DSD Windows Port

[n9mxq]

This program breathed new life into my RTL-SDR dongle.. Too much fun...hehe

 

[DaveNF2G]

OK, now I'm getting frustrated. I have read the manual for Virtual Audio Cable and re-read all of the messages in this thread about using it with DSD and still cannot get audio from my SDR to DSD.

I set the output from SDRSharp to Virtual Cable 1.

I went into the Windows sound applet and set Virtual Cable 1 as the default Recording device. I left my Sigmatel sound card as default Playback device.

I started up the VAC Control Panel and VAC Repeater apps to monitor what is going on.

I started up DSDF with the parameters for MotoTRBO that have worked for me.

I tuned the SDR to a frequency where I have successfully decoded MotoTRBO using the above-mentioned DSDF settings.

SDR showed no response to TRBO transmissions received via SDR.

I told VAC Repeater to monitor Virtual Cable 1 and could hear audio (digital sounds) during transmissions. However, VAC Control Panel showed 0 record streams and 1 playback stream with Repeater inactive, and 1 record stream and 1 playback stream with Repeater active. VAC and DSDF seem to be unaware of each other.

What am I missing?

Forgot to mention:

Dell Latitude E1505 laptop
Windows XP Pro SP3
1.6 GHz Intel T2050

 

[w9ran]

I've put together a (really lousy quality) short video of SDR# decoding P25 audio with DSD running on the same PC, using the DVB-T dongle as the receiver. The only way I could figure to record audio and video without stealing resources from the PC and thus biasing the test was to point a camera at the screen, so the video is basically unwatchable, except that you can see the errorbar display which shows the number of errors during realtime decoding (as horizontal rows of = in the scrolling text) in the DSD window.

P25 Decoding with SDR# and DSD - YouTube

The RF signal is identical for all users as this is the output of a P25 repeater, yet some voices are easier to understand than others even though errors are seen in all transmissions. Since the authors of DSD don't say much about how errors are detected and how the forward error correction is handled, it's hard to know what to do to optimize decoding. And it's possible that some audio distortion is present on the input signal. (While the setup in the video produces generally usable P25 audio, my laptop with a 1.4G mobile core duo CPU seems unable to keep up and the audio is impossible to understand due to audio dropouts).

I'll try to find better ways to record benchmarks but in the interim I thought this might be a useful benchmark for others who are experimenting with this combination. After the improvement from the filter changes Youssef made in v451, I'm getting pretty convinced that the CPU is bottleneck.

73, Bob W9RAN

 

[N1KK]

Your settings

Hi Bob

I appreciate the video. It just frustrated me more than I am already.

I could not tell from the video any of your SDRSharpe settings.

Have you made any changes to the settings for VAC since you posted your "How To" ?

When you start DSD do you just type DSD or do you add a " -xx" to make it more specific
to what you want to run

Keep up the great work!

Ken
N1KK

 

[n9mxq]

here's a shot of mine

Decoding P25

Pretty much load and run.. I use no -XX switches with DSD

SDR# select the proper device name for VAC (I'm registered with VAC, got tired of "TRIAL" interrupting hehe)

 

[DaveNF2G]

What did you do to get DSD to recognize VAC is its input?

 

[n9mxq]

Nothing, it found it on load.. Guess I'm one of the lucky ones...

 

[mtindor]

What did you do to get DSD to recognize VAC is its input?

In order for DSD to recognize VAC as it's input, you have to go into your control panel / sound configuration and under the Recording Devices set the VAC Line In as the default recording device.

The windows version of DSD will only work with the deault recording/playback devices. That's why you need to specify VAC as the default recording device.

Mike

 

[DaveNF2G]

Aside from selecting the VAC as a recording device and setting the levels, is there anything else required to make it the "default"? I don't see any obvious way to change the system's default sound devices.

 

[n9mxq]

Right click the speaker in your tool bar next to the clock, select recording devices, Right Click the VAC cable and select SET AS DEFAULT.

should be all you have to do, You can control the levels with SDR# volume.

If you can't get it I'd be happy to help remotely..

 

[SCPD]

Beware *some* computers will - upon detecting something plugged in/out of the microphone jack - select that as the new default thereby overriding your selection. If something is plugged into the mic jack, make sure it doesn't move. A wiggly cable can sometimes trigger this.

 

[mtindor]

Just to be clear, that's right-click on speaker, select Adjust Audio Properties, then click the Audio tab. There you'll see where you set the default recording / playback audio.

Mike

 

[n9mxq]

Just to be clear, that's right-click on speaker, select Adjust Audio Properties, then click the Audio tab. There you'll see where you set the default recording / playback audio.

Mike

Depending on your version of Windows. Vista and 7 are as I described.

 

[mtindor]

Depending on your version of Windows. Vista and 7 are as I described.

He's using XP, which is why I posted info for XP. I wasn't trying to take away from your assistance that you were giving him.

Mike

 

[n9mxq]

He's using XP, which is why I posted info for XP. I wasn't trying to take away from your assistance that you were giving him.

Mike

I didn't take it as such Mike.. Not at all, just clarifying what versions I was speaking of, which I should have done in the first post. :roll:

We're all here to help..

 

[DaveNF2G]

Thanks, Mike. You saved me from feeling even more stupid. LOL.

 

[mtindor]

I didn't take it as such Mike.. Not at all, just clarifying what versions I was speaking of, which I should have done in the first post. :roll:

We're all here to help..

Good deal, Gene. I agree, just hear to help.

73,

Mike

 

[mtindor]

Thanks, Mike. You saved me from feeling even more stupid. LOL.

Welcome, Dave. Don't worry, I've always got one up on you when it comes to feelin stupid.

Did you get it to work?

Mike

 

[N1KK]

RTL dongle

Besides Bob,

is anyone else using the RTL USB dongle with dsd ? I am not having much
luck decoding APCO. I believe my settings are exactly the same as BOB but still no
decode for more than a couple words then drop out.

Ken
N1KK

 

[N1KK]

your settings

Hi Bob,

I want to confirm I have the same settings. I think I do.

From the video you can't make out any of the settings. Would you mind listing them
starting right from the FRONT button that reveals if you are using default or 1024

Thanks
Ken
N1KK

I've put together a (really lousy quality) short video of SDR# decoding P25 audio with DSD running on the same PC, using the DVB-T dongle as the receiver. The only way I could figure to record audio and video without stealing resources from the PC and thus biasing the test was to point a camera at the screen, so the video is basically unwatchable, except that you can see the errorbar display which shows the number of errors during realtime decoding (as horizontal rows of = in the scrolling text) in the DSD window.

P25 Decoding with SDR# and DSD - YouTube

The RF signal is identical for all users as this is the output of a P25 repeater, yet some voices are easier to understand than others even though errors are seen in all transmissions. Since the authors of DSD don't say much about how errors are detected and how the forward error correction is handled, it's hard to know what to do to optimize decoding. And it's possible that some audio distortion is present on the input signal. (While the setup in the video produces generally usable P25 audio, my laptop with a 1.4G mobile core duo CPU seems unable to keep up and the audio is impossible to understand due to audio dropouts).

I'll try to find better ways to record benchmarks but in the interim I thought this might be a useful benchmark for others who are experimenting with this combination. After the improvement from the filter changes Youssef made in v451, I'm getting pretty convinced that the CPU is bottleneck.

73, Bob W9RAN