Left and Right channels getting mixed somehow

schast · 23rd June 2002, 18:42

Hi everyone, i'm having an unusual problem. I've used shoutcast before to stream mp3 audio with no problem, but when I try to stream a source via my line input, the left and right channels are getting mixed. You see, what i'm trying to do is set up a live feed from two police scanners. I bought an adapter from radio shack that will take my stereo input and divide it into two mono inputs, which I then connect one scanner to each mono input. I figured this would be nice since I then would have one scanner coming out of one speaker, and the other scanner coming out of the other speaker. What happens though is that they both get mixed, and I hear both scanners from both speakers when I listen to the stream.

Is there something I'm doing wrong? I am using a 24k stereo stream, is there something wrong with my line input plugin? Is there some other way I can do this without breaking it up into 2 separate streams? I thought this would be the best way, since if I want to focus on one scanner instead of the other I could just adjust the balance slider on winamp to move to one or the other side.

Thanks,

Shawn

DJ AmPs · 23rd June 2002, 20:39

You probably bought a mono adapter. Make sure the 1/8" plug has three conductors, and the RCA's are red and white.

-Amps

Tom · 23rd June 2002, 20:40

Could be a few things.
First make sure the adapter is working properly.
What are you using for the line in?
With mp3s the stereo channels are usually dependant on each other at low bitrates (joint stereo) to provide the highest quality at lowest bitrate. Try recording to a wave file and see if you get two independent channels.

Tom

schast · 24th June 2002, 03:09

I know my hardware is good since on the machine doing the streaming it comes out of the PC speakers just fine. I can fade left or right and only hear one scanner or the other.

What you said Tom about the joint stereo, is there a bitrate that it doesn't apply to? That seems more likely what is the problem, i'd just like to know more about it.

Thanks,

Shawn

Tom · 24th June 2002, 03:28

Try using Oddcast (http://www.oddsock.org/tools/dsp_oddcast/) and set it to use Stereo not Joint Stereo (click Adv Rec to use whatever is selected in your Recording Mixer). Although I'm not sure if joint stereo would cause this or not.

Tom

DJ AmPs · 24th June 2002, 03:50

Joint stereo would not cause this problem. Normal stereo should sound a little better though. Make sure you are actually broadcasting in stereo. If the first output is used, it will always revert to mono when using line in.. remember, Tom? =)

-amps

Tom · 24th June 2002, 04:03

He can't be using 1.8.2 since there is no 24 kbps stereo in that version. If he is using Fraunhofer then I think at low bitrates when set to joint stereo it can use intensity stereo which might cause this, still not sure.

Tom

schast · 10th July 2002, 03:35

Ok, sorry to be lacking in the details department but this was a question to an old problem I had. I wanted to try and get an answer before I tried again. Let's say i'm using the latest shoutcast source and server...40kbps, 22,050Hz, Stereo. Will I need to use output 2 to ensure stereo because of the mono line input problem that DJ Amps mentioned? Will 40kbps still be joint stereo?

I also found this on an mp3 encoding site, when talking about creating mp3s:

--------------------------------------------------------------------------------

Side Information
If joint stereo is used in M/S (middle/side) mode, the left and right channels aren't encoded separately. Instead, a "middle" channel is encoded as the sum of the left and right channels, while a " side" channel is stored as the difference between the left and the right. During the decoding process, side information is read back out of the frame and applied to the bitstream so that the original signal can be reconstructed as accurately as possible. The side information is essentially a set of instructions on how the whole puzzle should be re-assembled on the other end.

--------------------------------------------------------------------------------

Could this be my problem too? I don't know how shoutcast encodes the stream so I don't know how to fix my problem...if I can at all.

Shawn

stevecom · 12th September 2003, 22:05

Thank you for the Oddcast suggestion! I had the same problem and this works perfectly. As an added bonus, it even works properly with my SB Live! audio card using line input (the newest shoutcast dsp does not, although an older version I have does).

Thanks again!

>>> Try using Oddcast (http://www.oddsock.org/tools/dsp_oddcast/)

23rd June 2002, 18:42	#1
schast Junior Member Join Date: Dec 2000 Posts: 4	Left and Right channels getting mixed somehow Hi everyone, i'm having an unusual problem. I've used shoutcast before to stream mp3 audio with no problem, but when I try to stream a source via my line input, the left and right channels are getting mixed. You see, what i'm trying to do is set up a live feed from two police scanners. I bought an adapter from radio shack that will take my stereo input and divide it into two mono inputs, which I then connect one scanner to each mono input. I figured this would be nice since I then would have one scanner coming out of one speaker, and the other scanner coming out of the other speaker. What happens though is that they both get mixed, and I hear both scanners from both speakers when I listen to the stream. Is there something I'm doing wrong? I am using a 24k stereo stream, is there something wrong with my line input plugin? Is there some other way I can do this without breaking it up into 2 separate streams? I thought this would be the best way, since if I want to focus on one scanner instead of the other I could just adjust the balance slider on winamp to move to one or the other side. Thanks, Shawn

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23rd June 2002, 20:39	#2
DJ AmPs Major Dude Join Date: Mar 2002 Location: g Posts: 1,603	You probably bought a mono adapter. Make sure the 1/8" plug has three conductors, and the RCA's are red and white. -Amps

23rd June 2002, 20:40	#3
Tom Moderator Join Date: Apr 2000 Posts: 4,491	Could be a few things. First make sure the adapter is working properly. What are you using for the line in? With mp3s the stereo channels are usually dependant on each other at low bitrates (joint stereo) to provide the highest quality at lowest bitrate. Try recording to a wave file and see if you get two independent channels. Tom

24th June 2002, 03:09	#4
schast Junior Member Join Date: Dec 2000 Posts: 4	I know my hardware is good since on the machine doing the streaming it comes out of the PC speakers just fine. I can fade left or right and only hear one scanner or the other. What you said Tom about the joint stereo, is there a bitrate that it doesn't apply to? That seems more likely what is the problem, i'd just like to know more about it. Thanks, Shawn

24th June 2002, 03:28	#5
Tom Moderator Join Date: Apr 2000 Posts: 4,491	Try using Oddcast (http://www.oddsock.org/tools/dsp_oddcast/) and set it to use Stereo not Joint Stereo (click Adv Rec to use whatever is selected in your Recording Mixer). Although I'm not sure if joint stereo would cause this or not. Tom

24th June 2002, 03:50	#6
DJ AmPs Major Dude Join Date: Mar 2002 Location: g Posts: 1,603	Joint stereo would not cause this problem. Normal stereo should sound a little better though. Make sure you are actually broadcasting in stereo. If the first output is used, it will always revert to mono when using line in.. remember, Tom? =) -amps

24th June 2002, 04:03	#7
Tom Moderator Join Date: Apr 2000 Posts: 4,491	He can't be using 1.8.2 since there is no 24 kbps stereo in that version. If he is using Fraunhofer then I think at low bitrates when set to joint stereo it can use intensity stereo which might cause this, still not sure. Tom

10th July 2002, 03:35	#8
schast Junior Member Join Date: Dec 2000 Posts: 4	Ok, sorry to be lacking in the details department but this was a question to an old problem I had. I wanted to try and get an answer before I tried again. Let's say i'm using the latest shoutcast source and server...40kbps, 22,050Hz, Stereo. Will I need to use output 2 to ensure stereo because of the mono line input problem that DJ Amps mentioned? Will 40kbps still be joint stereo? I also found this on an mp3 encoding site, when talking about creating mp3s: -------------------------------------------------------------------------------- Side Information If joint stereo is used in M/S (middle/side) mode, the left and right channels aren't encoded separately. Instead, a "middle" channel is encoded as the sum of the left and right channels, while a " side" channel is stored as the difference between the left and the right. During the decoding process, side information is read back out of the frame and applied to the bitstream so that the original signal can be reconstructed as accurately as possible. The side information is essentially a set of instructions on how the whole puzzle should be re-assembled on the other end. -------------------------------------------------------------------------------- Could this be my problem too? I don't know how shoutcast encodes the stream so I don't know how to fix my problem...if I can at all. Shawn

12th September 2003, 22:05	#9
stevecom Junior Member Join Date: Sep 2003 Posts: 2	Thank you for the Oddcast suggestion! I had the same problem and this works perfectly. As an added bonus, it even works properly with my SB Live! audio card using line input (the newest shoutcast dsp does not, although an older version I have does). Thanks again! >>> Try using Oddcast (http://www.oddsock.org/tools/dsp_oddcast/)