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I’m not sure if this has been answered before. When you use the Edcast DSP version (recording from DSP) for encoding streams within Breakaway Broadcast the de-emphasis stage seem to do nothing.
I have found that with routing the audio to Edcast in the obvious manner it crashs. If I setup the pipes to take audio in from the soundcard then send it to pipe one. Then I select pipe one as the source input for Edcast it works. But as soon as you save the configuration by hitting reload that’s it – crash!!
I’ve got it working by setting inputs and outputs to the same soundcard. With Edcast in recording from DSP mode. Everything is good as long as you don’t expect to have any pre-emphasis limiting on your streams. This is any level.
What is the fix for this guys?
Howdy!
This behaviour is by design. BBP always does pre-emphasis. You choose how much — 15 to 75us. On the main output, you can choose whether to de-emphasize or not (as it could be feeding an external stereo generator at which point you’d want de-emphasis OFF).
The internal encoder output (plug-in), on the other hand, ALWAYS receives de-emphasized output, as there are no codecs that need pre-emphasis.
Crashing, on the other hand, should not happen. EdCast must be set to Record from DSP! The Live recording should be crossed out, as follows:
Does this solve the problem?
Best,
///LeifThanks Leif,
Yes it has been working in the "recording from dsp" mode. With no problems.
Let’s see if I get it right!
"Recording from DSP" with Edcast means it is ALWAYS getting the de-emphed version? I wasn’t sure this was happening as turning off the de-emph did nothing on the streams. I was suss as via headphones plugged into the soundcard it did.
As long as the "amount" changes on the streams I should be right. We intend on using Breakaway infront of a network of Barix boxes feeding FM & AM txers (yeah just to keep me on my toes). Final HF limiting to be done on site for the type of service it is. I’ll explain further if you want me to.
Cheers
PeteHi Leif,
Mate much debate has gone into this. This is for a small station with remote services in regional towns. Some don’t go over 4000 people. So there is a question of economics. Having said that I’m very much an advocate of "there is no reason for a regional to have a substandard audio quality service".
These are FM services so we need to observe the 50us for Australian FM. There will be AM services on there too (more on that later). For the reasons of cost with the ISP (and upload bandwidth at the studio). We will only be sending them one stream out from the studio. The ISP has a Shoutcast server on a linux box at their datacentre for us. This is the common point where all sites hookin to the stream as any listner would. This is a VPN setup by the ISP so no download fees as it’s not public. Just the costs of ADSL connections per end and little to them for running it. Not bad really, you could have 10+ of these VPN’s for the cost of a single 128k sat time.
Because of the one feed sending to FM and AM. I’ve settled on the Inovonics 222 (NRSC) AM compliance limters for both AM & FM (eh?). Yes that’s right! My reason is because we are only mono on FM as power is low in these towns and we need it to cover a BIG distances. I don’t need a stereo unit. Also the curve that is applied to get the boost for AM at the US AM standard is the same Pre-emph curve used for FM. (No imagination there) But lucky for me!! A simple mod to the Inovonics 222 at the factory and the Hi Freq roll off is defeated and the curve is still there. Presto MONO FM HF Limiter. Just spending 3500+ dollars for an Aphex Dominator didn’t cut it here. It’s stereo (we don’t need it) so for the same outlay we get 3 x 222 boxes.
Oh! The 222’s doing what they were really designed to do will be infront of the AM ers. The bandwidth for them is 5khz as they are not reall broadcasting services. They are off the top of the dial by our rules here. So we observe the SW setting there and everyone is happy.
Regards
PetePS I know this means Breakaway Live might be all we need at the studio instead of Broadcast. But there will be public streams (outside the VPN stuff) so I plan to set Broadcast to 15us. And go Medium – Vary light on the reduction out at the sites. I still think Broadcast is the one for streaming. The added bonus of the sparkle in the tops is nice on the streams even though you really don’t need the pre-emph for the main reason its there (FM). It’s is a real nice bonus!!
Pete
Hi Pete!
Whichever limiter you plan to use at the transmitter site, I feel extremely confident in saying that none does a cleaner job than Breakaway Broadcast, and believe me — I’ve tried the most expensive ones from the most famous companies 🙂.
Thus, by running Breakaway Broadcast at 50us withe de-emphasis, you will leave as little for the Inovonics to do as possible, and get cleaner on-air sound in the end.
Running Breakaway Live at the studio would not be good as the Inovonics unit would then have to perform the pre-emph limiting and clipping.
However.. As always, the very best solution would be to keep the processing at the transmitter site.
Breakaway is inexpensive enough that you could actually equip each site with a stable computer with breakaway broadcast — likely for less than $1000 AU per site! This has to be in the ballpark of what you’d pay for the Inononics, right?
///Leif
Leif,
You are close in your assumptions on the computer pricing. We have been using standalone pc’s out there with a simple muzo type compressor infront of the TXers for ages. Problem is the cost fo the pc to run Breakaway Broadcast and Jazler the playout software. It needs to be a decent machine as you know. This idea is not favoured even back at the studio! Running the two needs some serious CPU and is still in the 1000+ dollar range. Plus it’s a PC. We are trying to get rid of them in the field.
Streaming over the VPN with a constant trickle is the preferred way. It brings down the ability to localise but ups the ez and abiltiy to update and freshen up the program content. We only have 64k upload & 512k download ADSL speed available at the sites over the VPN. So dumping a stack of files in the back of several machines for local news etc will take forever. We tried it.
As this all comes down to cost. I can’t see a better way. Breakaway Broadcast at the studio (seperate machine to play out). With the pre-emph turned down to 15 so it still does a little. But the final say is done on site for whatever the service is AM or FM. I only suggested inovonics as it was a mono unit and we have had one here to play with. It worked ok.
Don’t forget Leif there is a mix of AM /FM TXers hanging off the VPN feed and there is the public streams. You are probably right. There is a fiar amount of "brand loyalty" for the big gun stuff. Doesn’t mean it’s delivering 😉
Did you say there actually is a PC at each transmitter site already, but it’s not powerful enough?
How fast is this PC? Perhaps we could make it work anyway. Latest BBP has a low-cpu mode which runs on a single core atom netbook, in full stereo, with mpx output.
I do know about that brand loyalty, and can only recommend doing your own a/b comparison, with a proper modulation monitor, to hear how much better you could sound with BBP.
Pre-emph at 15 is not a good way. If this is to work at all, pre-emph and de-emph need to be 50, to match what you’ll be broadcasting. That way, most of the peak-limiting work will be done already by the time it hits the transmitter site.
A friend of mine ran BBP at 15us because he thought it sounded better (well yeah, duh) and then 50us pre-emph at the stereo coder at the transmitter site. They ended up with a phone call from the VERY angry inspector from the swedish equivalent of the FCC, and nearly got fined for the extreme overmodulation. This is a heads-up warning — BBP will not do its job unless it’s configured correctly 🙂.
If they had had a proper modulation monitor, they would have seen this themselves, right away.
///Leif
I’m a little confused Leif. The pc’s are coming out. There will be a mixed bag of AM or FM TXers on the end of the feed. HF limiting must be done on site for whatever the TXer is for that site. Plus a little gain between the Barix and the TXer would be nice. Some TXers need a little more oomph to run them.
Pete
Alright, let me try to clear up the confusion:
– The only way to get this to work at all is to run BBP at 50us pre-emph. 15 will not yield proper peak control.
– With lossy links between the processor and the transmitter, you get what you get.
Optimal performance is reached by running BBP at each transmitter site. Sub-optimal performance is reached by taking the computers out.
Best of luck!
///Leif
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