Music Media Helper (Tools for Multichannel Audio & Music Videos)

[HomerJAU]

MediaInfo identifies all lossless 'Atmos' files as being "Meridian Lossless Packing FBA with 16-channel presentation" as well as being "MLP FBA 16-ch"....

That's just the Atmos definition. It doesn't mean the mix contains 16 channels. Its the way the channel data is encoded. "16-channel presentation" is the simplified name

 

[NCFan1999]

That's just the Atmos definition. It doesn't mean the mix contains 16 channels. Its the way the channel data is encoded. "16-channel presentation" is the simplified name

That's the thing, though; I'm trying to figure out why the channel data is having trouble outputting the audio in a 16-channel format.

 

[NCFan1999]

I guess you've verified the content is actually 9.1.6? Run it through MediaInfo and see what it says?

 

[HomerJAU]

Your posted bitstream information shows:
Number Of elements: 12
Channel distribution: Disabled

That is exactly what the decoder is doing. Creating 12 channels (7.1.4) without distribution to the additional channels for a 9.1.6 decode.

Case solved.

 

[spearse]

I think I found a bug-- I'm trying to extract/convert an Atmos .mp4 file to .m4a. When I drag a .mp4 file into the "extract audio from mkv" window, it deletes my .mp4 file then gives error message that it can't find that .mp4 file. Also, it permanently deletes the file, it's totally lost.
Bug: permanently deletes .mp4 file
Question: how can I convert .mp4 to .mka?

 

[HomerJAU]

You can just rename .mpa to .m4a as they both use an identical mpeg wrapper.

I will look at your reported issue and fix in next release, which should be in next few days.

 

[NCFan1999]

Your posted bitstream information shows:
Number Of elements: 12
Channel distribution: Disabled

That is exactly what the decoder is doing. Creating 12 channels (7.1.4) without distribution to the additional channels for a 9.1.6 decode.

Case solved.

Then why is it that some Atmos tracks still render out audio for the top front and top rear channels just fine but can't do it with others?

 

[AudiophileStyle]

Then why is it that some Atmos tracks still render out audio for the top front and top rear channels just fine but can't do it with others?

Likely because they are created and authored to do that.

 

[NCFan1999]

Likely because they are created and authored to do that.

First off, why? Second, if that's true, then that's just counter-intuitive. Third, I'm not gonna stop until this problem's solved; however it's done.

 

[AudiophileStyle]

First off, why? Second, if that's true, then that's just counter-intuitive. Third, I'm not gonna stop until this problem's solved; however it's done.

Atmos gives mixing engineers room to create a mix and control how it sounds, to a large extent, with some exceptions. This isn't seen as a problem to Dolby. I wish you luck in working with them to change the company's stance on decoding.

 

[pat bateman]

Hi Garry,

The MPEG-H decoder is making a blank center channel when the output is set to 5.1.4, or 7.1.4, or 9.2.6.
7.1 & 5.1 output however decodes properly with the center channel included. I can PM you some samples files if you'd like, but a screenshot video here - Screen Recording 2024-09-30 at 4.49.00 PM.mov

 

[HomerJAU]

Have you tried any other releases? Many mpeg-h fixes do not use a centre channel or it’s used only occasionally.

 

[pat bateman]

Have you tried any other releases? Many mpeg-h fixes do not use a centre channel or it’s used only occasionally.

Yes, and decoding some other releases, 7.1.4 retains the center channel, but in about half the cases, the decoding puts a blank center channel. Unless I choose 7.1 as mentioned - then the center channel is always decoded correctly.

 

[AudiophileStyle]

Yes, and decoding some other releases, 7.1.4 retains the center channel, but in about half the cases, the decoding puts a blank center channel. Unless I choose 7.1 as mentioned - then the center channel is always decoded correctly.

Where are you getting mpeg h albums?

 

[JediJoker]

Where are you getting mpeg h albums?

Presumably by (illegally) saving 360RA streams.

 

[HomerJAU]

Yes, and decoding some other releases, 7.1.4 retains the center channel, but in about half the cases, the decoding puts a blank center channel. Unless I choose 7.1 as mentioned - then the center channel is always decoded correctly.

I’ve seen plenty that use the top front centre in 24 channel mixes and not use the conventional Centre.

 

[AudiophileStyle]

Hi Garry, I have a new one for you :~)

I was sent a 9.1.4 file and I want to remix it to 7.1.4. This doesn't look possible in MMH. I see the option to go from 9.1.6 to 7.1.4, but when I add a file, it won't allow me to convert it.

Question 1: Is it possible to add a 9.1.4 option?
Question 2: Will a conversion to 7.1.4 then accomplish what the engineer sent me, "The wide fronts should go as a phantom between front and surrounds in your 7.1.4"


His 9.1.4 files are mapped like this:

1: L
2: R
3: C
4: Lfe
5: Lw (wide front)
6: Rw (wide front)
7: Ls (side/surround)
8: Rs (side/surround)
9: Lrs (rear/back)
10: Rrs (rear/back)
11: Ltf (height front)
12: Rtf (height front)
13: Ltr (height rear)
14: Rtr (height rear)

 

[HomerJAU]

I guess you want to use the Remix Channels tool to do this? You could mix the wides to fronts and sides in the remix and adjust the volume factor to keep more front level in the front mix. But it’s probably better to use a DAW to get the correct music balance.

(Thats an odd channel order BTW. Dolby puts the Wides after the bed channels)

 

[AudiophileStyle]

I guess you want to use the Remix Channels tool to do this? You could mix the wides to fronts and sides in the remix and adjust the volume factor to keep more front level in the front mix. But it’s probably better to use a DAW to get the correct music balance.

(Thats an odd channel order BTW. Dolby puts the Wides after the bed channels)

I hear ya.

When I attempted to use the Remix option, the convert button remained grayed out.

It’s only one album (so far) so I’m not too stressed. Fingers crossed I don’t need to buy more speakers.

 

[HomerJAU]

I’ll look at it today. There should be no reason MMH couldn’t support 9.1.4 as an input, I’ll just need to add that definition.