Re: [Wlug] Audio processing question
by John Stoffel
Andy> I thought so, too, but I cannot find a menu option or a command
Andy> line option to do it. Am I blind? :-) I'm running dream
Andy> version 2.1.1-svn808. In the SNAPSHOTS directory on sf.net, I
Andy> see dream-935 from Nov 2014 which is more recent but when I
Andy> compile it, it segfaults upon execution.
Hmm... maybe they have some newer code elsewhere? I'm not sure how I
could help at this point, beyond trying to compile the code with debug
info and then pulling it into gdb to get a backtrace.
I suspect you'll have to ask on the mailing list for dream, since what
I see on the web page implies that network stuff works... but not
sure.
I would think that dream could just pull the data directly from the
radio itself, to cut out the middle man here.
2 years, 7 months
Re: [Wlug] Audio processing question
by Andy Stewart
On 12/27/2015 05:38 PM, John Stoffel wrote:
>>>>>> "Andy" == Andy Stewart <andystewart(a)comcast.net> writes:
>
> Andy> Closer:
>
> Andy> nc -l -u 65535 | sox -r 48k -b 16 -c 1 -L -e signed -t raw - \
> Andy> -t wav radio.wav
>
> Andy> ...but....the mondiale decoder doesn't like reading radio.wav:
>
> Andy> sox WARN wav: Length in output .wav header will be wrong since can't
> Andy> seek to fix it..
>
> Andy> Still plugging away......
>
> So what mondiale decoder are you using, dream from sourceforge? I've
> just poked at the dream web page and it looks like it's got network
> input support, so I'm wondering if you cant' get the data from gprx ->
> nc -> dream -> speakers
>
> to do the decoding.
Hi John,
I thought so, too, but I cannot find a menu option or a command line
option to do it. Am I blind? :-) I'm running dream version
2.1.1-svn808. In the SNAPSHOTS directory on sf.net, I see dream-935
from Nov 2014 which is more recent but when I compile it, it segfaults
upon execution.
Andy
--
Andy Stewart (KB1OIQ)
Founder: Worcester Linux Users' Group
Founder: Chelmsford Linux Meetup Group
President: PART of Westford, MA (WB1GOF)
2 years, 7 months
Re: [Wlug] Audio processing question
by John Stoffel
>>>>> "Andy" == Andy Stewart <andystewart(a)comcast.net> writes:
Andy> Closer:
Andy> nc -l -u 65535 | sox -r 48k -b 16 -c 1 -L -e signed -t raw - \
Andy> -t wav radio.wav
Andy> ...but....the mondiale decoder doesn't like reading radio.wav:
Andy> sox WARN wav: Length in output .wav header will be wrong since can't
Andy> seek to fix it..
Andy> Still plugging away......
So what mondiale decoder are you using, dream from sourceforge? I've
just poked at the dream web page and it looks like it's got network
input support, so I'm wondering if you cant' get the data from gprx ->
nc -> dream -> speakers
to do the decoding.
John
2 years, 7 months
Re: [Wlug] Audio processing question
by Andy Stewart
On 12/27/2015 01:01 PM, Andy Stewart wrote:
> Here's a command that works, to give you a feel for the data formats
> involved:
>
> gqrx outputs RAW audio data to UDP port 65535
> netcat -l -u 65535 | aplay -r 48k -f S16_LE -t raw -c 1
> correct audio is heard
>
> Now, I want to get that into a WAV file or perhaps a fifo from which the
> mondiale decoder could get its input.
>
> netcat -l -u 65535 | sox ???
>
> The man page for sox is not for the faint of heart, and I'm not an audio
> expert.
>
> Any ideas?
>
> Thanks!
>
> Andy
>
Closer:
nc -l -u 65535 | sox -r 48k -b 16 -c 1 -L -e signed -t raw - \
-t wav radio.wav
...but....the mondiale decoder doesn't like reading radio.wav:
sox WARN wav: Length in output .wav header will be wrong since can't
seek to fix it..
Still plugging away......
Andy
--
Andy Stewart (KB1OIQ)
Founder: Worcester Linux Users' Group
Founder: Chelmsford Linux Meetup Group
President: PART of Westford, MA (WB1GOF)
2 years, 7 months
Re: [Wlug] Audio processing question
by Andy Stewart
On 12/26/2015 07:32 PM, Andy Stewart wrote:
> On 12/26/2015 06:17 PM, Frank Sweetser wrote:
>> I'd bet that you could use netcat do listen ona socket and dump the results directly to a file.
OK, I'm getting closer.
It turns out that the UDP audio stream is RAW. The "mondiale decoder"
wants to see WAV data. I think I need the correct incantation of the
sox command.
Here's a command that works, to give you a feel for the data formats
involved:
gqrx outputs RAW audio data to UDP port 65535
netcat -l -u 65535 | aplay -r 48k -f S16_LE -t raw -c 1
correct audio is heard
Now, I want to get that into a WAV file or perhaps a fifo from which the
mondiale decoder could get its input.
netcat -l -u 65535 | sox ???
The man page for sox is not for the faint of heart, and I'm not an audio
expert.
Any ideas?
Thanks!
Andy
--
Andy Stewart (KB1OIQ)
Founder: Worcester Linux Users' Group
Founder: Chelmsford Linux Meetup Group
President: PART of Westford, MA (WB1GOF)
2 years, 7 months
Re: [Wlug] Audio processing question
by John Stoffel
>>>>> "Andy" == Andy Stewart <andystewart(a)comcast.net> writes:
Andy> What I want to do is listen to the DRM broadcast in real time. I was
Andy> unsuccessful in getting Dream to read the WAV file while it was being
Andy> written.
>>
Andy> Does anybody have any suggestions as to how this could be done?
>>
>> Have you tried setting up a FIFO that each program opens and treats as
>> a WAV file? That might be the way to have them talk to each other.
>>
>>> mkfifo /var/tmp/radio
>>> gqrx --output /var/tmp/radio
>>> mondiale --input /var/tmp/radio
>>
>> though I havent' a clue what the two programs do at the commmand
>> level.
Andy> That is an interesting idea but gqrx doesn't let the user pick a
Andy> file name for saving the WAV audio. It creates a file name by
Andy> an internal algorithm. All I can do is pick the directory in
Andy> which that file is saved.
Andy> Is there a way that I can tie a file to a UDP port? gqrx will
Andy> output an audio stream on a UDP port. If I can make that look
Andy> like a file, perhaps "mondiale" will consume it.
Hmm... maybe using 'nc' (netcat) to listen to that UDP port and then
feed the info into either the FIFO or directly into the other tool?
Are they open source? It might just be time to hack some source to do
what you want... I also think the JACK audio thing might work, where
you setup some virtual Mics and Feeds to connect the two programs
together.
John
2 years, 7 months
Re: [Wlug] Audio processing question
by Andy Stewart
On 12/26/2015 06:17 PM, Frank Sweetser wrote:
> I'd bet that you could use netcat do listen ona socket and dump the results directly to a file.
>
I can't try it again until the DRM station broadcasts when I can receive
it. I knew I should have recorded the I and Q when I was listening to it!
I think this will work (not literally but you get the idea):
mkfifo /tmp/radio
gqrx > udp:65535
netcat -l -u 65535 > /tmp/radio
"mondiale decoder" < /tmp/radio
I'll let you know if this works. I'm also open to other suggestions,
and still looking at JACK.
Andy
--
Andy Stewart (KB1OIQ)
Founder: Worcester Linux Users' Group
Founder: Chelmsford Linux Meetup Group
President: PART of Westford, MA (WB1GOF)
2 years, 7 months
Re: [Wlug] Audio processing question
by Frank Sweetser
I'd bet that you could use netcat do listen ona socket and dump the results directly to a file.
On December 26, 2015 6:15:31 PM EST, Andy Stewart <andystewart(a)comcast.net> wrote:
>
>
>Is there a way that I can tie a file to a UDP port? gqrx will output
>an
>audio stream on a UDP port. If I can make that look like a file,
>perhaps "mondiale" will consume it.
>
>Andy
--
Sent from my Android device with K-9 Mail. Please excuse my brevity.
2 years, 7 months
Re: [Wlug] Audio processing question
by Andy Stewart
On 12/26/2015 04:13 PM, Steve Revilak wrote:
>> Hi gang,
>>
>> I think I need something like the Virtual audio cable, but I'd like to
>> know if there are other possibilities.
>>
>> I have two audio programs that I want to talk to each other: gqrx and
>> Dream.
> [..]
>
>
> Jack might be worth a try. http://www.jackaudio.org/
>
> Steve
Thanks, Steve, I'm looking at it but I'm not finding usage examples that
tie together two programs. I'll keep looking.
Andy
--
Andy Stewart (KB1OIQ)
Founder: Worcester Linux Users' Group
Founder: Chelmsford Linux Meetup Group
President: PART of Westford, MA (WB1GOF)
2 years, 7 months
Re: [Wlug] Audio processing question
by Andy Stewart
On 12/26/2015 05:10 PM, John Stoffel wrote:
>>>>>> "Andy" == Andy Stewart <andystewart(a)comcast.net> writes:
>
> Andy> Hi gang,
>
> Andy> I think I need something like the Virtual audio cable, but I'd like to
> Andy> know if there are other possibilities.
>
> Andy> I have two audio programs that I want to talk to each other: gqrx and
> Andy> Dream.
>
> Andy> gqrx is a software defined radio receiver that can save its audio as a
> Andy> WAV file, or it can stream audio via a UDP port.
>
> Andy> Dream is a digital radio mondiale (DRM) decoder. Digital radio mondiale
> Andy> is a shortwave radio broadcast in a digital format. Dream can read a
> Andy> WAV file, or it can read audio information from the microphone. It
> Andy> outputs a rather nicely sounding radio broadcast (mono or stereo
> Andy> depending on the broadcaster) with no static and no fading.
>
> Andy> I have succeeded in recording gqrx audio to a WAV file, and later having
> Andy> Dream decode it.
>
> Andy> What I want to do is listen to the DRM broadcast in real time. I was
> Andy> unsuccessful in getting Dream to read the WAV file while it was being
> Andy> written.
>
> Andy> Does anybody have any suggestions as to how this could be done?
>
> Have you tried setting up a FIFO that each program opens and treats as
> a WAV file? That might be the way to have them talk to each other.
>
>> mkfifo /var/tmp/radio
>> gqrx --output /var/tmp/radio
>> mondiale --input /var/tmp/radio
>
> though I havent' a clue what the two programs do at the commmand
> level.
Hi John,
That is an interesting idea but gqrx doesn't let the user pick a file
name for saving the WAV audio. It creates a file name by an internal
algorithm. All I can do is pick the directory in which that file is saved.
Is there a way that I can tie a file to a UDP port? gqrx will output an
audio stream on a UDP port. If I can make that look like a file,
perhaps "mondiale" will consume it.
Andy
--
Andy Stewart (KB1OIQ)
Founder: Worcester Linux Users' Group
Founder: Chelmsford Linux Meetup Group
President: PART of Westford, MA (WB1GOF)
2 years, 7 months
