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In another thread we are talking about STL (Studio Transmitter Link).
Leif talked about he is (or will) developing software for this.Leif, this is a VERY, VERY interesting feature!
My question is:
Wil this be a part of Breakaway (broadcast or live), or will this be seperate software?Let’s discuss some more in this thread.
Thanks in advance.
Yess… this would make it definitly complete…
I think there are many broadcasters who use BBP in a same manner as we do.
We are currently streaming a AAC 320kbps (Orban codec) stream through a Wifi connection
to our transmitter site.
The overall sound is very good but in PCM it would be perfect 8)Greetz,
Otto Spoileryes.. i wonder how will Leif make to look and work.
We also stream over wifi with PCM wav 48kHz (50-75ms latency).. but i am interest in Lefi’s prog… because it will have backup player and more .. currently we don’t have that in our software for sending.It ended up being delayed — I realized I needed some time away from the keyboard to avoid working myself to death. Still on my list, though 🙂.
///Leif
Leif,
Take your time. We don’t want you to have a bios burn out…. 😉
Pull the plug and take a holiday.
Greetz
Can I add my entirely selfishly impatient support for this product, especially if it can acheive results such as the MPX over E1 connection units out there (or maybe even better), but with TCP/IP.
I am oftem using 54mbps TCP/IP links on 5.8ghz (which still acheive 6mbps with low signal condidtions) and using all this potential to carry a mere 320Kbps audio stream.
What a dream it would be to carry a full mpx signal over one of these especially as raw PCM or maybe FLAC for those with bandwidth limits! Only one channel @192 khz would be needed (approx 3mbps) but if two separate streams could be implemented and both come out of seperate channels at the other end (like with my ongoing discussion about this..), this would add loads of value too. So in theory, this could carry two uncompressed mpxs over approx 6mbps link or approx 3mbps with FLAC. If this was the kind of idea you were working on, I’d be very excited by this.
Please make my dream a reality soon Leif.PS, for good measure, throw in a fallback audio playback engine which plays out pre-processed PCM or FLAC mpx files if the link goes down. I’m a great ideas man.. If only I knew how to write the code.. over to you Leif.. 🙂
I don’t think a Multiplex (MPX) signal over Internet is an option.
Somewhere on this forum Leif told us that this is not a good idea.
(Something about bandwidth).Correct me if i’m wrong.
STL link could be build in Breakaway Live at the Studio location, and at the transmitter location Breakaway Broadcast.
This is a GREAT feature for pirate stations here in the Netherlands.
For streaming MPX you would need 1mbit/s+ which you can’t get with a regular dsl line, at least not the upload. So in most cases you wouldn’t be able to use it.
Lack of bandwidth is only part of the problem.
No hardware supports MPX streaming, so you’d still need a computer at the transmitter site to receive the stream.
At that point, why not just run the processor on *that* computer instead? 🙂
///Leif
Hi Leif, its a good point but again, I was not planning to run this link over the internet, just over a private, direct TCP/IP connection.
[quote author=”Leif”]Lack of bandwidth is only part of the problem.
No hardware supports MPX streaming, so you’d still need a computer at the transmitter site to receive the stream.
///Leif[/quote]
Not exacltly true, these units from Elettronika sends MPX digitally over a 2mbps E1 connection.
http://www.broadcastwarehouse.com/elett … 06/product
I’m guessing probably using FLAC as the compression.. It is a software version of this which I aspire to as E1 connections are a specific protocol and not available in many countries.
There are a dozen or more programs and hardware solutions which can do this job over an internet connection or a direct tcp/ip connection. Most of these solutions use compression of some form although a minority do also support direct PCM but often with limited success.
There would be no point in making such a program unless it can bring something new to the party.
I can really only think of a couple of features which could be considered as a breakthrough in STL features.Firstly, I’d like to see an STL program (and a streaming program for thst matter) which uses FLAC, that would be nice, a lossless IP STL, the best commercially available product which is 100% reliable I have found so far uses a 320k WMA stream but this is still not lossless. A step up to FLAC would definately open my wallet.
The reason for wishing for mpx STL reception at the remote end is again to do with minimisation of investment in equipment (and software) which will be lost in the event of theft or communications authority raids. A PC running STL software, Breakaway, Airomate and remote control software will have cost $400+ alone not including the hardware costs would be lost and all would need to be replaced.
If there were a program capable of delivering either, the MPX over FLAC OR the L/R Lossless (no overshoots) then whis would help minimise costs as the Breakaway etc would be at the studio end and the only software running would be the STL program on the remote (TX) PC (which would need to priced in such a way that the TX is most of the cost and the RX is low cost and easily relicencable (maybe locked to the licence code in the TX program?)).
This would also allow for much lower-end (less costly) pcs to left at the TX site as the processing is handled at the studio end.[quote author=”yorkie98″]lost in the event of theft or communications authority raids[/quote]
I had to LOL at this 🙂. Okay, I see your point.
Seriously, I wouldn’t dream of changing a user again in this particular situation 🙂.
It would be interesting to run flac, the only problem is that it performs rather poorly on MPX signals. I use flac in mpxtool, and i’m lucky to achieve compression ratio 0.7. Flac compression usually achieves more like 0.4 with regular cd-quality audio — this is a huge difference.
Using MPEG-1 Layer 2 i was able to encode composite at 1.5mbps with barely 1% of overshoot, which would be completely acceptable performance wise, but still too hefty bandwidth-wise.
Composite does not need 192kHz — it would in fact be fine with 128kHz if carefully done. (15 kHz bandwidth is readily achievable at 32 kHz sampling rate, so 60 kHz is achiavable at 128 kHz sampling rate, and this covers MPX including RDS.)
It also doesn’t need 16-bit sampling. Not even on an awfully frigid day in hell will we achieve 100 dB SNR on the FM band during anything resembling normal circumstances. In fact, 12-bit sampling is enough, which gives us 72dB SNR. Considering that this -72dB noise floor is AFTER compression and clipping, we’re good.
128 kHz 12-bit 1-channel is 1.536 MBps. Literally half the size of 192 kHz 16-bit, and this is before even using a codec — this is still PCM.
I just did a test on this, and then FLAC’ed the result, and got a compression ratio of 0.57, above and beyond the downsampling already done. This meant that a 93mb flac file got down to 35mb.. That’s 1.15mbps, with no possibility of codec-induced overshoots or audible degradation.
Here’s what the result looks like:
Now, can a DSL line sustain 1.15mbps indefinitely without dropouts or glitches? Most cannot, I would think, but perhaps some can. Interesting thought.
This was reference settings though. More aggressive settings might use some more bits.
Edit: Here’s with more aggressive settings + RDS. 12-bit mpx audio, 128 kHz sampling, flac:
Total bitrate: 1.26 Mbps
10-bit (!!) mpx audio with RDS, 128khz sampling, flac:
The noise floor is a little higher than I’d ideally like, but considering the nature of FM, I’d accept it in a pinch — i doubt it would be audible in anything resembling normal circumstances.
Total bitrate: 1.0 Mbps
///Leif
Good work, so it’s looking do-able. As you rightly state, it’s unlikely a DSL line could sustain even a 1mbps stream constantly but it’s not my intention, I’m looking at this to work over a 5.8ghz 54mbps wireless point to point link so even in poor signal condidtions, 3-6mbps is acheivable and no problems with sustainability.
I’d suggest having the program work in two modes:
1. Stereo audio with options to use ultra-low bandwidth codecs like AAC+, medium bandwidth (MP3/WMA) right up to FLAC and PCM for lossless audio OR
2. Mpx with the flexibility to have high bandwidth, high SNR or lower bandwidth with the slightly lower SNR, even the 10 bit looked okay at a push.
I should imagine that there would need to be software downsampling/upsampling as many soundcards jump from 96 to 192khz and only do 16, 24 or 32 bit (my Emu 0404 does 96, 176.4 and 192 but not 128!).
Finally, not forgetting the fallback playout if the link is lost..This would make your program industry leading as all the current ones have limitations either in the codecs available, lack of fallback, lack of sound device selection or inflexible network settings and overall reliability. There is currently no program which I would call complete. Obviously i’m considering this as a standalone product as opposed to a part of breakaway (although it would work as a DSP plugin too..) as this would allow it to be marketed to a wider client base so also may bring those in looking for an STL solution and introduce them to breakaway. You could sell the STL at a reduced rate to Breakaway licence holders and also bundle a demo version of breakaway with the STL software. What a great cross-marketing opportunity!
This is your chance to lead the next generation of software STL programs and also compete with the current generation.
I’m sure this is a challenge but I’m also sure you are up to it. If this program is made to the standard of BBP, it will be excellent.
Thank you!
Only thing is, how would we handle the fallback playout if running as an MPX-link?
I suppose I could put an extremely optimized breakaway-processor with the low cpu clipper and stereo generator, to handle the fallback 🙂.///Leif
[quote author=”Leif”]Thank you!
Only thing is, how would we handle the fallback playout if running as an MPX-link?
I suppose I could put an extremely optimized breakaway-processor with the low cpu clipper and stereo generator, to handle the fallback 🙂.///Leif[/quote]
I was thinking that, If running in stereo mode, fallback would be normal stereo files, maybe pre-processed by a clever little batch processing tool (whoops, I’ve just created you another job..) which encodes files using the breakaway processor and saves them with whichever codec the user desires, although it would be advisable to save in the same format the STL is usually used in..?
OR in the case of MPX, ready processed PCM or FLAC files using the same clever batch tool…Your own suggestion would work also, I think in the case of fallback audio, the end user should expect the audio to not neccesarily be as good as the main audio but just as long as it does not allow over-deviation.
It sounds like you are really starting to get into this idea?
Definitely. I know it’s a necessary product.
I don’t believe I’ll make a public batch processor though, because there’s just no way of protecting it. My experience is that no matter how inexpensive and good value you make a product, there’s still some who would rather just take it for free, and other individuals with good reverse-engineering skills (and nothing better to do) who help them do it. This really takes the fun out of it, and forces me to worry about protection all the time. It’s also the reason why there won’t be a full control software version.
Anyway, MPX through wifi is a very interesting idea, I know at least a couple of stations personally that would use that right off the bat.
///Leif
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