Custom WIC decoder IE9+

Question

Hi,

I have followed the documentation at: http://msdn.microsoft.com/en-us/library/ee719883(v=vs.85).aspx. I have developed a WIC decoder that implements WICBitmapDecoder and WICBitmapFrameDecode based on AitCodec. I have digitally signed the DLL, and added the digital certificate to the trusted root certification authorities in Windows 7. 

I now have an issue where IE9 seems to be ignoring the codec. Are there any special registry entries that I may be missing? Does someone have the requisite registry settings in order for a signed custom WIC Codec to be used by IE9+?

Thanks,
Will

Answer 1

Will11,

as far as I know IE9 is not extensible in that way, probably because of security reasons. If your codec is registered correctly, Windows Explorer will use it to generate thumbnails and the Windows Image Viewer will be able to show your pictures. Although IE9 uses the WIC codecs to decode the standard image formats, you cannot register your own codec for IE9, at least there seems to be no offically supported way.

However, you should be able to add custom image format support to IE9 by writing a browser add-on.

Answer 2

Thanks for your response Crysler,

Well I'm a little concerned. Did I miss something? I spent days pouring over documentation. I have never found any reference to IE9 only using the standard image format codecs. If there is an unofficial, unsupported way, I will have to opt to take that route. As for the security concerns... the codec must be signed and trusted in order to properly function anyway. :)

> However, you should be able to add custom image format support to IE9 by writing a browser add-on.

Would this browser add-on be WIC based? We already have a browser helper object which works up to the point of refreshing. When new image frames are added we no longer have a reliable method of refreshing the images in IE9, probably due to the technology switch to direct rendering.

Answer 3

Hi Will11,

Internet Explorer does use WIC to decode image formats. However, as a web browser it only supports the common "web standard" image formats, including JPG, GIF, BMP, PNG and TIFF, and does not allow third party codecs to be used. The security concerns go deeper than whether or not the code is signed by a known third party; the intent is to minimize exposure to bugs in the third party's code which can expose IE to additional attack vectors.

Simon

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Answer 4

Hi Simon,

Thank-you for your response.

We're a Microsoft Partner, and we have relied on old image surface manipulation APIs for our product. This product integrates deeply with Internet Explorer. The prior generation APIs no longer function properly in IE9+ likely due to technology enhancements, namely the switch to accelerated page rendering. The main issue we had was that the image surface returned by the link above has changed internally, and no longer refreshes the image in IE9 properly with our method. We would like to schedule a conference call with you or someone related regarding this WIC codec as it is a very important aspect of our business. Could you please send me a private forum message, or reply to my project manager's message to you on Linked-In?

Thanks!
Will11