static void dsp_calculate_fft(dsp16_t *fft, dsp16_t *signal)
{
int i;
dsp16_t max_value;
dsp16_t temp[BUFFER_LENGTH];
dsp16_complex_t temp_res[BUFFER_LENGTH];
dsp16_vect_dotmul(temp, signal, fft_window, BUFFER_LENGTH);
dsp16_trans_realcomplexfft(temp_res, temp, BUFFER_LENGTH_LOG);
dsp16_vect_complex_abs(fft, temp_res, BUFFER_LENGTH);
for (i = 0; i < FFT_LENGTH; i++)
fft[i] += fft[BUFFER_LENGTH - i - 1];
max_value = dsp16_vect_max(fft, FFT_LENGTH);
dsp16_vect_realdiv(fft, fft, FFT_LENGTH, max_value + 1);
}
int real_division(int *size)
{
int cycle_count;
// Conditions
CHECK_CONDITIONS(VECT1_SIZE >= VECT2_SIZE)
CHECK_CONDITIONS(VECT3_SIZE > 0)
// Action
dsp16_debug_printf("vect1 = vect2 / %f\n", vect3[0]);
*size = VECT2_SIZE;
cycle_count = Get_sys_count();
dsp16_vect_realdiv(vect1, vect2, VECT2_SIZE, vect3[0]);
return Get_sys_count() - cycle_count;
}
static bool usb_stream_process(void)
{
buffer_t *input_buffer;
#if (defined __GNUC__)
dsp16_t * volatile dsp16_output_buffer;
#else
dsp16_t * dsp16_output_buffer;
#endif
int i, channel, size = 0;
// If no buffer is ready, then set under flow marker
if (usb_stream_context->current_full_buffer == -1)
return false;
// If the audio DAC is not ready to receive more data, then return
if (!audio_mixer_dacs_output_direct(NULL, 0))
return false;
// Select the current input buffer and make sure it is valid
input_buffer = usb_stream_context->input_buffers[usb_stream_context->current_full_buffer];
// Make sure this buffer is not already in the process of resampling
if (input_buffer->buffer_state != BUFFER_STATE_FULL)
return false;
// Mark this buffer as a "resampling" buffer
input_buffer->buffer_state = BUFFER_STATE_RESAMPLING;
// Select the current output buffer
dsp16_output_buffer = (dsp16_t *) usb_stream_context->output_buffers[usb_stream_context->current_output_buffer];
for (channel=0; channel<usb_stream_context->nb_channels; channel++)
{
// Interpolates the current channel buffer
dsp16_resampling_compute(usb_stream_context->ctx->resampling,
usb_stream_context->output_temp_buffer,
input_buffer->buffer[channel],
channel);
size = dsp16_resampling_get_output_current_buffer_size(usb_stream_context->ctx->resampling);
// Fill the array with audio samples and mix the channels
switch (usb_stream_context->nb_channels)
{
case 1:
memcpy(dsp16_output_buffer, usb_stream_context->output_temp_buffer, usb_stream_context->input_buffer_size);
break;
case 2:
for (i=0; i<size; i++)
dsp16_output_buffer[i*2] = ((dsp16_t *) usb_stream_context->output_temp_buffer)[i];
break;
default:
for (i=0; i<size; i++)
dsp16_output_buffer[i*usb_stream_context->nb_channels] = ((dsp16_t *) usb_stream_context->output_temp_buffer)[i];
}
// change channel
dsp16_output_buffer++;
}
// Re-selects the current output buffer
dsp16_output_buffer = (dsp16_t *) usb_stream_context->output_buffers[usb_stream_context->current_output_buffer];
// Scale the output buffer if the scaling is set
if (usb_stream_context->ctx->gain)
dsp16_vect_realdiv(dsp16_output_buffer, dsp16_output_buffer, size * usb_stream_context->nb_channels, usb_stream_context->ctx->gain);
// Send the buffer to the output channel
audio_mixer_dacs_output_direct(dsp16_output_buffer, size);
// Set the current input buffer as an empty buffer
input_buffer->buffer_state = BUFFER_STATE_EMPTY;
// Update the current output buffer index
usb_stream_context->current_output_buffer = (usb_stream_context->current_output_buffer+1)%AUDIO_STREAM_NB_OUTPUT_BUFFERS;
// Update the current full buffer pointer
i = (usb_stream_context->current_full_buffer+1)%AUDIO_STREAM_NB_INPUT_BUFFERS;
input_buffer = usb_stream_context->input_buffers[i];
if (input_buffer->buffer_state != BUFFER_STATE_FULL)
i = -1;
usb_stream_context->current_full_buffer = i;
return true;
}
