Re: real time voice communication by CPFSK

[Hiroki Sagara]

Thank you for your reply.

In my environment, an audio underrun occurred with or without "Throttle".
However, updating Ubuntu to 20.04 and gnuradio to 3.8.1.0 solved the problem.

It's not perfect yet, but it's a step forward.
Thank you and best regards,
Hiroki

2020年8月11日(火) 19:26 Marcus Müller <marcus.mueller@ettus.com>:

Hi 相良洸希,

First of all, if you are still setting things up, now would be a perfect
time to upgrade to Ubuntu 20.04, which brings GNU Radio 3.8, which is
better than 3.7.13.4.

This sounds like an interesting project!

I have a couple of observations:

1. NEVER use a "Throttle" in the same flowgraph as a hardware sink.
You're running into the two-clock problem, where the Throttle block
internally uses a different rate than your soundcard. Maybe simply
removing the Throttle solves the problem!

2. Your English is a pleasure to read, no need to apologize for it 

Best regards,

Marcus

PS: Instead of Ruby-forum, I recommend using the official mailing list
archive:

https://lists.gnu.org/archive/html/discuss-gnuradio/2015-01/msg00158.html

Ruby-forum just takes the mailing list archive, and displays it as "web
forum", which it really is not, and that has led to very much confusion
in the past.

On 11.08.20 08:26, 相良洸希 wrote:
> Hello!
>
> I am challenging real time voice communication by CPFSK.
>
> I am creating a flow graph like the one in the photo and testing it, but
> the audio is intermittently played due to audio underrun.
>
>
> I am new to GNUradio and I don't know the cause and solution. What is
> wrong? And is my approach correct?
>
>
> For the time being, I tried changing the buffer size of alsa with reference
> to this, but it could not be resolved. (I was able to play only when
> samples/symbol=1)
>
>
>
>
> The environment is Ubuntu 18.04 and gnuradio is 3.7.13.4.
>
>
> I'm sorry for my poor English.
>
> thank you for reading!
>