How to replay IQ or FM File created by DSDPlus?

[NickFi]

Hi All,
I am using DSDPlus v2.441. When I press the "R" key during a P25p2 call, the software saves an IQ file and an FM file in the DSDPlus folder. I could not figure out how to or if I can replay either of these files in DSDPlus. Can anybody let me know how to replay them? I don't mind if another software is required.

 

[morfis]

From the Notes.txt file:

FMP24 2.75

Added playback of FMP24-sourced .IQ files.
This is a developer function, but some users have expressed a desire to use it.
Command line: FMP24 -o<spec> <file.IQ

 

[mtindor]

And for raw audio WAV file that you have recorded, you would do:

dsdplus ? name_of_file.wav

 

[NickFi]

And for raw audio WAV file that you have recorded, you would do:

dsdplus ? name_of_file.wav

Thank you Mike, that command worked for me.

 

[NickFi]

From the Notes.txt file:

FMP24 2.75

Added playback of FMP24-sourced .IQ files.
This is a developer function, but some users have expressed a desire to use it.
Command line: FMP24 -o<spec> <file.IQ

Thank you, now that you mentioned, I remember reading that part of the document.
I tried now this command "D:\DSDPlus>fmp24 -o1 < 2023-11-20@194915.IQ" and I can play the file, but it is the raw IQ sound. Do you know if there is a way to demodulate it to the desired sound?

 

[cg]

You run DSDPlus then run the FMPx IQ file, making sure the FMPx output and the DSDPlus input match.

It only replays what is active during the recording. So if you were not holding on your target group and there was activity on another group, that is what is recorded. You don't have the ability to go back and choose other conversations to hear on different frequencies as the SDR was following the active CC then VC.

 

[NickFi]

You run DSDPlus then run the FMPx IQ file, making sure the FMPx output and the DSDPlus input match.

It only replays what is active during the recording. So if you were not holding on your target group and there was activity on another group, that is what is recorded. You don't have the ability to go back and choose other conversations to hear on different frequencies as the SDR was following the active CC then VC.

Thanks cg, but I still can't figure out what I have to do. I started DSDPlus by itself, then I called a batch file containing "fmp24 -rv -o1 < 2023-11-17@184238.IQ". I can hear the sound from the IQ file, but not the decoded voice.
In DSDPlus, I have the following options selected:

Input > Use Direct FMPx Linking
Input > No Source Audio Monitoring
Output > Synthesize All Digital Voice
Output > No Per-Call Recording
Output > Decode All Above Protocols (enabling all, including Decode P25)
Control > Combined CC/VC Monitor
Control > Hunt For Lost Control Channels
Control > Voice/Data Call Following

What am I doing wrong?

 

[cg]

Try removing the -rv from your batch file.
I made an IQ file and it played fine using
FMP24 -o20003 <test.IQ
DSDPlus -i20003 -o1

 

[NickFi]

Try removing the -rv from your batch file.
I made an IQ file and it played fine using
FMP24 -o20003 <test.IQ
DSDPlus -i20003 -o1

Thank you cg,

The parameters -o20003 and -i20003 imply that the RTL-SDR dongle has to be connected. For replay the IQ file, I don't know why would this be necessary, but I don't mind. I will try this at home and I will report if it works. I made a batch file where I can call both commands, but in different consoles (otherwise only the first one will be executed):

@Echo off
start cmd /k FMP24 -o20001 < 2023-11-17@184139.IQ
start cmd /k DSDPlus -i20001 -o1

 

[morfis]

The parameters -o20003 and -i20003 imply that the RTL-SDR dongle has to be connected.

No they don't. They are port numbers for data (audio) transport

 

[NickFi]

I run the following batch file, with the RTL-SDR receiver disconnected from the USB port and I get an error as below.
I also tried with the default linkId of 20001 and got the same error.

@Echo
start cmd /k FMP24 -o20003 < 2023-11-17@184139.IQ
rem introduce a waiting time of 10 seconds before the second command is executed.
timeout /t 10
start cmd /k DSDPlus -i20003 -o1



With the RTL-SDR plugged into the USB port:

If I type the commands in a console, I will have to open two consoles, because the first one does not complete:
D:\DSDPlus>FMP24 -o20003 <2023-11-20@194915.IQ
FMP24 2.85

Current working directory is "D:\DSDPlus"
SDR sampling rate = 2.400 MHz
Spectrum window width: 1024
FFT size: 32,768
Spectrum update rate: 10 Hz
Step size table: 5.000 6.250 7.500 12.500 15.000 25.000 100.000
DSD+ path is "D:\DSDPlus"
Primary frequency list: '.\FreqList.csv'
Secondary frequency list: '.\FreqList2.csv'
Database search distance: 99.90 miles
Base latitude/longitude: 19.7163 -155.6241
Using DSD+ link ID 20003
Optimizing FFT calculations... done.

Audio output device #1 = 'Realtek HD Audio 2nd output (Re'
Audio output device #2 = 'CABLE Input (VB-Audio Virtual C'
Audio output device #3 = 'Realtek Digital Output (Realtek'
Audio output device #4 = 'Speakers (2- USB PnP Audio Devi'


Processing I/Q recording

Waiting for DSD+ link with link ID 20003
Recording date: 2023/07/20 19:49:15

Sampling rate: 2.400000 Msps

Center frequency: 417.362500 MHz

No frequency data files found
Delaying for DSD+ link...

<EOF> Close spectrum window to exit.Accepted DSD+ link on link ID 20003
DSD+ link: remote has closed connection
Waiting for DSD+ link with link ID 20003
Accepted DSD+ link on link ID 20003

** Note that I updated the content of the first command after running the second command, as they interact with each other.

==========================
Now, I run the other command:

D:\DSDPlus>DSDPlus -i20003 -o1

DSD+ 2.441
Current working directory is "D:\DSDPlus"
Appending synthesized audio to file '1R-DSDPlus.wav'

Assuming FMPA/FMPP/FMP24 is signal source; auto polarity detect is disabled

audio output device #1 = 'Realtek HD Audio 2nd output (Re'
audio output device #2 = 'CABLE Input (VB-Audio Virtual C'
audio output device #3 = 'Realtek Digital Output (Realtek'
audio output device #4 = 'Speakers (2- USB PnP Audio Devi'

audio output device #1 (Realtek HD Audio 2nd output (Re) initialized

P25 data loaded; 3 networks, 61 sites, 154 channels
0 frequency records loaded
1016 radio records loaded
110 group records loaded
0 site records loaded
0 network records loaded
0 site loader records loaded
Fusion decoding enabled
D-STAR decoding enabled
NXDN4800 decoding enabled
NXDN9600 decoding enabled
DMR/MotoTRBO decoding enabled
P25 Phase 1 and Phase 2 decoding enabled
X2-TDMA decoding enabled
ProVoice decoding enabled

Mono audio decoding initiated; press Esc to exit...
Initiating FMPx link using link ID 20003...
FMPx link established; link ID = 20003
FMPx link established
FMPx link exit
Initiating FMPx link using link ID 20003...
FMPx link established; link ID = 20003
FMPx link established
FMPx link exit
Initiating FMPx link using link ID 20003...
FMPx link established; link ID = 20003
FMPx link established
====================

I cannot hear any sound. I just made another IQ record to be sure it contains voice and I still can't hear anything. Further, the FMP24 window shows FM 99.9, while my recording is at 417.5125 MHz

 

[mtindor]

Try removing the -rv from your batch file.
I made an IQ file and it played fine using
FMP24 -o20003 <test.IQ
DSDPlus -i20003 -o1

Do you run the latest version of DSDPlus, and is the latest version of FMP24 what you used? I don't have an RTL dongle. I have Airspys. And this simply does not work with FMPA and results in a crash every time FMPA -o20003 <test.IQ is ran.

Nevermind. This is probably due to FMPA likely not supporting it.

I do not have an RTL dongle, but if I run FMP24 -o20003 <test.IQ (using a test.IQ file I made with FMPA), it runs but I get:

Input is not an FMP24 IQ recording

So I cannot personally test this out. But it looks like what you say should work if one actually created the IQ file with FMP24.

M

 

[NickFi]

Do you run the latest version of DSDPlus, and is the latest version of FMP24 what you used? I don't have an RTL dongle. I have Airspys. And this simply does not work with FMPA and results in a crash every time FMPA -o20003 <test.IQ is ran.

Nevermind. This is probably due to FMPA likely not supporting it.

I do not have an RTL dongle, but if I run FMP24 -o20003 <test.IQ (using a test.IQ file I made with FMPA), it runs but I get:

Input is not an FMP24 IQ recording

So I cannot personally test this out. But it looks like what you say should work if one actually created the IQ file with FMP24.

M

Hi Mike, thanks for info. I am uploading now an IQ file which was created today using the RTL-SDR dongle. The location is Filebin | pvouonzf4hgdxqr5
The file has 285 MB. Please let me know if you succeed running it.

 

[mtindor]

Do you run the latest version of DSDPlus, and is the latest version of FMP24 what you used? I don't have an RTL dongle. I have Airspys. And this simply does not work with FMPA and results in a crash every time FMPA -o20003 <test.IQ is ran.

M

Hi Mike, thanks for info. I am uploading now an IQ file which was created today using the RTL-SDR dongle. The location is Filebin | pvouonzf4hgdxqr5
The file has 285 MB. Please let me know if you succeed running it.

Worked just fine using two command prompts.

FMP24 -o20003 <whateverTheNameWas.IQ
DSDPlus -i20003 -o1

I heard one voice call. It tuned to the various freqs automatically.

I like to run DSDPlus first, and then FMP24

 

[NickFi]

Worked just fine using two command prompts.

FMP24 -o20003 <whateverTheNameWas.IQ
DSDPlus -i20003 -o1

I heard one voice call. It tuned to the various freqs automatically.

I like to run DSDPlus first, and then FMP24

Excellent - I repeated the same as you, starting in two separate consoles, first with DSDPlus and then followed by FMP24 and I've also heard like two seconds of voice. I didn't select the best IQ file for sharing because I could not listen to any of them before

 

[NickFi]

I deleted the previous IQ file and I uploaded a slightly better one (more people talking), if anybody else wants to try it. The file will expire after one week. The location is the same as before, Filebin | pvouonzf4hgdxqr5 and the file has 264 MB.

 

[mtindor]

I deleted the previous IQ file and I uploaded a slightly better one (more people talking), if anybody else wants to try it. The file will expire after one week. The location is the same as before, Filebin | pvouonzf4hgdxqr5 and the file has 264 MB.

Yep, worked fine. 8 or 9 calls on that one. And actually pretty good decode for a 20 db SNR.. which is probably the minimum without experiencing a lot of decoding errors.

 

[NickFi]

It is very interesting that if I use the batch file I made to call the two executables, it will not work and it will complain about the missing RTL-SDR dongle. However, if I run the commands manually it will work without the dongle. I will figure out in the end what is going on and update the batch file. As you said, I have to start first the DSDPlus and then the FMP24.

So far I found out that the line in the batch file "start cmd /k FMP24.exe -o20003 <2023-11-21@200111.IQ" does not work as expected.

 

[NickFi]

I fixed it. Thanks for help, cg and Mike.

It was a problem related to the redirection that does not in the batch file, unless I add a ^ character in front of it. This is a working batch file that allows replaying an IQ file. Note that instead of < there is a ^< and this is not a mistake.

@Echo off

echo Starting DSDPlus.exe...
start cmd /k DSDPlus.exe -i20003 -o1

echo Waiting for DSDPlus.exe to initialize...
timeout /t 2

echo Starting FMP24.exe...
start cmd /k D:\DSDPlus\FMP24.exe -o20003 ^< D:\DSDPlus\2023-11-21@200111.IQ

 

[CanesFan95]

Bumping an old thread if you guys don't mind. What is the difference between these .IQ and .FM files? FM I assume is Frequency Modulation and what is "IQ"? Can these be played back like an .mp3 or .wav on a media player? Or are these some other kind of file. I guess I'm unclear what is different about these than the .wav or .mp3 radio source audio recordings.