JAVA & FFT + Sound Processing & Latency in JAVA
CASTalk.com Forum Index CASTalk.com
Discussion of DSP, FPGA, storage and embedded system.
 
 FAQFAQ   MemberlistMemberlist     RegisterRegister 
 ProfileProfile   Log in to check your private messagesLog in to check your private messages   Log inLog in 
 
Google
 
Web castalk.com
JAVA & FFT + Sound Processing & Latency in JAVA

 
Post new topic   Reply to topic    CASTalk.com Forum Index -> DSP
Author Message
QWERTY
Guest





Posted: Fri Dec 02, 2005 3:43 pm    Post subject: JAVA & FFT + Sound Processing & Latency in JAVA Reply with quote

Hello all!

I'm new on this group.
I started following it because I need help for project I'm working on
at my faculty.

I need to include an FFT algorithm in my project in order to manage
sound signal. Can anyone recommend me a good implementation of FFT in
JAVA, because, as I have read about it, there is many of
implementations which are not optimised.

Code examples about mnaging sound with FFT are wellcome :)


Another problem I encountered on is latency due to JAVA buffering.

My project should work in real time, so it is big challenge to avoid
the latency.
With Pentium IV, 2.8GHz, 768MB of RAM, I have latency of about 1
sec!!!!

Can anyone suggest how to solve theese, for me - very big, problems?

Thanks in advance!

You can contact me at igor_igor@vipTHIS.hr (remove THIS)
Back to top
Howard Long
Guest





Posted: Fri Dec 02, 2005 3:43 pm    Post subject: Re: JAVA & FFT + Sound Processing & Latency in JAVA Reply with quote

"QWERTY" <igor_igor@vip.hr> wrote in message
news:1133516631.727139.49570@g47g2000cwa.googlegroups.com...
Quote:
I need to include an FFT algorithm in my project in order to manage
sound signal. Can anyone recommend me a good implementation of FFT in
JAVA, because, as I have read about it, there is many of
implementations which are not optimised.

I am a C, not a Java developer, but this is quite a good complex FFT demo
http://sepwww.stanford.edu/oldsep/hale/FftLab.html although having looked at
the code it's hardly optimised.

Quote:
Code examples about mnaging sound with FFT are wellcome :)

Another problem I encountered on is latency due to JAVA buffering.

I am not sure what OS you are on, but latency in Windows, depending on the
API and drivers in use, can be awful. Generally speaking latency using the
MME (Multimedia extensions) API is usually worse than DirectSound.
DirectSound latency is generally worse than using ASIO.

Regards, Howard
Back to top
Ross Clement (Email addre
Guest





Posted: Fri Dec 02, 2005 5:16 pm    Post subject: Re: JAVA & FFT + Sound Processing & Latency in JAVA Reply with quote

I'm currently doing some "stuff" with the fftw3 library which is
written in C. You can access C (and other native) code from Java using
the JNI interface. When I put "fftw Java JNI" into Google there were a
lot of hits suggesting that people are doing this already. I don't have
time to sort through the links to find out which of them is best.

Cheers,

Ross-c
Back to top
Guest






Posted: Fri Dec 02, 2005 5:17 pm    Post subject: Re: JAVA & FFT + Sound Processing & Latency in JAVA Reply with quote

QWERTY wrote:
Quote:
Hello all!

I'm new on this group.
I started following it because I need help for project I'm working on
at my faculty.

I need to include an FFT algorithm in my project in order to manage
sound signal. Can anyone recommend me a good implementation of FFT in
JAVA, because, as I have read about it, there is many of
implementations which are not optimised.

I'm not sure if optimized JAVA code is not in fact an oxymoron.


Quote:
Code examples about mnaging sound with FFT are wellcome :)

Try FFTW, it's the standard for GPLed FFT source codes. Another one is
KISSFFT. Both are in C/C++.


Quote:

Another problem I encountered on is latency due to JAVA buffering.

My project should work in real time, so it is big challenge to avoid
the latency.
With Pentium IV, 2.8GHz, 768MB of RAM, I have latency of about 1
sec!!!!

1 sec latency is still real-time. (Definition of real-time: the latency
is bounded). State your requirements more precisely.

Quote:
Can anyone suggest how to solve theese, for me - very big, problems?

Thanks in advance!

Regards,
Andor
Back to top
 
Post new topic   Reply to topic    CASTalk.com Forum Index -> DSP All times are GMT
Page 1 of 1

 
You cannot post new topics in this forum
You cannot reply to topics in this forum
You cannot edit your posts in this forum
You cannot delete your posts in this forum
You cannot vote in polls in this forum




VoIP Electronics Powered by phpBB