applying esp-dsp IIR biquad to pipeline or element ?

[benbiles]

I meant to say the DSP processing is fully working!! Not with a question mark.

Can't see an edit post option on this forum. That's a shame.

[shabtronic]

Awesome you got it working - sucks about the firmware problem tho.

There is a edit option - it's a little pen next to the flag on the top right of anything you post.

Have fun!

[benbiles]

fully working in Stereo !!!!

The hardware was fine , you were correct , i needed to de-interleave I2S

int16-t to float -> de-interleave -> DSP L & DSP R -> float to int16_t -> re-interleave !!!

I untangled the code from equaliser.c so its own thing and called is dsprunner.c

awesome , super happy , thanks for your tips !!

[jaydeep.faldu]

Hi,

Hope you are doing good.
These conversation is very useful for me, based on this I have tried to implement LPF to remove noise from audio signal. But still I am getting noise in output with actual audio signal.

esp-idf version = stable release 4.4.1
Dev-Kit = https://github.com/W00ng/ESP32-S3-HMI-DevKit

My code is as following.(I am a beginner for I2S interface and audio signals)

Code: Select all

[Codebox=c file=Untitled.c]

#define AUDIO_SAMPLE_RATE  AUDIO_HAL_16K_SAMPLES
/* i2s_Sample_Rate * T * sizeof(uint8_t)
16bits,Mono，Record_time = T/2(s) */
#define BUF_SIZE  (16000 * 20 * sizeof(uint8_t))  
#define FRAME_SIZE  (1600)
#define SAMPLES_NUM (1024)

static uint32_t audio_index = 0;
static uint32_t audio_total = 0;
static uint8_t *audio_buffer = NULL;

#if 1

int N = SAMPLES_NUM;
// Input test array
__attribute__((aligned(16)))
float d[SAMPLES_NUM];
// output array
__attribute__((aligned(16)))
float y[SAMPLES_NUM];
__attribute__((aligned(16)))
float y_cf[SAMPLES_NUM*2];

#endif

void audio_record_task(void *args)
{
    static esp_err_t ret;
    static size_t bytes_read = 0;
    static size_t bytes_write = 0;
    while (1) 
    {

        if (mode == record) {
            ESP_LOGI(TAG, "record start");
            audio_index = 0;
            while ((mode == record) && (audio_index < (BUF_SIZE - 	FRAME_SIZE)))
            {
                ret = i2s_read(I2S_NUM_0, audio_buffer + audio_index, FRAME_SIZE, &bytes_read, 100);
                if (ret != ESP_OK) {
                    ESP_LOGE(TAG, "[echo] i2s read failed");
                    abort();
                }
                audio_index += FRAME_SIZE;
            }
            if (mode == record) mode = idle;

            ESP_LOGI(TAG, "record end");
        }
        else if (mode == play)
        {
            ESP_LOGI(TAG, "play start");
            ESP_LOGI(TAG, "audio_index = %d", audio_index);
            audio_total = audio_index;  //recorder length
            audio_index = 0;

            esp_err_t ret = ESP_OK, ret_hpf = ESP_OK;
            float coeffs_lpf[5];
            float coeffs_hpf[5];
            float w_lpf[5] = {0,0};
            // Calculate iir filter coefficients
            ret = dsps_biquad_gen_lpf_f32(coeffs_lpf, 0.1, 0.5);      // freq=0.1 and qfact=0.5
            if (ret  != ESP_OK)
            {
                ESP_LOGE(TAG, "Operation error LPF = %i", ret);
                return;
            }
#if 1
            while(audio_index < audio_total)
            {
				for (int i=audio_index,j=0; (i-audio_index) < SAMPLES_NUM ; i++,j++)
				{
					//d[j] = ((float)audio_buffer[i]/(float)32768);
					d[j] = (float)audio_buffer[i];
				}
				// Process input signal
				ret = dsps_biquad_f32(d, y, N, coeffs_lpf, w_lpf);
				if (ret  != ESP_OK)
				{
					ESP_LOGE(TAG, "Operation error biquad lpf= %i", ret);
					return;
				}

				for (int i=audio_index, j=0 ; (i-audio_index) < SAMPLES_NUM ; i++,j++)
				{
					y[j] = y[j] * 0.5;
					audio_buffer[i] = (int16_t)y[j];
				}
				audio_index += SAMPLES_NUM;
				vTaskDelay((10) / portTICK_PERIOD_MS);
            }
#endif

            audio_index = 0;
            while ((mode == play) && (audio_index < audio_total))
            {
                ret = i2s_write(I2S_NUM_0, audio_buffer + audio_index, FRAME_SIZE, &bytes_write, 100);
                if (ret != ESP_OK) {
                    ESP_LOGE(TAG, "[echo] i2s write failed");
                    abort();
                }
                audio_index += FRAME_SIZE;
            }
           if (mode == play) mode = idle;
            ESP_LOGI(TAG, "play end");
        }
        else
        {
            vTaskDelay((100) / portTICK_PERIOD_MS);  
        }
    }
    vTaskDelete(NULL);
}

void lv_tick_task(void *arg)
{
    while(1) 
    {
        vTaskDelay((10) / portTICK_PERIOD_MS);
        lv_task_handler();        
    }
}

void app_main(void)
{
    /* Initialize I2C 400KHz */
    ESP_ERROR_CHECK(bsp_i2c_init(I2C_NUM_0, 400000));
 
    /* Init TCA9554 */
    ESP_ERROR_CHECK(tca9554_init());
    ext_io_t io_conf = BSP_EXT_IO_DEFAULT_CONFIG();
    ext_io_t io_level = BSP_EXT_IO_DEFAULT_LEVEL();
    ESP_ERROR_CHECK(tca9554_set_configuration(io_conf.val));
    ESP_ERROR_CHECK(tca9554_write_output_pins(io_level.val));

    /* LVGL init */
    lv_init();                  //内核初始化
    lv_port_disp_init();	    //接口初始化
    lv_port_indev_init();       //输入设备初始化
    // lv_port_fs_init();       //文件系统初始化
    lv_port_tick_init();

    es8311_codec_config(AUDIO_SAMPLE_RATE);
    bsp_i2s_init(I2S_NUM_0, 16000);   //config channel_format=mono

    /* Allocate audio buffer */
    audio_buffer = heap_caps_malloc(BUF_SIZE, MALLOC_CAP_SPIRAM); 
    if (NULL == audio_buffer) {
        ESP_LOGE(TAG, "Failed allocate mem for audio buffer.");
        return;
    }

    ESP_LOGI(TAG, "UI init start");
    /* Init UI of example */             // ignore it for now
    ui_record();                             // just to start recording and play recording using display.

    ESP_LOGI(TAG, "UI started");
    xTaskCreate(lv_tick_task, "lv_tick_task", 4096, NULL, 1, NULL);
    xTaskCreate(audio_record_task, "audio_record_task", 4096*5, NULL, 5, NULL);
}

[/Codebox]

Please suggest me some improvements if I am doing anything wrong in LPF implementation. I have tried all the steps mentioned in previous replies and implemented this code so far.

Thanks in advance.