Why Multiple English (Surround 5.1) Audio Tracks?

[swampdaddy]

I generally rip all audio tracks without fully understanding them precisely. I've noticed that sometimes the director commentary could be the reason for the second track. For example, on my Westworld (1973) I seem to have two Surround 5.1 audio tracks that seem to be identical. Why might that be the case?

https://www.dropbox.com/s/z8gk2097um4st ... 2.png?dl=0

If I wanted to see more details about the audio tracks such as the amount of disk space used or the bit-rate or if I wanted to delete one of my subtitle tracks, how would you review or edit this data within the .MKV file?

Thanks,

Rob

[Woodstock]

Most likely reason for multiple "identical" tracks is that MakeMKV can (and usually does, unless told not to) copy a "lossless" track into its core "lossy" track, and the "lossless" version.

Post-rip track manipulation can be done with mkvtoolnix (no change to the tracks) or handbrake (compress the video while manipulating the other tracks). Audio tracks really are only a small fraction of the file size, so if you're not going to compress, removing an audio track isn't going to save you a lot of space.

[Grauhaar]

Audio tracks really are only a small fraction of the file size, so if you're not going to compress, removing an audio track isn't going to save you a lot of space.

In case on an f.e "DTS HD Master track" the size can be 4GB and more which is approx 10-15% of the complete file size. The size for each track can be shown with f.e. MediaInfo.

[aan3kk]

If you have two audio tracks with the identical format, eg. DTS-HD Master Audio 6 channels there is no way to identify which track is what beside from playing the file and listen. Recently I encountered many Blu-rays with identical audio tracks or "fallback tracks" like one Dolby Atmos and one Dolby Digital (for those players that can't handle Dolby Atmos at all).

To modify these mkv files you want mkvtoolnix. Open the GUI, drag&drop the file you want to modify into it and simply de-select the tracks you don't want, then start muxing. mkvtoolnix is excellent and does not overwrite your source file but either uses a unique name for your new file or ask you before overwriting.

You additionally have the option to change nearly everything of the resulting mkv file, like file title, track title, if a given track is default or forced and much more.

[swampdaddy]

Thanks guys, I appreciate the detailed responses!

[Thw0rted]

I came here with a sort of similar question -- I know vaguely why there are different audio tracks, but I'm wondering if there's an easy way to tell what they are without going in for every rip and listening to every track, then labeling them by hand with MKVToolnix. There are a lot of discs where I just ripped all the English tracks, and I can usually even guess which ones I might want to keep when transcoding, but I still wind up with an output file that just says "English" 3 or so times, rather than "Main", "Descriptive", "Commentary", etc.

If the disc metadata doesn't include any information about what kind of content the track has, it seems like the sort of thing ripe for crowdsourcing. Is there some kind of "index" site that captures this information in an automated format, akin to thetvdb or cddb? I could ask in a new thread if that's more appropriate, but I figured the participants in this one might have some ideas.

[mreedelp2]

I keep seeing questions like this. Personally, I don't care. I rip all English audio tracks. Why? Because no movie is the same. While watching the movie I select the audio track that sounds the best to me. It is impossible to set my sound system so I get the best sound out of one pre-determined default audio track. Sometimes it is the 7.1, sometimes it is the 5.1, sometimes it is the stereo. I have to choose.

[Grauhaar]

but I still wind up with an output file that just says "English" 3 or so times, rather than "Main", "Descriptive", "Commentary", etc.

The streams has no specific indicators. The selction of what is played is done over the Blu-ray Menus and you know, every Menu looks different. I don't think that there are specific rules how Blu-ray creators must name menus or track contents in the MPLs or whatever. The Menu selects the MPLS and in the MPLS are the stream parts and IDs for playing. So I believe there is no way to pass the wanted information into the mkv file.

If the disc metadata doesn't include any information about what kind of content the track has, it seems like the sort of thing ripe for crowdsourcing. Is there some kind of "index" site that captures this information in an automated format, akin to thetvdb or cddb? I could ask in a new thread if that's more appropriate, but I figured the participants in this one might have some ideas.

Would be fine, but I think that this is far beyond of MakeMKVs functionality which is a tool to break the encryption of Blu-rays and save the content into files.