Josef “Jeff” Sipek

2021-01-25

The Confusing World of USB

Amateur Radio License Map

Topographic maps

VHF/UHF Line of Sight Calculator

Hey What’s That — Line of sight calculator

Radio Mobile Online — RF coverage estimator

Telnet Access to DX Clusters and Reverse Beacon Network

FCC M3 Map of Effective Ground Conductivity in the US for AM Broadcast Stations

The Official U.S. Time

FreeBSD Sound: ALSA & Qt

Sound in FreeBSD is somewhat complicated because of the various portability and compatibility shims. Last week, I hit an annoying to diagnose situation: I plugged in a USB sound card and while the kernel and some applications detected it just fine, other applications didn’t seem to notice it at all.

At first, I thought it was a Qt issue since only Qt applications appeared broken. But then, mere minutes before emailing a FreeBSD mailing list, I managed to find a hint that it was likely an ALSA on FreeBSD issue. Some searching later, I learned that in order for ALSA to see the device, it needed a mapping to the actual OSS device.

So, after adding the following to ~/.asoundrc, any ALSA application (and therefore any Qt application) that tries to list the sound devices will see a “ft991a” device:

pcm.ft991a {
	type oss
	device /dev/dsp3
}

To make it more explicit, without adding the above stanza to .asoundrc:

  1. OSS applications work fine.
  2. PortAudio applications work fine.
  3. ALSA applications did not see the device.

With the stanza, everything seems to work.

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