Can someone who knows please explain pulseaudio, portaudio,
differences and advantages of each, etc. I tried to use pulseaudio
one time but all I got was pulsing audio. :\ I guess I'm just having
trouble keeping up with changes.
- Hi Rich,
>>>>> On Sat, 21 Jun 2008 18:49:08 -0000, "rich" <richwa4sxz@...> said:"You are in a maze of twisty little passages, all alike".
> Can someone who knows please explain pulseaudio, portaudio,
> differences and advantages of each, etc. I tried to use pulseaudio
> one time but all I got was pulsing audio. :\ I guess I'm just having
> trouble keeping up with changes.
PortAudio, PulseAudio and OSS are different ways in which fldigi can
access your sound card through the various sound systems.
OSS was the first audio backend in fldigi. It works with the Linux sound
system of the same name, which has now been replaced by ALSA but is
still supported via an emulation layer. (Though I hear it's finding a
new life in the Solaris world). Its only advantage, as an audio
backend, is that it's simple and doesn't require any external libraries.
The PortAudio backend was written subsequently to support OSS, ALSA and
JACK on Linux, CoreAudio on OS X, and also the various sound APIs on
Windows -- all through the same PortAudio library.
PulseAudio is more than an audio hardware access layer; refer to its
website or the wikipedia article for a summary of what it does. We
support it mainly because many Linux distributions are now integrating
it with their desktops, but also because it has a few interesting
features: it can take care of the resampling and volume control for us,
it can stream audio over the network, and it makes it easier to run
multiple fldigi instances (all accessing the same sound card).
In the future I hope that we can replace all of these with a libsydney
backend, without any loss of functionality, performance, sound system or
platform support. That'll be the day! Until then:
* Use PulseAudio if your Linux distro ships it, and you already have the
pulseaudio daemon running (this is the case with Fedora 8/9 and Ubuntu
8.04, probably also with the new openSUSE). Or if you want networked
audio, etc. etc.
* Otherwise, use PortAudio and select an ALSA hw:X,Y device, as this is
probably the most efficient way to access the hardware. PortAudio is
also the best way to access JACK, through which you can use other
programs as audio sources/sinks -- particularly useful with SDR
software. As with PulseAudio, you can select different capture and
playback audio devices.
* The OSS backend should be used only as a last resort. Note that it has
not been updated to support user-configurable sample rates.
- On Sat, 2008-06-21 at 23:48 +0100, Stelios Bounanos wrote:
> "You are in a maze of twisty little passages, all alike".You just took me back many years. :-)
Ted - wa0eir