audio loopback for wince

Ali Benamara

Hi Guys,

I can't believe that I can't find any where a working sample code to do audio loopback on WinCE and the TPSxxx chip. I have been struggling to make a wince loopback audio example. Basically I am looking for sample code to record audio from a mic and plays it back to the speakers in real-time on the TPSxxx chip under WinCE not linux. I tried evrything, events, double buffering, etc.. but the clicks are always there.

using stereo, 44100, 2 channels and 16 bits/sample. Ideally I would like to capture frames of 256 bytes (that's 64 left samples and 64 right samples). Is this possible at all with WinCE, I am starting to lose faith and I have already fried my brain over this.

thanks

over 14 years ago

0 Ali Benamara over 14 years ago

Intellectual 260 points

nothing here?

0 Don Dapkus over 14 years ago in reply to Ali Benamara

TI__Guru**** 189401 points

Hi, Ali,

Sorry for the delay. I thought I had responded to you previously...

What is the full part # of the TPS part you're using? The people who monitor this forum are not responsible for that part, and I need to highlight it to the appropriate team.

-d2

0 Ali Benamara over 14 years ago in reply to Don Dapkus

Intellectual 260 points

I am using TPS65950

0 Don Dapkus over 14 years ago in reply to Ali Benamara

TI__Guru**** 189401 points

Hi, Ali,

Wow, it's got it's own forum! I'm moving it over there for you now. Hopefully they can help you out.

-d2

0 Ali Benamara over 14 years ago in reply to Don Dapkus

Intellectual 260 points

wow me too. Instead of answering the question, you moved to I don't know where. Well Thank you , after a week of waiting and no official replies

0 Don Dapkus over 14 years ago in reply to Ali Benamara

TI__Guru**** 189401 points

Hi, Ali,

I moved it to the PMU forum which is were the apps engineers that support this product monitor. I will escalate it for you to get a response.

-d2

0 Gandhar Dighe over 14 years ago in reply to Don Dapkus

TI__Genius 15100 points

Hi Ali,

I can support you with any hw/firmware question on this device. Unfortunately for software you will have to ask the OMAP champs team. I will try to find out if the OMAP team has any code that you can use.

Sorry for the delay and inconvenience.

0 Ali Benamara over 14 years ago in reply to Gandhar Dighe

Intellectual 260 points

Thanks Gandhar,

I really really need it.

0 Gandhar Dighe over 14 years ago in reply to Ali Benamara

TI__Genius 15100 points

Hi Ali,

I asked your question to OMAP support team, see below for their reply. We dont have an application that you are looking for, following are some tricks you may try. Please let me know if this helps.

Looking at his question though, it appears he has the app working except he hears clicks – correct? Most likely his app is not able to keep up with rate time demand. I would try with lower sampling rate (maybe 8 KHz), 1 channel and increased buffering (at expense of latency of course) to make sure logic is working fine first. Then stretch the system and possibly optimize for his needs

0 Ali Benamara over 14 years ago in reply to Gandhar Dighe

Intellectual 260 points

No No No, that's not my problem, I was really hoping for a useful answer after waiting 3 weeks. Anyway, I am able to run the loopback audio (capture from mic and play to lineout) but only when I use 3 buffers for double buffering and a buffer size of 2048 bytes (512 stereo samples). This is a ridiculously long latency for a real-time application. I would like to be able to use a buffer size of 512 bytes (128 stereo samples).

Can you confirm if wince CANNOT do less 2048 buffer size. If that's the case that wow to Microsoft and probably we should start looking at using a linux version instead. Bummer.

-Ali

0 Gandhar Dighe over 14 years ago in reply to Ali Benamara

TI__Genius 15100 points

I dont know any forums/users for WinCE who can confirm this. You may have to use Linux.

Power management

Power management forum

audio loopback for wince