plan9fox/sys
qwx 7048f1ca11 games/opl3: use correct sampling rate
games/dmid uses the same sample rate as the chip for music, but other
applications do not.  opl3 and its older version opl2 (not in 9front)
read an input stream of commands in basically IMF format, something
used in other id Software games and some others, which assumes a
given input sampling rate:  700 Hz for Wolfenstein 3D music, 560 Hz
for Commander Keen, 60 Hz for Ultima 6, etc.

The opl3 emulation on the other hand is not really intended to run at
a sampling rate different that the chip's 49.716 kHz sampling rate.
Previously, we assumed it runs at 44.1 kHz and just used the input
rate as a divisor to get the number of samples per delay tic.

From what I understand, the correct way to use it for accurate
emulation is to run the opl chip emulator at its intended sampling
frequency, then downsample to 44.1 kHz.  This means better output
but more code.  The alternative is to basically do the same as
before rev 8433, except with no buffering, but at accuracy/quality
loss.  This change implements the former and just forks pcmconv to
deal with resampling.
2021-05-05 16:57:19 +02:00
..
doc /sys/doc: fix mkfile to and remove files that now can be regenerated 2017-05-09 16:23:48 +02:00
games/lib fortunes: That depends on how you define native. -- Andre Garzia 2021-02-09 23:11:08 -05:00
include lib9p: remove Srv.srvfd, make postsrv() and threadpostsrv() return the mountable file descriptor, update documentation 2021-05-01 19:58:58 +02:00
lib printfont: load all fonts for printfont all 2021-04-09 16:09:31 +02:00
man games/opl3: use correct sampling rate 2021-05-05 16:57:19 +02:00
src games/opl3: use correct sampling rate 2021-05-05 16:57:19 +02:00