/// <summary>
/// Decompress a JPEG image.
/// </summary>
/// <param name="jpegBuf">Pointer to a buffer containing the JPEG image to decompress. This buffer is not modified.</param>
/// <param name="jpegBufSize">Size of the JPEG image (in bytes).</param>
/// <param name="destPixelFormat">Pixel format of the destination image (see <see cref="SKColorType"/> "Pixel formats".)</param>
/// <param name="flags">The bitwise OR of one or more of the <see cref="TJFlags"/> "flags".</param>
/// <returns>Decompressed image of specified format.</returns>
/// <exception cref="TJException">Throws if underlying decompress function failed.</exception>
/// <exception cref="ObjectDisposedException">Object is disposed and can not be used anymore.</exception>
/// <exception cref="NotSupportedException">Convertion to the requested pixel format can not be performed.</exception>
public static SKBitmap Decompress(this TJDecompressor @this, IntPtr jpegBuf, ulong jpegBufSize, SKColorType destPixelFormat, TJFlags flags)
{
_ = @this ?? throw new ArgumentNullException(nameof(@this));
var targetFormat = TJSkiaUtils.ConvertPixelFormat(destPixelFormat);
@this.GetImageInfo(jpegBuf, jpegBufSize, targetFormat, out var width, out var height, out var stride, out var outBufSize);
var info = new SKImageInfo(width, height, destPixelFormat);
if (info.RowBytes != stride)
{
throw new NotSupportedException($"Skia expected the RowBytes/stride to be {info.RowBytes} for the given parameters but MozJPEG returns {stride}. Those values need to be equal.");
}
if (info.BytesSize != outBufSize)
{
throw new NotSupportedException($"Skia expected the BytesSize/number of bytes required to store the bitmap data to be {info.BytesSize} for the given parameters but MozJPEG returns {outBufSize}. Those values need to be equal.");
}
var dst = new SKBitmap(info);
var dstPtr = dst.GetPixels();
@this.Decompress(jpegBuf, jpegBufSize, dstPtr, outBufSize, targetFormat, flags, out _, out _, out _);
return(dst);
}
public static byte[] Compress(this TJCompressor @this, SKBitmap srcImage, TJSubsamplingOption subSamp, int quality, TJFlags flags)
{
_ = @this ?? throw new ArgumentNullException(nameof(@this));
_ = srcImage ?? throw new ArgumentNullException(nameof(srcImage));
var tjPixelFormat = TJSkiaUtils.ConvertPixelFormat(srcImage.ColorType);
var width = srcImage.Width;
var height = srcImage.Height;
var srcPtr = srcImage.GetPixels();
var stride = srcImage.RowBytes;
return(@this.Compress(srcPtr, stride, width, height, tjPixelFormat, subSamp, quality, flags));
}