Ejemplo n.º 1
0
 public Simulated WorkWith(float roomSize, float[] samples)
 {
     Position = position * roomSize;
     Distance = Position.Length();
     Samples  = FastConvolver.Convolve(this.samples, samples);
     return(this);
 }
Ejemplo n.º 2
0
 /// <summary>
 /// Constructs a benchmark for Cavern's <see cref="FastConvolver"/> filter.
 /// </summary>
 public Convolution(int length)
 {
     this.length = length;
     filter      = new FastConvolver(new float[length]);
 }
Ejemplo n.º 3
0
        static void Main(string[] args)
        {
            // Find where this executable is launched from
            string[] cargs = Environment.GetCommandLineArgs();
            _thisFolder = Path.GetDirectoryName(cargs[0]);
            if (String.IsNullOrEmpty(_thisFolder))
            {
                _thisFolder = Environment.CurrentDirectory;
            }

            string appData = Environment.GetFolderPath(Environment.SpecialFolder.CommonApplicationData);
            _impulsesFolder = Path.GetFullPath(Path.Combine(appData, "InguzEQ" + slash + "Impulses" + slash));

            string[] inFiles = new string[4];
            string inL = "";
            string inR = "";
            if (!DisplayInfo())
            {
                return;
            }

            bool ok = (args.Length > 0);
            bool longUsage = false;

            for (int j = 0; ok && j < args.Length; j++)
            {
                string arg = args[j];
                switch (args[j].ToUpperInvariant())
                {
                    case "/?":
                    case "-?":
                    case "/H":
                    case "/HELP":
                        ok = false;
                        longUsage = true;
                        break;

                    case "/L":
                    case "/0":
                        inFiles[0] = args[++j];
                        _nInFiles = Math.Max(_nInFiles, 1);
                        break;

                    case "/R":
                    case "/1":
                        inFiles[1] = args[++j];
                        _nInFiles = Math.Max(_nInFiles, 2);
                        break;

                    case "/2":
                        inFiles[2] = args[++j];
                        _nInFiles = Math.Max(_nInFiles, 3);
                        break;
                    case "/3":
                        inFiles[3] = args[++j];
                        _nInFiles = Math.Max(_nInFiles, 4);
                        break;

                    case "/LENGTH":
                        _filterLen = int.Parse(args[++j], CultureInfo.InvariantCulture);
                        if (_filterLen < 16)
                        {
                            throw new Exception("Length is too small.");
                        }
                        break;

                    case "/DBL":
                        _dbl = true;
                        break;

                    case "/PCM":
                        _pcm = true;
                        break;

                    case "/NODRC":
                        _noDRC = true;
                        break;

                    case "/NOSKEW":
                        _noSkew = true;
                        break;

                    case "/NONORM":
                        // No normalization of the impulse response (undocumented)
                        _noNorm = true;
                        break;

                    case "/SPLIT":
                        _split = true;
                        break;

                    case "/COPY":
                        _copy = true;
                        break;

                    case "/GAIN":
                        _gain = double.Parse(args[++j], CultureInfo.InvariantCulture);
                        break;

                    case "/ALL":
                        // Returns negative-time components as part of the impulse response
                        // (experimental, to be used for THD measurement)
                        _returnAll = true;
                        break;

                    case "/POWER":
                        // Raises sweep to power n
                        // (experimental, to be used for THD measurement)
                        _power = int.Parse(args[++j], CultureInfo.InvariantCulture);
                        break;

                    case "/FMIN":
                        // (experimental, i.e. broken)
                        _fmin = int.Parse(args[++j], CultureInfo.InvariantCulture);
                        _fminSpecified = true;
                        break;

                    case "/FMAX":
                        // (experimental, i.e. broken)
                        _fmax = int.Parse(args[++j], CultureInfo.InvariantCulture);
                        _fmaxSpecified = true;
                        break;

                    case "/DIRECT":
                        // Create filtered (direct-sound) filters
                        _doDirectFilters = true;
                        break;

                    case "/NOSUB":
                        // Don't apply subsonic filter to the impulse response
                        _noSubsonicFilter = true;
                        break;

                    case "/NOOVER":
                        // Don't override DRC's settings for filter type and length
                        _noOverrideDRC = true;
                        break;

                    case "/KEEPTEMP":
                        // Undocumented
                        _keepTempFiles = true;
                        break;

                    case "/REFCH":
                        // Override the reference-channel detection
                        _refchannel = int.Parse(args[++j], CultureInfo.InvariantCulture);
                        if (_refchannel<0 || _refchannel > _nInFiles - 1)
                        {
                            throw new Exception(String.Format("RefCh can only be from 0 to {0}.", _nInFiles-1));
                        }
                        break;

                    case "/ENV":
                        // Undocumented.  Save the Hilbert envelope
                        _env = true;
                        break;

                    case "-":
                        // ignore
                        break;

                    default:
                        ok = false;
                        break;
                }
            }
            if (!ok)
            {
                DisplayUsage(longUsage);
            }
            else
            {
                try
                {
                    if (!_noDRC)
                    {
                        if (!File.Exists(GetDRCExe()))
                        {
                            stderr.WriteLine("Denis Sbragion's DRC (http://drc-fir.sourceforge.net/) was not found.");
                            stderr.WriteLine("Only the impulse response will be calculated, not correction filters.");
                            stderr.WriteLine("");
                            _noDRC = true;
                        }
                    }
                    if (!_noDRC)
                    {
                        FileInfo[] drcfiles = new DirectoryInfo(_thisFolder).GetFiles("*.drc");
                        if (drcfiles.Length == 0)
                        {
                            stderr.WriteLine("No .drc files were found in the current folder.");
                            stderr.WriteLine("Only the impulse response will be calculated, not correction filters.");
                            stderr.WriteLine("");
                            _noDRC = true;
                        }
                    }

                    for(int i=0; i<_nInFiles; i++)
                    {
                        string inFile = inFiles[i];
                        if (String.IsNullOrEmpty(inFile))
                        {
                            stderr.WriteLine("Error: The {0} input file was not specified.", FileDescription(i));
                            return;
                        }
                        if (!File.Exists(inFile))
                        {
                            stderr.WriteLine("Error: The {0} input file {1} was not found.", FileDescription(i), inFile);
                            return;
                        }

                        for (int j = 0; j < i; j++)
                        {
                            if (inFile.Equals(inFiles[j]))
                            {
                                stderr.WriteLine("Warning: The same input file ({0}) was specified for both {1} and {2}!", inFile, FileDescription(j), FileDescription(i));
                                //stderr.WriteLine();
                            }
                        }
                    }

                    // Temporary
                    if (_nInFiles != 2)
                    {
                        stderr.WriteLine("Error: Two input files must be specified.");
                        return;
                    }
                    inL = inFiles[0];
                    inR = inFiles[1];
                    // end temporary

                    uint sampleRate;
                    List<SoundObj> impulses;
                    List<ISoundObj> filteredImpulses;
                    List<string> impDirects;
                    List<Complex[]> impulseFFTs;
                    List<double> maxs;

                    SoundObj impulseL;
                    SoundObj impulseR;
                    ISoundObj filteredImpulseL = null;
                    ISoundObj filteredImpulseR = null;

                    string impDirectL = null;
                    string impDirectR = null;

                    Complex[] impulseLFFT;
                    Complex[] impulseRFFT;
                    WaveWriter writer;

                    ISoundObj buff;
                    double g;

                    if (!_keepTempFiles)
                    {
                        _tempFiles.Add("rps.pcm");
                        _tempFiles.Add("rtc.pcm");
                    }

                    // Find the left impulse
                    stderr.WriteLine("Processing left measurement ({0})...", inL);
                    impulseL = Deconvolve(inL, out impulseLFFT, out _peakPosL);
                    sampleRate = impulseL.SampleRate;
                    _sampleRate = sampleRate;
                    double peakM = Math.Round(MathUtil.Metres(_peakPosL, sampleRate), 2);
                    double peakFt = Math.Round(MathUtil.Feet(_peakPosL, sampleRate), 2);
                    stderr.WriteLine("  Impulse peak at sample {0} ({1}m, {2}ft)", _peakPosL, peakM, peakFt);

                    // Write to PCM
                    string impFileL = Path.GetFileNameWithoutExtension(inL) + "_imp" + ".pcm";
                    if (!_keepTempFiles)
                    {
                        _tempFiles.Add(impFileL);
                    }
                    writer = new WaveWriter(impFileL);
                    writer.Input = impulseL;
                    writer.Format = WaveFormat.IEEE_FLOAT;
                    writer.BitsPerSample = 32;
                    writer.SampleRate = _sampleRate;
                    writer.Raw = true;
                    writer.Run();
                    writer.Close();

                    // Write the impulseFFT to disk
                    int L = impulseLFFT.Length;
                    string impTempL = Path.GetFileNameWithoutExtension(inL) + "_imp" + ".dat";
                    _tempFiles.Add(impTempL);
                    writer = new WaveWriter(impTempL);
                    writer.Input = new CallbackSource(2, sampleRate, delegate(long j)
                    {
                        if (j >= L / 2)
                        {
                            return null;
                        }
                        Complex si = impulseLFFT[j]; // +impulseLFFT[L - j - 1];
                        ISample s = new Sample2();
                        s[0] = si.Magnitude;
                        s[1] = si.Phase / Math.PI;
                        return s;
                    });
                    writer.Format = WaveFormat.IEEE_FLOAT;
                    writer.BitsPerSample = 32;
                    writer.SampleRate = _sampleRate;
                    writer.Raw = false;
                    writer.Run();
                    writer.Close();
                    writer = null;

                    impulseLFFT = null;
                    GC.Collect();

                    if (_doDirectFilters)
                    {
                        // Sliding low-pass filter over the impulse
                        stderr.WriteLine("  Filtering...");
                        filteredImpulseL = SlidingLowPass(impulseL, _peakPosL);

                        // Write PCM for the filtered impulse
                        impDirectL = Path.GetFileNameWithoutExtension(inL) + "_impfilt" + ".pcm";
                        if (!_keepTempFiles)
                        {
                            _tempFiles.Add(impDirectL);
                        }
                        writer = new WaveWriter(impDirectL);
                        writer.Input = filteredImpulseL;
                        writer.Format = WaveFormat.IEEE_FLOAT;
                        writer.SampleRate = _sampleRate;
                        writer.BitsPerSample = 32;
                        writer.Raw = false;
                        writer.Run();
                        writer.Close();
                        writer = null;
                        filteredImpulseL.Reset();
                    }

                    GC.Collect();
                    stderr.WriteLine("  Deconvolution: left impulse done.");
                    stderr.WriteLine();

                    // Find the right impulse
                    stderr.WriteLine("Processing right measurement ({0})...", inR);
                    impulseR = Deconvolve(inR, out impulseRFFT, out _peakPosR);
                    peakM = Math.Round(MathUtil.Metres(_peakPosR, sampleRate), 2);
                    peakFt = Math.Round(MathUtil.Feet(_peakPosR, sampleRate), 2);
                    stderr.WriteLine("  Impulse peak at sample {0} ({1}m, {2}ft)", _peakPosR, peakM, peakFt);

                    // Write to PCM
                    string impFileR = Path.GetFileNameWithoutExtension(inR) + "_imp" + ".pcm";
                    if (!_keepTempFiles)
                    {
                        _tempFiles.Add(impFileR);
                    }
                    writer = new WaveWriter(impFileR);
                    writer.Input = impulseR;
                    writer.Format = WaveFormat.IEEE_FLOAT;
                    writer.BitsPerSample = 32;
                    writer.SampleRate = _sampleRate;
                    writer.Raw = true;
                    writer.Run();
                    writer.Close();

                    // Write the impulseFFT magnitude to disk
                    L = impulseRFFT.Length;
                    string impTempR = Path.GetFileNameWithoutExtension(inR) + "_imp" + ".dat";
                    _tempFiles.Add(impTempR);
                    writer = new WaveWriter(impTempR);
                    writer.Input = new CallbackSource(2, impulseR.SampleRate, delegate(long j)
                    {
                        if (j >= L / 2)
                        {
                            return null;
                        }
                        Complex si = impulseRFFT[j]; // +impulseRFFT[L - j - 1];
                        ISample s = new Sample2();
                        s[0] = si.Magnitude;
                        s[1] = si.Phase / Math.PI;
                        return s;
                    });
                    writer.Format = WaveFormat.IEEE_FLOAT;
                    writer.BitsPerSample = 32;
                    writer.SampleRate = _sampleRate;
                    writer.Raw = false;
                    writer.Run();
                    writer.Close();
                    writer = null;

                    impulseRFFT = null;
                    GC.Collect();

                    if (_doDirectFilters)
                    {
                        // Sliding low-pass filter over the impulse
                        stderr.WriteLine("  Filtering...");
                        filteredImpulseR = SlidingLowPass(impulseR, _peakPosR);

                        // Write PCM for the filtered impulse
                        impDirectR = Path.GetFileNameWithoutExtension(inR) + "_impfilt" + ".pcm";
                        if (!_keepTempFiles)
                        {
                            _tempFiles.Add(impDirectR);
                        }
                        writer = new WaveWriter(impDirectR);
                        writer.Input = filteredImpulseR;
                        writer.Format = WaveFormat.IEEE_FLOAT;
                        writer.BitsPerSample = 32;
                        writer.SampleRate = _sampleRate;
                        writer.Raw = false;
                        writer.Run();
                        writer.Close();
                        writer = null;
                        filteredImpulseR.Reset();
                    }

                    GC.Collect();

                    stderr.WriteLine("  Deconvolution: right impulse done.");
                    stderr.WriteLine();

                    // Join the left and right impulse files (truncated at 65536) into a WAV
                    // and normalize loudness for each channel
                    stderr.WriteLine("Splicing and normalizing (1)");
                    ChannelSplicer longstereoImpulse = new ChannelSplicer();

                    // (Don't normalize each channel's volume separately if _returnAll, it's just too expensive)
                    if (_returnAll)
                    {
                        buff = impulseL;
                    }
                    else
                    {
                        buff = new SoundBuffer(new SampleBuffer(impulseL).Subset(0, 131071));
                        g = Loudness.WeightedVolume(buff);
                        (buff as SoundBuffer).ApplyGain(1 / g);
                    }
                    longstereoImpulse.Add(buff);

                    if (_returnAll)
                    {
                        buff = impulseR;
                    }
                    else
                    {
                        buff = new SoundBuffer(new SampleBuffer(impulseR).Subset(0, 131071));
                        g = Loudness.WeightedVolume(buff);
                        (buff as SoundBuffer).ApplyGain(1 / g);
                    }
                    longstereoImpulse.Add(buff);

                    ISoundObj stereoImpulse = longstereoImpulse;

                    _impulseFiles.Add("Impulse_Response_Measured.wav: stereo impulse response from measurements");
                    writer = new WaveWriter("Impulse_Response_Measured.wav");
                    writer.Input = longstereoImpulse;
                    writer.Format = WaveFormat.IEEE_FLOAT;
                    writer.BitsPerSample = 32;
                    writer.SampleRate = _sampleRate;
                    writer.Normalization = -1;
                    writer.Raw = false;
                    writer.Run();
                    writer.Close();
                    writer = null;

                    if (_env)
                    {
                        // Also save the Hilbert envelope
                        HilbertEnvelope env = new HilbertEnvelope(8191);
                        env.Input = longstereoImpulse;
                        _impulseFiles.Add("Impulse_Response_Envelope.wav: Hilbert envelope of the impulse response");
                        writer = new WaveWriter("Impulse_Response_Envelope.wav");
                        writer.Input = env;
                        writer.Format = WaveFormat.IEEE_FLOAT;
                        writer.BitsPerSample = 32;
                        writer.SampleRate = _sampleRate;
                        writer.Normalization = -1;
                        writer.Raw = false;
                        writer.Run();
                        writer.Close();
                        writer = null;
                    }

                    if (_dbl)
                    {
                        // Create DBL files for Acourate
                        _impulseFiles.Add("PulseL.dbl: impulse response, raw data (64-bit float), left channel ");
                        _impulseFiles.Add("PulseR.dbl: impulse response, raw data (64-bit float), right channel");
                        _impulseFiles.Add("  (use skew=" + (_peakPosL - _peakPosR) + " for time alignment)");
                        WriteImpulseDBL(stereoImpulse, "PulseL.dbl", "PulseR.dbl");
                    }

                    if (_pcm)
                    {
                        // Create PCM files for Octave (etc)
                        _impulseFiles.Add("LUncorrected.pcm: impulse response, raw data (32-bit float), left channel");
                        _impulseFiles.Add("RUncorrected.pcm: impulse response, raw data (32-bit float), right channel");
                        WriteImpulsePCM(stereoImpulse, "LUncorrected.pcm", "RUncorrected.pcm");
                    }

                    stereoImpulse = null;
                    longstereoImpulse = null;
                    buff = null;
                    GC.Collect();

                    if (_doDirectFilters)
                    {
                        // Same for the filtered impulse response
                        stderr.WriteLine("Splicing and normalizing (2)");
                        ChannelSplicer longstereoImpulseF = new ChannelSplicer();

                        buff = new SoundBuffer(new SampleBuffer(filteredImpulseL).Subset(0, 131071));
                        double gL = Loudness.WeightedVolume(buff);
                        (buff as SoundBuffer).ApplyGain(1 / gL);
                        longstereoImpulseF.Add(buff);
                        FilterProfile lfgDirectL = new FilterProfile(buff, 0.5);

                        buff = new SoundBuffer(new SampleBuffer(filteredImpulseR).Subset(0, 131071));
                        double gR = Loudness.WeightedVolume(buff);
                        (buff as SoundBuffer).ApplyGain(1 / gR);
                        longstereoImpulseF.Add(buff);
                        FilterProfile lfgDirectR = new FilterProfile(buff, 0.5);

                        _impulseFiles.Add("Impulse_Response_Filtered.wav: approximation to direct-sound impulse response");
                        writer = new WaveWriter("Impulse_Response_Filtered.wav");
                        writer.Input = longstereoImpulseF;
                        writer.Format = WaveFormat.IEEE_FLOAT;
                        writer.BitsPerSample = 32;
                        writer.SampleRate = _sampleRate;
                        writer.Normalization = -1;
                        writer.Raw = false;
                        writer.Run();
                        writer.Close();
                        double gg = writer.Gain;
                        writer = null;
                        longstereoImpulseF = null;

                        ChannelSplicer longstereoImpulseD = new ChannelSplicer();

                        Mixer diffuse = new Mixer();
                        diffuse.Add(impulseL, 1.0);
                        diffuse.Add(filteredImpulseL, -1.0);
                        buff = new SoundBuffer(new SampleBuffer(diffuse).Subset(0, 131071));
                        (buff as SoundBuffer).ApplyGain(1 / gL);
                        longstereoImpulseD.Add(buff);
                        FilterProfile lfgDiffuseL = new FilterProfile(buff, 0.5);

                        diffuse = new Mixer();
                        diffuse.Add(impulseR, 1.0);
                        diffuse.Add(filteredImpulseR, -1.0);
                        buff = new SoundBuffer(new SampleBuffer(diffuse).Subset(0, 131071));
                        (buff as SoundBuffer).ApplyGain(1 / gR);
                        longstereoImpulseD.Add(buff);
                        FilterProfile lfgDiffuseR = new FilterProfile(buff, 0.5);

                        _impulseFiles.Add("Impulse_Response_Diffuse.wav: approximation to diffuse-field remnant");
                        writer = new WaveWriter("Impulse_Response_Diffuse.wav");
                        writer.Input = longstereoImpulseD;
                        writer.Format = WaveFormat.IEEE_FLOAT;
                        writer.BitsPerSample = 32;
                        writer.SampleRate = _sampleRate;
                        writer.Gain = gg;
                        writer.Raw = false;
                        writer.Run();
                        writer.Close();
                        writer = null;

                        // Filter the diffuse-field curve against double the diffuse-field curve
                        FilterImpulse fiDiffuse = new FilterImpulse(8192, HRTF.diffuseDiff0() * 2, FilterInterpolation.COSINE, sampleRate);
                        FastConvolver co = new FastConvolver(longstereoImpulseD, fiDiffuse);
                        SoundBuffer buffd = new SoundBuffer(co);
                        _impulseFiles.Add("Impulse_Response_Diffuse_Comp.wav: filtered diffuse-field remnant");
                        writer = new WaveWriter("Impulse_Response_Diffuse_Comp.wav");
                        writer.Input = buffd.Subset(4096);
                        writer.Format = WaveFormat.IEEE_FLOAT;
                        writer.BitsPerSample = 32;
                        writer.SampleRate = _sampleRate;
                        writer.Gain = gg;
                        writer.Raw = false;
                        writer.Run();
                        writer.Close();
                        writer = null;

                        longstereoImpulseD = null;

                        bool any = false;
                        string jsonFile = "Diff.json";
                        FileStream fs = new FileStream(jsonFile, FileMode.Create);
                        StreamWriter sw = new StreamWriter(fs);
                        sw.WriteLine("{");
                        FilterProfile lfgDiffL = lfgDirectL - lfgDiffuseL;
                        if (lfgDiffL != null)
                        {
                            if (any) sw.WriteLine(",");
                            any = true;
                            sw.Write(lfgDiffL.ToJSONString("DiffL", "Diffuse field relative to direct, left channel"));
                        }
                        FilterProfile lfgDiffR = lfgDirectR - lfgDiffuseR;
                        if (lfgDiffR != null)
                        {
                            if (any) sw.WriteLine(",");
                            any = true;
                            sw.Write(lfgDiffR.ToJSONString("DiffR", "Diffuse field relative to direct, right channel"));
                        }
                        sw.WriteLine("}");
                        sw.Close();
                        fs.Close();
                    }
                    buff = null;
                    GC.Collect();

                    System.Console.Error.WriteLine();

                    if (!_noDRC)
                    {
                        // Analyze the freq response
                        // and create targets
                        // target_full.txt and target_half.txt
                        stderr.WriteLine("Analyzing response curves.");
                        Prep(impTempL, impTempR, "Impulse_Response_Measured.wav", "NoCorrection");

                        // Call DRC to create the filters
                        // then splice the DRC left & right output files together
                        stderr.WriteLine("Preparing for DRC.");
                        if (DoDRC(impFileL, impFileR, impDirectL, impDirectR, _peakPosL, _peakPosR, "Impulse_Response_Measured.wav", "Impulse_Response_Filtered.wav"))
                        {
                            stderr.WriteLine("Success!");
                        }
                    }

                    // Report names of the impulse files created
                    if (_impulseFiles.Count == 0)
                    {
                        System.Console.Error.WriteLine("No impulse response files were created.");
                    }
                    if (_impulseFiles.Count > 0)
                    {
                        System.Console.Error.WriteLine("Impulse response files were created:");
                        foreach (string f in _impulseFiles)
                        {
                            string s = "  " + f;
                            System.Console.Error.WriteLine(s);
                        }
                    }

                    // Report names of the filter files created
                    if (_filterFiles.Count == 0 && !_noDRC)
                    {
                        System.Console.Error.WriteLine("No correction filter files were created.");
                    }
                    if (_filterFiles.Count > 0)
                    {
                        System.Console.Error.WriteLine("Correction filter files were created:");
                        foreach (string f in _filterFiles)
                        {
                            string s = "  " + f;
                            if (_copy)
                            {
                                try
                                {
                                    File.Copy(f, Path.Combine(_impulsesFolder, f), true);
                                    s += " (copied)";
                                }
                                catch (Exception e)
                                {
                                    s += " (not copied: " + e.Message + ")";
                                }
                            }
                            System.Console.Error.WriteLine(s);
                        }
                    }
                    if (_peakPosL == _peakPosR)
                    {
                        System.Console.Error.WriteLine();
                        System.Console.Error.WriteLine("Zero time difference between channels.  Are you sure the recordings are correct?");
                    }
                }
                catch (Exception e)
                {
                    stderr.WriteLine();
                    stderr.WriteLine(e.Message);
                    stderr.WriteLine(e.StackTrace);
                }
                finally
                {
                    foreach (string tempFile in _tempFiles)
                    {
                        try
                        {
                            File.Delete(tempFile);
                        }
                        catch (Exception) { /* ignore */ }
                    }
                }
            }
            stderr.Flush();
        }
Ejemplo n.º 4
0
 static ISoundObj LowPassFiltered(ISoundObj input, double freqStart, double gainEnd)
 {
     uint sampleRate = input.SampleRate;
     FilterProfile lfg = new FilterProfile();
     lfg.Add(new FreqGain(freqStart, 0));
     lfg.Add(new FreqGain(0.499*sampleRate, gainEnd));
     FastConvolver conv = new FastConvolver();
     conv.Input = input;
     conv.impulse = new FilterImpulse(8192, lfg, FilterInterpolation.COSINE, sampleRate);
     return conv;
 }
Ejemplo n.º 5
0
        static void FindPeaks(ISoundObj impulse)
        {
            // Input: a single-channel impulse

            // Find the peak positions:
            // - unfiltered
            // - filtered with various bandpass filters

            uint sr = impulse.SampleRate;
            ushort nc = impulse.NumChannels;

            double peakM = Math.Round(MathUtil.Metres(_peakPosL, sr), 2);
            double peakFt = Math.Round(MathUtil.Feet(_peakPosL, sr), 2);
            stderr.WriteLine("  Impulse peak at sample {0} ({1}m, {2}ft)", _peakPosL, peakM, peakFt);

            FilterImpulse fi;
            WaveWriter wri;
            FastConvolver co;

            fi = new FilterImpulse(2048, bandpass(400,sr), FilterInterpolation.COSINE, sr);
            co = new FastConvolver(impulse, fi);
            wri = new WaveWriter("bp_400.wav", nc, sr, 16, DitherType.NONE, WaveFormat.PCM);
            wri.Input = co;
            wri.Normalization = -1;
            wri.Run();
            wri.Close();

            fi = new FilterImpulse(2048, bandpass(6000, sr), FilterInterpolation.COSINE, sr);
            co = new FastConvolver(impulse, fi);
            wri = new WaveWriter("bp_6000.wav", nc, sr, 16, DitherType.NONE, WaveFormat.PCM);
            wri.Input = co;
            wri.Normalization = -1;
            wri.Run();
            wri.Close();

            // and

            fi = new FilterImpulse(2048, bandpass(160, sr), FilterInterpolation.COSINE, sr);
            co = new FastConvolver(impulse, fi);
            wri = new WaveWriter("bp_160.wav", nc, sr, 16, DitherType.NONE, WaveFormat.PCM);
            wri.Input = co;
            wri.Normalization = -1;
            wri.Run();
            wri.Close();

            fi = new FilterImpulse(2048, bandpass(2560, sr), FilterInterpolation.COSINE, sr);
            co = new FastConvolver(impulse, fi);
            wri = new WaveWriter("bp_2560.wav", nc, sr, 16, DitherType.NONE, WaveFormat.PCM);
            wri.Input = co;
            wri.Normalization = -1;
            wri.Run();
            wri.Close();

            fi = new FilterImpulse(2048, bandpass(18000, sr), FilterInterpolation.COSINE, sr);
            co = new FastConvolver(impulse, fi);
            wri = new WaveWriter("bp_18k.wav", nc, sr, 16, DitherType.NONE, WaveFormat.PCM);
            wri.Input = co;
            wri.Normalization = -1;
            wri.Run();
            wri.Close();
        }
Ejemplo n.º 6
0
        static bool ExecDRC(string drcfile, string target, string outfile, string infileL, string infileR, int peakPosL, int peakPosR, string stereoImpulseFile)
        {
            GC.Collect();
            bool ok = false;
            string args;
            FastConvolver conv;
            WaveWriter wri;
            if (!File.Exists(drcfile))
            {
                stderr.WriteLine();
                stderr.WriteLine("{0} not found.", drcfile);
                return ok;
            }

            string tmpL;
            string tmpR;
            tmpL = Path.GetFileNameWithoutExtension(infileL) + ".tmp";
            tmpR = Path.GetFileNameWithoutExtension(infileR) + ".tmp";
            _tempFiles.Add(tmpL);
            _tempFiles.Add(tmpR);

            stderr.WriteLine("Exec DRC for {0}, left channel", drcfile);
            stderr.WriteLine();
            ok = RunDRC(drcfile, infileL, target, tmpL, peakPosL, out args);

            if (ok)
            {
                stderr.WriteLine();
                stderr.WriteLine("Exec DRC for {0}, right channel", drcfile);
                stderr.WriteLine();
                ok = RunDRC(drcfile, infileR, target, tmpR, peakPosR, out args);
            }

            if (ok)
            {
                stderr.WriteLine();
                if (_noSkew)
                {
                    stderr.WriteLine("Creating stereo filter {0}", outfile + ".wav" );
                }
                else
                {
                    stderr.WriteLine("Creating stereo filter {0} (skew {1} samples)", outfile + ".wav", peakPosR - peakPosL);
                }
                ISoundObj stereoFilter = Splice(tmpL, peakPosL, tmpR, peakPosR, outfile + ".wav");
                stderr.WriteLine();

                // Convolve noise with the stereo filter
                /*
                NoiseGenerator noise = new NoiseGenerator(NoiseType.WHITE_FLAT, 2, (int)131072, stereoFilter.SampleRate, 1.0);
                conv = new FastConvolver();
                conv.impulse = stereoFilter;
                conv.Input = noise;

                wri = new WaveWriter(drcfile + "_Test.wav");
                wri.Input = conv;
                wri.Format = WaveFormat.IEEE_FLOAT;
                wri.BitsPerSample = 32;
                wri.SampleRate = _sampleRate;
                wri.Normalization = -1;
                wri.Run();
                wri.Close();
                wri = null;
                conv = null;
                noise = null;
                 * */

                // Convolve filter with the in-room impulse response
                WaveReader rea = new WaveReader(stereoImpulseFile);
                conv = new FastConvolver();
                conv.impulse = rea;
                conv.Input = stereoFilter;

                if (_pcm)
                {
                    _impulseFiles.Add("LCorrected_" + outfile + ".pcm: corrected test convolution, raw data (32-bit float), left channel");
                    _impulseFiles.Add("RCorrected_" + outfile + ".pcm: corrected test convolution, raw data (32-bit float), right channel");
                    WriteImpulsePCM(conv, "LCorrected_" + outfile + ".pcm", "RCorrected_" + outfile + ".pcm");
                }

                wri = new WaveWriter(outfile + "_TestConvolution.wav");
                wri.Input = conv;
                wri.Format = WaveFormat.PCM;
                wri.Dither = DitherType.TRIANGULAR;
                wri.BitsPerSample = 16;
                wri.SampleRate = _sampleRate;
                wri.Normalization = -1;
                wri.Run();
                wri.Close();
                rea.Close();
                wri = null;
                rea = null;
                conv = null;

                GC.Collect();
            }
            return ok;
        }
Ejemplo n.º 7
0
        static void Prep(string infileL, string infileR, string stereoImpulseFile, string outFile)
        {
            // Input files are complex
            // 0=mag, 1=phase/pi (so it looks OK in a wave editor!)
            // FFTs of the room impulse response

            // Take two half-FFT-of-impulse WAV files
            // Average them, into an array

            int n;
            SoundBuffer buff;
            WaveWriter wri;
            //          NoiseGenerator noise;
            FastConvolver conv;

            /*
            // Convolve noise with the in-room impulse
            noise = new NoiseGenerator(NoiseType.WHITE_FLAT, 2, (int)131072, stereoImpulse.SampleRate, 1.0);
            conv = new FastConvolver();
            conv.impulse = stereoImpulse;
            conv.Input = noise;

            wri = new WaveWriter("ImpulseResponse_InRoom.wav");
            wri.Input = conv;
            wri.Format = WaveFormat.IEEE_FLOAT;
            wri.BitsPerSample = 32;
            wri.Normalization = 0;
            wri.Run();
            wri.Close();
            wri = null;
            conv = null;
            */

            WaveReader rdrL = new WaveReader(infileL);
            buff = new SoundBuffer(rdrL);
            n = (int)buff.ReadAll();
            uint sampleRate = buff.SampleRate;
            uint nyquist = sampleRate / 2;

            double binw = (nyquist / (double)n);

            WaveReader rdrR = new WaveReader(infileR);

            IEnumerator<ISample> enumL = buff.Samples;
            IEnumerator<ISample> enumR = rdrR.Samples;

            // For easier processing and visualisation
            // read this in to an ERB-scale (not quite log-scale) array
            // then we can smooth by convolving with a single half-cosine.
            //

            int nn = (int)ERB.f2bin(nyquist, sampleRate) + 1;

            double[] muff = new double[nn];

            int prevbin = 0;
            int nbin = 0;
            double v = 0;
            int j = 0;
            while (true)
            {
                double f = (double)j * binw;    // equiv freq, Hz

                int bin = (int)ERB.f2bin(f, sampleRate); // the bin we drop this sample in
                if (bin > nn)
                {
                    // One of the channels has more, but we're overrun so stop now
                    break;
                }

                j++;
                bool more = false;
                more |= enumL.MoveNext();
                more |= enumR.MoveNext();
                if (!more)
                {
                    muff[prevbin] = v / nbin;
                    break;
                }

                v += enumL.Current[0];  // magnitude
                v += enumR.Current[0];  // magnitude
                nbin++;

                if (bin > prevbin)
                {
                    muff[prevbin] = v / nbin;
                    v = 0;
                    nbin = 0;
                    prevbin = bin;
                }
            }

            double[] smoo = ERB.smooth(muff, 38);

            // Pull out the freq response at ERB centers
            FilterProfile lfg = ERB.profile(smoo, sampleRate);

            // Write this response as a 'target' file
            /*
            FileStream fs = new FileStream("target_full.txt", FileMode.Create);
            StreamWriter sw = new StreamWriter(fs, Encoding.ASCII);
            foreach (FreqGain fg in lfg)
            {
                sw.WriteLine("{0} {1:f4}", Math.Round(fg.Freq), fg.Gain);
            }
            sw.Close();
            */
            /*
            fs = new FileStream("target_half.txt", FileMode.Create);
            sw = new StreamWriter(fs, Encoding.ASCII);
            foreach (FreqGain fg in lfg)
            {
                sw.WriteLine("{0} {1:f4}", Math.Round(fg.Freq), fg.Gain/2);
            }
            sw.Close();
            */

            // Create a filter to invert this response
            FilterProfile ifg = new FilterProfile();
            foreach (FreqGain fg in lfg)
            {
                ifg.Add(new FreqGain(fg.Freq, -fg.Gain));
            }

            ISoundObj filterImpulse = new FilterImpulse(0, ifg, FilterInterpolation.COSINE, sampleRate);
            filterImpulse.SampleRate = sampleRate;

            // Write the filter impulse to disk
            string sNoCorr = outFile + ".wav";
            wri = new WaveWriter(sNoCorr);
            wri.Input = filterImpulse; // invertor;
            wri.Format = WaveFormat.IEEE_FLOAT;
            wri.BitsPerSample = 32;
            wri.SampleRate = _sampleRate;
            wri.Normalization = -1;
            wri.Run();
            wri.Close();
            _filterFiles.Add(sNoCorr);

            /*
            // Convolve noise with the NoCorrection filter
            noise = new NoiseGenerator(NoiseType.WHITE_FLAT, 2, (int)131072, stereoImpulse.SampleRate, 1.0);
            conv = new FastConvolver();
            conv.impulse = invertor;
            conv.Input = noise;

            wri = new WaveWriter("NoCorrection_Test.wav");
            wri.Input = conv;
            wri.Format = WaveFormat.IEEE_FLOAT;
            wri.BitsPerSample = 32;
            wri.SampleRate = _sampleRate;
            wri.Normalization = 0;
            wri.Run();
            wri.Close();
            wri = null;
            conv = null;
            */

            // Convolve this with the in-room impulse response

            WaveReader rea = new WaveReader(outFile + ".wav");
            conv = new FastConvolver();
            conv.impulse = rea;
            conv.Input = new WaveReader(stereoImpulseFile);
            wri = new WaveWriter(outFile + "_TestConvolution.wav");
            wri.Input = conv;
            wri.Format = WaveFormat.PCM;
            wri.Dither = DitherType.TRIANGULAR;
            wri.BitsPerSample = 16;
            wri.SampleRate = _sampleRate;
            wri.Normalization = -1;
            wri.Run();
            wri.Close();
            rea.Close();
            wri = null;
            conv = null;
        }
Ejemplo n.º 8
0
        static SoundObj GetEQImpulse(ISoundObj mainImpulse, uint sampleRate, out string filterName)
        {
            DateTime dtStart = DateTime.Now;
            SoundObj filterImpulse = null;

            // Construct a string describing the filter
            string filterDescription = "EQ" + _eqBands + "_" + _inputSampleRate + "_" + _eqLoudness + "_" + FlatnessFilterPath(_impulsePath, sampleRate, _eqFlatness);

            bool nothingToDo = (_eqLoudness==0);
            nothingToDo &= (_impulsePath == null) || (_eqFlatness == 100);

            List<string> fgd = new List<string>();
            foreach (FreqGain fg in _eqValues)
            {
                fgd.Add(fg.Freq + "@" + fg.Gain);
                nothingToDo &= (fg.Gain == 0);
            }
            filterDescription = filterDescription + String.Join("_", fgd.ToArray());
            filterDescription = filterDescription + "_IM_" + _impulsePath;

            // Cached filters are named by hash of this string
            filterName = "EQ" + filterDescription.GetHashCode().ToString("x10").ToUpperInvariant();
            if (nothingToDo)
            {
                Trace.WriteLine("EQ flat");
                WriteJSON(_eqValues, null, null);
                return null;
            }
            else
            {
                Trace.WriteLine(filterName);
            }
            string filterFile = Path.Combine(_tempFolder, filterName + ".filter");

            // Does the cached filter exist?
            if (File.Exists(filterFile))
            {
                try
                {
                    // Just read the cached EQ filter from disk
                    filterImpulse = new WaveReader(filterFile);
                }
                catch (Exception e)
                {
                    if (_debug)
                    {
                        Trace.WriteLine("GetEQImpulse1: " + e.Message);
                    }
                }
            }
            if(filterImpulse==null)
            {
                // Construct a filter impulse from the list of EQ values
                SoundObj eqFilter = new FilterImpulse(0, _eqValues, FilterInterpolation.COSINE, _inputSampleRate);
                filterImpulse = eqFilter;

                ISoundObj qtFilter = GetQuietnessFilter(_inputSampleRate, _eqLoudness);
                if (qtFilter != null)
                {
                    // Convolve the two, to create a EQ-and-loudness filter
                    FastConvolver tmpConvolver = new FastConvolver();
                    tmpConvolver.partitions = 0;
                    tmpConvolver.impulse = qtFilter;
                    tmpConvolver.Input = eqFilter;
                    filterImpulse = tmpConvolver;
                }

                ISoundObj ftFilter = GetFlatnessFilter(_impulsePath, mainImpulse, _eqFlatness);
                if (ftFilter != null)
                {
                    // Convolve the two, to create a EQ-and-loudness filter
                    FastConvolver tmpConvolver2 = new FastConvolver();
                    tmpConvolver2.partitions = 0;
                    tmpConvolver2.impulse = filterImpulse;
                    tmpConvolver2.Input = ftFilter;
                    filterImpulse = tmpConvolver2;
                }

                // Blackman window to make the filter smaller?

                try
                {
                    // Write the filter impulse to disk
                    WaveWriter wri = new WaveWriter(filterFile);
                    wri.Input = filterImpulse;
                    wri.Format = WaveFormat.IEEE_FLOAT;
                    wri.BitsPerSample = 64;
                    wri.Run();
                    wri.Close();

                    if (_debug)
                    {
                        // DEBUG: Write the filter impulse as wav16
                        wri = new WaveWriter(filterFile + ".wav");
                        wri.Input = filterImpulse;
                        wri.Format = WaveFormat.PCM;
                        wri.BitsPerSample = 16;
                        wri.Normalization = -1.0;
                        wri.Dither = DitherType.NONE;//.TRIANGULAR;
                        wri.Run();
                        wri.Close();
                    }

                    // Write a JSON description of the filter
                    WriteJSON(_eqValues, filterImpulse, filterName);
                }
                catch (Exception e)
                {
                    if (_debug)
                    {
                        Trace.WriteLine("GetEQImpulse2: " + e.Message);
                    }
                }
            }
            filterImpulse.Reset();
            if (_debug)
            {
                TimeSpan ts = DateTime.Now.Subtract(dtStart);
                Trace.WriteLine("GetEQImpulse " + ts.TotalMilliseconds);
            }

            // Copy the filter's JSON description (if available) into "current.json"
            CopyJSON(filterName);

            return filterImpulse;
        }
Ejemplo n.º 9
0
        static ISoundObj DecodeBFormatUHJ(ISoundObj source)
        {
            ISoundObj input = source;
            uint sr = input.SampleRate;
            /*
            if (_ambiUseShelf)
            {
                // Shelf-filters
                // boost W at high frequencies, and boost X, Y at low frequencies
                FilterProfile lfgXY = new FilterProfile();
                lfgXY.Add(new FreqGain(_ambiShelfFreq / 2, 0));
                lfgXY.Add(new FreqGain(_ambiShelfFreq * 2, -1.25));
                FilterImpulse fiXY = new FilterImpulse(0, lfgXY, FilterInterpolation.COSINE, sr);

                FilterProfile lfgW = new FilterProfile();
                lfgW.Add(new FreqGain(_ambiShelfFreq / 2, 0));
                lfgW.Add(new FreqGain(_ambiShelfFreq * 2, 1.76));
                FilterImpulse fiW = new FilterImpulse(0, lfgW, FilterInterpolation.COSINE, sr);
            }
            if (_ambiUseDistance)
            {
                // Distance compensation filters
                // apply phase shift to X, Y at (very) low frequencies
                double fc = MathUtil.FcFromMetres(_ambiDistance);
                IIR1 discomp = new IIR1LP(sr, fc, 8192);    // tbd: chain this
            }
            */

            // Transformation filters
            //
            // Primary reference:
            // Gerzon 1985 "Ambisonics in Multichannel Broadcasting and Video"
            //
            // Coefficients from: http://en.wikipedia.org/wiki/Ambisonic_UHJ_format:
            // S = 0.9396926*W + 0.1855740*X
            // D = j(-0.3420201*W + 0.5098604*X) + 0.6554516*Y
            // Left = (S + D)/2.0
            // Right = (S - D)/2.0
            // which makes
            // Left = (0.092787 + 0.2549302j)X + (0.4698463 - 0.17101005j)W + (0.3277258)Y
            // Right= (0.092787 - 0.2549302j)X + (0.4698463 + 0.17101005j)W - (0.3277258)Y
            //
            // Coefficients from: http://www.york.ac.uk/inst/mustech/3d_audio/ambis2.htm
            // Left = (0.0928 + 0.255j)X + (0.4699 - 0.171j)W + (0.3277)Y
            // Right= (0.0928 - 0.255j)X + (0.4699 + 0.171j)W - (0.3277)Y

            // The Mid-Side versions are simpler
            // L+R = (0.0928 + 0.255j)X + (0.4699 - 0.171j)W + (0.3277)Y + ((0.0928 - 0.255j)X + (0.4699 + 0.171j)W - (0.3277)Y)
            //     = (0.1856)X          + (0.9398)W
            // L-R = (0.0928 + 0.255j)X + (0.4699 - 0.171j)W + (0.3277)Y - ((0.0928 - 0.255j)X + (0.4699 + 0.171j)W - (0.3277)Y)
            //     =          (0.510j)X +          (0.342j)W + (0.6554)Y
            // but since we're delaying signal via convolution anyway, not *too* much extra processing to do in LR mode...

            // Separate the WXY channels
            ISoundObj channelW = new SingleChannel(input, 0);
            ISoundObj channelX = new SingleChannel(input, 1, true);
            ISoundObj channelY = new SingleChannel(input, 2, true);

            // Z not used; height is discarded in UHJ conversion.
            // Don't assume it's there; horizontal-only .AMB files won't have a fourth channel
            //          ISoundObj channelZ = new SingleChannel(input, 3);

            // Phase shift j is implemented with Hilbert transforms
            // so let's load up some filters, multiply by the appropriate coefficients.
            int len = 8191;
            PhaseMultiplier xl = new PhaseMultiplier(new Complex(0.0927870, 0.25493020), len, sr);
            PhaseMultiplier wl = new PhaseMultiplier(new Complex(0.4698463, -0.17101005), len, sr);
            PhaseMultiplier yl = new PhaseMultiplier(new Complex(0.3277258, 0.00000000), len, sr);
            PhaseMultiplier xr = new PhaseMultiplier(new Complex(0.0927870, -0.25493020), len, sr);
            PhaseMultiplier wr = new PhaseMultiplier(new Complex(0.4698463, 0.17101005), len, sr);
            PhaseMultiplier yr = new PhaseMultiplier(new Complex(-0.3277258, 0.00000000), len, sr);

            // The convolvers to filter
            FastConvolver cwl = new FastConvolver(channelW, wl);
            FastConvolver cxl = new FastConvolver(channelX, xl);
            FastConvolver cyl = new FastConvolver(channelY, yl);
            FastConvolver cwr = new FastConvolver(channelW, wr);
            FastConvolver cxr = new FastConvolver(channelX, xr);
            FastConvolver cyr = new FastConvolver(channelY, yr);

            // Sum to get the final output of these things:
            Mixer mixerL = new Mixer();
            mixerL.Add(cwl, 1.0);
            mixerL.Add(cxl, 1.0);
            mixerL.Add(cyl, 1.0);

            Mixer mixerR = new Mixer();
            mixerR.Add(cwr, 1.0);
            mixerR.Add(cxr, 1.0);
            mixerR.Add(cyr, 1.0);

            // output in stereo
            ChannelSplicer uhj = new ChannelSplicer();
            uhj.Add(mixerL);
            uhj.Add(mixerR);

            return uhj;
        }
Ejemplo n.º 10
0
        static ISoundObj DecodeBFormatBinaural(ISoundObj source)
        {
            throw new NotImplementedException();

            ISoundObj input = source;
            uint sr = input.SampleRate;

            // Convolve the BFormat data with the matrix filter
            if (!String.IsNullOrEmpty(_bformatFilter))
            {
                string ignore;
                WaveReader rdr = GetAppropriateImpulseReader(_bformatFilter, out ignore);
                FastConvolver ambiConvolver = new FastConvolver(source, rdr);
                input = ambiConvolver;
            }

            // Cardioid directed at four (or six) virtual loudspeakers
            IEnumerator<ISample> src = input.Samples;
            CallbackSource bin = new CallbackSource(2, sr, delegate(long j)
            {
                if (src.MoveNext())
                {
                    ISample s = src.Current;
                    double w = s[0];
                    double x = s[1];
                    double y = s[2];
                    double z = s[3];
                    double wFactor = -0.5;
                    double left = x + y + z + (wFactor * w);
                    double right = x - y + z + (wFactor * w);
                    ISample sample = new Sample2(left, right);
                    return sample;
                }
                return null;
            });

            return bin;
        }
Ejemplo n.º 11
0
        static void LoadImpulse()
        {
            DateTime dtStart = DateTime.Now;
            string theImpulsePath = null;
            string theEQImpulseName = null;
            ISoundObj main = GetMainImpulse(out theImpulsePath);
            uint sr = (main == null ? _inputSampleRate : main.SampleRate);
            if (sr == 0)
            {
                if (_debug) { Trace.WriteLine("oops: no sample rate!"); }
                sr = 44100;
            }
            ISoundObj eq = GetEQImpulse(main, sr, out theEQImpulseName);
            ISoundObj combinedFilter = null;

            if (main == null && eq != null)
            {
                combinedFilter = eq;
            }
            else if (main != null && eq == null)
            {
                combinedFilter = main;
            }
            else if (main != null && eq != null)
            {
                // Check whether we have (and can load) a cached version of the combined filter
                string tempString = theEQImpulseName + "_" + theImpulsePath;
                string filterName = "CC" + tempString.GetHashCode().ToString("x10").ToUpperInvariant();
                string filterFile = Path.Combine(_tempFolder, filterName + ".filter");
                if (_debug)
                {
                    Trace.WriteLine(filterName);
                }
                if (File.Exists(filterFile))
                {
                    try
                    {
                        // Just read the cached EQ filter from disk
                        combinedFilter = new WaveReader(filterFile);
                    }
                    catch (Exception e)
                    {
                        if (_debug)
                        {
                            Trace.WriteLine("LoadImpulse1: " + e.Message);
                        }
                    }
                }

                if (combinedFilter == null)
                {
                    // Convolve the room-correction impulse with the EQ impulse to make just one.
                    // (this is quite slow)
                    FastConvolver temp = new FastConvolver();
                    temp.partitions = 0;
                    temp.impulse = eq;
                    temp.Input = main;
                    combinedFilter = temp;

                    try
                    {
                        // Write the combined impulse
                        temp.Reset();
                        WaveWriter tempWriter = new WaveWriter(filterFile);
                        tempWriter.Format = WaveFormat.IEEE_FLOAT;
                        tempWriter.BitsPerSample = 64;
                        tempWriter.Input = temp;
                        tempWriter.Run();
                        tempWriter.Close();

                        if (_debug)
                        {
                            // DEBUG: Write the combined impulse as WAV16
                            temp.Reset();
                            tempWriter = new WaveWriter(filterFile + ".wav");
                            tempWriter.Format = WaveFormat.PCM;
                            tempWriter.BitsPerSample = 16;
                            tempWriter.Gain = 0.1;
                            tempWriter.Dither = DitherType.NONE;//.TRIANGULAR;
                            tempWriter.Input = temp;
                            tempWriter.Run();
                            tempWriter.Close();
                        }
                    }
                    catch (Exception e)
                    {
                        if (_debug)
                        {
                            Trace.WriteLine("LoadImpulse2: " + e.Message);
                        }
                    }
                }
            }

            _MainConvolver.impulse = combinedFilter;

            if (combinedFilter != null)
            {
                // Calculate loudness-adjusted volume of each channel of the impulse
                _impulseVolumes.Clear();
                for (ushort j = 0; j < combinedFilter.NumChannels; j++)
                {
                    double v = Loudness.WeightedVolume(combinedFilter.Channel(j));
                    _impulseVolumes.Add(v);
                    if (_debug)
                    {
                        Trace.WriteLine("WV{0}: {1}", j, v);
                    }
                }
            }
            combinedFilter = null;

            if (_debug)
            {
                TimeSpan ts = DateTime.Now.Subtract(dtStart);
                Trace.WriteLine("Loadmpulse " + ts.TotalMilliseconds);
            }
        }