Re: [ts-7000] Re: latest status of i2s on TS-7400

[Ciaccia <>]

Hi Igor,
As you know with linux there always are multiple ways for doing the same thing. This also happens with sound, and right now there are 2 different ways for it: ALSA and OSS. OSS is included with kernel 2.4 and in the 2.6 is obsolete, ALSA became part of the official tree with the 2.6. The TS kernel 2.4 has OSS support for the EP93XX I2S controller/CS4271, which (if I'm not wrong) uses DMA, but lacks the powerful feature of ALSA.

I you want to stay with the TS official release (thing I think you are going to do), you could always compile ALSA as a separate module for the 2.4 and load it as needed (this I think will be tricky).

First of all you need to decide if you want/need to go the ALSA way, or if OSS is enugh for you needs. Then you can decide what to do next.

-ALSA fully supports full-duplex
-ALSA supports MIDI
-ALSA allows to query the sound cards capabilities
-ALSA allows abstraction of the underlying hardware
-ALSA is able to emulate OSS in order to run old applications

-OSS (sometimes) supports full-duplex
-OSS (usually) don't support MIDI
...

Read the point 1.7 Why should I use ALSA/What is the matter with the OSS/Free
here: http://www.alsa-project.org/~jfulmer/alsa-faq.html

Let me know what you decide, then we will see what to do next...
Bye
Andrea

----- Original Message ----
From: curoles <>
To:
Sent: Friday, May 18, 2007 6:32:33 PM
Subject: [ts-7000] Re: latest status of i2s on TS-7400

Andrea,

I need to play audio files (wav,mp3). I do not know how
much from "advanced ALSA" features I need, I just would
like to invest my time in something that will work in all
cases, rather than base my design on i2s driver, struggle
with lack of functionality and then move to ALSA.

Things that I know: I have to use DMA, I like to use abstarctions
ALSA introduces, I do not care about codec, solution has
to be extensible (features list will grow), I better use
stable/officialy supported distro like TS-Linux 2.4.

I did not know status of ALSA on TS-2.4 and ALSA generally on
TS-7400, this is why created the post. If my messages sound
unclear this is because I have little experience with
ALSA and TS.

Thanks,
Igor

--- In .com, Ciaccia < .> wrote:
>
> > > I did this, I can find the patches and make them available for
you.
> >
> > That would be nice. I see that you gone thru all these things in
> > Jan, did you actually manage to get sound via i2s? Anyway, I am
very
> > interested in your patches, this way or another I must have i2s
> > running, your code will save weeks of my work time...
>
> I think I don't completely understand what you mean with "get
sound with i2s"...
> If you just want to "get sound with i2s" you can use the TS 2.4
kernel, it comes with a
> i2s-cs4271 module in it.
>
> I wanted to have a fully working ALSA support for I2S/CS4271, so I
moved to the 2.6.
> If my goal was just to send some PCM data to the sound card and I
did not need all the
> power/flexibility of ALSA, the TS-2.4 kernel could have done the
trick.
>
> Igor, what do you need exactly? If you don't need advanced ALSA
features, forget about my posts.
> If you just want to send some data to your card, you can use the
original TS-2.4 kernel.
>
> > Btw, i2s driver that TS took from cirrus, is it what ALSA code
uses
> > down the road, I mean is it what called to do the job?
>
> I don't understand the line above. The TS-2.4 comes with an ALSA
driver (originally from cirrus).
> The driver "works", but some basic ALSA functionalities
(especially MMAP, also called "zero-copy" communication) are
missing...
>
> I think I misunderstood your first post...
>
> Andrea
>
>
>
>
>
____________ _________ _________ _________ _________ _________ _
____________ ___
> Moody friends. Drama queens. Your life? Nope! - their life, your
story. Play Sims Stories at Yahoo! Games.
> http://sims. yahoo.com/
>

---

Need a vacation? Get great deals 
  to amazing places on Yahoo! Travel. 
__._,_.___

SPONSORED LINKS

Single board computer	Hardware	Computer running slow
Linux os

Your email settings: Individual Email|Traditional
Change settings via the Web (Yahoo! ID required)
Change settings via email: =Email Delivery: Digest | m("yahoogroups.com?subject","ts-7000-fullfeatured");=Change Delivery Format: Fully Featured">Switch to Fully Featured
Visit Your Group | Yahoo! Groups Terms of Use | =Unsubscribe

__,_._,___