SimdCodecs

using Sdcb.SimdCodecs;
using Sdcb.SimdCodecs.Abstractions;

byte[] file = File.ReadAllBytes("photo.webp");   // JPEG, PNG, TIFF, WebP, GIF, JPEG 2000, JBIG2

// 按魔数识别格式，只读文件头
if (!SimdCodecs.TryReadInfo(file, out ImageInfo info)) throw new InvalidDataException();
Console.WriteLine($"{info.Width}×{info.Height}, {info.BitDepth}-bit, {info.FrameCount} frame(s), {info.Orientation}");

// 解码到你自己的缓冲区（R G B A）
byte[] rgba = new byte[info.Width * info.Height * 4];
SimdCodecs.TryDecodeIntoRgba8(file, rgba);

// 直接写进 SkiaSharp / WPF / OpenCV 的像素内存，中间没有 RGBA 帧
using SKBitmap bmp = new(info.Width, info.Height, SKColorType.Bgra8888, SKAlphaType.Unpremul);
unsafe
{
    Span<byte> dst = new((byte*)bmp.GetPixels(), bmp.RowBytes * bmp.Height);
    SimdCodecs.TryDecodeInto(file, dst, bmp.RowBytes, ImagePixelFormat.Bgra32);
}

// OCR 只要灰度：彩色 JPEG 直接取 Y 平面，色度整个跳过
byte[] grey = new byte[info.Width * info.Height];
SimdCodecs.TryDecodeInto(file, grey, info.Width, ImagePixelFormat.Gray8);

using Sdcb.SimdCodecs.Jpeg;

// SIMD 编码器：基线 / 优化 Huffman / 渐进，4:2:0 或 4:4:4，可带 EXIF 与 XMP
byte[] jpeg = JpegEncoder.Encode(rgba, info.Width, info.Height, channels: 4, new JpegEncodeOptions
{
    Quality = 90,
    Subsampling = JpegSubsampling.Chroma420,
    Progressive = true,
});
File.WriteAllBytes("photo.jpg", jpeg);

// 动图 WebP / GIF 的合成帧（带时长）、多页 TIFF 的每一页，同一套 API
if (SimdCodecs.TryOpenFrames(file, out IImageFrameReader? reader))
using (reader)
{
    for (int i = 0; i < reader.FrameCount; i++)
    {
        reader.TryGetFrameInfo(i, out ImageFrameInfo frame);
        byte[] buffer = new byte[frame.Info.Width * frame.Info.Height * 4];
        reader.TryDecodeFrameInto(i, buffer, stride: 0, ImagePixelFormat.Rgba32);
        Console.WriteLine($"#{i}: {frame.Info.Width}×{frame.Info.Height}, {frame.Duration?.TotalMilliseconds} ms");
    }
}