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author | ariff <ariff@FreeBSD.org> | 2006-11-26 12:24:06 +0000 |
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committer | ariff <ariff@FreeBSD.org> | 2006-11-26 12:24:06 +0000 |
commit | 7b36f6d96b710844a6d2abd90a94bc169f72a5d1 (patch) | |
tree | be8f05cc6b2e41975dd084107c4db8978e7c9734 /UPDATING | |
parent | 70fe7b890e66532cef253d3bad928093268a24fd (diff) | |
download | FreeBSD-src-7b36f6d96b710844a6d2abd90a94bc169f72a5d1.zip FreeBSD-src-7b36f6d96b710844a6d2abd90a94bc169f72a5d1.tar.gz |
Welcome to Once-a-year Sound Mega-Commit. Enjoy numerous updates and fixes
in every sense.
General
-------
- Multichannel safe, endian safe, format safe
* Large part of critical pcm filters such as vchan.c, feeder_rate.c,
feeder_volume.c, feeder_fmt.c and feeder.c has been rewritten so that
using them does not cause the pcm data to be converted to 16bit little
endian.
* Macrosses for accessing pcm data safely are defined within sound.h in
the form of PCM_READ_* / PCM_WRITE_*
* Currently, most of them are probably limited for mono/stereo handling,
but the future addition of true multichannel will be much easier.
- Low latency operation
* Well, this require lot more works to do not just within sound driver,
but we're heading towards right direction. Buffer/block sizing within
channel.c is rewritten to calculate precise allocation for various
combination of sample/data/rate size. As a result, applying correct
SNDCTL_DSP_POLICY value will achive expected latency behaviour simmilar
to what commercial 4front driver do.
* Signal handling fix. ctrl+c of "cat /dev/zero > /dev/dsp" does not
result long delay.
* Eliminate sound truncation if the sound data is too small.
DIY:
1) Download / extract
http://people.freebsd.org/~ariff/lowlatency/shortfiles.tar.gz
2) Do a comparison between "cat state*.au > /dev/dsp" and
"for x in state*.au ; do cat $x > /dev/dsp ; done"
- there should be no "perceivable" differences.
Double close for PR kern/31445.
CAVEAT: Low latency come with (unbearable) price especially for poorly
written applications. Applications that trying to act smarter
by requesting (wrong) blocksize/blockcount will suffer the most.
Fixup samples/patches can be found at:
http://people.freebsd.org/~ariff/ports/
- Switch minimum/maximum sampling rate limit to "1" and "2016000" (48k * 42)
due to closer compatibility with 4front driver.
Discussed with: marcus@ (long time ago?)
- All driver specific sysctls in the form of "hw.snd.pcm%d.*" have been
moved to their own dev sysctl nodes, notably:
hw.snd.pcm%d.vchans -> dev.pcm.%d.vchans
Bump __FreeBSD_version.
Driver specific
---------------
- Ditto for sysctls.
- snd_atiixp, snd_es137x, snd_via8233, snd_hda
* Numerous cleanups and fixes.
* _EXPERIMENTAL_ polling mode support using simple callout_* mechanisme.
This was intended for pure debugging and latency measurement, but proven
good enough in few unexpected and rare cases (such as problematic shared
IRQ with GIANT devices - USB). Polling can be enabled/disabled through
dev.pcm.0.polling. Disabled by default.
- snd_ich
* Fix possible overflow during speed calibration. Delay final
initialization (pcm_setstatus) after calibration finished.
PR: kern/100169
Tested by: Kevin Overman <oberman@es.net>
* Inverted EAPD for few Nec VersaPro.
PR: kern/104715
Submitted by: KAWATA Masahiko <kawata@mta.biglobe.ne.jp>
Thanks to various people, notably Joel Dahl, Yuriy Tsibizov, Kevin Oberman,
those at #freebsd-azalia @ freenode and others for testing.
Joel Dahl will do the manpage update.
Diffstat (limited to 'UPDATING')
-rw-r--r-- | UPDATING | 13 |
1 files changed, 13 insertions, 0 deletions
@@ -21,6 +21,19 @@ NOTE TO PEOPLE WHO THINK THAT FreeBSD 7.x IS SLOW: developers choose to disable these features on build machines to maximize performance. +20061126: + Sound infrastructure has been updated with various fixes and + improvements. Most of the changes are pretty much transparent, + with exceptions of followings: + 1) All sound driver specific sysctls (hw.snd.pcm%d.*) have been + moved to their own dev sysctl nodes, for example: + hw.snd.pcm0.vchans -> dev.pcm.0.vchans + 2) /dev/dspr%d.%d has been deprecated. Each channel now has its + own chardev in the form of "dsp%d.<function>%d", where <function> + is p = playback, r = record and v = virtual, respectively. Users + are encouraged to use these devs instead of (old) "/dev/dsp%d.%d". + This does not affect those who are using "/dev/dsp". + 20061122: The following binaries have been disconnected from the build: mount_devfs, mount_ext2fs, mount_fdescfs, mount_procfs, mount_linprocfs, |