/// <summary>
/// VorbisFileWriter that actually writes to a stream
/// </summary>
/// <param name="outStream">Stream to be written to</param>
/// <param name="sampleRate">The sample rate to use</param>
/// <param name="channels">The number of channels to use</param>
/// <param name="quality">The base quality for Vorbis encoding</param>
public VorbisFileWriter(Stream outStream, int sampleRate, int channels, float quality = 0.5f)
{
this.outStream = outStream;
SampleRate = sampleRate;
Channels = channels;
if (!startBuffers.ContainsKey(sampleRate))
{
throw new InvalidOperationException($"Vorbis writer does not support {sampleRate} sample rate.");
}
// Stores all the static vorbis bitstream settings
Console.WriteLine($"Initiating variable bit rate: {channels} channels, {sampleRate} sample rate, {quality} quality");
var info = VorbisInfo.InitVariableBitRate(channels, sampleRate, quality);
// set up our packet->stream encoder
var serial = MainWindow.MainRandom.Next();
oggStream = new OggStream(serial);
// =========================================================
// HEADER
// =========================================================
// Vorbis streams begin with three headers; the initial header (with
// most of the codec setup parameters) which is mandated by the Ogg
// bitstream spec. The second header holds any comment fields. The
// third header holds the bitstream codebook.
var headerBuilder = new HeaderPacketBuilder();
var comments = new Comments();
var infoPacket = headerBuilder.BuildInfoPacket(info);
var commentsPacket = headerBuilder.BuildCommentsPacket(comments);
var booksPacket = headerBuilder.BuildBooksPacket(info);
oggStream.PacketIn(infoPacket);
oggStream.PacketIn(commentsPacket);
oggStream.PacketIn(booksPacket);
// Flush to force audio data onto its own page per the spec
FlushPages(oggStream, outStream, true);
// =========================================================
// BODY (Audio Data)
// =========================================================
processingState = ProcessingState.Create(info);
// Append some zeros at the start so the result has the same length as the input
int bufferSize = startBuffers[sampleRate];
float[][] outSamples = new float[channels][];
for (int ch = 0; ch < channels; ch++)
{
outSamples[ch] = new float[bufferSize];
}
processingState.WriteData(outSamples, bufferSize);
}
private static void ProcessChunk(float[][] floatSamples, ProcessingState processingState, OggStream oggStream, int writeBufferSize)
{
processingState.WriteData(floatSamples, writeBufferSize, 0);
while (!oggStream.Finished && processingState.PacketOut(out OggPacket packet))
{
oggStream.PacketIn(packet);
}
}
/// <summary>
/// Encodes and writes a number of float samples
/// </summary>
/// <param name="floatSamples">The samples. The array shape is [channel][sample]</param>
/// <param name="count">The number of samples to write.</param>
public void WriteFloatSamples(float[][] floatSamples, int count)
{
//Console.WriteLine($"Writing {count} samples!");
processingState.WriteData(floatSamples, count);
while (!oggStream.Finished && processingState.PacketOut(out var packet))
{
//Console.WriteLine($"Got packet with {packet.PacketData.Length} bytes of data");
oggStream.PacketIn(packet);
FlushPages(oggStream, outStream, false);
}
}
