VOGONS


Reply 40 of 47, by robertmo

User metadata
Rank l33t++
Rank
l33t++
VileRancour wrote:

Yeah, most games using digitized audio / speech work just fine with the current code (off the top of my head, only Perestroika aka Toppler doesn't).

Also:
Battle Bugs
StarControl 1
Tv Sports Football

Reply 41 of 47, by VileR

User metadata
Rank l33t
Rank
l33t

For some reason I was sure that digital audio in Star Control 1 was exclusive to the Amiga... did the PC version really feature that??

I had a SB when I first played it, but the only compatible card supported was the AdLib, so all I remember is those OPL2 sounds...

[ WEB ] - [ BLOG ] - [ TUBE ] - [ CODE ]

Reply 42 of 47, by bloodbat

User metadata
Rank Oldbie
Rank
Oldbie

Here's a patch for the latest SVN that integrates Ripsaw's along with the ability to select the experimental PC Speaker patch, usage is as before:

pcspeaker=true,exp or false.

in your .conf file or you can change it in real time with config.

Attachments

  • Filename
    svn_exp_patch_new.diff
    File size
    2.71 KiB
    Downloads
    366 downloads
    File license
    Fair use/fair dealing exception

Reply 46 of 47, by Roxor

User metadata
Rank Newbie
Rank
Newbie
VileRancour wrote:

Not talking just about the timer issues... there's also the whole approach behind generating the waveforms - aka the aforementioned "clicks and pops" issue (an accurate model would fix it by always treating silence as a straight line either at the "top" or "bottom" of the waveform, rather than the center, but that would screw things up for the mixer by introducing a permanent offset/bias).
A different issue, but it's yet another example of how problematic a 100% accurate model could be.

Well, that bias problem could be solved by adding a high-pass filter to the DOSBox mixer. In fact, it would be a good idea to add it anyway, as the OPL emulation output has such a bias for certain pieces of music, and that interferes with the surround processing on some soundcards, such as the Sound Blaster X-Fi series.

I actually wrote a simple 4Hz high-pass filter for Winamp's Nullsoft Signal Processing Studio DSP plugin. Works wonders for making synthesised music stop screwing with my sound card.

Here's the source for the preset, which can be copied into the relevant boxes in the editor. It's based on Wikipedia's sample code for a high-pass filter, just modified to work in the Signal Processing Studio.

Initialisation code:

assign(megabuf(0),0);
assign(megabuf(1),0);
assign(megabuf(2),0);
assign(megabuf(3),0);
dt = 1/srate;
RC = 1/(2*$PI*4); // set time constant for 4Hz corner frequency
alpha = RC / (RC +dt);

Per sample code:

x = spl0;
y = spl1;
spl0 = alpha * megabuf(0) + alpha * (x - megabuf(1));
spl1 = alpha * megabuf(2) + alpha * (y - megabuf(3));
assign(megabuf(0), spl0);
assign(megabuf(1), x);
assign(megabuf(2), spl1);
assign(megabuf(3), y);