Icecast Streaming Media Server

[wgaryg]

Hi.
We are attempting to implement an icecast server at our church. I have built a machine

SuperMicro Server
Dual P4 2.8ghz
512mb ram
160 GB, 100 MB/s, 8 MB Cache, 7200 RPM
USB Sound Blaster MP3+
Centos 5.2
Icecast 2.3.2

I have tried DarkIce 0.19
and ices 2.0.1

All audio sounds like it is dragging. the pitch is much lower than the live version.

Can anyone point me in the right direction?

Thanks

[DJ-Zath]

hi!

your problem is most-likely caused by an invalid or incorrect samplerate

this is more of an issue in your encoder than Icecast itself..

heres what to check for...

make SURE you are using a samplerate that is in multiples of 11.. i.e. :

11.025 (11 Khz), 22.050 (22 Khz) and 44100 (44 Khz)

do NOT use 4, 8, 20, 24, 48, 96 or 128Khz, etc etc etc.. samplerates!

also make sure the encoder is set for the proper mode: mono or stereo

"Dragging" audio is common when using a soundcard/encoder set to 48 kHz.. while cheapo (built in) soundcards can only work with no more than 44.1 Khz..

make SURE your soundcard settings AND encoder/DSP settings MATCH! they BOTH MUST show the same samplerate and it should be a multiple of 11!

That should solve your problem.

-DjZ-

[wgaryg]

Here is my darkice.cfg


[general]
duration = 0 # duration of encoding, in seconds. 0 means forever
bufferSecs = 5 # size of internal slip buffer, in seconds
reconnect = yes # reconnect to the server(s) if disconnected

[input]
device = /dev/dsp # OSS DSP soundcard device for the audio input
sampleRate = 44100 # sample rate in Hz. try 11025, 22050 or 44100
bitsPerSample = 16 # bits per sample. try 16
channel = 2 # channels. 1 = mono, 2 = stereo

[icecast2-0]
bitrateMode = cbr # constant bit rate
format = mp3 # format of the stream: ogg vorbis
bitrate = 128 # bitrate of the mp3 stream sent to the server
quality = 0.8 # encoding quality
server = 127.0.0.1
port = 8000 # port of the IceCast server, usually 8000
password = azed321 # source password to the IceCast server
mountPoint = live.mp3 # mount point of this stream on the IceCast server
name = test
description = test
url = http://test.com
genre = christian # genre of the stream
public = no # advertise this stream?

[DJ-Zath]

Hi there again!

This is a sticky situation!

My FIRST question is about the SOUNDCARD and is it FULLY linux-compatable??

if I recall, you said you were using a USB soundcard- those usually are meant for WINDOWS and don't run too well in Linux.. (perhaps someone else out there can varify this...) I, myself, don't use Linux for encoding- mainly because I heard all too many times how Linux has "issues" with dissappearing or malfunctioning soundcards- and expecially USB.. but, I could be wrong here! (this was an old long-standing issue and perhaps its been corrected)

I have also noticed you have the quality settings set to 8.. try setting to 1 or 9.. (again, this depends on the encoder/CODEC.. LAME, for example, reads the quality-settings in reverse where 1 is better that 9... )

I use all hardware encoding, its the best way to do it (and the most-expensive)

have you tried using another enocder/stream onto the server to see if its still experiencing these issues? what about the receivers? are all your listeners experiencing this issue or only cirtain ones and, if so, what are they using to listen in with- hardware and software-wise??

a "dragging" stream is definately a samplerate incompatability issue- but where this incompatability is occurring, is the bear of this.. I notice you haven't said much about the soundcard itself...

Like I mentioned above, I thought you said it was a USB soundcard- most USB soundcards are designed to run under Windows and WDM which uses a form of "time-slicing" and "sample-slicing" to allow "intermode mixing" of the various sources in a common multimedia application.. LINUX IS KNOWN TO **NOT** WORK TOO WELL WITH WDM-COMPLIANT DEVICES and USB WDM could be "asking for trouble" even more!

I recommend you have a "test stream" log into your server and/or try using a Windows box set up to stream..

OH OH!

I just thought of one other thing it can be.... are you playing the source media (mp3 files) directly without re-encoding them? AND those files are at a samplerate OTHER than 44.100?

example: streaming a 48Khz mp3 at 44.1 khz using the direct method

Direct method will NOT require a soundcard and your stream will not pass through the soundcard at all

The ONLY way to fix THIS issue is to RE-ENCODE the source media (commonly known as "transcoding") OR change the stream samplerate OR (most-recommended IF you plan to insert live mic/material) re-encode the entire stream through a local CODEC via a local audio pipeline (this means to play the media into the soundcard and then (re)encode it at the source) you will need to install a LIVE INPUT DSP or CODEC to achieve this- but its the PERFERRED method since it corrects differing bitrates and samplerrates to the current/proper bitrate/ samplerate "on the fly".. BUT it will require extra CPU grunt and it DOES pass all audio through the soundcard's outpput and then back to the input. admittingly, this can be a task to set up the internal "loopback" on the soundcard in Linux.. but its inexpensive to do.. and shoud yield satisfactory resaults.

I don't know much, if anything about DarkIce but I believe LiveIce is the name of the DSP module you'll need to install...

If you are merely playing mp3 files as a playlist without a live mic or local audio, then you can either obtain a stream transcoder or re-encode the mp3 files to be the EXACT SAME bitrate and samplerate and mode of the streaming server (or change the streaming server's settings to match the mp3s but with a risk/chance that your listeners will have problems receiving the feed)

I hope this helps.. I tried to explain it the best I can without being TOO confusing... sometimes it can be quite difficult to get it all set up right.. sorry I couldn't be of more help.

-DjZ-

[wgaryg]

The sound card is a

Sound Blaster USB MP3+

I am going to look everything keeps coming back to a sound card issue since I am streaming the audio live from our mixer.

I have a Sound Blaster Live I can use if I can find a riser card to use so that I can install it in my 1U server

Thanks

[DJ-Zath]

hi again:

I had that EXACT same problem.. IU server and needing a "lefty" 90 degree riser.. I found only ONE place on the net that had them (well, something close enough to work) they were $10 apiece.. problem is abmx charged me $40 to SHIP it and since I baught 2 the bill was close to $60! SHEESH!

but I NEEDED them!

in case it helps you: abmx.com

good luck!

-DjZ-


**NOTICE**!
I made an ERROR in the url..and tried to correct it, howwever the system refused to allow me to edit the message- I had to WAIT 15 minutes befor it let me pass the corrected message to you sorry for the WRONG website!

KarlH: I understand that you have to limit posts.. but were you aware that the limit applies to edited posts too?

[wgaryg]

Thanks I will keep that in mind, I just cracked open another 1u server in the back room and found an unused riser card in there.

If all goes well I will be installing this tomorrow afternoon.

Thanks