serenity/Libraries/LibAudio/WavLoader.cpp

/*
 * Copyright (c) 2018-2020, Andreas Kling <kling@serenityos.org>
 * All rights reserved.
 *
 * Redistribution and use in source and binary forms, with or without
 * modification, are permitted provided that the following conditions are met:
 *
 * 1. Redistributions of source code must retain the above copyright notice, this
 *    list of conditions and the following disclaimer.
 *
 * 2. Redistributions in binary form must reproduce the above copyright notice,
 *    this list of conditions and the following disclaimer in the documentation
 *    and/or other materials provided with the distribution.
 *
 * THIS SOFTWARE IS PROVIDED BY THE COPYRIGHT HOLDERS AND CONTRIBUTORS "AS IS"
 * AND ANY EXPRESS OR IMPLIED WARRANTIES, INCLUDING, BUT NOT LIMITED TO, THE
 * IMPLIED WARRANTIES OF MERCHANTABILITY AND FITNESS FOR A PARTICULAR PURPOSE ARE
 * DISCLAIMED. IN NO EVENT SHALL THE COPYRIGHT HOLDER OR CONTRIBUTORS BE LIABLE
 * FOR ANY DIRECT, INDIRECT, INCIDENTAL, SPECIAL, EXEMPLARY, OR CONSEQUENTIAL
 * DAMAGES (INCLUDING, BUT NOT LIMITED TO, PROCUREMENT OF SUBSTITUTE GOODS OR
 * SERVICES; LOSS OF USE, DATA, OR PROFITS; OR BUSINESS INTERRUPTION) HOWEVER
 * CAUSED AND ON ANY THEORY OF LIABILITY, WHETHER IN CONTRACT, STRICT LIABILITY,
 * OR TORT (INCLUDING NEGLIGENCE OR OTHERWISE) ARISING IN ANY WAY OUT OF THE USE
 * OF THIS SOFTWARE, EVEN IF ADVISED OF THE POSSIBILITY OF SUCH DAMAGE.
 */

#include <AK/NumericLimits.h>
#include <AK/OwnPtr.h>
#include <LibAudio/Buffer.h>
#include <LibAudio/WavLoader.h>
#include <LibCore/File.h>
#include <LibCore/IODeviceStreamReader.h>

namespace Audio {

WavLoaderPlugin::WavLoaderPlugin(const StringView& path)
    : m_file(Core::File::construct(path))
{
    if (!m_file->open(Core::IODevice::ReadOnly)) {
        m_error_string = String::formatted("Can't open file: {}", m_file->error_string());
        return;
    }

    valid = parse_header();
    if (!valid)
        return;

    m_resampler = make<ResampleHelper>(m_sample_rate, 44100);
}

WavLoaderPlugin::WavLoaderPlugin(const ByteBuffer& buffer)
{
    m_stream = make<InputMemoryStream>(buffer);
    if (!m_stream) {
        m_error_string = String::formatted("Can't open memory stream");
        return;
    }

    valid = parse_header();
    if (!valid)
        return;

    m_resampler = make<ResampleHelper>(m_sample_rate, 44100);
}

bool WavLoaderPlugin::sniff()
{
    return valid;
}

RefPtr<Buffer> WavLoaderPlugin::get_more_samples(size_t max_bytes_to_read_from_input)
{
#ifdef AWAVLOADER_DEBUG
    dbgln("Read WAV of format PCM with num_channels {} sample rate {}, bits per sample {}", m_num_channels, m_sample_rate, m_bits_per_sample);
#endif
    size_t samples_to_read = static_cast<int>(max_bytes_to_read_from_input) / (m_num_channels * (m_bits_per_sample / 8));
    RefPtr<Buffer> buffer;
    if (m_file) {
        auto raw_samples = m_file->read(max_bytes_to_read_from_input);
        if (raw_samples.is_empty())
            return nullptr;
        buffer = Buffer::from_pcm_data(raw_samples, *m_resampler, m_num_channels, m_bits_per_sample);
    } else {
        buffer = Buffer::from_pcm_stream(*m_stream, *m_resampler, m_num_channels, m_bits_per_sample, samples_to_read);
    }
    //Buffer contains normalized samples, but m_loaded_samples should contain the amount of actually loaded samples
    m_loaded_samples += samples_to_read;
    m_loaded_samples = min(m_total_samples, m_loaded_samples);
    return buffer;
}

void WavLoaderPlugin::seek(const int position)
{
    if (position < 0 || position > m_total_samples)
        return;

    m_loaded_samples = position;
    size_t byte_position = position * m_num_channels * (m_bits_per_sample / 8);

    if (m_file)
        m_file->seek(byte_position);
    else
        m_stream->seek(byte_position);
}

void WavLoaderPlugin::reset()
{
    seek(0);
}

bool WavLoaderPlugin::parse_header()
{
    OwnPtr<Core::IODeviceStreamReader> file_stream;
    bool ok = true;

    if (m_file)
        file_stream = make<Core::IODeviceStreamReader>(*m_file);

    auto read_u8 = [&]() -> u8 {
        u8 value;
        if (m_file) {
            *file_stream >> value;
            if (file_stream->handle_read_failure())
                ok = false;
        } else {
            *m_stream >> value;
            if (m_stream->has_any_error())
                ok = false;
        }
        return value;
    };

    auto read_u16 = [&]() -> u16 {
        u16 value;
        if (m_file) {
            *file_stream >> value;
            if (file_stream->handle_read_failure())
                ok = false;
        } else {
            *m_stream >> value;
            if (m_stream->has_any_error())
                ok = false;
        }
        return value;
    };

    auto read_u32 = [&]() -> u32 {
        u32 value;
        if (m_file) {
            *file_stream >> value;
            if (file_stream->handle_read_failure())
                ok = false;
        } else {
            *m_stream >> value;
            if (m_stream->has_any_error())
                ok = false;
        }
        return value;
    };

#define CHECK_OK(msg)                                                      \
    do {                                                                   \
        if (!ok) {                                                         \
            m_error_string = String::formatted("Parsing failed: {}", msg); \
            return {};                                                     \
        }                                                                  \
    } while (0);

    u32 riff = read_u32();
    ok = ok && riff == 0x46464952; // "RIFF"
    CHECK_OK("RIFF header");

    u32 sz = read_u32();
    ok = ok && sz < 1024 * 1024 * 1024; // arbitrary
    CHECK_OK("File size");
    ASSERT(sz < 1024 * 1024 * 1024);

    u32 wave = read_u32();
    ok = ok && wave == 0x45564157; // "WAVE"
    CHECK_OK("WAVE header");

    u32 fmt_id = read_u32();
    ok = ok && fmt_id == 0x20746D66; // "FMT"
    CHECK_OK("FMT header");

    u32 fmt_size = read_u32();
    ok = ok && fmt_size == 16;
    CHECK_OK("FMT size");
    ASSERT(fmt_size == 16);

    u16 audio_format = read_u16();
    CHECK_OK("Audio format");     // incomplete read check
    ok = ok && audio_format == 1; // WAVE_FORMAT_PCM
    ASSERT(audio_format == 1);
    CHECK_OK("Audio format"); // value check

    m_num_channels = read_u16();
    ok = ok && (m_num_channels == 1 || m_num_channels == 2);
    CHECK_OK("Channel count");

    m_sample_rate = read_u32();
    CHECK_OK("Sample rate");

    read_u32();
    CHECK_OK("Byte rate");

    read_u16();
    CHECK_OK("Block align");

    m_bits_per_sample = read_u16();
    CHECK_OK("Bits per sample"); // incomplete read check
    ok = ok && (m_bits_per_sample == 8 || m_bits_per_sample == 16 || m_bits_per_sample == 24);
    ASSERT(m_bits_per_sample == 8 || m_bits_per_sample == 16 || m_bits_per_sample == 24);
    CHECK_OK("Bits per sample"); // value check

    // Read chunks until we find DATA
    bool found_data = false;
    u32 data_sz = 0;
    u8 search_byte = 0;
    while (true) {
        search_byte = read_u8();
        CHECK_OK("Reading byte searching for data");
        if (search_byte != 0x64) //D
            continue;

        search_byte = read_u8();
        CHECK_OK("Reading next byte searching for data");
        if (search_byte != 0x61) //A
            continue;

        u16 search_remaining = read_u16();
        CHECK_OK("Reading remaining bytes searching for data");
        if (search_remaining != 0x6174) //TA
            continue;

        data_sz = read_u32();
        found_data = true;
        break;
    }

    ok = ok && found_data;
    CHECK_OK("Found no data chunk");
    ASSERT(found_data);

    ok = ok && data_sz < INT32_MAX;
    CHECK_OK("Data was too large");

    int bytes_per_sample = (m_bits_per_sample / 8) * m_num_channels;
    m_total_samples = data_sz / bytes_per_sample;

    return true;
}

ResampleHelper::ResampleHelper(double source, double target)
    : m_ratio(source / target)
{
}

void ResampleHelper::process_sample(double sample_l, double sample_r)
{
    m_last_sample_l = sample_l;
    m_last_sample_r = sample_r;
    m_current_ratio += 1;
}

bool ResampleHelper::read_sample(double& next_l, double& next_r)
{
    if (m_current_ratio > 0) {
        m_current_ratio -= m_ratio;
        next_l = m_last_sample_l;
        next_r = m_last_sample_r;
        return true;
    }

    return false;
}

}