public float[] GetBCH(BCH bch, bool debug = false)
{
Log.Information($"encoding BCH: [{bch.Text}]");
if (Log.IsEnabled(Serilog.Events.LogEventLevel.Debug))
{
var binary = bch.Binary.ToArray();
for (int i = 0; i < bch.Text.Length; i++)
{
var chunk = new string(binary.Skip(8 * i).Take(8).Select(x => x == 1 ? '1' : '0').ToArray());
var b = Convert.ToByte(chunk, 2);
Log.Debug($"decoded BCH: {(char)b} ({string.Concat(chunk.Select(x => x.ToString()).ToArray())})");
}
}
var bitLength = 4;
var one = Enumerable.Repeat(1f, bitLength).ToArray();
var zero = Enumerable.Repeat(-1f, bitLength).ToArray();
var bin = debug
? Enumerable.Range(0, bch.Binary.Count()).Select(x => x / 8 % 2 == 0 ? zero : one).SelectMany(x => x).ToArray()
: bch.Binary.Select(x => x == 1 ? one : zero).SelectMany(x => x).ToArray();
var padding = new float[ImageWidth - bin.Length];
return(Enumerable.Range(0, bitLength).Select(_ => GetLine(bin.Concat(padding).ToArray())).SelectMany(x => x).ToArray());
}
private static void Send(string filename, BCH bch = null)
{
var fax = new Fax(16000);
Log.Information($"loading: {filename}");
using var original = Image.FromFile(filename);
Log.Information($"original image: {original.Width}x{original.Height}");
var scalingFactor = fax.ImageWidth / (float)original.Width;
using var scaled = new Bitmap(fax.ImageWidth, (int)Math.Round(original.Height * scalingFactor));
using var graphics = Graphics.FromImage(scaled);
graphics.InterpolationMode = System.Drawing.Drawing2D.InterpolationMode.HighQualityBicubic;
graphics.DrawImage(original, 0, 0, scaled.Width, scaled.Height);
Log.Information($"scaled image: {scaled.Width}x{scaled.Height}");
var wavFilename = Path.Combine(Path.GetDirectoryName(filename), $"{Path.GetFileNameWithoutExtension(filename)}.wav");
using var writer = new WaveFileWriter(wavFilename, new WaveFormat(fax.SampleRate, 1));
var start = fax.GetStart();
writer.WriteSamples(start, 0, start.Length);
var phasing = fax.GetPhasing();
writer.WriteSamples(phasing, 0, phasing.Length);
if (bch != null)
{
var header = fax.GetBCH(bch);
writer.WriteSamples(header, 0, header.Length);
//var debug = fax.GetBCH(bch, true);
//writer.WriteSamples(debug, 0, debug.Length);
}
for (int y = 0; y < scaled.Height; y++)
{
var pixels = Enumerable.Range(0, scaled.Width).Select(x => scaled.GetPixel(x, y).GetBrightness() * 2f - 1).ToArray();
var samples = fax.GetLine(pixels);
writer.WriteSamples(samples, 0, samples.Length);
}
var stop = fax.GetStop();
writer.WriteSamples(stop, 0, stop.Length);
Log.Information($"wrote: {wavFilename}");
}