DSD on FreeBSD

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clemfm

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I'm continuing with attempts to build a usable DSD setup on Linux (including DSD+ in WINE), however BSD may be the solution to OSS being removed from the Linux 2.6 kernel.

Here's a very interesting article by Dmitry Sergeevich Silnov, Department of Information Systems and Technologies, National Research Nuclear University MEPhI (Moscow Engineering Physics Institute), Moscow, Russia. From the International Journal of Electrical and Computer Engineering (IJECE)
Vol. 6, No. 3, June 2016, pp. 1072 ~ 1076 ISSN:2088-8708,DOI:10.11591/ijece.v6i3.9843

http://www.iaescore.com/journals/index.php/IJECE/article/download/461/335

A pre-built "package" is referred to, or implied:

"FreeBSD allows using ready-to-use software tools required for interception of radio waves and saving the results. The system is launched with a single command and requires no human involvement in the operation. This system allows complete automation of the radio waves interception process and also saving the intercepted results. There have been some similar solutions before, but they could only retransmit the sound to various websites without the possibility to listen to the talks history. The system produces read-to- use audio files which allow editing and improving the sound quality, saving the data, and replaying the audio files at any moment. Let’s describe each app in the package separately.
Rtl_fm. This utility is designed for operating directly with a USB tuner. It is used to set the operating frequency, the shift, the parameters of the recorded sound, and to adjust some other settings. The output is a sound file in its original condition.
SOX. This is a multitask utility for sound file processing. We input a sound file in its original condition, as taken from the USB tuner, into the utility. The sound is converted depending on the selected parameters. Here we have WAV as the sound file format. Then it is used for further processing of the sound file; it has filters for high and low frequencies and allows removing noises or pauses.
DSD. This utility is used if receiving an encoded signal. The encoded signal is loaded into the utility, and it produces a decoded audio signal that can be listened to online and saved.
The command that launches the system when ready-to-listen WAV files are created. Each file contains individual talks that can be separated with the SOX utility which finds the frames of every talk according to the pauses:
rtl_fm-Mfm-f$1-d0 -p22 -s48k-F9-Edeemp |\
sox -v 5.0 -r 48k -e signed-integer -c 1 -b 16 -t raw - -t wav - | \
dsd -u 1 -v99 -i /dev/stdin -o /dev/stdout | \
sox -v 5.0 -e signed-integer -r 8000 -c 1 -b 16 -t raw - $curdir/$1_$DT/$1.wav silence 1 0.30 1% 10.3 1%"

I have been unable to locate this 'package'. Next I'll obtain the above papers references, which will hopefully reveal further information.

Otherwise, I will 'simply' proceed to install FreeBSD and DSD myself...
 
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clemfm

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Hello clem;

To install SOX on FreeBSD or TrueOS ...

That's it.
Yes, however what I was referring to, was the articles apparent reference to a custom FreeBSD distro, with DSD etc already installed and configured.
 

SCPD

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Yes, however what I was referring to, was the articles apparent reference to a custom FreeBSD distro, with DSD etc already installed and configured.
I've read the linked article. I did not interpret this way.
 

clemfm

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References from the paper linked above:

REFERENCES
[1] Kiley P. and Benedett T., “Public safety interoperability with an SCA military radio using the P25 waveform,” in Military Communications Conference, 2007. MILCOM IEEE, pp.1-8, 2007.

Public Safety Interoperability with an SCA Military Radio using the P25 Waveform - IEEE Xplore Document


[2] Clark S., et al., “Why (Special Agent) Johnny (Still) Can't Encrypt: A Security Analysis of the APCO Project 25 Two-Way Radio System,” in USENIX Security Symposium, 2011.

https://www.usenix.org/legacy/event/sec11/tech/full_papers/Clark.pdf

[3] Glass S., et al., “A software-defined radio receiver for APCO Project 25 signals,” in Proceedings of the 2009 International Conference on Wireless Communications and Mobile Computing: Connecting the World Wirelessly, pp. 67-72, 2009.

http://citeseerx.ist.psu.edu/viewdoc/download?doi=10.1.1.540.9501&rep=rep1&type=pdf

[4] Cigirkan G., et al., “Efficient and Reliable Multicast of Data in APCO P25 Systems,” in Vehicular Technology Conference (VTC Spring), IEEE 81st, pp. 1-5, 2015.

Efficient and Reliable Multicast of Data in APCO P25 Systems - IEEE Xplore Document

[5] J. Joost, “Exploring Possible Vulnerabilities of 868MHz Communication Systems: A Step-By-Step Framework,” 2015.

http://referaat.cs.utwente.nl/conference/23/paper/7506/exploring-possible-vulnerabilities-of-868mhz-communication-systems-a-step-by-step-framework.pdf

[6] B. Benjamin and L. Shamir, “Assessing the efficacy of benchmarks for automatic speech accent recognition,” Proceedings of the 8th International Conference on Mobile Multimedia Communications. ICST (Institute for Computer Sciences, Social-Informatics and Telecommunications Engineering), 2015.

Assessing the efficacy of benchmarks for automatic speech accent recognition

Some will require a subscription, through a college etc
 

clemfm

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It turns out that FreeBSD has a version of OSS as standard, being newpcm. Another version, which supports more features and sound cards is available, called 4front. I have stayed with newpcm, as osstest works with my sound cards.

I have also now installed DSD's dependencies, however when I try dsd:


$ ./dsd -a
Digital Speech Decoder 1.7.0-dev (build:v1.6.0-86-g7ee04e5)
mbelib version 1.3.0
PortAudio not supported in this build of dsd


More research and posts to follow.....
 

clemfm

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SUCCESS!

I have now used DSD to successfully decoded a P25 test WAV file that I downloaded.

The setup is simply the latest version of FreeBSD with the FreeBSD OSS and Pulseaudio packages installed. My hardware is a HP t5470 Thin Client. There is no need for ALSA OSS emulation as FreeBSD still supports an OSS installation.

I will report back, in more detail, once I have decoded something off the air. I am in a rural area cannot simply scan for traffic as there is very little about, however I do have frequencies of the local fire service which I will try and decode.
 
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