Icecast Streaming Media Server

[boxhead201b]

Hi Everyone;

I am using Ices and IceCast 2.0 to stream live *mono* audio. I noticed that when I change the channels setting from 2 to 1 in my encode area, the audio is distorted on the client ... the audio plays very slowly. I can't figure out how to fix this, because the live audio is mono and I do not want to convert it to "stereo." Any ideas anyone? Here is my ices.xml:

<ices>
<background>1</background>
<logpath>/home/iceuser/log</logpath>
<logfile>ices.log</logfile>
<loglevel>4</loglevel>
<consolelog>0</consolelog>
<pidfile>/home/iceuser/ices.pid</pidfile>

<stream>
<metadata>
<name>Test Stream</name>
<genre>music</genre>
<description>A test stream</description>
<url>http://icecast.mydomain.com</url>
</metadata>

<input>
<module>oss</module>
<param name="rate">44100</param>
<param name="channels">2</param>
<param name="device">/dev/dsp</param>
<param name="metadata">0</param>
<param name="metadatafilename">live.ogg</param>
</input>

<instance>
<hostname>localhost</hostname>
<port>8000</port>
<password>hackme</password>
<mount>/jerseycityscanner.ogg</mount>
<yp>0</yp>
<reconnectdelay>2</reconnectdelay>
<reconnectattempts>5</reconnectattempts>
<maxqueuelength>80</maxqueuelength>

<downmix>1</downmix>

<resample>
<in-rate>44100</in-rate>
<out-rate>22050</out-rate>
</resample>

<encode>
<nominal-bitrate>32000</nominal-bitrate>
<samplerate>22050</samplerate>
<channels>2</channels>
<quality>-1</quality>
</encode>
</instance>
</stream>
</ices>

[karlH]

If mono is all you're going to get then why not change the input to have channels 1, you won't then have to enable downmix and encode will just take channels 1. You have stated both nominal-bitrate and quality when really only one or the other should do.

karl.

[boxhead201c]

Ok;

I got the following to work, but I would like to get my bitrates as low as possible. I can only seem to get 44khz to work. Any lower and I get slow or fast audio on the output. I don't understand why this is occurring. Can anyone suggest settings that will work for bitrates lower than 44khz? Here is a snippet of my current setup file:

<input>
<module>oss</module>
<param name="rate">44100</param>
<param name="channels">1</param>
<param name="device">/dev/dsp</param>
<param name="metadata">0</param>
<param name="metadatafilename">live.ogg</param>
</input>

<instance>
<hostname>localhost</hostname>
<port>8000</port>
<password>hackme</password>
<mount>/jerseycityscanner.ogg</mount>
<yp>0</yp>
<reconnectdelay>2</reconnectdelay>
<reconnectattempts>5</reconnectattempts>
<maxqueuelength>80</maxqueuelength>

<encode>
<quality>0</quality>
<nominal-bitrate>65536</nominal-bitrate>
<maximum-bitrate>131072</maximum-bitrate>
<minimum-bitrate>-1</minimum-bitrate>
<managed>0</managed>
<samplerate>44100</samplerate>
<channels>1</channels>
</encode>

[karlH]

If you are using the aotuv tuned libvorbis then quality -2 is possible, which is near the 32k mark for 44.1khz stereo. The last official Xiph release allows for quality -1 as the lowest which is around 48kbps at 44.1khz stereo. Using mono or a lesser samplerate will reduce the the bitrate.

Remember if you read from the dsp at 44100 and want to encode at say 32000 then you'll need to resample. Again, you have quality and nominal-bitrate in the encode section, decide what bitrate you want to achieve if you are limited.

karl.