Examples
Here are some examples of how you can use the tools described previously to fix your movie playing woes. I will state again:
Remember: It doesn't really matter what combination of filters your using, as long as the final result is what YOU want.
Therefore, this is not the only way to fix the problems, but it worked for my system. So you can apply similar techiniques to fix your own issues.
Trailer not playing DTS Soundtrack
Ok, so you have a file which isn't playing in Dolby Digital, or in this case DTS. I can tell this as on my AV receive it tells me what type of signal it is decoding. It was just displaying "Linear PCM (48Hz)" and not the desired "DTS". This is how I troubleshooted the problem.
Open the file in graphedit:
From this we can see the "ffdshow Audio Decoder" is responsible for handle the audio for the file. At this point you could right click on "ffdshow Audio Decoder" to have a play with the settings to see if you can get the DTS soundtrack to play. However, I knew there was a filter called AC3Filter (which you can get here) that has support for movies with both Dolby Digital and DTS soundtracks, with a nice simple interface. I therefore installed AC3Filter.
After rebooting the PC, and opening the file in graphedit, the problem still remained and "ffdshow Audio Decoder" was still handling the sound. This is where FilmMerit comes in.
Open FilmMerit and locate AC3Filter, I set this to "0800000 Preferred" and "ffdshow Audio Decoder" to "040000 Unlikely". Rebooted the PC, and went back into graphedit to find the following:
As you can see the desired AC3Filter is now being used. Now it was just a case of right clicking on AC3Filter to make sure all the settings were set accordingly:
Finally, played the file in graphedit which revealed "DTS" appearing on my AV receiver!
Note; as the merit has been increased to preferred for AC3Filter it is used for most other movie files also. This is a good thing though as its still giving the desired results for those files also.
In Summary then; use Graphedit to troubleshoot your problems, change the settings and insert other filters or decoders to see if they improve things. Once you've found the combination, make the changes in FilmMerit to make them permanent.