My method for doing this is tedious and was hoping you had a quick tip or a link to doing this efficiently.
So was mine...but I'm more than happy to share. The software I used for this portion was:
- Sony Vegas Platinum 8.0 (though any program which supports VST audio effects will work)
- WAV to AC3 Encoder (Freeware)
- V.I. Stereo to 5.1 Converter (Freeware, reguires a program that supports VST)
- tsMuxer GUI (Freeware)
Okay, I'll use Empire as an example, which needed one 5.1 track and two 2.0 tracks. Obviously, I took the stereo CD and trimmed the portion I needed. Then, I saved it as a Stereo PCM WAV at 16bits and 48kHz for the eventual 2.0 tracks.
Next was to create the channels for my 5.1 file. In Vegas, I used the VST effect program V.I. Stereo to 5.1 Converter. If you decide to use it, you can read its manual to figure out how best to do this for you. The important thing is to end up with 6 separate Mono PCM Wav files at 16bits and 48kHz: Front Left, Front Right, Surround Left, Surround Right, Center, and LFE.
Now, it's time to create the AC3s. Make sure you know the format of the AC3 files you're trying to merge them with. For example, Empire's 2.0 tracks are 224Kbps and flagged as Dolby Surround. So, using WAV to AC3 Encoder, I reencode my Stereo WAV files in that same format.
For the 5.1, I needed an AC3 at 512Kbps. Using Wav to AC3 Encoder's "Mux Wizard", I added all of my Mono WAVs to the appropriate channels. Then, I encoded my new file at the proper bitrate.
Then, I used tsMuxerGUI to create two M2TS files, one for my splash screen and one for the movie, and saved them to my HD. Then, I used tsMuxerGUI again to "join" those two M2TS files and save them as an AVCHD (Blu-Ray). The most difficult part was getting the new chapter stops right with the added introduction.
It's probably not the most efficient solution. But, when I was in a panic trying to fix this mess, it was the best I could come up with.