// cf. http://stackoverflow.com/questions/4598872/creating-hbitmap-from-memory-buffer/4616394#4616394
Bitmap *BitmapFromData(const char *data, size_t len)
{
ImgFormat format = GfxFormatFromData(data, len);
if (Img_TGA == format)
return tga::ImageFromData(data, len);
if (Img_WebP == format)
return webp::ImageFromData(data, len);
if (Img_JP2 == format)
return fitz::ImageFromData(data, len);
if (Img_JPEG == format && JpegUsesArithmeticCoding(data, len))
return fitz::ImageFromData(data, len);
ScopedComPtr<IStream> stream(CreateStreamFromData(data, len));
if (!stream)
return NULL;
if (Img_JXR == format)
return WICDecodeImageFromStream(stream);
Bitmap *bmp = Bitmap::FromStream(stream);
if (bmp && bmp->GetLastStatus() != Ok) {
delete bmp;
bmp = NULL;
}
// GDI+ under Windows XP sometimes fails to extract JPEG image dimensions
if (bmp && Img_JPEG == format && (0 == bmp->GetWidth() || 0 == bmp->GetHeight())) {
delete bmp;
bmp = fitz::ImageFromData(data, len);
}
return bmp;
}
bool IsGdiPlusNativeFormat(const char *data, size_t len)
{
ImgFormat fmt = GfxFormatFromData(data, len);
return Img_BMP == fmt || Img_GIF == fmt ||
(Img_JPEG == fmt && !JpegUsesArithmeticCoding(data, len)) ||
Img_PNG == fmt || Img_TIFF == fmt;
}
// Windows' JPEG codec doesn't support arithmetic coding
static bool JpegUsesArithmeticCoding(const char* data, size_t len) {
CrashIf(GfxFormatFromData(data, len) != Img_JPEG);
ByteReader r(data, len);
for (size_t ix = 2; ix + 9 < len && r.Byte(ix) == 0xFF; ix += r.WordBE(ix + 2) + 2) {
if (0xC9 <= r.Byte(ix + 1) && r.Byte(ix + 1) <= 0xCB) {
// found the start of a frame using arithmetic coding
return true;
}
}
return false;
}
// Windows' PNG codec fails to handle an edge case, resulting in
// an infinite loop (cf. http://cxsecurity.com/issue/WLB-2014080021 )
static bool PngRequiresPresetDict(const char* data, size_t len) {
CrashIf(GfxFormatFromData(data, len) != Img_PNG);
ByteReader r(data, len);
for (size_t ix = 8; ix + 12 < len && r.DWordBE(ix) < len - ix - 12; ix += r.DWordBE(ix) + 12) {
if (r.DWordBE(ix + 4) == 0x49444154 /* IDAT */) {
// check the zlib header's FDICT flag
// (even if this image claims not to be zlib compressed!)
return (r.Byte(ix + 9) & (1 << 5)) != 0;
}
}
return false;
}
const WCHAR *GfxFileExtFromData(const char *data, size_t len)
{
switch (GfxFormatFromData(data, len)) {
case Img_BMP: return L".bmp";
case Img_GIF: return L".gif";
case Img_JPEG: return L".jpg";
case Img_JXR: return L".jxr";
case Img_PNG: return L".png";
case Img_TGA: return L".tga";
case Img_TIFF: return L".tif";
case Img_WebP: return L".webp";
case Img_JP2: return L".jp2";
default: return NULL;
}
}
// adapted from http://cpansearch.perl.org/src/RJRAY/Image-Size-3.230/lib/Image/Size.pm
Size BitmapSizeFromData(const char *data, size_t len)
{
Size result;
ByteReader r(data, len);
switch (GfxFormatFromData(data, len)) {
case Img_BMP:
if (len >= sizeof(BITMAPFILEHEADER) + sizeof(BITMAPINFOHEADER)) {
BITMAPINFOHEADER bmi;
bool ok = r.UnpackLE(&bmi, sizeof(bmi), "3d2w6d", sizeof(BITMAPFILEHEADER));
CrashIf(!ok);
result.Width = bmi.biWidth;
result.Height = bmi.biHeight;
}
break;
case Img_GIF:
if (len >= 13) {
// find the first image's actual size instead of using the
// "logical screen" size which is sometimes too large
size_t ix = 13;
// skip the global color table
if ((r.Byte(10) & 0x80))
ix += 3 * (1 << ((r.Byte(10) & 0x07) + 1));
while (ix + 8 < len) {
if (r.Byte(ix) == 0x2C) {
result.Width = r.WordLE(ix + 5);
result.Height = r.WordLE(ix + 7);
break;
}
else if (r.Byte(ix) == 0x21 && r.Byte(ix + 1) == 0xF9)
ix += 8;
else if (r.Byte(ix) == 0x21 && r.Byte(ix + 1) == 0xFE) {
const char *commentEnd = r.Find(ix + 2, 0x00);
ix = commentEnd ? commentEnd - data + 1 : len;
}
else if (r.Byte(ix) == 0x21 && r.Byte(ix + 1) == 0x01 && ix + 15 < len) {
const char *textDataEnd = r.Find(ix + 15, 0x00);
ix = textDataEnd ? textDataEnd - data + 1 : len;
}
else if (r.Byte(ix) == 0x21 && r.Byte(ix + 1) == 0xFF && ix + 14 < len) {
const char *applicationDataEnd = r.Find(ix + 14, 0x00);
ix = applicationDataEnd ? applicationDataEnd - data + 1 : len;
}
else
break;
}
}
break;
case Img_JPEG:
// find the last start of frame marker for non-differential Huffman/arithmetic coding
for (size_t ix = 2; ix + 9 < len && r.Byte(ix) == 0xFF; ) {
if (0xC0 <= r.Byte(ix + 1) && r.Byte(ix + 1) <= 0xC3 ||
0xC9 <= r.Byte(ix + 1) && r.Byte(ix + 1) <= 0xCB) {
result.Width = r.WordBE(ix + 7);
result.Height = r.WordBE(ix + 5);
}
ix += r.WordBE(ix + 2) + 2;
}
break;
case Img_JXR:
case Img_TIFF:
if (len >= 10) {
bool isBE = r.Byte(0) == 'M', isJXR = r.Byte(2) == 0xBC;
CrashIf(!isBE && r.Byte(0) != 'I' || isJXR && isBE);
const WORD WIDTH = isJXR ? 0xBC80 : 0x0100, HEIGHT = isJXR ? 0xBC81 : 0x0101;
size_t idx = r.DWord(4, isBE);
WORD count = idx <= len - 2 ? r.Word(idx, isBE) : 0;
for (idx += 2; count > 0 && idx <= len - 12; count--, idx += 12) {
WORD tag = r.Word(idx, isBE), type = r.Word(idx + 2, isBE);
if (r.DWord(idx + 4, isBE) != 1)
continue;
else if (WIDTH == tag && 4 == type)
result.Width = r.DWord(idx + 8, isBE);
else if (WIDTH == tag && 3 == type)
result.Width = r.Word(idx + 8, isBE);
else if (WIDTH == tag && 1 == type)
result.Width = r.Byte(idx + 8);
else if (HEIGHT == tag && 4 == type)
result.Height = r.DWord(idx + 8, isBE);
else if (HEIGHT == tag && 3 == type)
result.Height = r.Word(idx + 8, isBE);
else if (HEIGHT == tag && 1 == type)
result.Height = r.Byte(idx + 8);
}
}
break;
case Img_PNG:
if (len >= 24 && str::StartsWith(data + 12, "IHDR")) {
result.Width = r.DWordBE(16);
result.Height = r.DWordBE(20);
}
break;
case Img_TGA:
if (len >= 16) {
result.Width = r.WordLE(12);
result.Height = r.WordLE(14);
}
break;
case Img_WebP:
if (len >= 30 && str::StartsWith(data + 12, "VP8 ")) {
result.Width = r.WordLE(26) & 0x3fff;
result.Height = r.WordLE(28) & 0x3fff;
}
else {
result = webp::SizeFromData(data, len);
}
break;
case Img_JP2:
if (len >= 32) {
size_t ix = 0;
while (ix < len - 32) {
uint32_t lbox = r.DWordBE(ix);
uint32_t tbox = r.DWordBE(ix + 4);
if (0x6A703268 /* jp2h */ == tbox) {
ix += 8;
if (r.DWordBE(ix) == 24 && r.DWordBE(ix + 4) == 0x69686472 /* ihdr */) {
result.Width = r.DWordBE(ix + 16);
result.Height = r.DWordBE(ix + 12);
}
break;
}
else if (lbox != 0 && ix < UINT32_MAX - lbox) {
ix += lbox;
}
else {
break;
}
}
}
break;
}
if (result.Empty()) {
// let GDI+ extract the image size if we've failed
// (currently happens for animated GIF)
Bitmap *bmp = BitmapFromData(data, len);
if (bmp)
result = Size(bmp->GetWidth(), bmp->GetHeight());
delete bmp;
}
return result;
}