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#include "FFT_Overlapped_OA_F32.h"
void FFT_Overlapped_OA_F32::execute(audio_block_f32_t *block, float *complex_2N_buffer) //results returned inc omplex_2N_buffer
int targ_ind;
//get a pointer to the latest data
//audio_block_f32_t *block = AudioStream_F32::receiveReadOnly_f32();
if (!block) return;
//add a claim to this block. As a result, be sure that this function issues a "release()".
//Also, be sure that the calling function issues its own release() to release its claim.
//shuffle all of input data blocks in preperation for this latest processing
AudioStream_F32::release(buff_blocks[0]); //release the oldest one...this is the release the corresponds to the claim above
for (int i = 1; i < N_BUFF_BLOCKS; i++) buff_blocks[i - 1] = buff_blocks[i];
buff_blocks[N_BUFF_BLOCKS - 1] = block; //append the newest input data to the complex_buffer blocks
//copy all input data blocks into one big block...the big block is interleaved [real,imaginary]
targ_ind = 0;
//Serial.print("Overlapped_FFT_F32: N_BUFF_BLOCKS = "); Serial.print(N_BUFF_BLOCKS);
//Serial.print(", audio_block_samples = "); Serial.println(audio_block_samples);
for (int i = 0; i < N_BUFF_BLOCKS; i++) {
for (int j = 0; j < audio_block_samples; j++) {
complex_2N_buffer[2*targ_ind] = buff_blocks[i]->data[j]; //real
complex_2N_buffer[2*targ_ind+1] = 0; //imaginary
//call the FFT...windowing of the data happens in the FFT routine, if configured
audio_block_f32_t* IFFT_Overlapped_OA_F32::execute(float *complex_2N_buffer) { //real results returned through audio_block_f32_t
//Serial.print("Overlapped_IFFT_F32: N_BUFF_BLOCKS = "); Serial.print(N_BUFF_BLOCKS);
//Serial.print(", audio_block_samples = "); Serial.println(audio_block_samples);
//call the IFFT...any follow-up windowing is handdled in the IFFT routine, if configured
//prepare for the overlap-and-add for the output
audio_block_f32_t *temp_buff = buff_blocks[0]; //hold onto this one for a'll get overwritten later
for (int i = 1; i < N_BUFF_BLOCKS; i++) buff_blocks[i - 1] = buff_blocks[i]; //shuffle the output data blocks
buff_blocks[N_BUFF_BLOCKS - 1] = temp_buff; //put the oldest output buffer back in the list
//do overlap and add with previously computed data
int output_count = 0;
for (int i = 0; i < (N_BUFF_BLOCKS-1); i++) { //Notice that this loop does NOT do the last block. That's a special case after.
for (int j = 0; j < audio_block_samples; j++) {
buff_blocks[i]->data[j] += complex_2N_buffer[2*output_count]; //add only the real part into the previous results
//now write in the newest data into the last block, overwriting any garbage that might have existed there
for (int j = 0; j < audio_block_samples; j++) {
buff_blocks[N_BUFF_BLOCKS - 1]->data[j] = complex_2N_buffer[2*output_count]; //overwrite with the newest data
//send the oldest data. Don't issue the release command here because we will release it the next time through this routine
//transmit(buff_blocks[0]); //don't release this buffer because we re-use it every time this is called
return buff_blocks[0]; //send back the pointer to this audio block...but don't release it because we'll re-use it here