BakaMusicPlayer/Bmp.Core.Lite/Playback/Inputs/DffAudioStream.cs

using System.Runtime.InteropServices;
using System.Text;
using Bmp.Core.Common.Utility;
using Bmp.Core.Lite.Playback.Outputs.NAudioASIO.Originals;
using NAudio.Wave;
using WaveFormat = NAudio.Wave.WaveFormat;

namespace Bmp.Core.Lite.Playback.Inputs;

public class DffAudioStream : DsdAudioStream, IHaveDecoderInfo, IHaveAsioSampleFormat
{
    private const string ID_FRM8 = "FRM8";
    private const string ID_DSD = "DSD ";
    private const string ID_SND = "SND ";
    private const string ID_FS = "FS  ";
    private const string ID_CHNL = "CHNL";
    private const string ID_CMPR = "CMPR";
    private const string ID_DST = "DST ";
    private const string ID_LSCO = "LSCO";
    private const string ID_PROP = "PROP";
    private const string ID_DIIN = "DIIN";
    private const string ID_MARK = "MARK";

    private const int FILE_VERSION = 0x01050000;

    string IHaveDecoderInfo.DecoderName => "DFF";
    string? IHaveDecoderInfo.FileFormat => "V1.5";

    public AsioSampleType? AsioSampleFormat => AsioSampleType.DSDInt8MSB1;

    public static bool IsDffFile(Stream stream)
    {
        if (stream.Length > 4)
        {
            using var binaryReader = new BinaryReader(stream, Encoding.UTF8, true);
            var signatureDSD = Encoding.ASCII.GetString(binaryReader.ReadBytes(4));
            if (signatureDSD == ID_FRM8) return true;
        }
        return false;
    }

    [StructLayout(LayoutKind.Sequential, Pack = 1, CharSet = CharSet.Ansi)]
    public struct ID
    {
        [MarshalAs(UnmanagedType.ByValTStr, SizeConst = 4)]
        public string Value;
    }

    [StructLayout(LayoutKind.Sequential, Pack = 1, CharSet = CharSet.Ansi)]
    public struct Chunk
    {
        [MarshalAs(UnmanagedType.ByValTStr, SizeConst = 4)]
        public string Id;

        private readonly long chunkDataSize;
        public long DataSize => chunkDataSize.NetworkOrderToHostOrder();
    }

    private readonly Stream _underlyingStream;
    private readonly bool _disposeStream;
    private readonly int _fileVersion;
    private readonly int _sampleRate;
    private readonly short _channelCount;
    private readonly IReadOnlyCollection<string> _channelIds;
    private readonly bool _isDstEncoded;
    private readonly short _loudspeakerConfig;
    private readonly long _dataOffset;
    private readonly long _dataSize;

    public DffAudioStream(string urlOrPath) : this(InputSourceProviderLite.ReadContentAsSeekableStream(urlOrPath), true)
    {
    }

    public DffAudioStream(Stream underlyingStream, bool disposeStream)
    {
        _underlyingStream = underlyingStream;
        _disposeStream = disposeStream;

        var ck = new Chunk();
        var sizeOfCk = Marshal.SizeOf<Chunk>();
        var sizeOfId = Marshal.SizeOf<ID>();

        if (underlyingStream.Length < sizeOfCk) throw new InvalidDataException("too small as dff file");
        underlyingStream.ReadStruct(ref ck);
        if (ck.Id != ID_FRM8) throw new InvalidDataException("invalid FRM8 signature");

        var frm8Size = ck.DataSize;
        var id = underlyingStream.ReadStruct<ID>();
        if (id.Value != ID_DSD) throw new InvalidDataException("invalid DSD signature");

        while (_underlyingStream.Position < (frm8Size + sizeOfCk))
        {
            underlyingStream.ReadStruct(ref ck);
            switch ((ck.Id, ck.DataSize))
            {
                case ("FVER", 4):
                    _fileVersion = _underlyingStream.ReadStruct<int>().NetworkOrderToHostOrder();
                    if (_fileVersion != FILE_VERSION) throw new InvalidDataException("invalid File version");
                    continue;

                default:
                    switch (ck.Id)
                    {
                        case ID_PROP:
                            underlyingStream.ReadStruct(ref id);
                            if (id.Value != ID_SND) throw new InvalidDataException("invalid SND signature");
                            var id_prop_end = _underlyingStream.Position - sizeOfId + ck.DataSize;
                            while (_underlyingStream.Position < id_prop_end)
                            {
                                underlyingStream.ReadStruct(ref ck);
                                switch (ck.Id, ck.DataSize)
                                {
                                    case (ID_FS, 4):
                                        _sampleRate = _underlyingStream.ReadStruct<int>().NetworkOrderToHostOrder();
                                        break;

                                    case (ID_LSCO, 2):
                                        _loudspeakerConfig = _underlyingStream.ReadStruct<short>().NetworkOrderToHostOrder();
                                        break;

                                    default:

                                        switch (ck.Id)
                                        {
                                            case ID_CHNL:
                                                _channelCount = _underlyingStream.ReadStruct<short>().NetworkOrderToHostOrder();
                                                _channelIds = Enumerable.Range(0, _channelCount).Select(_ => _underlyingStream.ReadStruct<ID>().Value).ToArray();
                                                break;

                                            case ID_CMPR:
                                                var compressionId = _underlyingStream.ReadStruct<ID>().Value;
                                                _isDstEncoded = compressionId == ID_DST;
                                                var len = _underlyingStream.ReadStruct<byte>();
                                                var text = Encoding.UTF8.GetString(_underlyingStream.ReadBytes(len));
                                                break;

                                            default:
                                                //skip unknown chunk
                                                _underlyingStream.Seek(ck.DataSize, SeekOrigin.Current);
                                                break;
                                        }
                                        break;
                                }

                                //align: pad byte char with value 0, used for making chunks an even length.
                                _underlyingStream.Seek(_underlyingStream.Position % 2, SeekOrigin.Current);
                            }
                            break; //case ID_PROP:

                        case ID_DIIN:
                            var id_diin_end = _underlyingStream.Position - sizeOfId + ck.DataSize;
                            while (_underlyingStream.Position < id_diin_end)
                            {
                                underlyingStream.ReadStruct(ref ck);
                                switch (ck.Id)
                                {
                                    case ID_MARK:
                                        var hours = _underlyingStream.ReadStruct<short>().NetworkOrderToHostOrder();
                                        var minutes = _underlyingStream.ReadStruct<byte>();
                                        var second = _underlyingStream.ReadStruct<byte>();
                                        var samples = _underlyingStream.ReadStruct<uint>().NetworkOrderToHostOrder();
                                        var offset = _underlyingStream.ReadStruct<int>().NetworkOrderToHostOrder();

                                        // 0 TrackStart
                                        // 1 TrackStop
                                        // 2 ProgramStart
                                        // 4 Index  Entry point of an Index
                                        var type = _underlyingStream.ReadStruct<short>().NetworkOrderToHostOrder();

                                        // 0 All channels
                                        var channel = _underlyingStream.ReadStruct<short>().NetworkOrderToHostOrder();

                                        var trackFlags = _underlyingStream.ReadStruct<short>().NetworkOrderToHostOrder();

                                        var textLen = _underlyingStream.ReadStruct<int>().NetworkOrderToHostOrder();
                                        var text = Encoding.UTF8.GetString(_underlyingStream.ReadBytes(textLen));
                                        break;

                                    default:
                                        //skip unknown chunk
                                        _underlyingStream.Seek(ck.DataSize, SeekOrigin.Current);
                                        break;
                                }

                                _underlyingStream.Seek(_underlyingStream.Position % 2, SeekOrigin.Current);
                            }

                            break; // case ID_DIIN:

                        case ID_DSD:
                            _dataOffset = _underlyingStream.Position;
                            _dataSize = ck.DataSize;
                            _underlyingStream.Seek(ck.DataSize, SeekOrigin.Current);
                            continue;

                        default:
                            //skip unknown chunk
                            underlyingStream.Seek(ck.DataSize, SeekOrigin.Current);
                            break;
                    }

                    break;
            }

            //align: pad byte char with value 0, used for making chunks an even length.
            _underlyingStream.Seek(_underlyingStream.Position % 2, SeekOrigin.Current);

            if (_isDstEncoded) throw new NotSupportedException("DST is not support");

            WaveFormat = WaveFormat.CreateCustomFormat(WaveFormatEncoding.Unknown, _sampleRate, _channelCount, _sampleRate / 8 * _channelCount, _channelCount, 1);
        }

        _underlyingStream.Position = _dataOffset;
    }

    protected override void Dispose(bool disposing)
    {
        base.Dispose(disposing);
        if (_disposeStream) _underlyingStream.Dispose();
    }

    public override int Read(byte[] buffer, int offset, int countRequired)
    {
        var mod = countRequired % _channelCount;
        var count = countRequired;
        if (mod != 0) count -= mod;

        var read = _underlyingStream.Read(buffer, offset, count);

        // MSB / LSB Convert?
        //for (var i = 0; i < read; i++) buffer[i] = BitReverseTable[buffer[i]];

        return read;
    }

    public override WaveFormat WaveFormat { get; }
    public override long Length => _dataSize;
    public override long Position { get => _underlyingStream.Position - _dataOffset; set => _underlyingStream.Position = _dataOffset + value - value % _channelCount; }
}