Thanks for the nice pictures, neither option will be implemented any soon,
the "keep value" is of no use because OFF is zero and nothing else.

1Index: src/hardware/pcspeaker.cpp
2===================================================================
3RCS file: /cvsroot/dosbox/dosbox/src/hardware/pcspeaker.cpp,v
4retrieving revision 1.24
5diff -u -r1.24 pcspeaker.cpp
6--- src/hardware/pcspeaker.cpp	15 Jul 2007 16:36:27 -0000	1.24
7+++ src/hardware/pcspeaker.cpp	4 May 2009 06:49:01 -0000
8@@ -305,15 +305,21 @@
9 	if(spkr.chan) spkr.chan->AddSamples_m16(len,(Bit16s*)MixTemp);
10 
11 	//Turn off speaker after 10 seconds of idle or one second idle when in off mode
12+	bool turnoff = false;
13 	Bitu test_ticks = PIC_Ticks;
14-	if ((spkr.last_ticks+10000)<test_ticks) {
15-		spkr.last_ticks=0;
16-		if(spkr.chan) spkr.chan->Enable(false);
17+	if ((spkr.last_ticks + 10000) < test_ticks) turnoff = true;
18+	if((spkr.mode == SPKR_OFF) && ((spkr.last_ticks + 1000) < test_ticks)) turnoff = true;
19+
20+	if(turnoff){
21+		if(spkr.volwant == 0) { 
22+			spkr.last_ticks = 0;
23+			if(spkr.chan) spkr.chan->Enable(false);
24+		} else {
25+			if(spkr.volwant > 0) spkr.volwant--; else spkr.volwant++;
26+		
27+		}
28 	} 
29-	if((spkr.mode == SPKR_OFF) && ((spkr.last_ticks+1000) <test_ticks)) {
30-		spkr.last_ticks=0;
31-		if(spkr.chan) spkr.chan->Enable(false);
32-	}
33+
34 }
35 class PCSPEAKER:public Module_base {
36 private:

I had the decrement at SPKR_VOLUME/1000; but that gave a slight hum. This doesn't produce and audable sound.

There are sometimes very small clicks, but those aren't recorded so they don't come from the pcspeaker emulation.

The drawback is that turning off the pcspeaker takes 5 seconds this way.

The PC speaker emulation seems to cause clicking even in the Windows desktop when playing Wizardry 7. After applying the patch, I noticed a few clicks when alt-tabbing and it stopped occurring after a short period of time. Then I disabled the turnoff and the clicks occurred all the time when doubleclicking folders or text files.

This does not occur when I play .wav files directly though. This only happens after a sound effect is played in the game using PC speaker and persists until PC Speaker emulation is disabled or DOSBox is closed. Wizardry 7 is also screwy with sfx in general under DOSBox. (SFX other than PC Speaker sound horrible.) Do you have any suggestions on what I can try to change to fix the PC Speaker clicking with this game or any idea what is happening?

Malignant Manor wrote:

The PC speaker emulation seems to cause clicking even in the Windows desktop when playing Wizardry 7. After applying the patch, I noticed a few clicks when alt-tabbing and it stopped occurring after a short period of time. Then I disabled the turnoff and the clicks occurred all the time when doubleclicking folders or text files.

This does not occur when I play .wav files directly though. This only happens after a sound effect is played in the game using PC speaker and persists until PC Speaker emulation is disabled or DOSBox is closed. Wizardry 7 is also screwy with sfx in general under DOSBox. (SFX other than PC Speaker sound horrible.) Do you have any suggestions on what I can try to change to fix the PC Speaker clicking with this game or any idea what is happening?

This has to do with the way the PC speaker emulation code handles silence. If you open the PC speaker output in a wave editor, you will see that the line representing the silence isn't centered until the speaker is shut off, and this is why you are experiencing those clicking sounds. Even with Qbix's patch, the silence isn't really centered until the speaker is deactivated. The only way to fix this would be to alter the code, perhaps even completely rewrite it (I don't really know C++ so I can't say for sure).

If you can't code, the only thing you can do is avoid switching to other programs while playing PC speaker games.

The patch works for the Secret Agent game.

Just to clarify in case it is needed, the popping sounds in Wizardry 7 do not seem to be related to PC speaker emulation shutoff. PC speaker emulation causing the sound screw ups after a sound is played and switching to the Windows desktop happens no matter what game is tested. Of course, this wasn't an issue before because there was a 1 second delay before shutoff. With the patch, there is a 10 second delay, but that isn't a big deal.

so the "only" problem remaining would be the fact that the sound pops if you switch away from DOSBox ?
Just don't do that ?

I think I remember DOSBox doing that to me before and I had to change both priority values in dosbox.conf to the same.

so the "only" problem remaining would be the fact that the sound pops if you switch away from DOSBox ?
Just don't do that ?

Not for Wizardry 7. That game pops after every sfx but doesn't seem to be related to PC speaker emulation shutoff. All sfx options (SB, Adlib, etc) are mangled in DOSBox for that game or don't work. PC speaker emulation is the only one that sounds correct but with a popping issue. That patch should help a lot of other games though.

I think I remember DOSBox doing that to me before and I had to change both priority values in dosbox.conf to the same.

Thanks, priority "pause" when DOSBox isn't focused fixes the Windows desktop sfx issues when switching out of DOSBox and PC speaker emulation is on.

Edit: The forums didn't seem to want to add attachments or it needs a human to authorize.

Here is a sample of the sfx played through DOSBox, a door opening with Sound Blaster and PC speaker emulation. (Off the top of my head, this is the only game I own that I have problems with the sound emulation.)

If you mute the FM channel in the DOSBox mixer, do you get sound in Wizardry 7 when the Sound Blaster option is enabled? I think the game may be using a trick to play sound effects on the OPL2 chip. I have another game that can do this, and the result is similar.

Muting the FM channel mutes the SB sfx.

I'm having difficultly implementing this patch. Where is this particular bit of code located?

Thanks.

The file name is at the top of the patch's block, for the exact location check
the comments around the unchanged lines.

*sigh*

All that work for nothing. The sound still pops at the beginning at end of each sound effect when using the PC Speaker, and the SB emu plays horrendously distorted sounds.

I have a feeling that because so few people play this game, a solution will most likely never be produced.

Yeah could be.

Keen also sounds funny. It should sound more like this

I think that Metal Mutant by Silmarils also uses the same tricks as Wizardry 7 to try to use the OPL chip as a DAC. Since Metal Mutant doesn't let you choose your sound card, you probably have to disable SB emulation to force it to use PC speaker sound. I haven't tried playing it in DOSBox for a while so I'm not 100% sure.

Wiz7 didn't sound any better on the OPL than it did via the PC Speaker though, so figuring out why the clicks are happening in DOSBox would probably be a better idea than trying to figure out the OPL-as-DAC thing.

I've made some modifications to dosbox's pc speaker emulation. Basically I just added a highpass filter, which makes the waveform look similar to what a real pc speaker outputs. Attached picture shows the difference. Top is vanilla dosbox 0.74, middle is dosbox-0.74 with my mod, bottom is a recording I nicked from another post in this thread. They aren't the exact same sounds, but you probably get the idea. I'll post more in the development section later. This might help with the popping issue.

In case the attached pic doesn't show up, here's a link:
http://i27.tinypic.com/2dqr61k.png

ripa wrote:

I've made some modifications to dosbox's pc speaker emulation.

Looks good. Did you contact the authors to see if it can be included in 0.75?

JAL

Looks good. Did you contact the authors to see if it can be included in 0.75?

Not yet, but they read this forum.

I made a slight improvement (attachment: top dosbox, bottom real). Now there's a bit of overshoot in the "tail" (decay). A bit too much compared to the real thing. This hasn't fixed Wizardry 7's popping by the way. I'm trying to understand the pc speaker code to find out why. Anyone have a recording of Wizardry 7 on a real pc?

Do you think you could upload some WAV files to compare? I'm interested to hear what it sounds like.