waveaudiostream.cpp

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#include "./waveaudiostream.h"
 
#include "../mpegaudio/mpegaudioframestream.h"
 
#include "../exceptions.h"
#include "../mediaformat.h"
 
#include <c++utilities/conversion/stringconversion.h>
#include <c++utilities/io/binaryreader.h>
 
using namespace std;
using namespace CppUtilities;
 
namespace TagParser {


std::uint64_t WaveFormatHeader::parse(CppUtilities::BinaryReader &reader, std::uint64_t maxSize, Diagnostics &diag)
{
    uint64_t bytesRead = 0;
    if (maxSize < 16) {
        diag.emplace_back(DiagLevel::Warning, "\"fmt \" segment is truncated.", "parsing WAVE format header");
        return bytesRead;
    }
 
    formatTag = reader.readUInt16LE();
    channelCount = reader.readUInt16LE();
    sampleRate = reader.readUInt32LE();
    bytesPerSecond = reader.readUInt32LE();
    chunkSize = reader.readUInt16LE();
    bitsPerSample = reader.readUInt16LE();
    bytesRead = 16;
 
    // read extended header unless format is PCM
    if (formatTag == 0x0001u || formatTag == 0x0003u) {
        return bytesRead;
    }
    if ((maxSize -= 16) < 2) {
        diag.emplace_back(DiagLevel::Warning, "\"fmt \" segment is truncated (extended header missing).", "parsing WAVE format header");
        return bytesRead;
    }
    const auto extensionSize = reader.readUInt16LE();
    bytesRead += 2;
    if ((maxSize -= 2) < 2) {
        diag.emplace_back(DiagLevel::Warning, "\"fmt \" segment is truncated (extended header truncated).", "parsing WAVE format header");
        return bytesRead;
    }
 
    // skip extended header unless format is "WAVE_FORMAT_EXTENSIBLE"
    if (formatTag != 65534) {
        reader.stream()->seekg(extensionSize, ios_base::cur);
        bytesRead += extensionSize;
        return bytesRead;
    }
 
    // read extended header for "WAVE_FORMAT_EXTENSIBLE"
    if (extensionSize != 22) {
        diag.emplace_back(DiagLevel::Warning, "\"fmt \" extended header has unexptected size.", "parsing WAVE format header");
        return bytesRead;
    }
    bitsPerSample = reader.readUInt16LE();
    channelMask = reader.readUInt32LE();
    guid1 = reader.readUInt64BE();
    guid2 = reader.readUInt64BE();
    return bytesRead += 22;
}

MediaFormat WaveFormatHeader::format() const
{
    switch (formatTag) {
    case 0x0001u:
        return MediaFormat(GeneralMediaFormat::Pcm, SubFormats::PcmIntLe);
    case 0x0003u:
        return MediaFormat(GeneralMediaFormat::Pcm, SubFormats::PcmFloatIeee);
    case 0x0050u:
        return MediaFormat(GeneralMediaFormat::Mpeg1Audio, SubFormats::Mpeg1Layer2);
    case 0x0055u:
        return MediaFormat(GeneralMediaFormat::Mpeg1Audio, SubFormats::Mpeg1Layer3);
    default:
        switch (guid2) {
        case 0x000800000aa00389b71:
            switch (guid1) {
            case 0x0100000000001000ul:
                return MediaFormat(GeneralMediaFormat::Pcm, SubFormats::PcmIntLe);
            case 0x0300000000001000ul:
                return MediaFormat(GeneralMediaFormat::Pcm, SubFormats::PcmFloatIeee);
            }
            break;
        }
        return GeneralMediaFormat::Unknown;
    }
}


WaveAudioStream::WaveAudioStream(iostream &stream, std::uint64_t startOffset)
    : AbstractTrack(stream, startOffset)
    , m_dataOffset(0)
{
    m_mediaType = MediaType::Audio;
}

WaveAudioStream::~WaveAudioStream()
{
}
 
TrackType WaveAudioStream::type() const
{
    return TrackType::WaveAudioStream;
}

void WaveAudioStream::addInfo(const WaveFormatHeader &waveHeader, AbstractTrack &track)
{
    track.m_format += waveHeader.format();
    track.m_formatId = numberToString(waveHeader.formatTag);
    track.m_channelCount = waveHeader.channelCount;
    track.m_samplingFrequency = waveHeader.sampleRate;
    track.m_bytesPerSecond = waveHeader.bytesPerSecond;
    track.m_chunkSize = waveHeader.chunkSize;
    track.m_bitsPerSample = waveHeader.bitsPerSample;
    track.m_bitrate = waveHeader.bitrate();
}
 
void WaveAudioStream::internalParseHeader(Diagnostics &diag, AbortableProgressFeedback &progress)
{
    CPP_UTILITIES_UNUSED(progress)
 
    const string context("parsing RIFF/WAVE header");
    if (!m_istream) {
        throw NoDataFoundException();
    }
    if (m_reader.readUInt32BE() != 0x52494646u) {
        throw NoDataFoundException();
    }
    m_istream->seekg(static_cast<streamoff>(m_startOffset + 8));
    if (m_reader.readUInt32BE() != 0x57415645u) {
        throw NoDataFoundException();
    }
    while (!m_dataOffset) {
        const auto segmentId = m_reader.readUInt32BE();
        auto restHeaderLen = static_cast<std::uint64_t>(m_reader.readUInt32LE());
        switch (segmentId) {
        case 0x666D7420u: { // format segment
            WaveFormatHeader waveHeader;
            const auto bytesRead = waveHeader.parse(m_reader, restHeaderLen, diag);
            addInfo(waveHeader, *this);
            restHeaderLen -= bytesRead;
        } break;
        case 0x64617461u: // data segment
            m_dataOffset = static_cast<std::uint64_t>(m_istream->tellg());
            m_size = restHeaderLen;
            m_sampleCount = m_size / m_chunkSize;
            m_duration = TimeSpan::fromSeconds(static_cast<double>(m_sampleCount) / static_cast<double>(m_samplingFrequency));
            break;
        default:;
        }
        m_istream->seekg(static_cast<std::streamoff>(restHeaderLen), ios_base::cur);
    }
    if (m_format.general != GeneralMediaFormat::Mpeg1Audio || !m_dataOffset) {
        return;
    }
    m_istream->seekg(static_cast<streamoff>(m_dataOffset));
    MpegAudioFrame frame;
    frame.parseHeader(m_reader, diag);
    MpegAudioFrameStream::addInfo(frame, *this);
    m_bitrate = frame.isXingFramefieldPresent()
        ? ((static_cast<double>(m_size) * 8.0)
              / (static_cast<double>(frame.xingFrameCount() * frame.sampleCount()) / static_cast<double>(frame.samplingFrequency())) / 1024.0)
        : frame.bitrate();
    m_bytesPerSecond = static_cast<std::uint32_t>(m_bitrate * 125);
    m_duration = TimeSpan::fromSeconds(static_cast<double>(m_size) / (m_bitrate * 128.0));
}
 
} // namespace TagParser