[arm-allstar] DSP & RPi2

[Doug Crompton]

Dave,

Anyone that has heard me talk about this in the past knows my mantra about usbradio. In general depending on what DSP features are used and how it is setup the audio stinks. I can pick out nodes running usbradio systems in a minute and when I have them switch to simpleusb it is like day and night quality wise. For some reason there are many people that don't hear this or maybe just put up with it. I happen to have a good ear for audio quality and I often find that many do not. Perhaps thats why there is not more uproar about usbradio and maybe also why the current digital modes on VHF/UHF with their crappy audio seem to be accepted by so many. The poor usbradio audio is even worse on the small boards and in my opinion not even acceptable.

So that being said there will be an answer in the future. We are currently working on a new channel driver using ALSA rather then the now deprecated OSS and that is only the beginning. Current testing with using ALSA has shown a tremendous improvement.  Until we get the entire package together at least in preliminary form I cannot promise anything but it looks very favorable for a really high quality DSP system built new from the ground up. I won't go into all the features now but suffice to say it will be very flexible allowing virtually any ALSA device to be an input or output and the DSP will use better open source libraries.

Until then I would not recommend anything but simpleusb for the BBB and RPi2 and in my opinion for any Allstar system but you gotta do what you gotta do! 

Allstar is known for its superb audio quality. The best in the ham VOIP community. That is what we strive for and I won't be happy with anything less.

Now that we have pre and de-emphasis as well as squelch tail elimination in simpleusb it makes it a lot more acceptable to many users at least temporarily.  

I hope that answers your question. The bottom line is the current usbradio is not worth trying to fix and probably could not be fixed in its current form. This is much more a SW than a HW issue.

So hang in there and stay tuned for more news on this in the near future.
73 Doug
WA3DSP
http://www.crompton.com/hamradio


> From: vk4dak at bigpond.com
> Date: Tue, 28 Apr 2015 10:16:12 +1000
> To: arm-allstar at hamvoip.org
> Subject: [arm-allstar] DSP & RPi2
> 
> Hi All
> 
> I was wondering if someone may be able to advise if anyone has had success as yet in getting DSP up and running on the Pi2? I have heard of some people having "choppy" audio and yet some apparently have it running fine.
> I would love the facility to change/swap CTCSS and other details simply thru the software and the better quality audio that also comes with the USB Radio driver and use flat audio into the URI/software.
> 
> I see there is the usbradio.conf file there to be played with but do we have any facility to try this on the current version? Would changing the rpt.conf to usb/radio allow the driver to be utilised or are there other dependancies to be installed? Is there a tune "helper" facility available to assist in setting the audio levels in the software etc - I have had a look around however I am unable to find it as yet.
> 
> After all - that's what its all about - trial and error or "crash management" 
> 
> Look forward to your replies.
> Dave
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> Visit the BBB web page - http://www.crompton.com/hamradio/BeagleBoneBlackAllstar/
> 
 		 	   		  
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