_to_process > frames_left) frames_to_process = frames_left;
vDSP_vadd(m_output_accumulation + output_offset + channel, KRENGINE_MAX_OUTPUT_CHANNELS, conv_data_complex.realp + fft_size - frames_left, 1, m_output_accumulation + output_offset + channel, KRENGINE_MAX_OUTPUT_CHANNELS, frames_to_process);
frames_left -= frames_to_process;
output_offset = (output_offset + frames_to_process * KRENGINE_MAX_OUTPUT_CHANNELS) % (KRENGINE_REVERB_MAX_SAMPLES * KRENGINE_MAX_OUTPUT_CHANNELS);
}
}
}
@@ -219,7 +235,7 @@ void KRAudioManager::renderReverb()
if(impulse_response_sample) {
int impulse_response_blocks = impulse_response_sample->getFrameCount() / KRENGINE_AUDIO_BLOCK_LENGTH + 1;
for(int impulse_response_block=0; impulse_response_block < impulse_response_blocks; impulse_response_block++) {
renderReverbImpulseResponse(impulse_response_sample, impulse_response_block);
renderReverbImpulseResponse(impulse_response_sample, impulse_response_block * KRENGINE_AUDIO_BLOCK_LENGTH, KRENGINE_AUDIO_BLOCK_LOG2N);
}
}
}
@@ -296,6 +312,8 @@ void KRAudioManager::initSiren()
m_reverb_workspace[2].realp = m_reverb_workspace_data + KRENGINE_REVERB_WORKSPACE_SIZE * 4;
m_reverb_workspace[2].imagp = m_reverb_workspace_data + KRENGINE_REVERB_WORKSPACE_SIZE * 5;
m_reverb_sequence = 0;
m_fft_setup = vDSP_create_fftsetup( 16, kFFTRadix2);
// ----====---- Initialize Core Audio Objects ----====----

9
KREngine/kraken/KRAudioManager.h
View File

@@ -44,10 +44,10 @@ const int KRENGINE_AUDIO_MAX_POOL_SIZE = 32;
const int KRENGINE_AUDIO_MAX_BUFFER_SIZE = 64*1024;
const int KRENGINE_AUDIO_BUFFERS_PER_SOURCE = 3;
const int KRENGINE_AUDIO_BLOCK_LENGTH = 256; // Length of one block to process. Determines the latency of the audio system and sets size for FFT's used in HRTF convolution
const int KRENGINE_AUDIO_BLOCK_LOG2N = 8; // 2 ^ KRENGINE_AUDIO_BLOCK_LOG2N = KRENGINE_AUDIO_BLOCK_LENGTH
const int KRENGINE_AUDIO_BLOCK_LENGTH = 512; // Length of one block to process. Determines the latency of the audio system and sets size for FFT's used in HRTF convolution
const int KRENGINE_AUDIO_BLOCK_LOG2N = 9; // 2 ^ KRENGINE_AUDIO_BLOCK_LOG2N = KRENGINE_AUDIO_BLOCK_LENGTH
const int KRENGINE_REVERB_WORKSPACE_SIZE = 1024;
const int KRENGINE_REVERB_WORKSPACE_SIZE = KRENGINE_AUDIO_BLOCK_LENGTH * 4;
const int KRENGINE_REVERB_MAX_SAMPLES = 435200; // At least 10s reverb impulse response length, divisible by KRENGINE_AUDIO_BLOCK_LENGTH
const int KRENGINE_MAX_REVERB_IMPULSE_MIX = 16; // Maximum number of impulse response filters that can be mixed simultaneously
@@ -131,6 +131,7 @@ private:
float *m_reverb_input_samples; // Circular-buffered reverb input, single channel
int m_reverb_input_next_sample; // Pointer to next sample in reverb buffer
int m_reverb_sequence;
KRAudioSample *m_reverb_impulse_responses[KRENGINE_MAX_REVERB_IMPULSE_MIX];
float m_reverb_impulse_responses_weight[KRENGINE_MAX_REVERB_IMPULSE_MIX];
@@ -148,7 +149,7 @@ private:
void renderReverb();
void renderHRTF();
void renderITD();
void renderReverbImpulseResponse(KRAudioSample *impulse_response, int impulse_response_block);
void renderReverbImpulseResponse(KRAudioSample *impulse_response, int impulse_response_offset, int frame_count_log_2);
};
#endif /* defined(KRAUDIO_MANAGER_H) */