Converting an input audio file to a monophonic FLAC file

Question

I have the following method which basically converts an input audio file to a monophonic FLAC file.

Now I am getting Member has cyclomatic complexity of 21 (105%) message in Visual Studio, while I've taken care of improving it as in the beginning it was longer, now there's not much I can remove from it as it pretty much fulfills my needs.

Should I just ignore this warning ?

private static void Convert(string inputFile, string outputFile, IProgress<double> progress = null)
{
 if (inputFile == null) throw new ArgumentNullException("inputFile");
 if (outputFile == null) throw new ArgumentNullException("outputFile");
 int stream = 0;
 int mixer = 0;
 try
 {
 stream = Bass.BASS_StreamCreateFile(inputFile, 0, 0,
 BASSFlag.BASS_STREAM_DECODE | BASSFlag.BASS_SAMPLE_FLOAT | BASSFlag.BASS_STREAM_PRESCAN);
 if (stream == 0) throw new BassException("Could not create stream");
 var info = Bass.BASS_ChannelGetInfo(stream);
 if (info == null) throw new BassException("Could not retrieve stream info");
 var freq = info.freq;
 mixer = BassMix.BASS_Mixer_StreamCreate(freq, 1,
 BASSFlag.BASS_MIXER_END | BASSFlag.BASS_SAMPLE_FLOAT | BASSFlag.BASS_STREAM_DECODE);
 if (mixer == 0) throw new BassException("Could not create mixer");
 bool addChannel = BassMix.BASS_Mixer_StreamAddChannel(mixer, stream, BASSFlag.BASS_MIXER_NORAMPIN);
 if (!addChannel) throw new BassException("Could not add stream to mixer");
 long getLength = Bass.BASS_ChannelGetLength(stream);
 if (getLength == -1) throw new BassException("Could not get channel length");
 var encoder = new EncoderFLAC(mixer)
 {
 Force16Bit = true,
 FLAC_Verify = true,
 OutputFile = outputFile
 };
 if (!encoder.Start(null, IntPtr.Zero, false))
 throw new InvalidOperationException("Could not start encoder");
 const int samples = 65536;
 const int bytes = (samples * sizeof(float)) | (int)BASSData.BASS_DATA_FLOAT;
 var buffer = new float[samples];
 long bytesRead = 0;
 while (Bass.BASS_ChannelIsActive(mixer) == BASSActive.BASS_ACTIVE_PLAYING)
 {
 int getData = Bass.BASS_ChannelGetData(mixer, buffer, bytes);
 bytesRead += getData;
 if (progress != null) progress.Report(1.0d / getLength * bytesRead);
 }
 encoder.Stop();
 if (getLength / sizeof(short) != bytesRead)
 throw new InvalidOperationException("Output length not equal to input length");
 }
 catch (Exception ex)
 {
 throw new InvalidOperationException("Conversion failed", ex);
 }
 finally
 {
 if (stream != 0) Bass.BASS_StreamFree(stream);
 if (mixer != 0) Bass.BASS_StreamFree(mixer);
 }
}

Answer 1

I think your code would become much simpler and more readable if you encapsulated all the BASS-related functionality from into separate types.

Something like:

class Stream
{
 private readonly int handle;
 // add overload that supports setting offset and lenght, if you need that
 public Stream(string inputFile, BASSFlag flags)
 {
 handle = BASS_StreamCreateFile(inputFile, 0, 0, flags);
 if (handle == 0)
 throw new BassException("Could not create stream");
 }
 public ChannelInfo GetInfo()
 {
 var result = Bass.BASS_ChannelGetInfo(stream);
 if (result == null)
 throw new BassException("Could not retrieve stream info");
 return result;
 }
 // etc.
}

This would simplify the start of your code to just:

Stream stream = new Stream(inputFile,
 BASSFlag.BASS_STREAM_DECODE | BASSFlag.BASS_SAMPLE_FLOAT | BASSFlag.BASS_STREAM_PRESCAN);
var info = stream.GetInfo();