private async Task <Stream> DibToBmpStreamAsync(Stream stream, CancellationToken token)
{
int dibSize = (int)stream.Length;
int fileHeaderSize = Marshal.SizeOf <BITMAPFILEHEADER>();
int bmpSize = fileHeaderSize + dibSize;
var buffer = new byte[bmpSize];
await stream.ReadFixedAsync(buffer.AsMemory(fileHeaderSize, dibSize), token).ConfigureAwait(false);
var infoHeader = MemoryMarshal.Read <BITMAPINFOHEADER>(buffer.AsSpan(fileHeaderSize));
var fileHeader = new BITMAPFILEHEADER
{
bfType = BITMAPFILEHEADER.BM,
bfSize = fileHeaderSize + infoHeader.biSize + infoHeader.biSizeImage,
bfReserved1 = 0,
bfReserved2 = 0,
bfOffBits = fileHeaderSize + infoHeader.biSize + infoHeader.biClrUsed * 4
};
MemoryMarshal.Write(buffer, ref fileHeader);
return(new MemoryStream(buffer));
}
private Stream DibToBmpStream(Stream stream)
{
int dibSize = (int)stream.Length;
int fileHeaderSize = Marshal.SizeOf <BITMAPFILEHEADER>();
int bmpSize = fileHeaderSize + dibSize;
var buffer = new byte[bmpSize];
stream.ReadFixed(buffer.AsSpan(fileHeaderSize, dibSize));
var infoHeader = MemoryMarshal.Read <BITMAPINFOHEADER>(buffer.AsSpan(fileHeaderSize));
var fileHeader = new BITMAPFILEHEADER
{
bfType = BITMAPFILEHEADER.BM,
bfSize = fileHeaderSize + infoHeader.biSize + infoHeader.biSizeImage,
bfReserved1 = 0,
bfReserved2 = 0,
bfOffBits = fileHeaderSize + infoHeader.biSize + infoHeader.biClrUsed * 4
};
MemoryMarshal.Write(buffer, ref fileHeader);
return(new MemoryStream(buffer));
}