Audio Processing?

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Deep Thought
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Re: Audio Processing?

Post by Deep Thought » Fri Dec 13, 2013 10:02 am

Bojcha wrote:Will just say that i don't understand need for 128k stream where input is AM receiver.
Then you don't really understand what he is trying to do.
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Bojcha
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Re: Audio Processing?

Post by Bojcha » Fri Dec 13, 2013 3:47 pm

Ofcourse i understand. I respect that. Point is that kbits are wasted .. and money. So, i would say that you don't understand.
Same can be achived with 96kbps or even less and maybe diff codec. Not to mention mobile devices.

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Re: Audio Processing?

Post by Deep Thought » Fri Dec 13, 2013 8:09 pm

Uh, no. Why would anyone trying to deliver a quality mp3 stream of a 15 KHz stereo audio signal use anything less than 128 kbps? I agree about the more advanced codecs allowing lower bitrates but you also have to go with what is most universally supported on the listener end, and right now that is mp3.

128 kbps is a sweet spot compromise between "excessive" bitrates (what is this, 1995?) and audio quality.
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Re: Audio Processing?

Post by BroadcastDoc » Fri Dec 13, 2013 9:29 pm

Really, if you have the option, do a high and low quality stream. For example, 128k MP3 for desktop clients, and something like 64k AAC for mobile clients. I do a straight 128k MP3, and we do occasionally get complaints of excessive buffering from mobile clients. I'm going to probably end up doing both.
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Re: Audio Processing?

Post by Deep Thought » Sat Dec 14, 2013 12:05 am

WXYG's 24 kbps AAC+ stream plays a lot higher than its pay grade but I can still hear the artifacts. Probably OK for most mobile applications since there isn't much expectation of anything approaching 'hi fi'.
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Re: Audio Processing?

Post by BroadcastDoc » Sat Dec 14, 2013 4:28 pm

The AAC codec is pretty impressive - 24kbps is not a lot to work with, but it can be acceptable. I've found that 64kbps seems to be a good combination of quality vs. data rate.
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bigic
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Re: Audio Processing?

Post by bigic » Mon Oct 06, 2014 8:37 am

This is how NOT to do it:
http://www.radioas.fm/
It's a CHR/Hot AC station broadcasting on FM to an area of northern Serbia. They process audio on Optimod 8500 (or 8600 AFAIK) and they send that audio to both their FM transmitters and online. Their online stream has lots of high-frequency distortion, especially on songs with lots of high end, because of the MP3 codec trying to compress the Optimod audio heavily processed for FM transmitters.

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Bojcha
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Re: Audio Processing?

Post by Bojcha » Tue Oct 07, 2014 7:56 am

Hehe Bigic..
Where you from?
True! Their stream is crap! But many do like that "sound" ! Also they have many transmitters and sends L/R to every of them with who-knows what stereo-coders.
As usuall techicians over there thinks they are smart. Once they even contacted me but does not accept bit different approach. :)

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Re: Audio Processing?

Post by bigic » Wed Oct 08, 2014 10:48 am

@Bojcha
I'm from a small town in southern Serbia. There are many other Serbian stations online, but it's rare that a station's stream sounds as bad as this.
EDIT: Excuse for not using English, but vidim da si postavio strim jagodinskog Max FM-a. Inače, što se tiče slanja audija na predajnike, Index je katastrofalan u tom pogledu. Oni na većini svojih predajnika šalju audio-signal preko satelita, gde je bitrate katastrofalan za MP2 kodek (128 kbps). To znači da su sve visoke frekvencije iznad 12khz odsečene, stereo je skoro nepostojeć a kompresionih artefakata ima na tone.

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Bojcha
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Re: Audio Processing?

Post by Bojcha » Fri Feb 13, 2015 10:25 am

bigic wrote:@Bojcha
I'm from a small town in southern Serbia. There are many other Serbian stations online, but it's rare that a station's stream sounds as bad as this.
EDIT: Excuse for not using English, but vidim da si postavio strim jagodinskog Max FM-a. Inače, što se tiče slanja audija na predajnike, Index je katastrofalan u tom pogledu. Oni na većini svojih predajnika šalju audio-signal preko satelita, gde je bitrate katastrofalan za MP2 kodek (128 kbps). To znači da su sve visoke frekvencije iznad 12khz odsečene, stereo je skoro nepostojeć a kompresionih artefakata ima na tone.
Uhh, skroz sam zaboravio na ovaj forum :)
Pa da.. imas tu razne kombinacije sve u svemu propast je kod nas - ali ne bas svuda ;)

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