public static byte[] EncodeParallelExample(Gif gif)
{
var stopwatch = new Stopwatch();
stopwatch.Start();
var encodeProgress = new EncodeProgress();
gif.EncodeParallel(progress =>
{
Console.WriteLine("Encode progress: {0}/{1}", progress.Progress, progress.FrameCount);
encodeProgress = progress;
});
while (!encodeProgress.Completed)
{
Thread.Sleep(100);
}
if (encodeProgress.Exception != null)
{
throw encodeProgress.Exception;
}
stopwatch.Stop();
Console.WriteLine("GIF encoded in {0:n2}s to binary.", stopwatch.Elapsed.TotalSeconds);
return(encodeProgress.Bytes);
}
/// <summary>
/// Encode GIF in multiple threads.
/// </summary>
public void EncodeParallel(Action <EncodeProgress> onProgress, int scale = 1) // TODO: Refact.
{
if (_free)
{
throw new Exception("The Free version doesn't support this feature. Please consider buying the Full version of Power GIF.");
}
const string header = "GIF89a";
var width = (ushort)(Frames[0].Texture.width * scale);
var height = (ushort)(Frames[0].Texture.height * scale);
var globalColorTable = new List <Color32>();
var applicationExtension = new ApplicationExtension();
var encoded = new Dictionary <int, List <byte> >();
var encodeProgress = new EncodeProgress {
FrameCount = Frames.Count
};
var colorTables = new List <Color32> [Frames.Count];
var distinctColors = new Dictionary <int, List <Color32> >();
var manualResetEvent = new ManualResetEvent(false);
for (var i = 0; i < Frames.Count; i++)
{
var frame = Frames[i];
ThreadPool.QueueUserWorkItem(context =>
{
var distinct = frame.Texture.GetPixels32().Distinct().ToList();
lock (distinctColors)
{
distinctColors.Add((int)context, distinct);
if (distinctColors.Count == Frames.Count)
{
manualResetEvent.Set();
}
}
}, i);
}
manualResetEvent.WaitOne();
for (var i = 0; i < Frames.Count; i++)
{
var colors = distinctColors[i];
var add = colors.Where(j => !globalColorTable.Contains(j)).ToList();
if (globalColorTable.Count + add.Count <= 256)
{
globalColorTable.AddRange(add);
colorTables[i] = globalColorTable;
}
else if (colors.Count <= 256) // Introduce local color table.
{
colorTables[i] = colors;
}
else
{
onProgress(new EncodeProgress {
Completed = true, Exception = new Exception($"Frame #{i} contains more than 256 colors!")
});
return;
}
}
ReplaceTransparentColor(ref globalColorTable);
for (var i = 0; i < Frames.Count; i++) // Don't use Parallel.For to leave .NET compatibility.
{
ThreadPool.QueueUserWorkItem(context =>
{
var index = (int)context;
var colorTable = colorTables[index];
var localColorTableFlag = (byte)(colorTable == globalColorTable ? 0 : 1);
var localColorTableSize = GetColorTableSize(colorTable);
byte transparentColorFlag = 0, transparentColorIndex = 0;
byte max;
var colorIndexes = GetColorIndexes(Frames[index].Texture, scale, colorTable, localColorTableFlag, ref transparentColorFlag, ref transparentColorIndex, out max);
var graphicControlExtension = new GraphicControlExtension(4, 0, (byte)Frames[index].DisposalMethod, 0, transparentColorFlag, (ushort)(100 * Frames[index].Delay), transparentColorIndex);
var imageDescriptor = new ImageDescriptor(0, 0, width, height, localColorTableFlag, 0, 0, 0, localColorTableSize);
var minCodeSize = LzwEncoder.GetMinCodeSize(max);
var lzw = LzwEncoder.Encode(colorIndexes, minCodeSize);
var tableBasedImageData = new TableBasedImageData(minCodeSize, lzw);
var bytes = new List <byte>();
bytes.AddRange(graphicControlExtension.GetBytes());
bytes.AddRange(imageDescriptor.GetBytes());
if (localColorTableFlag == 1)
{
bytes.AddRange(ColorTableToBytes(colorTable, localColorTableSize));
}
bytes.AddRange(tableBasedImageData.GetBytes());
lock (encoded)
{
encoded.Add(index, bytes);
encodeProgress.Progress++;
if (encoded.Count == Frames.Count)
{
var globalColorTableSize = GetColorTableSize(globalColorTable);
var logicalScreenDescriptor = new LogicalScreenDescriptor(width, height, 1, 7, 0, globalColorTableSize, 0, 0);
var binary = new List <byte>();
binary.AddRange(Encoding.UTF8.GetBytes(header));
binary.AddRange(logicalScreenDescriptor.GetBytes());
binary.AddRange(ColorTableToBytes(globalColorTable, globalColorTableSize));
binary.AddRange(applicationExtension.GetBytes());
binary.AddRange(encoded.OrderBy(j => j.Key).SelectMany(j => j.Value));
binary.Add(0x3B); // GIF Trailer.
encodeProgress.Bytes = binary.ToArray();
encodeProgress.Completed = true;
}
onProgress(encodeProgress);
}
}, i);
}
}
