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OpenAudio_ArduinoLibrary/AudioConvert_F32.h

81 lines
2.8 KiB

#ifndef _AudioConvert_I16toF32
#define _AudioConvert_I16toF32
#include <AudioStream_F32.h>
class AudioConvert_I16toF32 : public AudioStream_F32 //receive Int and transmits Float
{
public:
AudioConvert_I16toF32(void) : AudioStream_F32(1, inputQueueArray_f32) { };
void update(void) {
//get the Int16 block
audio_block_t *int_block;
int_block = AudioStream::receiveReadOnly(); //int16 data block
if (!int_block) return;
//allocate a float block
audio_block_f32_t *float_block;
float_block = AudioStream_F32::allocate_f32();
if (float_block == NULL) return;
//convert to float
convertAudio_I16toF32(int_block, float_block, AUDIO_BLOCK_SAMPLES);
//transmit the audio and return it to the system
AudioStream_F32::transmit(float_block,0);
AudioStream_F32::release(float_block);
AudioStream::release(int_block);
};
private:
audio_block_f32_t *inputQueueArray_f32[1]; //2 for stereo
static void convertAudio_I16toF32(audio_block_t *in, audio_block_f32_t *out, int len) {
//WEA Method. Should look at CMSIS arm_q15_to_float instead: https://www.keil.com/pack/doc/CMSIS/DSP/html/group__q15__to__x.html#gaf8b0d2324de273fc430b0e61ad4e9eb2
const float MAX_INT = 32678.0;
for (int i = 0; i < len; i++) out->data[i] = (float)(in->data[i]);
arm_scale_f32(out->data, 1.0/MAX_INT, out->data, out->length); //divide by 32678 to get -1.0 to +1.0
}
};
class AudioConvert_F32toI16 : public AudioStream_F32 //receive Float and transmits Int
{
public:
AudioConvert_F32toI16(void) : AudioStream_F32(1, inputQueueArray_Float) {};
void update(void) {
//get the float block
audio_block_f32_t *float_block;
float_block = AudioStream_F32::receiveReadOnly_f32(); //float data block
if (!float_block) return;
//allocate a Int16 block
audio_block_t *int_block;
int_block = AudioStream::allocate();
if (int_block == NULL) return;
//convert back to int16
convertAudio_F32ToI16(float_block, int_block, AUDIO_BLOCK_SAMPLES);
//return audio to the system
AudioStream::transmit(int_block);
AudioStream::release(int_block);
AudioStream_F32::release(float_block);
};
private:
audio_block_f32_t *inputQueueArray_Float[1];
static void convertAudio_F32ToI16(audio_block_f32_t *in, audio_block_t *out, int len) {
//WEA Method. Should look at CMSIS arm_float_to_q15 instead: https://www.keil.com/pack/doc/CMSIS/DSP/html/group__float__to__x.html#ga215456e35a18db86882e1d3f0d24e1f2
const float MAX_INT = 32678.0;
for (int i = 0; i < len; i++) {
out->data[i] = (int16_t)(max(min( (in->data[i] * MAX_INT), MAX_INT), -MAX_INT));
}
}
};
#endif