[Speex-dev] Integrating speex with VideoNet application: Constantbackground noise

[Carine Liang]

Hi Jean-Marc,

I finally make it work! Thanks for telling me that the algo will not work for 8-bit PCM. In fact I've tried using 16 bit PCM last time, but apparently there's a bug. The bug lies with the RecBuffer. The RecBuffer must be set to 320bytes instead of 160 bytes since every sample is now 16 bit. 

The compression is amazing, from 320 bytes to 38bytes!

Thanks a million,
Carine

----- Original Message ----
From: Jean-Marc Valin <jean-marc.valin at usherbrooke.ca>
To: Carine Liang <carineliang at yahoo.com.sg>
Cc: speex-dev at xiph.org
Sent: Tuesday, 26 December 2006 6:58:06 PM
Subject: Re: [Speex-dev] Integrating speex with VideoNet application: Constantbackground noise

> Thanks. I've got the code for sampleenc and sampledec. But I didn't
> know how to verify whether the decoded file is correct. So I tried to
> analyse the decoded output and compile with my input.

How about actually listening to the output first?

> Test case: PCM samples, 8 bit, 8000 samples per sec. When I pulled

Where in the manual does it say that 8-bit PCM is a valid input?

[...]

> Is my decoded output expected? 

Yes. Based on the "garbage in, garbage out" principle.

> Since I'm dealing with a 8 bit sample,
> am I right to say that I will not have the "big/little endian" issue?

No, just the "not the right type in the first place" issue.

> What has gone wrong???

Euh, maybe not paying enough attention to the manual and the sample code?

    Jean-Marc

> 
> Regards, Carine
> 
> 
> ----- Original Message ---- From: Jean-Marc Valin
> <jean-marc.valin at usherbrooke.ca> To: Carine Liang
> <carineliang at yahoo.com.sg> Cc: John Miles <jmiles at pop.net>;
> speex-dev at xiph.org Sent: Monday, 25 December 2006 10:22:44 AM 
> Subject: Re: [Speex-dev] Integrating speex with VideoNet application:
> Constantbackground noise
> 
> Have you tried starting with sampleenc/sampledec instead of doing 
> everything from scratch. That and the manual should contain
> everything that's needed.
> 
> Jean-Marc
> 
> Carine Liang a écrit :
>> Hi,
>> 
>> 
>> 
>> I'm still unable to get rid of the background noise though I've 
>> changed the PCM samples to 16 bit. I'm began to wonder if I can
>> just take the PCM samples and encode them.
>> 
>> What my application tries to do is to record the voice from a 
>> microphone, encode it, send it via the socket to a peer, decode at 
>> the peer's side and play the voice. My application works fine
>> without the codec but I need to achieve a lower data rate. Anyone
>> has done that before?
>> 
>> Is there anyone who's deal with encoding and decoding PCM samples
>> in windows?
>> 
>> Please help.
>> 
>> Carine
>> 
>> ----- Original Message ---- From: John Miles <jmiles at pop.net> To: 
>> Carine Liang <carineliang at yahoo.com.sg>; speex-dev at xiph.org Sent: 
>> Friday, 3 November 2006 12:32:43 AM Subject: RE: [Speex-dev] 
>> Integrating speex with VideoNet application: Constantbackground
>> noise
>> 
>> 
>> 
>> 
>> 
>> DIV { MARGIN:0px;}
>> 
>> 
>> 
>> Yes, it's necessary; Speex will encode signed 16-bit PCM data and 
>> decode to the same format.  See the examples that come with it.
>> 
>> 
>> 
>> 8-bit audio is not something you would ever want to use.
>> 
>> 
>> 
>> 
>> 
>> ------------------------------------------------------------------------
>> 
>> 
>> 
>> _______________________________________________ Speex-dev mailing 
>> list Speex-dev at xiph.org 
>> http://lists.xiph.org/mailman/listinfo/speex-dev
> 
> 
> 
> 
> 
> 
> Send instant messages to your online friends
> http://asia.messenger.yahoo.com






Send instant messages to your online friends http://asia.messenger.yahoo.com 
-------------- next part --------------
An HTML attachment was scrubbed...
URL: http://lists.xiph.org/pipermail/speex-dev/attachments/20061228/5c0a8407/attachment.html