MuditaOS/module-audio/Audio/decoder/decoderWAV.cpp

/*
 *  @file decoderWAV.cpp
 *  @author Mateusz Piesta (mateusz.piesta@mudita.com)
 *  @date 06.04.19
 *  @brief 
 *  @copyright Copyright (C) 2019 mudita.com
 *  @details
 */

#include "decoderWAV.hpp"

namespace audio {

    decoderWAV::decoderWAV(const char *fileName) :
            decoder(fileName),
            tag(std::make_unique<Tags>()) {

        if (fd == NULL) {
            return;
        }

        if (vfs.fread(&waveHeader, 1, sizeof(waveHeader), fd) != sizeof(WAVE_FormatTypeDef)) {
            return;
        }

        //TODO:M.P; implement support for sample size different than 16bit
        //pcmsamplesbuffer.reserve(1024);

        tag->total_duration_s = (fileSize - sizeof(WAVE_FormatTypeDef)) / waveHeader.ByteRate;
        tag->duration_min = tag->total_duration_s / 60;
        tag->duration_hour = tag->duration_min / 60;
        tag->duration_sec = tag->total_duration_s % 60;
        tag->sample_rate = waveHeader.SampleRate;
        tag->num_channel = waveHeader.NbrChannels;

        sampleRate = waveHeader.SampleRate;
        bitsPerSample = waveHeader.BitPerSample;
        chanNumber = waveHeader.NbrChannels;
    }

    std::unique_ptr<Tags> decoderWAV::fetchTags() {

        tag->filePath.append(filePath);
        auto pos = filePath.rfind("/");
        if (pos == std::string::npos) {
            tag->title.append(filePath);
        } else {
            tag->title.append(&filePath[pos + 1]);
        }

        return std::make_unique<Tags>(*tag);
    }

    uint32_t decoderWAV::decode(uint32_t samplesToRead, int16_t *pcmData) {
        uint32_t samples_read = 0;

/* TODO:M.P; implement support for sample size different than 16bit
    if(samplesToRead > pcmsamplesbuffer.max_size()){
        pcmsamplesbuffer.resize(samplesToRead);
    }*/

        switch (bitsPerSample) {
            case 8:
                //TODO:M.P not supported
                break;

            case 16:
                samples_read = vfs.fread(pcmData, sizeof(int16_t), samplesToRead, fd);
                break;

            case 24:
                //TODO:M.P not supported
                break;

            case 32:
                //TODO:M.P not supported
                break;

        }

        if (samples_read) {
            /* Calculate frame duration in seconds */
            position += (float) ((float) (chanNumber == 2 ? samplesToRead / chanNumber : samplesToRead) /
                                 (float) (sampleRate));
        }

        return samples_read;
    }

    void decoderWAV::setPosition(float pos) {

        vfs.fseek(fd, (fileSize * pos) + sizeof(WAVE_FormatTypeDef), SEEK_SET);
        // Calculate new position
        position = (float) ((float) (vfs.ftell(fd) / sizeof(int16_t) / chanNumber) / (float) (sampleRate));

    }

}