public static unsafe IBitmapSource FromPointer(IntPtr data, long length)
{
var ctx = UIntPtr.Zero;
var imageHandle = UIntPtr.Zero;
var options = UIntPtr.Zero;
var image = UIntPtr.Zero;
MemoryBitmapSource b;
try {
ctx = LibHeifNative.HeifContextAlloc();
var err = LibHeifNative.HeifContextReadFromMemoryWithoutCopy(ctx, data, (UIntPtr)length, UIntPtr.Zero);
if (CheckErrPtr(err))
{
throw new Exception("Failed.");
}
var imageCount = LibHeifNative.HeifContextGetNumberOfTopLevelImages(ctx);
if (imageCount == 0)
{
throw new Exception("Failed.");
}
var imageIDs = new heif_item_id[imageCount];
fixed(heif_item_id *ptr = imageIDs)
{
imageCount = LibHeifNative.HeifContextGetListOfTopLevelImageIDs(ctx, (UIntPtr)ptr, imageCount);
}
err = LibHeifNative.HeifContextGetImageHandle(ctx, imageIDs[0], ref imageHandle);
if (CheckErrPtr(err))
{
throw new Exception("Failed.");
}
var depth = LibHeifNative.HeifImageHandleGetLumaBitsPerPixel(imageHandle);
if (depth < 0)
{
throw new Exception("Failed.");
}
options = LibHeifNative.HeifDecodingOptionsAlloc();
var hasAlpha = LibHeifNative.HeifImageHandleHasAlphaChannel(imageHandle) != 0;
HeifChroma chroma;
int targetDepth;
int targetChannel;
if (depth <= 8)
{
chroma = HeifChroma.HeifChromaInterleavedRgba;
targetDepth = 8;
targetChannel = 4;
}
else if (hasAlpha)
{
chroma = HeifChroma.HeifChromaInterleavedRrggbbaaLe;
targetDepth = 16;
targetChannel = 4;
}
else
{
chroma = HeifChroma.HeifChromaInterleavedRrggbbLe;
targetDepth = 16;
targetChannel = 3;
}
err = LibHeifNative.HeifDecodeImage(imageHandle, ref image, HeifColorspace.HeifColorspaceRgb,
chroma, options);
if (CheckErrPtr(err) || image == UIntPtr.Zero)
{
throw new Exception("Failed.");
}
var width = LibHeifNative.HeifImageGetWidth(image, HeifChannel.HeifChannelInterleaved);
var height = LibHeifNative.HeifImageGetHeight(image, HeifChannel.HeifChannelInterleaved);
b = new MemoryBitmapSource(width, height, targetDepth, targetChannel);
var strideSource = 0;
var strideDest = b.Stride;
var raw = LibHeifNative.HeifImageGetPlaneReadonly(image, HeifChannel.HeifChannelInterleaved, ref strideSource);
var ptrBegin = b.Scan0;
if (strideSource != strideDest)
{
for (var line = 0; line < height; line++)
{
var src = raw + line * strideSource;
var dst = ptrBegin + line * strideDest;
Buffer.MemoryCopy(src.ToPointer(), dst.ToPointer(), strideSource, strideDest);
}
}
else
{
Buffer.MemoryCopy(raw.ToPointer(), ptrBegin.ToPointer(), strideSource * height, strideDest * height);
}
Console.WriteLine();
// ReSharper disable once SwitchStatementMissingSomeEnumCasesNoDefault
switch (chroma)
{
case HeifChroma.HeifChromaInterleavedRgba:
PixelTool.BGRA2RGBA(b.Scan0, (UIntPtr)(width * height));
break;
case HeifChroma.HeifChromaInterleavedRrggbbaaLe:
PixelTool.DEPTHCONVERT(b.Scan0, (UIntPtr)(width * height * 4), (UIntPtr)depth);
break;
case HeifChroma.HeifChromaInterleavedRrggbbLe:
PixelTool.DEPTHCONVERT(b.Scan0, (UIntPtr)(width * height * 3), (UIntPtr)depth);
break;
}
}
finally {
if (ctx != UIntPtr.Zero)
{
LibHeifNative.HeifContextFree(ctx);
}
if (imageHandle != UIntPtr.Zero)
{
LibHeifNative.HeifImageHandleRelease(imageHandle);
}
if (options != UIntPtr.Zero)
{
LibHeifNative.HeifDecodingOptionsFree(options);
}
if (image != UIntPtr.Zero)
{
LibHeifNative.HeifImageRelease(image);
}
}
return(b);
}
