Another example of a negligence with a cost of incompatibility and enormous amount of support time. Ahead Nero installs a number of DirectShow filters into $(Program Files)\Common Files\Ahead\DSFilter directory. One of the files is NeResize.ax and it hosts a Nero Resize filter. Let us take a closer look:
CLSID: {30002E0C-C574-481E-A5DE-90AE54A79E10} (note that Nero 8 ships the same buggy stuff with new CLSID of {3D0A27C9-B4D6-487B-AFE4-E3CABD4B81F9} – 11.05.2010)
Merit: 0x00400000 (MERIT_UNLIKELY)
Input Pin’s Media Type: major type GUID_NULL, subtype GUID_NULL
Output Pin’s Media Type: major type GUID_NULL, subtype GUID_NULL
The filter is clearly a video filter:
So the filter register itself under a merit that allows taking it during Intelligent Connect, it registers using media type wildcard which is clearly widely than the filter can affectively operate with and the most interesting part is: with certain video media types the filter crashes (memory access violation) during pin connection negotiation process. That is, inaccurate filter may be crashing third party software it has nothing to deal with at all.
*** Unhandled Exception Process: 0x000001d4, Thread: 0x00000ce4, Date: 6/29/2009, Time: 11:20:56 AM, Application: C:\Program Files\... Module: C:\..., Product Version: 1.7.1.1, File Version: 1.7.1.20014, File Time: 23.06.2009, 19:02 Code: 0xc0000005, Flags: 0x00000000, Address: 0x05fc6c65 Parameters: 0x00000001, 0x15be9030 ** Call Stack NeResize!05fc6c65 DllUnregisterServer +21909 @05fc0000 NeResize!05fc7888 DllUnregisterServer +25016 @05fc0000 NeResize!05fc7204 DllUnregisterServer +23348 @05fc0000
Additionally to that the filter does not allow its insertion in debugging environment, and it seems even with Visual Studio running without a debugging session active. Which means that developer may be unaware of issues until incompatibility comes up at a later stage such as testing, or at production site.
It is not the first Nero filter which is bringing real problems. Basically any user who want to keep his system far from issues while still having Nero installed, needs to do find $(Program Files)\Common Files\Ahead\DSFilter directory and immediately rename it to some ~DSFilter in order to invalidate all Nero filters registration.
A few quotes from Guidelines for Registering Filters:
Avoid specifying MEDIATYPE_None, MEDIASUBTYPE_None, or GUID_NULL in the AMOVIESETUP_MEDIATYPE information for a pin. IFilterMapper2 treats these as wildcards, which can slow the graph-building process.
Nero Resize does specify and obviously slows the system down.
Choose the lowest merit value possible. Here are some guidelines:
…
Special purpose filter; any filter that is created directly by the application: MERIT_DO_NOT_USE
Nero Resize uses higher value and thus affects proper applications.
Software developers will be safer to prevent from DirectShow Filter Graph Manager considering the buggy filter to be used during Intelligent Connect by implementing IAMGraphBuilderCallback interface.
Good news from Ahead! With Nero 8 they ship the same buggy filter but with a new CLSID {3D0A27C9-B4D6-487B-AFE4-E3CABD4B81F9}. If you maintain a black list for buggy DirectShow filters, you might want to update it with this one.
Nero is a lot worse than this. For example they also install their own splitters – the symptoms in other applications being you can no longer seek ! Indeed, Nero is banned here as you can not debug video software with Nero installed as they detect a debugger is running and cause a Windows message that a debugger is running so your app has been terminated; of course the message doesn’t tell you it was Nero causing it, and it was several lost days of development trying to work out why we got that message even when trying to play an uncompressed video file! So, when implementing blacklisting, don’t just rely on CLSID’s, you should also block any filter with “Nero” in its friendly name, though if you do stick with just CLSIDs then blocking the resize, splitters and colour convertors is probably enough.
On a computer where one is going to do debugging, renaming directory $(Program Files)\Common Files\Ahead\DSFilter seems to be good enough.
The cleaner way is to do
for %i in (*.ax) do regsvr32 /u %ifirst, of course.