Save as Quad-Wav

[Sam_Zen]

This came up due to another topic about the "Save as Wav' department.
I checked things out there, and, because I'm used to publish my work in 4 discrete sound-channels, I also checked the 'save as quad-wav' options. An heritage of Olivier, and, I guess, very seldom used.
It appeared that the resulting wav-files are not contructed properly. And they can't be, because OMPT only has 2 output channels, not 4.

If a tracker is saved as a quad-file, still all sound is mixed in channels 1 and 2, while channels 3 and 4 are empty.
Quite logical, because only a 2 channel stereo panorama can be covered with codes, not a panning between 1 and 3.

So my request is a negative one : Please remove these quad-options in the "Save as Wav' as long as it's not functioning well.

(A request within a request : Please don't start a discussion about Dolby 5.1 or Home Theatre, because it's not relevant)

[LPChip]

Actually you're mistaken.

MODPlug does have support for quad output, and this becomes noticable when using the surround panning feature. I can't really tell you how it works, cus I never experimented with it, but it does work.

[Sam_Zen]

Hm. My mistake was, that I checked this only with a XM-file. I did notice the 'surround' button, but it was greyed out.
I really should switch to the IT-format.. (and see how to convert the existing XM's)
I will do some experiments and make a report.

[Snu]

its quite simple really, just set mpt to quad mode; then turn surround on for a channel - instead of adding a 'stereo' effect, the sound is now panned to the back speakers.
you can use the S90 and S91 to switch it between the two.

the problem with this of course is that to create a partially faded sound, you need two copies of it playing - one to the front and one to the back - then adjust the volumes to change the balance.

[speed-goddamn-focus]

(A request within a request : Please don't start a discussion about Dolby 5.1 or Home Theatre, because it's not relevant)

It is relevant, because when you select surround for a channel without using a quad output mode, mpt will output the sound encoded in dolby prologic format whether you want it to or not, and you will need a receiver capable of decoding it to enjoy it. Sorry to disrespect your request within a request, but I think those things should be mentioned when talking about 4 channel output (which is designed for surround sound, even if you don't use it that way).

[Sam_Zen]

just set mpt to quad mode; then turn surround on for a channel

Thanks. I rest my case.
Setting the mpt playback soundcard settings to quad makes a difference (SB Live).
Although in realtime playback it still doesn't work properly, but when saving as quad-wav now, the content is correct.
Good enough for me so far.

the problem with this of course is that to create a partially faded sound, you need two copies of it playing - one to the front and one to the back - then adjust the volumes to change the balance.

Yep. For this purpose I duplicated channels in a song quite often, even if it was only because I wanted a position in the middle of the pairs 1-2 and 3-4 channels.

when you select surround for a channel without using a quad output mode, mpt will output the sound encoded in dolby prologic format whether you want it to or not

You're right about that. It will be an encoded stereosignal instead of 4 discrete channels.
I checked the surround option in the player-tab, and it can only be active in 2C outputmode, not in quad.
I don't agree (I disrespect my own sub-request here) about 4 channel output being designed for surround. Long before the Dolby system, electronic composers used tape-recorders capable of using 4 different tracks at the same time. So I prefer, from a scientific point of view, to simply name channels 1, 2, 3 and 4. What the position is of each speaker to reproduce the channel, is arbitrary.

[speed-goddamn-focus]

Setting the mpt playback soundcard settings to quad makes a difference (SB Live).
Although in realtime playback it still doesn't work properly, but when saving as quad-wav now, the content is correct.

About realtime playback, I think you also have to set the right amount of speakers in "Sound and Audio Devices" in Windows Control Panel.

[LPChip]

As this feature request isn't really a feature request, I'm moving it to general chatter.

[Sam_Zen]

2 LPChip
The right move. I've taken the freedom to change the title of the topic.
2 speed-goddamn-focus
Windows Control Panel follows the setting of the surroundmixer-app of the SB Live, in this case 4 speakers.
But you're right, I have to investigate why playing back a saved quad-wav works ok, while realtime playback still not.

In the meantime I'm extremely pleased with this quad-file export. It's a big step towards the final octo-channels.
But to use this, I first have to convert hundreds of modules to the IT-format, so I'm a busy man for a while.
I converted some old MOD-files as test. The switch to the IT-format went ok, but before saving, the panning sliders of each channel had to be adjusted accordingly. The MOD handles a fixed order-setting for channel-panning : L-R-R-L etc.
This setting gets lost in the conversion, so it has to be reset to achieve the same situation.
The test is not over yet.

[Sam_Zen]

More testing because I'm able to playback a quad-wav correctly to 4 different speakers with JetAudio.
Since the Setup/Player settings are valid when saving as WAV, I did some experimenting.
The activation of the Bass and the Reverb option appears to be added only to the material of channels 1 and 2.
If the Surround option is activated, the final content of 1 and 2 is also added to channel 3 and 4.

[Sam_Zen]

I have updated my pages about creating four channels wavs with the addition of the MPT options.
http://www.louigiverona.com/webarchive/samzen/4c/4chow_uk.html