portapack-mayhem/firmware/application/io_wave.cpp

/*
 * Copyright (C) 2016 Jared Boone, ShareBrained Technology, Inc.
 * Copyright (C) 2016 Furrtek
 * Copyright (C) 2024 Mark Thompson
 *
 * This file is part of PortaPack.
 *
 * This program is free software; you can redistribute it and/or modify
 * it under the terms of the GNU General Public License as published by
 * the Free Software Foundation; either version 2, or (at your option)
 * any later version.
 *
 * This program is distributed in the hope that it will be useful,
 * but WITHOUT ANY WARRANTY; without even the implied warranty of
 * MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE.  See the
 * GNU General Public License for more details.
 *
 * You should have received a copy of the GNU General Public License
 * along with this program; see the file COPYING.  If not, write to
 * the Free Software Foundation, Inc., 51 Franklin Street,
 * Boston, MA 02110-1301, USA.
 */

#include "io_wave.hpp"
#include "utility.hpp"

bool WAVFileReader::open(const std::filesystem::path& path) {
    size_t i = 0;
    char ch;
    const uint8_t tag_INAM[4] = {'I', 'N', 'A', 'M'};
    const uint8_t tag_data[4] = {'d', 'a', 't', 'a'};
    struct data_t data_header;
    char title_buffer[32]{0};
    uint32_t riff_size, inam_search_start, title_size;
    size_t search_limit = 0;

    // Already open ?
    if (path.string() == last_path.string()) {
        rewind();
        return true;
    }

    // Reinitialize to avoid old data when switching files
    title_string = "";
    sample_rate_ = 0;
    bytes_per_sample = 0;

    auto error = file_.open(path);

    if (!error.is_valid()) {
        if (!file_.read((void*)&header, sizeof(header)).is_ok())  // Read header (RIFF and WAVE)
            return false;

        // Assuming here that RIFF & WAV & fmt chunk ID's are all correct...
        riff_size = 8 + header.cksize;

        // check for the "data" chunk ID
        if (memcmp(header.data.ckID, tag_data, 4) == 0) {
            data_start = 20 + header.fmt.cksize + 8;
            data_size_ = header.data.cksize;
            inam_search_start = data_start + data_size_;
        } else {
            // data header wasn't where we guessed; skip over one unexpected chunk (perhaps LIST/INFO/INAM)
            inam_search_start = 20 + header.fmt.cksize;
            file_.seek(20 + header.fmt.cksize + 8 + header.data.cksize);
            if (!file_.read((void*)&data_header, sizeof(data_header)).is_ok())
                return false;

            if (memcmp(data_header.ckID, tag_data, 4) == 0) {
                data_start = 20 + header.fmt.cksize + 8 + header.data.cksize + 8;
                data_size_ = data_header.cksize;
            } else
                return false;
        }

        // Look for INAM (title) tag
        if (inam_search_start < riff_size) {
            file_.seek(inam_search_start);
            while (file_.read((void*)&ch, 1).is_ok()) {
                if (ch == tag_INAM[i++]) {
                    if (i == 4) {
                        // Tag found, copy title
                        file_.read((void*)&title_size, sizeof(uint32_t));
                        if (title_size > 32) title_size = 32;
                        file_.read((void*)&title_buffer, title_size);
                        title_string = title_buffer;
                        break;
                    }
                } else {
                    if (ch == tag_INAM[0])
                        i = 1;
                    else
                        i = 0;
                }
                if (search_limit == 256)
                    break;
                else
                    search_limit++;
            }
        }

        sample_rate_ = header.fmt.nSamplesPerSec;
        bytes_per_sample = header.fmt.wBitsPerSample / 8;

        rewind();

        last_path = path;

        return true;
    } else {
        return false;
    }
}

void WAVFileReader::rewind() {
    file_.seek(data_start);
}

std::string WAVFileReader::title() {
    return title_string;
}

uint32_t WAVFileReader::ms_duration() {
    return ::ms_duration(data_size_, sample_rate_, bytes_per_sample);
}

void WAVFileReader::data_seek(const uint64_t Offset) {
    file_.seek(data_start + (Offset * bytes_per_sample));
}

/*int WAVFileReader::seek_mss(const uint16_t minutes, const uint8_t seconds, const uint32_t samples) {
        const auto result = file_.seek(data_start + ((((minutes * 60) + seconds) * sample_rate_) + samples) * bytes_per_sample);

        if (result.is_error())
                return 0;

        return 1;
}*/

uint16_t WAVFileReader::channels() {
    return header.fmt.nChannels;
}

uint32_t WAVFileReader::sample_rate() {
    return sample_rate_;
}

uint32_t WAVFileReader::data_size() {
    return data_size_;
}

uint32_t WAVFileReader::sample_count() {
    return data_size_ / bytes_per_sample;
}

uint16_t WAVFileReader::bits_per_sample() {
    return header.fmt.wBitsPerSample;
}

Optional<File::Error> WAVFileWriter::create(
    const std::filesystem::path& filename,
    size_t sampling_rate_set,
    const std::string& title_set) {
    sampling_rate = sampling_rate_set;
    title = title_set;
    const auto create_error = FileWriter::create(filename);
    if (create_error.is_valid()) {
        return create_error;
    } else {
        return update_header();
    }
}

Optional<File::Error> WAVFileWriter::update_header() {
    header_t header{sampling_rate, (uint32_t)bytes_written_ - sizeof(header_t), info_chunk_size};

    const auto seek_0_result = file_.seek(0);
    if (seek_0_result.is_error()) {
        return seek_0_result.error();
    }

    const auto old_position = seek_0_result.value();

    const auto write_result = file_.write(&header, sizeof(header));
    if (write_result.is_error()) {
        return write_result.error();
    }

    const auto seek_old_result = file_.seek(old_position);
    if (seek_old_result.is_error()) {
        return seek_old_result.error();
    }

    return {};
}

Optional<File::Error> WAVFileWriter::write_tags() {
    tags_t tags{title};

    const auto write_result = file_.write(&tags, sizeof(tags));
    if (write_result.is_error()) {
        return write_result.error();
    }

    info_chunk_size = sizeof(tags);

    return {};
}