diff --git a/Emby.Drawing/Common/ImageHeader.cs b/Emby.Drawing/Common/ImageHeader.cs
index 7b819c2fd6..f37f396f59 100644
--- a/Emby.Drawing/Common/ImageHeader.cs
+++ b/Emby.Drawing/Common/ImageHeader.cs
@@ -121,7 +121,7 @@ namespace Emby.Drawing.Common
///
/// The binary reader.
/// System.Int16.
- private static short ReadLittleEndianInt16(BinaryReader binaryReader)
+ private static short ReadLittleEndianInt16(this BinaryReader binaryReader)
{
var bytes = new byte[sizeof(short)];
@@ -137,7 +137,7 @@ namespace Emby.Drawing.Common
///
/// The binary reader.
/// System.Int32.
- private static int ReadLittleEndianInt32(BinaryReader binaryReader)
+ private static int ReadLittleEndianInt32(this BinaryReader binaryReader)
{
var bytes = new byte[sizeof(int)];
for (int i = 0; i < sizeof(int); i += 1)
@@ -205,25 +205,30 @@ namespace Emby.Drawing.Common
///
private static ImageSize DecodeJfif(BinaryReader binaryReader)
{
+ // A JPEG image consists of a sequence of segments,
+ // each beginning with a marker, each of which begins with a 0xFF byte
+ // followed by a byte indicating what kind of marker it is.
+ // Source: https://en.wikipedia.org/wiki/JPEG#Syntax_and_structure
while (binaryReader.ReadByte() == 0xff)
{
byte marker = binaryReader.ReadByte();
- short chunkLength = ReadLittleEndianInt16(binaryReader);
- if (marker == 0xc0)
+ short chunkLength = binaryReader.ReadLittleEndianInt16();
+ // SOF0: Indicates that this is a baseline DCT-based JPEG,
+ // and specifies the width, height, number of components, and component subsampling
+ // SOF2: Indicates that this is a progressive DCT-based JPEG,
+ // and specifies the width, height, number of components, and component subsampling
+ if (marker == 0xc0 || marker == 0xc2)
{
- binaryReader.ReadByte();
- int height = ReadLittleEndianInt16(binaryReader);
- int width = ReadLittleEndianInt16(binaryReader);
- return new ImageSize
- {
- Width = width,
- Height = height
- };
+ // https://help.accusoft.com/ImageGear/v18.2/Windows/ActiveX/IGAX-10-12.html
+ binaryReader.ReadByte(); // We don't care about the first byte
+ int height = binaryReader.ReadLittleEndianInt16();
+ int width = binaryReader.ReadLittleEndianInt16();
+ return new ImageSize(width, height);
}
if (chunkLength < 0)
{
- var uchunkLength = (ushort)chunkLength;
+ ushort uchunkLength = (ushort)chunkLength;
binaryReader.ReadBytes(uchunkLength - 2);
}
else