[Icecast] Re: low bandwidth broadcasting using ices2

[Andy Baxter]

On Sun, 29 Aug 2004 17:53:29 -0700, Ralph Giles wrote:

> On Mon, Aug 30, 2004 at 03:03:28AM +0100, Andy Baxter wrote:
> 
>> Is there any way to bring the bitrate in ices2 down below 32 kbps?
> 
> Generally the trick for this is to downsample the audio before encoding. 
> You can ask ices to do this with a resample stanza in the config file:
> 
>     <resample>
>         <in-rate>44100</in-rate>
>         <out-rate>22050</out-rate>
>     </resample>

Thanks, that does it.

> 
>> Specifically, I have a machine with 2 versions of oggenc on it, one
>> from debian woody, and one compiled from source. The woody version will
>> encode mono wavs down to 16kbps, but the (later) hand compiled version
>> will only go down to 32 kbps. The quality of the 16kbps files isn't that
>> great, but it's still ok to listen to - no obvious distortion or spurious
>> noises, just a loss of clarity.
> 
> You don't tell us what compression options you tried, but hopefully the 
> resampling issue is the one you're missing.
> 

The ones I've tried are: 

channels	sample rate	nominal bitrate
2		44100		65536		good stereo sound
2		44100		131072		probably better but I can't hear the difference.
1		44100		32768		streams at 35-40 kbps, good sound
1		44100		16384		encoder won't start.
1		22050		16384		streams at about 25 kbps
1		14700		16384		streams at about 21-23 kbps. starting to sound
						bad.
1		22050		16384 with managed bitrate, max=18000. works, but sounds weird
						and metallic.
1		11025		16384		streams at 19-20 kbps. sounds flat and dull.

I reckon I should be able to find something that will do alright from
these, so cheers.

andy.