Re: [linuxham] Trying fldigi 2.04 install
- Hi Tim,
This is EXACTLY what I am experiencing. Also, does it with most other
The very odd thing was that one of the digital ham programs, (and I can
not remember which one for sure, but was included on one of the PSKmail
disks or similarly Live disks), actually did work OK and the other
programs one the same disk, did not work correctly. Either they had the
ticking problem or could not even play any sound, yet another program on
the disk worked FB.
I might mention that the audio player on the Ubuntu 7.10 version that I
am using, does work OK. In fact, I can even get the Realtek card to work
and play via the front panel jack too. So this seems to be something at
the program level. Maybe it is not at the ALSA level?
Tim Gimmel wrote:
> I'm not 100 percent this is the same issue, but I have a Toshiba laptop
> with a Realtek HDA (Intel) sound system with a similar problem. I would
> describe it as a "ticking" sound in the audio. Same problem with gMFSK,
> WSJT 6 or any ham radio program for that matter. However regular sound
> such as music is fine. I have a bug report in at alsa-project.org
> (#3484). If it sounds similar let me know, and Rick if your hardware is
> similar please add to bug report:
> Dave if you have any info on how the tones are produced I would be
> grateful! This is my "Ham" laptop and using it for digital is the last
> thing I need to make it complete.
- Hi Tim,
Tim Gimmel wrote:
> Rick,Portaudio is a cross platform API. It sits between your application and
> The new portaudio stuff in Fldigi 2.05 fixed my problem with the
> "ticking" sound. Can you tell me how it (portaudio) works, or give me
> some hints that I can give to the alsa folks? WSJT 6 uses portaudio
> also and would love to be able to make it work correctly. I have to
> admit I have been working with Linux for over 10 years and I still just
> don't understand the audio system. If you know of a site that has a
> good explanation of Linux audio from oss to alsa to portaudio I would
> love to read it!
the underlying sound system, in most cases folks are using ALSA.
In your case, you were able to use Portaudio and the FLdigi code to
force a supported sample rate that your Intel HD sound card could handle
natively. This is 44,100, 48,000. The card won't support lower sample
rates, but digital apps want to use them, like 8000, 11,025, etc. There
are a variety of standard sample rates for sound cards, yours does not
support all of these (at least in Linux and ALSA.) And that's why the
ticking. ALSA had to up convert, and the Intel HD driver for ALSA is not
up to the task right now.
Portaudio and a forced (in FLDIGI) supported sample rate fixed the
ticking because no conversion was then needed on the sound stream.
If WSJT can select a sample rate, you should be able to take care of the
problem easily. You might want to ask Joe to put that in the code.
Rick Kunath, k9ao