Recording separate audio channels

Hi all!

I've been ripping some samples from good old amiga games in making music and the WinUAE has served me quite well in this purpose, but there is a problem though...

My Edirol FA-66, although a very good sound card for music making indeed is, it only can output two channels at a time (and so can the integrated Realtek HD sound chip in my laptop also). This becomes a problem when I want to record single samples from a game, like for example a certain sample in the Star Control I hierarchy winning music

In normal stereo mode WinUAE routes 2 audio channels to left and 2 channels to right speaker. Now if I want to record a sample from the left channel 1, it also contains the unwanted signal from left channel 2.
I can choose 4 channel playback or 5.1. channel playback: That way
only left channel 1 is routed to left speaker and right channel 1 is routed to right and the L2 and R2 are routed to non-existing back speakers.

In some cases the samples I want mercifully are in the front channels so I can record them properly. Too bad, in the Star control example the samples go to the back channels and I don't see a way to extract them from there...

I can't swap the back channels to front from either of my sound cards' drivers. (Even the realtek audio HD driver gives options only for 2 speaker configuration since the laptop only has those 2 speakers.)

I don't think there's a way to swap the front and back channels in WinUAE? There is the swap Right and left channels thingy, but it won't help since the back channels remain in the back. It would be great to have an option to route the 4 amiga audio channels in whichever way you like in WinUAE!

Ah, and for the sample ripper... It produces something like 0.00001 seconds long clicks with samplerate of 258000 Hz, so I think it's not quite functioning?

[TCD]

Hmm, interesting. Sample ripper works fine for me (except for a very few games). But mapping the four audio channels of the Amiga to any possible audio speaker config seems to be quite a big task .
Could you upload Star Control to the zone. It might be possible to rip the samples in a quite 'native' Amiga way .

[Toni Wilen]

Debugger (Shift+F12) "am"-command can be used to disable channels (am <bit mask>, for example am 8 = only channel 4)

Sample ripper works fine here.. Check winuaelog.txt after sample ripper has saved few samples.

Thanks for the swift responses!

I will try the debugger and the ripper again later today, as for now "duty calls"
I actually got the desired samples from the SC since at some points the other channel didn't luckily intervene but I bet there's gonna be some use for this in the future!

Took a while before I found time to test it, but Yes! It works!
With the debugger I could filter out the "magnificent" orchestra hits and record them with audacity nicely. For some reason the sample ripper keeps giving those oddball results, but it matters not anymore.

Now, on to Turrican 2...

Ah... Messing around Turrican 2 made me realize that the sample ripper rips some shorter samples like drum hits ok, but longer ones like the echoing roar in the beginning of the final flying sequence are sampled as several very short sequences.

If you stitch together these 60 or so little nibbles of a sound, you get a whole sample. But, I prefer the debugger & bit masking way

[Toni Wilen]

Turrican 2 music player uses software mixing (>4 channels), samples it plays are created in real-time.

[NoX1911]

Resampling the analog output is not the best way to get the samples. I would try to dump the memory first and re-play the dump with audacity. Most of the time you can clearly see the samples between raw data and code.

If not successful (procedural sound or whatever) try to record an avi file with lowest video setting and lossless audio (wav) and split the avi to wave (with virtualdub for example). Not sure if winuae has a function for dedicated sound recording.

This way you preserve exact samples. Afterwards you can re- or upsample the way you like. I personally try to preserve the 8bit aliasing. It has typical amiga scratchiness and sounds brighter/higher (compared to oversampling/interpolation), depends on PC sound card though. Most cards have fixed internal samplerate (=always resample) and such things.

NoX1911, thank you for the professional information! Now I just feel a bit inane

Being of tinkering nature I would like to try that memory dump technique, although I don't know jack about memory dumping... If you've got the time, could you give me some pointers? (He he, the coding related pun intended...)

In the WinUAE debugger I see there are several memory dumping options. Are you referring to the "m <address> [<lines>]" one here? If so, how can I "clearly see the samples between raw data and code"? And finally, where does WinUAE dump the memory contents to? Does it create a new file in some folder X?

Please be patient, I want to learn

Hmmh... I was a bit too eager to ask questions before exploring... sorry 'bout that.

So with the "S <file> <addr> <n>" I can save some or all of the Amiga memory. Is this the correct one to use?

How big a block I should save anyway? I tried saving some from 100 lines to 100000 lines to a file and tried to "import raw" those files in Audacity, but then I need to input the sampling rate and whether it is 8-bit, 16-bit, signed or unsigned, little-endian or big-endian... So far all I've got is junk. Is this the correct procedure at all?

With a little googling I found that Amiga sound chip has max 28867 Hz sampling rate and signed 8-bit dynamics and 68000 family has big-endian notation. Is this relevant information for the procedure or am I just ?

[Toni Wilen]

Much easier method: click save state button in misc panel and change file type to "memory dump" (or something like that)

Originally Posted by Toni Wilen

Much easier method: click save state button in misc panel and change file type to "memory dump" (or something like that)

Indeed it was. Thanks!

And I actually got results! The sounds really are discernible from all the other junk with almost any audio settings. No matter whether I chose big- or small endian, mono or stereo, 16 or 8 bit, I could play it. Although it's for the best to choose the ones matching the original, I reckon.

In the case of Rolling thunder, the real sampling rate doesn't seem to be anywhere near the max of 28867 Hz: It plays the samples too fast so I had to slow it down in Audacity. Now to try with other sampling rates.

Originally Posted by Toni Wilen

Debugger (Shift+F12) "am"-command can be used to disable channels (am <bit mask>, for example am 8 = only channel 4)

Tried this with WinUAE 4.2.0 but "am 8" at debugger seems to crash the program. These days I should rather write something else?

[ross]

Originally Posted by rimrunner

Tried this with WinUAE 4.2.0 but "am 8" at debugger seems to crash the program. These days I should rather write something else?

M<a/b/s> <val> Enable or disable audio channels, bitplanes or sprites.