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.
Now that we have these new functions,
we can also make them return an error
instead of calling sysfatal() like
postmountsrv().
Remove the confusing Srv.srvfd, as it
is only temporarily used and return
it from postsrv() instead.
To use srvrease()/srvaquire() we need to have a way to spawn
new processes to handle the service loop. This functionality
was provided by the internal _forker() function which was
eigther rfork or libthread based implementation depending on
if postmountsrv() or threadpostmountsrv() where called.
For servers who want to use srv() directly, _forker would not
be initialized so srvrelease() could not be used.
To untangle this, we get rid of the global _forker handler
and put the handler in the Srv structure. Which will get
initialized (when nil) to eigther srvforker() or threadsrvforker()
depending on if the thread or non-thread entry points where used.
For symmetry, we provde new threadsrv() and threadpostsrv()
functions which handle the default initialization of Srv.forker.
This also allows a user to provide his own forker function,
maybe to conserve stack space.
To avoid dead code, we put each of these function in their
own object file. Note, this also allows a user to define its
own srvforker() symbol.
this fixes real-time applications.
-n previously specified a rate divisor rather than the rate itself,
which was used for specific applications outside of 9front. instead,
just set the rate directly, more useful and straightforward.
Remove unused fields and factor common fields into a
new PMach struct in port/portdat.h.
The fields machno, splpc and proc are not moved to
PMach as they are part of the known offsets from
assembly (l.s).
Resample is well known for taking a long time to resize an image. This
patch brings an important performance boost (in my test image, time
was reduced from ~2850ms to ~500ms). It does that by extracting FP
multiplication and division out of the innermost loop of
resamplex/resampley.
The results differ slightly from the current implementation: in my
test: ~0.3% of the bytes had a ±2 difference in their value, which I
attribute to rounding errors. I'm personally not concerned with that
deviation, given the performance gains. However, I recommend testing
it just to be sure I didn't overlook anything.
José Miguel Sánchez García
The patch does the following:
1. Adds recognition of executable script (shebang) files.
2. Returns correct MIME type for mbox files (RFC 4155).
3. Returns XML instead of HTML type in some cases.
changeset: 8411:19f6a88ea241
branch: mbp-2011
user: Romano <unobe@cpan.org>
date: Sat Apr 17 14:35:21 2021 -0700
files: sys/src/cmd/upas/fs/imap.c
description:
When an imap fetch fails, it's helpful at times to know the underlying
cause. This provides more details by providing the underlying error
message.
unlike other tools like iconv(1), a crop(1) without arguments or with
ones resulting in a no-op, like `-t 0 0', errors out. other options
like `-i 0' do not error. this breaks assumptions and results in
tedious intermediary steps or hacks like:
foo | {crop -t $1 $2 >[2]/null || cat} > baz.bit
instead, just ignore the check. subsequent code doesn't make
assumptions on that.
/sys/src/cmd/mksyslib uses `{basename $stem .$objtype}^.c to get the
source file name for *.acid files. /sys/lib/acid/thread expects
sched.$objtype.acid. This lets /sys/src/libthread/mkfile generate
that file.
