Welcome to Doom9's Forum, THE in-place to be for everyone interested in DVD conversion.

Before you start posting please read the forum rules. By posting to this forum you agree to abide by the rules.

 

Go Back   Doom9's Forum > General > Audio encoding

Reply
 
Thread Tools Search this Thread Display Modes
Old 25th April 2015, 03:43   #41  |  Link
hello_hello
Registered User
 
Join Date: Mar 2011
Posts: 3,969
Quote:
Originally Posted by Motenai Yoda View Post
indeed lame 3.98+ has a relatively new slighty different -q switch levels than older ones.
I'd remember the quality range as being from q0 to q5 but I guess I remembered that wrong.

Cheers.
hello_hello is offline   Reply With Quote
Old 25th April 2015, 04:30   #42  |  Link
hello_hello
Registered User
 
Join Date: Mar 2011
Posts: 3,969
Quote:
Originally Posted by Loomes View Post
One more question comes to my mind: Since eac3to and qaac both can to normalization, should I do it with eac3to or qaac? I suppose it makes no difference?
I've no idea, to be honest. You'd hope the end result would be the same either way, although......... thinking about it..... for QAAC to normalise properly the audio would need to get to it "unclipped". If the peaks are already clipped then the audio is effectively already normalised, albeit with clipping.

If you set 32 as the highest BPS mode (bits per sample) in the audio encoder configuration I think that implies floating point, in which case the audio shouldn't be clipped on the way through. For a BPS mode of 24 or less that'd mean the input is integer so it probably would be clipped. I'll have to test that later..... send some audio with peaks above zero to QAAC with the BPS mode set to 32 and check to see they were normalised errrr.... normally..... and not clipped at all. I'm pretty sure with a BPS mode of 24 or less they will be, but I will test that out as it'll be handy to know. Maybe not until tomorrow, but I will.
hello_hello is offline   Reply With Quote
Old 25th April 2015, 06:45   #43  |  Link
Ghitulescu
Registered User
 
Ghitulescu's Avatar
 
Join Date: Mar 2009
Location: Germany
Posts: 5,624
Quote:
Originally Posted by filler56789 View Post
Surely you haven't understood the problem. I am not talking about channel *mapping*, I'm talking about (properly-flagged) channel *layouts*. I still see no good-reason why AAC does not (or should not) support 2.1, 3.1 or 4.1, for example.[/url]
Quote:
Originally Posted by hello_hello View Post
I'm not even sure if I can recall any discreet 2.1/3.1/4.1ch audio in the wild. Do you actually have a need to encode it?
Here's one example
Lots of quatropfonic albums are encoded as 4.0 or 4.1.
__________________
Born in the USB (not USA)
Ghitulescu is offline   Reply With Quote
Old 25th April 2015, 10:35   #44  |  Link
hello_hello
Registered User
 
Join Date: Mar 2011
Posts: 3,969
Quote:
Originally Posted by Ghitulescu View Post
Here's one example
Lots of quatropfonic albums are encoded as 4.0 or 4.1.
I had a bit of a look through your thread. It seems to indicate what I suspected, that many/most hardware players/decoders aren't going to be happy with those formats either. I guess applying the same logic that's been applied to AAC here it means hardware players aren't adequate for multi-channel audio either.

While I was messing around trying to create 2.1ch/3.1ch/4.1ch AAC audio yesterday I kept wondering to myself why I was bothering as if I had audio in those formats and I was wanting to re-encode it, I'd probably convert it to another format in the process? I see you thought the same thing. For ffdshow users it'd be easy enough to enable it's mixer filter and decode via DirectShow. I assume it'd be possible to convert from one multi-channel format to another using Avisynth, but I just added the Matrix Mixer DSP to foobar2000's conversion chain.

In this case I reduced the centre channel by 60dB (that seems to be the maximum) reduced the over-all gain by 60dB (for a total of -120dB), and I boosted all the other channels by 60dB to compensate. If the input had been 4.1 channel there'd be no centre channel to turn down to nothing, but you could always duplicate the LFE channel in the centre channel at -60b to create a centre channel with nothing in it that way.

Once that was done it was simply a matter of opening a 5.1ch file (because I've got no 4.1ch files) and converting it directly to 5.1ch AAC..... to simulate converting 4.1ch directly to 5.1ch AAC with a silent centre channel. All that intermediate wave file creating and editing and exporting and converting seems like it's something to be avoided if possible.


Last edited by hello_hello; 25th April 2015 at 18:51.
hello_hello is offline   Reply With Quote
Old 25th April 2015, 12:53   #45  |  Link
filler56789
SuperVirus
 
filler56789's Avatar
 
Join Date: Jun 2012
Location: Antarctic Japan
Posts: 915
Quote:
Originally Posted by hello_hello View Post
I had a bit of a look through your thread. It seems to indicate what I suspected, that many/most hardware players/decoders aren't going to to happy with those formats either. I guess applying the same logic that's been applied to AAC here it means hardware players aren't adequate for multi-channel audio either.
It all depends on the definition of "multichannel" which one decides to accept.
IF by "multichannel" one means 5.1-and-7.1-only, because
5.1-and-7.1 is all that has always existed , ...

The point is, I myself and 5 other people don't back lousy specifications nor lazy implementations End-Of-OT.
filler56789 is offline   Reply With Quote
Old 25th April 2015, 14:00   #46  |  Link
Ghitulescu
Registered User
 
Ghitulescu's Avatar
 
Join Date: Mar 2009
Location: Germany
Posts: 5,624
I belong to the school of thought that hardware players MUST be entrusted with playing files. Whereas computers only to proces the raw files to feed the former.

My lifetime experience showed me that people that entrust their work to software players do not benefit from the high quality of standalones and are forced to reencode the files every time the software player is changed. I ahd to do this only when the (industry) standards changed (they allow for one generation "legacy" - eg DVD players could play VCDs, BD players could play DVDs (but no VCDs) and so on).

For me it is very important to stay within indsutry standards. And one workaround (thanks again Tebasuna) is to add muted channels where the HW players expect them.
__________________
Born in the USB (not USA)
Ghitulescu is offline   Reply With Quote
Old 25th April 2015, 19:09   #47  |  Link
hello_hello
Registered User
 
Join Date: Mar 2011
Posts: 3,969
Quote:
Originally Posted by filler56789 View Post
It all depends on the definition of "multichannel" which one decides to accept.
How's that? You claimed AAC isn't adequate for multi-channel encoding based on your particular definition of multi-channel and I pointed out it appears using the same definition hardware players aren't adequate either.

Quote:
Originally Posted by filler56789 View Post
IF by "multichannel" one means 5.1-and-7.1-only, because 5.1-and-7.1 is all that has always existed
No I'm pretty sure multi-channel also includes all the additional multi-channel layouts AAC supports, and the lack of support for a couple of old formats doesn't change the definition.

Quote:
Originally Posted by filler56789 View Post
The point is, I myself and 5 other people don't back lousy specifications nor lazy implementations
Is that like not being willing to buy a turntable because it won't play old 78rpm records even though you don't actually own any old 78rpm records or do you have an extensive collection of 2.1ch/3.1ch/4.1 channel audio you need to convert?

Last edited by hello_hello; 25th April 2015 at 20:16.
hello_hello is offline   Reply With Quote
Old 25th April 2015, 20:14   #48  |  Link
hello_hello
Registered User
 
Join Date: Mar 2011
Posts: 3,969
Quote:
Originally Posted by Ghitulescu View Post
I belong to the school of thought that hardware players MUST be entrusted with playing files. Whereas computers only to proces the raw files to feed the former.
That's the double standard we've all come to admire. You must use a hardware player for playing files but if it won't, process them with a PC so it can, but don't play them with a PC because the hardware player is still somehow better. Or something.....

Quote:
Originally Posted by Ghitulescu View Post
My lifetime experience showed me that people that entrust their work to software players do not benefit from the high quality of standalones and are forced to reencode the files every time the software player is changed. I ahd to do this only when the (industry) standards changed (they allow for one generation "legacy" - eg DVD players could play VCDs, BD players could play DVDs (but no VCDs) and so on).
Seriously? I'm calling bullshit.
Can you name one commonly used file/codec and software combination to which that would apply? Just one example? Why on earth would you change software players if it means not being able to play your files? And where did the old software player go?
Every single video file on my hard drive plays using the current version of MPC-HC and VLC and some date back to 2003.

If you encode you might want to re-encode with each new generation of codec, but that probably only happens at about the same rate of change as it does for industry standard formats.

Quote:
Originally Posted by Ghitulescu View Post
For me it is very important to stay within indsutry standards.
And you don't see the irony of it being important to you mostly because you use industry standard players?

Quote:
Originally Posted by Ghitulescu View Post
And one workaround (thanks again Tebasuna) is to add muted channels where the HW players expect them.
Could you clarify...... the 4.1ch audio from your audio DVDs..... how many generations old is it? It's just that using a PC to convert it to a different format compatible with your current hardware seems to completely contradict your entire post. Where did your one generation of legacy support go?

Not that I've got any issue with changing formats, only the ridiculous justifications you've offered with it.

Last edited by hello_hello; 27th April 2015 at 15:26.
hello_hello is offline   Reply With Quote
Old 25th April 2015, 20:52   #49  |  Link
filler56789
SuperVirus
 
filler56789's Avatar
 
Join Date: Jun 2012
Location: Antarctic Japan
Posts: 915
@hello_hello: I did NOT disagree with you (or with myself) about that topic.
I just thought your « » was rather misplaced
But this is just my stupid opinion, of course

Last edited by filler56789; 25th April 2015 at 20:57. Reason: wrong emoticon
filler56789 is offline   Reply With Quote
Old 25th April 2015, 21:03   #50  |  Link
Ghitulescu
Registered User
 
Ghitulescu's Avatar
 
Join Date: Mar 2009
Location: Germany
Posts: 5,624
Quote:
Originally Posted by hello_hello View Post
Just one example? Why on earth would you change software players if it means not being able to play your files? And where did the old software player go?
Every single video file on my hard drive plays using the current version of MPC-HC and VLC and some date back to 2003.
And you don't see the irony of it being important to you mostly because you use industry standard players?
As well as my double standard, you either kept what you could play or upgraded your players to match the files. Same Mary, different dress.
Quote:
Originally Posted by hello_hello View Post
Could you clarify...... the 4.1ch audio from your audio DVDs..... how many generations old is it? It's just that using a PC to convert it to a different format compatible with your current hardware seems to completely contradict your entire post. Where did your one generation of legacy support go?

Not that I've got any issue with changing formats, only the ridiculous justifications you've offered with it.
You missed a lot of things, but you simply cannot more.
I changed the player for one that sends all data digitally (HDMI) to my AVR, instead of 6 analogue cables.
My problem was that I missed that my Pio can't do DVD-Audio.
This has nothing to do with the standards per se, just with the artificial segmentation of the market. Not a big deal, as I have only a few of them, and I will anyway buy no one in the future.

Now, that Pink Floyd SACD, if you could use google, was the Alan Parsons mix from the original 4track tapes. It was supposed to be a new standard back then, but it didn't caught.

I saved the music losslessly in a different format. One generation, bit-perfect, two in total if we count the digitization, three if the LFE is considered, too. And this will be bit-perfect also in the future, as it will be directly (losslessly, bit-perfect) repacked or used as such in the BD-audio or as the audio part of the BD-video, which is the current standard.

PS: I still burn CDs/DVDs/BDs in the old-fashioned, space-wasting, low-quality formats. And guess what, I can drop any of them in any player that belongs at least to the same generation or newer and can watch it on any TV compatible with the player. Two technical generations are always allowed.
__________________
Born in the USB (not USA)
Ghitulescu is offline   Reply With Quote
Old 26th April 2015, 10:27   #51  |  Link
hello_hello
Registered User
 
Join Date: Mar 2011
Posts: 3,969
Quote:
Originally Posted by Ghitulescu View Post
As well as my double standard, you either kept what you could play or upgraded your players to match the files. Same Mary, different dress.
So no example then? I thought not.

I've been using MPC and MPC-HC for years (the oldest MPC installer I have on my hard drive is dated 2003). I don't recall ever having deleted (or converted) a video simply because I could no longer play it using the PC (I just found the appropriate codec or installed a different player), and even if I had, it wouldn't have been a video I'd re-encoded from DVD or Bluray. Aside from mpeg1/2, mpeg4 (Xvid/Divx) and h264, have there been other formats commonly used to re-encode video? Formats that can't be played today with most software players?
The most commonly used formats MPC-HC couldn't natively play would have been RealPlayer and QuickTime but it could use their codecs if the players were installed. These days, it can play them on it's own. I image VLC can do likewise and they'd have to be the two most popular freeware players.

Quote:
Originally Posted by Ghitulescu View Post
You missed a lot of things, but you simply cannot more.
I changed the player for one that sends all data digitally (HDMI) to my AVR, instead of 6 analogue cables.
My problem was that I missed that my Pio can't do DVD-Audio.
This has nothing to do with the standards per se, just with the artificial segmentation of the market. Not a big deal, as I have only a few of them, and I will anyway buy no one in the future.
Yes, you forgot to mention industry standard players with drives for playing two generations of discs aren't necessarily going to be able to connect correctly to other previous/future/current generation devices.

Quote:
Originally Posted by Ghitulescu View Post
I saved the music losslessly in a different format. One generation, bit-perfect, two in total if we count the digitization, three if the LFE is considered, too. And this will be bit-perfect also in the future, as it will be directly (losslessly, bit-perfect) repacked or used as such in the BD-audio or as the audio part of the BD-video, which is the current standard.
Yep, we all use PCs for that sort of thing despite the fact we're apparently only supposed to use hardware players to play them, but it's doubtful in the future we'll have to downgrade software to an older version to play/edit/convert it. More likely we could just play it as it is while remapping the channels on the fly and send it out in an AVR friendly format.

Quote:
Originally Posted by Ghitulescu View Post
PS: I still burn CDs/DVDs/BDs in the old-fashioned, space-wasting, low-quality formats. And guess what, I can drop any of them in any player that belongs at least to the same generation or newer and can watch it on any TV compatible with the player. Two technical generations are always allowed.
And for devices without a disc drive? Bum up, head in the sand?
I can put my modern, compressed, space saving files on a USB stick and play them using any player in this house. I can still burn discs if necessary. I just rarely need to.

I understand your concerns. I also tend to stick to hardware compatible formats. Not the industry standard ones, but the commonly used formats most industry standard players can also play these days.
I can't form the conclusion a hardware player will play my video with a higher quality than my PC connected to my TV via HDMI though, because I can't see a quality difference. What am I missing?

Last edited by hello_hello; 27th April 2015 at 11:43. Reason: spelling
hello_hello is offline   Reply With Quote
Old 26th April 2015, 11:11   #52  |  Link
kuchikirukia
Registered User
 
Join Date: Oct 2014
Posts: 434
Quote:
Originally Posted by filler56789 View Post
The point is, I myself and 5 other people don't back lousy specifications nor lazy implementations End-Of-OT.
I'm with you.
I refuse to use any hard drive, USB stick, SSD, tape, floppy, CD or DVD drive because they all neglect to support reading Edison phonograph cylinders and stone etchings.


Sent from my tin can over smoke signal.
kuchikirukia is offline   Reply With Quote
Old 26th April 2015, 15:25   #53  |  Link
filler56789
SuperVirus
 
filler56789's Avatar
 
Join Date: Jun 2012
Location: Antarctic Japan
Posts: 915
Quote:
Originally Posted by kuchikirukia View Post
I'm with you.
I refuse to use any hard drive, USB stick, SSD, tape, floppy, CD or DVD drive because they all neglect to support reading Edison phonograph cylinders and stone etchings.


Sent from my tin can over smoke signal.
Thanks for completely misunderstanding what I wrote.

Or should I say, for *pretending* to misunderstand what I wrote?
After all, some people need some "good" (read: lame) excuses for postwhoring.

Actually, your reply was rather fallacious.

Last edited by filler56789; 26th April 2015 at 18:08. Reason: better wording
filler56789 is offline   Reply With Quote
Old 27th April 2015, 15:16   #54  |  Link
hello_hello
Registered User
 
Join Date: Mar 2011
Posts: 3,969
I'm still trying to understand why some encoders (FDK and QAAC) actively reject some channel layouts. Others simply remap to a channel layout they want to use (FhG and Nero) which to me seems a bit naughty. I'd rather have a "no I won't do that" error message.

I played around a little with QAAC as it's the only AAC encoder I have that'll reject channel layouts it doesn't like and let you specify exactly the layout you want. I used a 4ch audio file and the standard 4ch layouts listed at the bottom of this page: https://trac.ffmpeg.org/wiki/AudioCh...n#Muteachannel

They are:

3.1: FL+FR+FC+LFE
4.0: FL+FR+FC+BC
Quad: FL+FR+BL+BR
Quad: (side) FL+FR+SL+SR

When specifying a channel layout QAAC encoded the 4.0 and Quad layouts correctly, and it didn't reject the Quad (side) layout (although the Apple encoder remaps "Quad (side)" to "Quad" as explained here, but it completely rejects 3.1ch. Looking at the list of channel layouts on the QAAC page I linked to that's hardly a surprise, but as none of the AAC encoders will encode 3.1ch (they either reject it or encode is as 4.0) there must be a reason for it beyond Apple not having bothered implementing 3.1ch encoding, or there's an AAC conspiracy taking place, but I'm not sure what the reason is.

I didn't play around with too many channel number/layout combinations other than the 4ch ones, but so far all the AAC encoders either refuse to encode 4.1ch or they remap it to something else, but once again I'd assume there's a reason.

And of course there's always the exception that makes the rule. 2.1ch is either encoded as 3ch or rejected, except by Nero. The Nero encoder will happily distinguish between 2.1ch and 3ch and encode either correctly. I don't know why.

Last edited by hello_hello; 27th April 2015 at 15:31.
hello_hello is offline   Reply With Quote
Old 27th April 2015, 17:51   #55  |  Link
Ghitulescu
Registered User
 
Ghitulescu's Avatar
 
Join Date: Mar 2009
Location: Germany
Posts: 5,624
There is no problem to make a file with any channel configuration one would like.
That an encoder/muxer rejects a file, it does because their programmers consider that certain configurations have no sense (no HW supported), not because it cannot be done.

In a Jesusian parable: a computer may equally split an invoice among 3 people, just that in real life no one can pay 33€ and 33.33 cents.
__________________
Born in the USB (not USA)
Ghitulescu is offline   Reply With Quote
Old 27th April 2015, 19:42   #56  |  Link
filler56789
SuperVirus
 
filler56789's Avatar
 
Join Date: Jun 2012
Location: Antarctic Japan
Posts: 915
Some more food for the thought:

As AC3, DTS and MLP were designed to support 1.1, 2.1, two types of 3.0/3.1 and two types of 4.0/4.1, probably their designers were thinking about the needs of the content creators/producers; I mean, if someone wants to create, for example, a 4-channel-only audio track, fine, then he/she will not need to create 2 additional dummy channels because of half-assed format_specifications /firmware /software.

Now, regarding the AAC specs:
¿why define TWO methods for identifying a channel layout? What's the point?

Last edited by filler56789; 27th April 2015 at 20:23. Reason: add MLP to the list
filler56789 is offline   Reply With Quote
Old 27th April 2015, 22:12   #57  |  Link
nevcairiel
Registered Developer
 
Join Date: Mar 2010
Location: Hamburg/Germany
Posts: 9,770
There isn't really two methods to define it, there is one method to explicitly define every single channel .. and one method to simply not define anything, and let the defaults apply.
In most cases, this is because at first, there was only the implicit defaults, and then someone thought it would be nice to have support for more, and the second method was born in a addendum to the original spec.

FWIW, encoding anything that is not a "default" channel layout will cause trouble sooner or later, and if only during playback as players get confused. Ever tried sending 4 channel audio over HDMI, without modification? Good luck communicating the speaker mask to the HDMI receiver.
I gave my LAV Audio a special mode that remaps all "uncommon" channel layouts into a default layout with silent channels to combat such problems. Before, I've had problems with 5.0 missing a center, since it got interpreted as 4.1 over HDMI (and some other broken combinations, too).
__________________
LAV Filters - open source ffmpeg based media splitter and decoders

Last edited by nevcairiel; 27th April 2015 at 22:16.
nevcairiel is online now   Reply With Quote
Old 28th April 2015, 11:53   #58  |  Link
hello_hello
Registered User
 
Join Date: Mar 2011
Posts: 3,969
The way I understand it the "default" layout is the layout for wave files, which is here (under default channel ordering):

https://msdn.microsoft.com/en-us/lib...=vs.85%29.aspx
Here's the first six.

1. Front Left - FL
2. Front Right - FR
3. Front Center - FC
4. Low Frequency - LF
5. Back Left - BL
6. Back Right - BR
7. Front Left of Center - FLC
8. Front Right of Center - FRC
9. Back Center - BC

You can't omit a channel as such, as the following channels would then "move up" one, so for example if you had a 3ch wave file that was actually channels 1, 2 and 4 you'd end up with the LFE channel in the centre channel. To enable specifying any channel configuration, the ChannelMask system is used (there's a list further down the page I linked to). The channel order remains exactly the same as above, but now you can specify which channels a wave file consists of. Without a channel mask, the default order is assumed.

The QAAC encoder is the only AAC encoder with a --chanmask command line option allowing you to over-ride the channel mapping of the wave file and set your own. For 4 channel configurations......

3.1: FL+FR+FC+LFE - 0x00000015
4.0: FL+FR+FC+BC - 0x00000107
Quad: FL+FR+BL+BR - 0x00000033
Quad: (side) FL+FR+SL+SR - 0x00000603 (QAAC remaps this to the Quad channel layout internally)

Please feel free to check I'm using the correct channel masks, but QAAC will accept any of the above channel masks in the command line except the first, which it rejects. It encodes the rest correctly (aside from internally remapping SL+SR to BL+BR). If you try to encode a 4ch wave file with the 3.1ch mask using any of the AAC encoders, it'll either be remapped to the 4.0ch mapping without warning, or it'll be rejected (depending on the encoder).

I'm not yet subscribing to an AAC conspiracy theory, so I'm trying to understand why that'd be when I don't see any reason why AAC couldn't be used to encode 3.1ch (or any channel mask you care to specify), at least in theory, yet all the AAC encoders refuse to do so. There must be a reason for it. A reason why 3.1ch AAC must be a bad thing..... I assume?

It might relate to hardware players/receivers generally not knowing what 3.1ch is and assuming it's some other 4ch configuration, although that'd mean hardware players would be similarly ignorant of 4.1ch, and those designing the specs for AAC decided that'd be a good reason for those formats to be illegal. That still leaves the 2.1ch exception unexplained though, in respect to why Nero will encode 2.1ch correctly but the rest of the AAC encoder won't.

Quote:
Originally Posted by filler56789 View Post
Now, regarding the AAC specs:
¿why define TWO methods for identifying a channel layout? What's the point?
Other than the above, is there another method? The post you linked to earlier refers to a "program_config_element()" or lack thereof, and how AAC channel ordering is handled without it.
I'd been working under the assumption it's used to specify the default AAC channel ordering for encoding, but now I think it's just specifying the default mapping for decoding when there's none specified in the AAC stream itself.

The link refers to SCE's, CPE's and LFE's and how they're assigned to channels when no assignment is specified.
Understanding AAC
SCE = single channel element
CPE= channel pair element
LFE = low frequency element

If the number of single channel elements is odd they're output starting at the centre speaker and from there in pairs outwards (front left+right, back left+right etc). If there's an even number they start with left and right.
A CPE seems to be counted as two SCE's so the same method of assigning channels is still used when there's a combination of SCE's and CPE's.
I'm thinking it even conforms to the wave file channel order with the LFE channel removed (although I'm not 100% sure there). It seems AAC knows the difference between a SCE and a LFE but there's no default speaker mapping for multiple LFE's.

And that makes sense when you look at the order in which AAC stores encoded audio (for 5.1ch).
FC FL FR SL SR LFE
It'd be encoded as a SCE, two CPEs and a LFE.

Mind you even the implicit channel ordering seems to indicate not only is 3.1ch AAC possible, if there's no explicit channel mapping, three channels and a LFE should result in 3.1ch output, the way I read it.......
There must be a reason.....

Last edited by hello_hello; 28th April 2015 at 17:57.
hello_hello is offline   Reply With Quote
Old 28th April 2015, 12:57   #59  |  Link
Ghitulescu
Registered User
 
Ghitulescu's Avatar
 
Join Date: Mar 2009
Location: Germany
Posts: 5,624
Unfortunately, there was no intention from Microsoft to finalize things.

Historically they may suggest they intend to finish the things, for instance to set legal values for the myriad of RESERVED fields and values all over their data structures, but they never did this. They simply created a new, usually incompatible format, and went along.

I don't know why hello_hello considers that particular sequence to be THE ONE, namely FL, FR, FC, LFE, BL, BR, when some of the first creators of a multi channel sound files, eg Dolby, specified a different order, namely L, C, R, BL, BR, LFE in 1991, when Microsoft just finished to set the RIFF adaptation to WAV.

So, once again, Microsoft comes 2007 and stir the standards to a new assignment (when she realised multichannel audio is the future). Why did she this? Because she could. Microsoft showed people that she'll not obey other party standards but her own. That's the power of a (quasi)monopole. Those that impose the rules always win.

Concerning the HW players and unusual channel configurations. Well, these had no problems to map correctly the channels, as no Microsoft "imagination" was involved in this. A DVD-Audio player would play 4.1 files perfectly (L,R,LFE,Ls,Rs). A computer relying on Microsoft code and formats would have a problem, unless the programmers managed to get workarounds (like custom channel mapping and stuff).
__________________
Born in the USB (not USA)
Ghitulescu is offline   Reply With Quote
Old 28th April 2015, 13:52   #60  |  Link
hello_hello
Registered User
 
Join Date: Mar 2011
Posts: 3,969
Quote:
Originally Posted by Ghitulescu View Post
Unfortunately, there was no intention from Microsoft to finalise things.
Mono and stereo wave files have been around for a long time. I think the idea behind the wave file channel ordering was simply to increase the number of channels without making too much of a mess. When the two channels in a stereo wave file are left and right, why when you add a third (ie centre) would it be logical to put it in the middle?

Quote:
Originally Posted by Ghitulescu View Post
I don't know why hello_hello considers that particular sequence to be THE ONE, namely FL, FR, FC, LFE, BL, BR, when some of the first creators of a multi channel sound files, eg Dolby, specified a different order, namely L, C, R, BL, BR, LFE in 1991, when Microsoft just finished to set the RIFF adaptation to WAV.
The wave file format is THE intermediate PC format used when converting between one format and another. Import a 5.1ch AC3 file into Audacity and then do the same for 5.1ch AAC file. They'll both be imported using the wave file channel order.
Re-encode from one format to another and it'll be decoded using the channel order for wave files and a wave file channel mask for the encoder to know which particular channels are included. I don't know why that needs explaining to Ghitulescu unless some decoders decode use a different channel order and encoders accept different channel masks to define the input channels.

Quote:
Originally Posted by Ghitulescu View Post
Concerning the HW players and unusual channel configurations. Well, these had no problems to map correctly the channels, as no Microsoft "imagination" was involved in this. A DVD-Audio player would play 4.1 files perfectly (L,R,LFE,Ls,Rs). A computer relying on Microsoft code and formats would have a problem, unless the programmers managed to get workarounds (like custom channel mapping and stuff).
So your recent efforts to convert 4.1ch audio to 5.1ch audio? That was all Microsoft's fault and nothing to do with your hardware not decoding 4.1ch correctly?

Last edited by hello_hello; 28th April 2015 at 14:06.
hello_hello is offline   Reply With Quote
Reply

Tags
aac, ac3, neroaacenc, qaac

Thread Tools Search this Thread
Search this Thread:

Advanced Search
Display Modes

Posting Rules
You may not post new threads
You may not post replies
You may not post attachments
You may not edit your posts

BB code is On
Smilies are On
[IMG] code is On
HTML code is Off

Forum Jump


All times are GMT +1. The time now is 15:10.


Powered by vBulletin® Version 3.8.11
Copyright ©2000 - 2019, vBulletin Solutions Inc.