Troubleshooting • cant use alsa library on raspberry pi 5

Code:

    printf("alsa start\n");    int err;    snd_pcm_t *capture_handle, *playback_handle;    snd_pcm_hw_params_t *hw_params;    unsigned char *buffer;    int sample_rate = SAMPLE_RATE;    int dir;    snd_pcm_uframes_t frames = 32;    snd_pcm_uframes_t bufferSize, periodSize;    double x_prev = 0.0;    double y_prev = 0.0;    double b0 = 1.0;    double b1 = -0.8;    double a1 = 0.0;    printf("alsa open capture handle\n");    err = snd_pcm_open(&capture_handle, "default", SND_PCM_STREAM_CAPTURE, 0);    if(err < 0)    {        fprintf(stderr, "Capture open error: %s\n", snd_strerror(err));        exit(1);    }    printf("alsa open playback handle\n");    err = snd_pcm_open(&playback_handle, "default", SND_PCM_STREAM_PLAYBACK, 0);    if(err < 0)    {        fprintf(stderr, "Playback open error: %s\n", snd_strerror(err));        exit(1);    }    printf("alsa pcm hw param alloc\n");    snd_pcm_hw_params_alloca(&hw_params);    printf("alsa capture_handle set start\n");    err = snd_pcm_hw_params_any(capture_handle, hw_params);    if (err < 0) {        fprintf(stderr, "snd_pcm_hw_params_any cant set hw params. [%s]\n", snd_strerror(err));        exit(1);    }    err = snd_pcm_hw_params_set_access(capture_handle, hw_params, SND_PCM_ACCESS_RW_INTERLEAVED);    if (err < 0) {        fprintf(stderr, "snd_pcm_hw_params_set_access cant set hw params. [%s]\n", snd_strerror(err));        exit(1);    }    err = snd_pcm_hw_params_set_format(capture_handle, hw_params, SND_PCM_FORMAT_S16_LE);    if (err < 0) {        fprintf(stderr, "snd_pcm_hw_params_set_format cant set hw params. [%s]\n", snd_strerror(err));        exit(1);    }    err = snd_pcm_hw_params_set_channels(capture_handle, hw_params, NUM_CHANNELS);    if (err < 0) {        fprintf(stderr, "snd_pcm_hw_params_set_channels cant set hw params. [%s]\n", snd_strerror(err));        exit(1);    }    err = snd_pcm_hw_params_set_rate_near(capture_handle, hw_params, &sample_rate, &dir);    if (err < 0) {        fprintf(stderr, "snd_pcm_hw_params_set_rate_near cant set hw params. [%s]\n", snd_strerror(err));        exit(1);    }    err = snd_pcm_hw_params_set_buffer_size_near(capture_handle, hw_params, &bufferSize);    if (err < 0) {        fprintf(stderr, "snd_pcm_hw_params_set_buffer_size_near cant set hw params. [%s]\n", snd_strerror(err));        exit(1);    }    err = snd_pcm_hw_params_set_period_size_near(capture_handle, hw_params, &periodSize, &dir);    if (err < 0) {        fprintf(stderr, "snd_pcm_hw_params_set_period_size_near cant set hw params. [%s]\n", snd_strerror(err));        exit(1);    }    err = snd_pcm_hw_params(capture_handle, hw_params);    if (err < 0) {        fprintf(stderr, "alsa cant set hw params. [%s]\n", snd_strerror(err));        exit(1);    }    snd_pcm_hw_params_get_buffer_size(hw_params, &bufferSize);    snd_pcm_hw_params_get_period_size(hw_params, &periodSize, &dir);    printf("Buffer size: %lu frames\n", bufferSize);    printf("Period size: %lu frames\n", periodSize);    printf("alsa playback_handle set start\n");    snd_pcm_hw_params_any(playback_handle, hw_params);    snd_pcm_hw_params_set_access(playback_handle, hw_params, SND_PCM_ACCESS_RW_INTERLEAVED);    snd_pcm_hw_params_set_format(playback_handle, hw_params, SND_PCM_FORMAT_S16_LE);    snd_pcm_hw_params_set_channels(playback_handle, hw_params, NUM_CHANNELS);    snd_pcm_hw_params_set_rate_near(playback_handle, hw_params, &sample_rate, 0);    snd_pcm_hw_params(playback_handle, hw_params);    printf("alsa playback_handle set success\n");    printf("alsa buf malloc\n");    buffer = (unsigned char*)malloc(BUFFER_SIZE*NUM_CHANNELS*2);    while(1)    {        printf("main loop start\n");        err = snd_pcm_readi(capture_handle, buffer, BUFFER_SIZE);        if(err<0)        {            fprintf(stderr, "Capture read error[%d]: %s\n", err, snd_strerror(err));            break;        }        for(int i = 0; i < BUFFER_SIZE * NUM_CHANNELS * 2; i += 2)        {            short sample = ((short)buffer[i + 1] << 8) | buffer[i];            double x = (double)sample / 32768.0;            double y = b0 * x + b1 * x_prev + a1 * y_prev;            x_prev = x;            y_prev = y;            short filter_sample = (short)(y * 32768.0);            buffer[i] = (unsigned char)(filter_sample & 0xFF);            buffer[i+1] = (unsigned char)((filter_sample >> 8) & 0xFF);        }        err = snd_pcm_writei(playback_handle, buffer, BUFFER_SIZE);        if(err < 0)        {            fprintf(stderr, "Playback write error: %s\n", snd_strerror(err));            break;        }    }    free(buffer);    snd_pcm_close(capture_handle);    snd_pcm_close(playback_handle);    exit(0);

Code:

    printf("alsa start\n");    int err;    snd_pcm_t *capture_handle, *playback_handle;    snd_pcm_hw_params_t *hw_params;    unsigned char *buffer;    int sample_rate = SAMPLE_RATE;    double x_prev = 0.0;    double y_prev = 0.0;    double b0 = 1.0;    double b1 = -0.8;    double a1 = 0.0;    printf("alsa open capture handle\n");    err = snd_pcm_open(&capture_handle, "default", SND_PCM_STREAM_CAPTURE, 0);    if(err < 0)    {        fprintf(stderr, "Capture open error: %s\n", snd_strerror(err));        exit(1);    }    printf("alsa open playback handle\n");    err = snd_pcm_open(&playback_handle, "default", SND_PCM_STREAM_PLAYBACK, 0);    if(err < 0)    {        fprintf(stderr, "Playback open error: %s\n", snd_strerror(err));        exit(1);    }    printf("alsa pcm hw param alloc\n");    snd_pcm_hw_params_alloca(&hw_params);    printf("alsa capture_handle set start\n");    err = snd_pcm_hw_params_any(capture_handle, hw_params);    if (err < 0) {        fprintf(stderr, "snd_pcm_hw_params_any cant set hw params. [%s]\n", snd_strerror(err));        exit(1);    }    err = snd_pcm_hw_params_set_access(capture_handle, hw_params, SND_PCM_ACCESS_RW_INTERLEAVED);    if (err < 0) {        fprintf(stderr, "snd_pcm_hw_params_set_access cant set hw params. [%s]\n", snd_strerror(err));        exit(1);    }    err = snd_pcm_hw_params_set_format(capture_handle, hw_params, SND_PCM_FORMAT_S16_LE);    if (err < 0) {        fprintf(stderr, "snd_pcm_hw_params_set_format cant set hw params. [%s]\n", snd_strerror(err));        exit(1);    }    err = snd_pcm_hw_params_set_channels(capture_handle, hw_params, NUM_CHANNELS);    if (err < 0) {        fprintf(stderr, "snd_pcm_hw_params_set_channels cant set hw params. [%s]\n", snd_strerror(err));        exit(1);    }    err = snd_pcm_hw_params_set_rate_near(capture_handle, hw_params, &sample_rate, 0);    if (err < 0) {        fprintf(stderr, "snd_pcm_hw_params_set_rate_near cant set hw params. [%s]\n", snd_strerror(err));        exit(1);    }    err = snd_pcm_hw_params(capture_handle, hw_params);    if (err < 0) {        fprintf(stderr, "alsa cant set hw params. [%s]\n", snd_strerror(err));        exit(1);    }    printf("alsa playback_handle set start\n");    err = snd_pcm_hw_params_any(playback_handle, hw_params);    if (err < 0) {        fprintf(stderr, "playback_handle cant set hw params. [%s]\n", snd_strerror(err));        exit(1);    }    err = snd_pcm_hw_params_set_access(playback_handle, hw_params, SND_PCM_ACCESS_RW_INTERLEAVED);    if (err < 0) {        fprintf(stderr, "snd_pcm_hw_params_set_access cant set hw params. [%s]\n", snd_strerror(err));        exit(1);    }    err = snd_pcm_hw_params_set_format(playback_handle, hw_params, SND_PCM_FORMAT_S16_LE);    if (err < 0) {        fprintf(stderr, "snd_pcm_hw_params_set_format cant set hw params. [%s]\n", snd_strerror(err));        exit(1);    }    err = snd_pcm_hw_params_set_channels(playback_handle, hw_params, NUM_CHANNELS);    if (err < 0) {        fprintf(stderr, "snd_pcm_hw_params_set_channels cant set hw params. [%s]\n", snd_strerror(err));        exit(1);    }    err = snd_pcm_hw_params_set_rate_near(playback_handle, hw_params, &sample_rate, 0);    if (err < 0) {        fprintf(stderr, "snd_pcm_hw_params_set_rate_near cant set hw params. [%s]\n", snd_strerror(err));        exit(1);    }    err = snd_pcm_hw_params(playback_handle, hw_params);    if (err < 0) {        fprintf(stderr, "alsa cant set hw params. [%s]\n", snd_strerror(err));        exit(1);    }    printf("alsa playback_handle set success\n");    printf("alsa buf malloc\n");    buffer = (unsigned char*)malloc(BUFFER_SIZE*NUM_CHANNELS*2);    while(1)    {        printf("main loop start\n");        err = snd_pcm_readi(capture_handle, buffer, BUFFER_SIZE);        if(err<0)        {            fprintf(stderr, "Capture read error[%d]: %s\n", err, snd_strerror(err));            break;        }        for(int i = 0; i < BUFFER_SIZE * NUM_CHANNELS * 2; i += 2)        {            short sample = ((short)buffer[i + 1] << 8) | buffer[i];            double x = (double)sample / 32768.0;            double y = b0 * x + b1 * x_prev + a1 * y_prev;            x_prev = x;            y_prev = y;            short filter_sample = (short)(y * 32768.0);            buffer[i] = (unsigned char)(filter_sample & 0xFF);            buffer[i+1] = (unsigned char)((filter_sample >> 8) & 0xFF);        }        err = snd_pcm_writei(playback_handle, buffer, BUFFER_SIZE);        if(err < 0)        {            fprintf(stderr, "Playback write error: %s\n", snd_strerror(err));            break;        }    }    free(buffer);    snd_pcm_close(capture_handle);    snd_pcm_close(playback_handle);    exit(0);    

Code:

# aplay -l**** List of PLAYBACK Hardware Devices ****card 0: sndrpihifiberry [snd_rpi_hifiberry_dacplusadcpro], device 0: HiFiBerry DAC+ADC Pro HiFi multicodec-0 [HiFiBerry DAC+ADC Pro HiFi multicodec-0]  Subdevices: 1/1  Subdevice #0: subdevice #0# arecord -l**** List of CAPTURE Hardware Devices ****card 0: sndrpihifiberry [snd_rpi_hifiberry_dacplusadcpro], device 0: HiFiBerry DAC+ADC Pro HiFi multicodec-0 [HiFiBerry DAC+ADC Pro HiFi multicodec-0]  Subdevices: 1/1  Subdevice #0: subdevice #0