An Icecast server can offer multiple streams off of one ip:port pair via a mechanism known as a “mount point”. That trailing string after the right-most slash is the name of the mount point. I think it defaults to the word “mount” but I don’t see how that is a stumbling block since every Icecast stream employs that nomenclature.
It is up to the listener’s computer as to how to open the stream based on the extension .mp3 so that is out of your control.
Although in my case I don’t use the extension and it works in most cases, I think based on the server type header information.
As a test, try clicking each of these to see what it does on your computer:
http://colostreaming.com:8000/botewild.m3u
http://colostreaming.com:8000/botewild.mp3
http://colostreaming.com:8000/botewild
The audio levels are also critical. Driving the encoder too hard could result in tinny audio; conversely, driving the encoder with too weak audio will result in muddy sound. If I listen carefully to my feeds I can detect the tiniest bit of stair-stepping during audio peaks, but overall I quite like the audio on there as I strive to set a good example with it. FYI, my feeds use a Windows application called RadioFeed which incorporates the lame encoder. It’s a great free program that’s perfect for putting a scanner stream online.
As for Chipmunks, it sounds like you might be changing the sample rate without actually resampling the audio. Does your Icecast server play a recorded introductory announcement at the start of each stream session?
Bote
···
From: app_rpt-users-bounces@ohnosec.org [mailto:app_rpt-users-bounces@ohnosec.org] On Behalf Of Tony KT9AC
Sent: Friday, 23 September, 2011 11:58
To: app_rpt-users@ohnosec.org; Steve Passmore
Subject: Re: [App_rpt-users] Streaming questions
Thanks Steve, I’ll play with these settings. I initially tried 3K as a cutoff but still hear the “artifacts” noise that comes with Allison announcing things (that’s how I test quietly). It reminds me of how P25 sounds on the fringe, so its likely something in the conversion to MP3 from RAW or GSM.
I guess for streaming, we don’t need a range like what a radio would provide (say 300-3000hz), but perhaps something narrower.
To answer Bote as well, I’m using these standard settings for Lame, and most changes from say 8K to 22.05K make it sound like Chipmunks got into the system. I’m still learning the settings.
I still need to figure out how to get the stream to work at the base URL, not requiring a filename.
Tony
— On Fri, 9/23/11, Steve Passmore k6kya@hokeynet.net wrote:
From: Steve Passmore k6kya@hokeynet.net
Subject: Re: [App_rpt-users] Streaming questions
To: app_rpt-users@ohnosec.org
Date: Friday, September 23, 2011, 12:03 AM
Got my Highs and Lows swapped… oops
On 9/22/2011 22:00, Steve Passmore wrote:
I don’t believe wav is a stream-able protocol. The metallic sound is more an artifact of compression than the protocol used. You might try bumping up the bitrate and/or adding a lowpass filter to strip off the highest frequencies, this is commonly done with stream encoders. I’ve added a highpass filter to remove PL. I imagine you could do low pass the same way. Here’s what I use.
outstreamcmd=/bin/sh,-c,/usr/bin/lame --preset cbr 24 --highpass 0.2 -r -m m -s 8 --bitwidth 16 - - | /usr/bin/ezstream -c /etc/ezstream.xml
Steve
