void AudioAnalyzeFFT256::update(void)
{
audio_block_t *block;
block = receiveReadOnly();
if (!block) return;
if (!prevblock) {
prevblock = block;
return;
}
copy_to_fft_buffer(buffer, prevblock->data);
copy_to_fft_buffer(buffer+256, block->data);
//window = AudioWindowBlackmanNuttall256;
//window = NULL;
if (window) apply_window_to_fft_buffer(buffer, window);
arm_cfft_radix4_q15(&fft_inst, buffer);
// G. Heinzel's paper says we're supposed to average the magnitude
// squared, then do the square root at the end.
if (count == 0) {
for (int i=0; i < 128; i++) {
uint32_t tmp = *((uint32_t *)buffer + i);
uint32_t magsq = multiply_16tx16t_add_16bx16b(tmp, tmp);
sum[i] = magsq / naverage;
}
} else {
for (int i=0; i < 128; i++) {
uint32_t tmp = *((uint32_t *)buffer + i);
uint32_t magsq = multiply_16tx16t_add_16bx16b(tmp, tmp);
sum[i] += magsq / naverage;
}
}
if (++count == naverage) {
count = 0;
for (int i=0; i < 128; i++) {
output[i] = sqrt_uint32_approx(sum[i]);
}
outputflag = true;
}
release(prevblock);
prevblock = block;
}
void AudioAnalyzeFFT256::update(void)
{
audio_block_t *block;
block = receiveReadOnly();
if (!block) return;
#if AUDIO_BLOCK_SAMPLES == 128
if (!prevblock) {
prevblock = block;
return;
}
copy_to_fft_buffer(buffer, prevblock->data);
copy_to_fft_buffer(buffer+256, block->data);
//window = AudioWindowBlackmanNuttall256;
//window = NULL;
if (window) apply_window_to_fft_buffer(buffer, window);
arm_cfft_radix4_q15(&fft_inst, buffer);
// G. Heinzel's paper says we're supposed to average the magnitude
// squared, then do the square root at the end.
if (count == 0) {
for (int i=0; i < 128; i++) {
uint32_t tmp = *((uint32_t *)buffer + i);
uint32_t magsq = multiply_16tx16t_add_16bx16b(tmp, tmp);
sum[i] = magsq / naverage;
}
} else {
for (int i=0; i < 128; i++) {
uint32_t tmp = *((uint32_t *)buffer + i);
uint32_t magsq = multiply_16tx16t_add_16bx16b(tmp, tmp);
sum[i] += magsq / naverage;
}
}
if (++count == naverage) {
count = 0;
for (int i=0; i < 128; i++) {
output[i] = sqrt_uint32_approx(sum[i]);
}
outputflag = true;
}
release(prevblock);
prevblock = block;
#elif AUDIO_BLOCK_SAMPLES == 64
if (prevblocks[2] == NULL) {
prevblocks[2] = prevblocks[1];
prevblocks[1] = prevblocks[0];
prevblocks[0] = block;
return;
}
if (count == 0) {
count = 1;
copy_to_fft_buffer(buffer, prevblocks[2]->data);
copy_to_fft_buffer(buffer+128, prevblocks[1]->data);
copy_to_fft_buffer(buffer+256, prevblocks[1]->data);
copy_to_fft_buffer(buffer+384, block->data);
if (window) apply_window_to_fft_buffer(buffer, window);
arm_cfft_radix4_q15(&fft_inst, buffer);
} else {
count = 2;
const uint32_t *p = (uint32_t *)buffer;
for (int i=0; i < 128; i++) {
uint32_t tmp = *p++;
int16_t v1 = tmp & 0xFFFF;
int16_t v2 = tmp >> 16;
output[i] = sqrt_uint32_approx(v1 * v1 + v2 * v2);
}
}
release(prevblocks[2]);
prevblocks[2] = prevblocks[1];
prevblocks[1] = prevblocks[0];
prevblocks[0] = block;
#endif
}
void AudioAnalyzeFFT1024::update(void)
{
audio_block_t *block;
block = receiveReadOnly();
if (!block) return;
switch (state) {
case 0:
blocklist[0] = block;
state = 1;
break;
case 1:
blocklist[1] = block;
state = 2;
break;
case 2:
blocklist[2] = block;
state = 3;
break;
case 3:
blocklist[3] = block;
state = 4;
break;
case 4:
blocklist[4] = block;
state = 5;
break;
case 5:
blocklist[5] = block;
state = 6;
break;
case 6:
blocklist[6] = block;
state = 7;
break;
case 7:
blocklist[7] = block;
// TODO: perhaps distribute the work over multiple update() ??
// github pull requsts welcome......
copy_to_fft_buffer(buffer+0x000, blocklist[0]->data);
copy_to_fft_buffer(buffer+0x100, blocklist[1]->data);
copy_to_fft_buffer(buffer+0x200, blocklist[2]->data);
copy_to_fft_buffer(buffer+0x300, blocklist[3]->data);
copy_to_fft_buffer(buffer+0x400, blocklist[4]->data);
copy_to_fft_buffer(buffer+0x500, blocklist[5]->data);
copy_to_fft_buffer(buffer+0x600, blocklist[6]->data);
copy_to_fft_buffer(buffer+0x700, blocklist[7]->data);
if (window) apply_window_to_fft_buffer(buffer, window);
arm_cfft_radix4_q15(&fft_inst, buffer);
// TODO: support averaging multiple copies
for (int i=0; i < 512; i++) {
uint32_t tmp = *((uint32_t *)buffer + i); // real & imag
uint32_t magsq = multiply_16tx16t_add_16bx16b(tmp, tmp);
output[i] = sqrt_uint32_approx(magsq);
}
outputflag = true;
release(blocklist[0]);
release(blocklist[1]);
release(blocklist[2]);
release(blocklist[3]);
blocklist[0] = blocklist[4];
blocklist[1] = blocklist[5];
blocklist[2] = blocklist[6];
blocklist[3] = blocklist[7];
state = 4;
break;
}
}
