File content as of revision 2:c939d0501184:

#include "Recorder.h"

#define RAM_TOTAL 2048

AnalogOut dacout(p18);
AnalogIn adcin(p20);
DigitalOut led_play_ok(LED1);
DigitalOut led_rec_ok(LED2);

Ticker ticker;
extern float *buffer;
int rp = 0;
int wp = 0;
int dropout = 0;

#define WAVFILE_ERROR_PRINT(RESULT) \
    do { \
        WavFileResult R = RESULT; \
        if (R != WavFileResultOK) { \
            char wavfile_error_print_text[BUFSIZ]; \
            wavfile_result_string(R, wavfile_error_print_text, sizeof(wavfile_error_print_text)); \
            printf("%s (code=%d)\r\n", wavfile_error_print_text, R); \
            return 1; \
        } \
    } while(0)


void tickplay(void)
{
    /*
     * Check the play underflow
     */
    if (rp != wp) {
        dacout = buffer[rp];
        rp = (rp + 1) & (RAM_TOTAL - 1);
    } else {
        dropout++;
    }
    led_play_ok = !led_play_ok;
}

void tickrec(void)
{
    int np = (wp + 1) & (RAM_TOTAL - 1);
    if (np != rp) {
        buffer[wp] = adcin;
        wp = np;
    } else {
        dropout++;
    }
    led_rec_ok = !led_rec_ok;
}

int play(const char *filename)
{
    WavFileResult result;
    wavfile_info_t info;
    wavfile_data_t data;

    WAVFILE *wf = wavfile_open(filename, WavFileModeRead, &result);
    WAVFILE_ERROR_PRINT(result);
    WAVFILE_ERROR_PRINT(wavfile_read_info(wf, &info));

    //printf("[PLAY:%s]\r\n", filename);
    //printf("\tWAVFILE_INFO_AUDIO_FORMAT(&info)    = %d\r\n", WAVFILE_INFO_AUDIO_FORMAT(&info));
    //printf("\tWAVFILE_INFO_NUM_CHANNELS(&info)    = %d\r\n", WAVFILE_INFO_NUM_CHANNELS(&info));
    //printf("\tWAVFILE_INFO_SAMPLE_RATE(&info)     = %d\r\n", WAVFILE_INFO_SAMPLE_RATE(&info));
    //printf("\tWAVFILE_INFO_BYTE_RATE(&info)       = %d\r\n", WAVFILE_INFO_BYTE_RATE(&info));
    //printf("\tWAVFILE_INFO_BLOCK_ALIGN(&info)     = %d\r\n", WAVFILE_INFO_BLOCK_ALIGN(&info));
    //printf("\tWAVFILE_INFO_BITS_PER_SAMPLE(&info) = %d\r\n", WAVFILE_INFO_BITS_PER_SAMPLE(&info));

    const int interval_us =  1000000 / WAVFILE_INFO_SAMPLE_RATE(&info);

    rp = 0;
    wp = 0;
    dropout = 0;
    ticker.attach_us(tickplay, interval_us);
    while (1) {
        int np = (wp + 1) & (RAM_TOTAL - 1);
        while (np == rp) {
            wait_us(1);
        }
        WAVFILE_ERROR_PRINT(wavfile_read_data(wf, &data));
        if (WAVFILE_DATA_IS_END_OF_DATA(&data)) {
            break;
        }
        buffer[wp] = WAVFILE_DATA_CHANNEL_DATA(&data, 0);
        wp = np;
    }
    ticker.detach();
    dacout = 0.5;
    led_play_ok = 0;
    //printf("\t-- Play done. (dropout=%d) --\r\n", dropout);

    WAVFILE_ERROR_PRINT(wavfile_close(wf));
    return 0;
}

int rec(const char *filename, const int nsec)
{
    WavFileResult result;
    wavfile_info_t info;
    wavfile_data_t data;

    WAVFILE_INFO_AUDIO_FORMAT(&info)    = 1;
    WAVFILE_INFO_NUM_CHANNELS(&info)    = 1;
    WAVFILE_INFO_SAMPLE_RATE(&info)     = 11025;
    WAVFILE_INFO_BYTE_RATE(&info)       = 22050;
    WAVFILE_INFO_BLOCK_ALIGN(&info)     = 2;
    WAVFILE_INFO_BITS_PER_SAMPLE(&info) = 16;

    WAVFILE *wf = wavfile_open(filename, WavFileModeWrite, &result);
    WAVFILE_ERROR_PRINT(result);
    WAVFILE_ERROR_PRINT(wavfile_write_info(wf, &info));

    //printf("[REC:%s]\r\n", filename);
    //printf("\tWAVFILE_INFO_AUDIO_FORMAT(&info)    = %d\r\n", WAVFILE_INFO_AUDIO_FORMAT(&info));
    //printf("\tWAVFILE_INFO_NUM_CHANNELS(&info)    = %d\r\n", WAVFILE_INFO_NUM_CHANNELS(&info));
    //printf("\tWAVFILE_INFO_SAMPLE_RATE(&info)     = %d\r\n", WAVFILE_INFO_SAMPLE_RATE(&info));
    //printf("\tWAVFILE_INFO_BYTE_RATE(&info)       = %d\r\n", WAVFILE_INFO_BYTE_RATE(&info));
    //printf("\tWAVFILE_INFO_BLOCK_ALIGN(&info)     = %d\r\n", WAVFILE_INFO_BLOCK_ALIGN(&info));
    //printf("\tWAVFILE_INFO_BITS_PER_SAMPLE(&info) = %d\r\n", WAVFILE_INFO_BITS_PER_SAMPLE(&info));

    const int interval_us =  1000000 / WAVFILE_INFO_SAMPLE_RATE(&info);
    const unsigned int samples_for_nsec = WAVFILE_INFO_SAMPLE_RATE(&info) * nsec;

    rp = 0;
    wp = 0;
    dropout = 0;
    unsigned int count = 0;
    ticker.attach_us(tickrec, interval_us);
    WAVFILE_DATA_NUM_CHANNELS(&data) = 1;
    while (1) {
        while (rp == wp) {
            wait_us(1);
        }

        WAVFILE_DATA_CHANNEL_DATA(&data, 0) = buffer[rp];
        rp = (rp + 1) & (RAM_TOTAL - 1);
        WAVFILE_ERROR_PRINT(wavfile_write_data(wf, &data));

        count++;
        if (count > samples_for_nsec) {
            break;
        }
    }
    ticker.detach();
    led_rec_ok = 0;
    //printf("\t-- Rec done. (dropout=%d) --\r\n", dropout);

    WAVFILE_ERROR_PRINT(wavfile_close(wf));
    return 0;
}