I'm sure I recall a similar problem in another thread..... maybe another forum...... where the OS was Win7 and the DirectShow decoder was whatever codec Microsoft supplies with Windows. For some reason it was decoding as YUY2. The DirectShow fix was to install ffdshow and use the
Win7DSFilterTweaker to disable the Microsoft codec. Assuming it's the same problem......
But yeah...... indexing with L-smash or ffms2 might be better than using DirectShowSource. Muxing the TS file as an MKV first might also be helpful.