public void TestWindowing()
{
float[] samples = new float[] {
1, 1, 1, 1, 1, 1, 1, 1, 1, 1,
0, 0, 0, 0, 0, 0, 0, 0, 0, 0,
-1, -1, -1, -1, -1, -1, -1, -1, -1, -1
};
byte[] samplesAsBytes = new byte[samples.Length * 4];
Buffer.BlockCopy(samples, 0, samplesAsBytes, 0, samplesAsBytes.Length);
var source = new MemorySourceStream(new System.IO.MemoryStream(samplesAsBytes), new AudioProperties(1, 44100, 32, AudioFormat.IEEE));
var windower = new StreamWindower(source, 10, 10);
float[] frame = new float[10];
// Read first 10 items that are 1
windower.ReadFrame(frame);
CollectionAssert.AreEqual(frame, Enumerable.Repeat(1f, 10).ToArray());
// Read next 10 items that are 0
windower.ReadFrame(frame);
CollectionAssert.AreEqual(frame, Enumerable.Repeat(0f, 10).ToArray());
// Read last 10 items that are -1
windower.ReadFrame(frame);
CollectionAssert.AreEqual(frame, Enumerable.Repeat(-1f, 10).ToArray());
}
private static void DecodeAudio(string filename)
{
FFmpegReader reader = new FFmpegReader(filename, Type.Audio);
Console.WriteLine("length {0}, frame_size {1}, sample_rate {2}, sample_size {3}, channels {4}",
reader.AudioOutputConfig.length,
reader.AudioOutputConfig.frame_size,
reader.AudioOutputConfig.format.sample_rate,
reader.AudioOutputConfig.format.sample_size,
reader.AudioOutputConfig.format.channels);
int sampleBlockSize = reader.AudioOutputConfig.format.channels * reader.AudioOutputConfig.format.sample_size;
int output_buffer_size = reader.AudioOutputConfig.frame_size *
reader.AudioOutputConfig.format.channels * reader.AudioOutputConfig.format.sample_size;
byte[] output_buffer = new byte[output_buffer_size];
int samplesRead;
long timestamp;
Type type;
MemoryStream ms = new MemoryStream();
// read full stream
while ((samplesRead = reader.ReadFrame(out timestamp, output_buffer, output_buffer_size, out type)) > 0)
{
Console.WriteLine("read " + samplesRead + " @ " + timestamp);
// read samples into memory
int bytesRead = samplesRead * sampleBlockSize;
ms.Write(output_buffer, 0, bytesRead);
}
// seek back to start
reader.Seek(0, Type.Audio);
// read again (output should be the same as above)
while ((samplesRead = reader.ReadFrame(out timestamp, output_buffer, output_buffer_size, out type)) > 0)
{
Console.WriteLine("read " + samplesRead + " @ " + timestamp);
}
reader.Dispose();
// write memory to wav file
ms.Position = 0;
MemorySourceStream mss = new MemorySourceStream(ms, new AudioProperties(
reader.AudioOutputConfig.format.channels,
reader.AudioOutputConfig.format.sample_rate,
reader.AudioOutputConfig.format.sample_size * 8,
reader.AudioOutputConfig.format.sample_size == 4 ? AudioFormat.IEEE : AudioFormat.LPCM));
IeeeStream ieee = new IeeeStream(mss);
NAudioSinkStream nAudioSink = new NAudioSinkStream(ieee);
WaveFileWriter.CreateWaveFile(filename + ".ffmpeg.wav", nAudioSink);
}
