Send MPX

nelson c

Well-known member
It is possible in the next versions of RadioCaster to set starting sample frequency of 192? Currently the maximum allowed is 96. FLAC straming using that frequency and the signal would be sent MPX (multiplexed signal with the FM transmitters that work, which contains the audio along with the Stereo and RDS), you could make links from the studio to the transmitter site. I know a piece of hardware that does this, but it is very expensive and with this "small change" this would be possible via software.
 
From what I understand if it is possible to make a link to 192 Khz in flac, Everything is already there to send the MPX. only be used layers player also play at that frequency. (eg Winamp think it is not possible). in the next version of RadioCaster be made ??free Carries out tests and discuss here. :)

Another thing: I have a problem with the PC of Broadcast:
Sometimes (I think when caster radius does not close properly), you lose all the settings and I have to set everything up again.
 
Ok, so MPX is handled somewhere else, RadioCaster just needs to support 192kHz. I think that's possible.

Regarding settings problem, are you using the latest RadioCaster version? There used to be such a problem but it was fixed.

You can also try pre-release version: http://dl.djsoft.net/beta/RadioCaster_setup.exe
Changes:
- metadata source can be URL
- fixed several broadcasting-related problems
- fixed several minor bugs
 
Hello, I'm traveling so here, so here I could not test whether the error is already fixed until next week.

Regarding sending MPX signal:

For this to work is a great chain everything should work to 192 Khz.
You forgot something important: the capture of audio, streaming is useless to 192 khz if only allowed one entry of 96 khz. ;D


I explain a bit in case anyone is interested:
For digital links at the transmitter site and leave only the transmitter and a PC requires a good soundcard (Eg ESI  Jil@ works well for this). 192 kHz sounds are inaudible to humans, which is why many plates "lie in specifications" and really do not reach those frequencies that is where exactly are the stereo and RDS data.

In order to understand better explain step by step:
-Classic configuration:
Music in Boss Radio --> Mixer --> Sound Processor--> stereo generator--> RDS generator--> FM transmitter.
-Settings link:
* Music in Boss Radio --> Mixer --> Sound Processor--> stereo generator--> RDS generator--> soundcard input (192 kHz) --> 192 Khz Streaming flac--> Internet.
* Internet--> Aimp (is the only player I found 192 khz send layers to the sound card, most uncertain output 96kHz) --> Output soundcard--> FM transmitter.

Warning:
This is ONLY used to the link, you should not send the audio to the website as it is perceived as mono, and includes pre-emphasis (so you'll notice a lot of treble stereo produced by the generator).
Using this configuration is virtually no loss in sound quality and you can use a single processor may sound, RDS and stereo generator for multiple radios  :).
 
You can already use sound card for playback and encoding @ 192kHz in both RadioBOSS and RadioCaster, just enter "192000" in the Sample rate field (this field allows entering custom numbers, so you're not limited to the ones listed).

The latest RadioCaster v1.4 allows encoding at 192kHz.

Let me know how it goes...
 
djsoft said:
You can already use sound card for playback and encoding @ 192kHz in both RadioBOSS and RadioCaster, just enter "192000" in the Sample rate field (this field allows entering custom numbers, so you're not limited to the ones listed).

The latest RadioCaster v1.4 allows encoding at 192kHz.

Let me know how it goes...

Sorry, did not know that! Next week I perform these tests and discuss here the results. thanks
 
djsoft said:
Ok, so MPX is handled somewhere else, RadioCaster just needs to support 192kHz. I think that's possible.

Regarding settings problem, are you using the latest RadioCaster version? There used to be such a problem but it was fixed.

You can also try pre-release version: http://dl.djsoft.net/beta/RadioCaster_setup.exe
Changes:
- metadata source can be URL
- fixed several broadcasting-related problems
- fixed several minor bugs

Hello Dmitry.

Sorry to revive this old topic.

I'm testing this characteristic of MPX shipping and does not work. (stereo signal is lost in the coding for FLAC).

The strange thing is that files already encoded in flac if they work (not are encoded in real time).
Here attached a demonstration of the MPX signal encoded (not in real time) that contains stereo.
You can notice that the sound is stereo using the MPX Tool program. (However if the sound is in mono, is heard from RadioBOSS unless RadioBOSS output fence toward a transmitter and there is tuned with a FM receiver)


If you need to test, a mpx with stereo signal can be generated from StereoTool (and virtual sound plates with a sampling frequency of 192.000).
If the output of stereotool is directly heard the audio is mono and with many high, then if that audio MPX entering tool returns to be stereo.

I'm back to looking at the hardware that sends MPX Ethernet equipment and it does for PCM encoding,
Maybe this is a limitation of the Flac encoding in real time (I think that delete impossible to hear frequencies but doing so eliminates these signals used for FM transmission).
I guess that it is the reason because this company will prefer the PCM format that does not compress anything.

Are there any plan to include this format for streaming and playback in RadioBOSS and RadioCaster?

Link signal MPX witch Stereo + MPXTool : http://musiconefm.com/Borrar/MPX.rar
 
FLAC compression doesn't remove any frwquencies, it just compresses the signal, but no modifications are made. The compression is lossless. I'm not sure why the signal becomes mono, though. How do you have setup the FLAC encoding?
 
Attached here is the configuration.
I am using the line also with 192,000 Khz input.

in any part of the coding is resample to 44 kHz not? because this could be the problem.

When playing flac with MPX files and is transmitted it works correctly.

Thanks
 

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You have Channels: mono - that's the reason why it's not stereo.

It will resample the file to the playback sample rate (the one you have selected in Playback-Devices-Main). If you want 192kHz without resampling, then you should also use 192kHz for playback.
 
djsoft said:
You have Channels: mono - that's the reason why it's not stereo.

It will resample the file to the playback sample rate (the one you have selected in Playback-Devices-Main). If you want 192kHz without resampling, then you should also use 192kHz for playback.

It is not necessary to use stereo coding.
just mpx signal is a composite signal that subtracting signals to the mono signal is obtained L and r. signal (this the fm receivers made it)
Here attached an image showing this.
on the other hand the pilot stereo (19 Khz) is a signal that instructs receptors that signal is stereo and this activates this mechanism.
The pilot stereo Flac encoding passes, but the sound is not stereo.

Obviously I have in reproduction 192,000 khz output.
the sound is mono because somewhere is suprinen from 23 to 53 KHz frequencies.
 

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I'd suggest you to try the Stereo mode for FLAC, just in case. RadioBOSS does not curt any frequencies, not FLAC encoder do so. The only reason why you may lose Stereo is Mono FLAC encoding, I think.

You can test it using the Stream Archive feature: set it to record your broadcast @19kHz, FLAC and then use audio editor to see if there's anything wrong with it.
 
I am sure that mono coding has nothing to do with the problem. anyway I could not test yet because I have not had the opportunity to bring any transmitter FM radio station studios. When it performs the tests I will comment on the results.
 
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