static NativeStreamEncoder InitializeEncoder(AudioInfo audioInfo, Stream output)
{
Contract.Requires(audioInfo != null);
Contract.Requires(output != null);
Contract.Requires(output.CanWrite);
Contract.Requires(output.CanSeek);
var result = new NativeStreamEncoder(output);
result.SetChannels((uint)audioInfo.Channels);
result.SetBitsPerSample((uint)audioInfo.BitsPerSample);
result.SetSampleRate((uint)audioInfo.SampleRate);
result.SetTotalSamplesEstimate((ulong)audioInfo.SampleCount);
return(result);
}
public void Initialize(Stream stream, AudioInfo audioInfo, MetadataDictionary metadata, SettingsDictionary settings)
{
Contract.Ensures(_encoder != null);
Contract.Ensures(_encoder.GetState() == EncoderState.Ok);
Contract.Ensures(_multiplier > 0);
_encoder = InitializeEncoder(audioInfo, stream);
_metadataBlocks = new List <NativeMetadataBlock>(3); // Assumes one metadata block, one picture and one seek table
_multiplier = (float)Math.Pow(2, audioInfo.BitsPerSample - 1);
uint compressionLevel;
if (string.IsNullOrEmpty(settings["CompressionLevel"]))
{
compressionLevel = 5;
}
else if (!uint.TryParse(settings["CompressionLevel"], out compressionLevel) || compressionLevel > 8)
{
throw new InvalidSettingException(string.Format(CultureInfo.CurrentCulture,
Resources.SampleEncoderBadCompressionLevel, settings["CompressionLevel"]));
}
_encoder.SetCompressionLevel(compressionLevel);
var vorbisCommentBlock = new NativeVorbisCommentBlock();
foreach (var field in new MetadataToVorbisCommentAdapter(metadata))
{
vorbisCommentBlock.Append(field.Key, field.Value);
}
_metadataBlocks.Add(vorbisCommentBlock);
// Add a seek table, unless SeekPointInterval = 0:
uint seekPointInterval;
if (string.IsNullOrEmpty(settings["SeekPointInterval"]))
{
seekPointInterval = 10;
}
else if (!uint.TryParse(settings["SeekPointInterval"], out seekPointInterval))
{
throw new InvalidSettingException(string.Format(CultureInfo.CurrentCulture,
Resources.SampleEncoderBadSeekPointInterval, settings["SeekPointInterval"]));
}
if (seekPointInterval > 0)
{
_metadataBlocks.Add(new NativeSeekTableBlock(
(int)Math.Ceiling(audioInfo.SampleCount / (double)audioInfo.SampleRate / seekPointInterval),
audioInfo.SampleCount));
}
// Add a picture block, if cover art is available:
if (metadata.CoverArt != null)
{
_metadataBlocks.Add(new CoverArtToPictureBlockAdapter(metadata.CoverArt));
}
_encoder.SetMetadata(_metadataBlocks);
EncoderInitStatus initStatus = _encoder.Initialize();
if (initStatus != EncoderInitStatus.Ok)
{
throw new IOException(string.Format(CultureInfo.CurrentCulture,
Resources.SampleEncoderInitializationError, initStatus));
}
}