A couple of questions about a few Dolby codecs.

[NickNewb]

I'm ripping the U.S. version of TMNT (the 2003 CGI movie) on blu-ray, and it has Dolby TrueHD audio. From what I understand, Dolby TrueHD does NOT work like DTS-HD Master Audio with the core + extension. If you rip ONLY the Dolby TrueHD stream and you try to play your movie in a player that does not support it, there is nothing for your player to fall back on. You will get no sound. So you need to rip BOTH the Dolby TrueHD stream, and the Dolby Digital Surround stream that MakeMKV flags as the 'core audio.'

I'm trying to understand why it is flagged as 'core audio' though. Can anyone explain?

Also, the following picture shows the 4 English streams for the movie. What is the difference between the ones I've labeled in red as 1 and 3? The track I've labeled as 1 also has the Default Audio flag set to YES. And just to test, I popped this disc into my standalone blu-ray player and went to watch the movie using the default settings, and sure enough, yep, I was not getting the highest quality experience. You have to manually use the pop-up menu to change the audio to the TrueHD setting. My question though is, why is that first track even there? Why didn't they simply include the TrueHD track, and the one nested below it, so that by default, I'd pop this in my blu-ray player and it'd use TrueHD if it could?



Further on this blu-ray, for the deleted scenes, there are 5, count 'em, 5 of (what appears to be) the exact same audio stream. Why would the manufacturer do this? I've listened to them all and they all sound the same to me.



And finally (for now, heh), I am confused by the naming convention Dolby uses. There is something called Dolby Digital Surround EX and Dolby Digital EX. The Dolby Digital Surround EX page indicates you can use it at home under the heading '6.1 Channels at Home.' Then....The Dolby Digital EX page says it 'represents the home theater version of Dolby Digital Surround EX.' Ummm....Ok....so they're both for home use. I'm confused because I've seen a blu-ray movie that has Dolby Digital Surround EX and a different one that has Dolby Digital EX. Why? What's the difference?

[ndjamena]

It's the core audio because it's the actual audio, the TrueHD is essentially an extension there for any hardware capable of decoding it. It just depends on how you look at it.

There is no difference between 1 and 3. 1 is the AC3 version of the sound track, 3 is the TrueHD version. It does make sense like that, but of course you can point out why that explanation is silly if you like.

Generally when you find multiple identical audio tracks, it's because it's trying to match the tracks in other titles for continuous play. You'd have to look at how the disc is actually authored to figure out why it's doing it exactly. Of course there's always the possibility of it simply being badly authored.

As far as I can tell, Surround isn't a different codec to EX, it's just a higher standard of it enforced by Lucusfilm. Kind of like a "not tested on animals" certification. I'm fairly certain EX isn't an actual codec anyway, just a method of audio mixing that makes it easier to extract extra channels from 5.1. I may be wrong though.