From mboxrd@z Thu Jan  1 00:00:00 1970
From: Takashi Iwai <tiwai@suse.de>
Subject: Re: Audigy2 in SNDRV_PCM_FMTBIT_S32_LE mode.
Date: Wed, 19 May 2004 12:32:03 +0200
Sender: alsa-devel-admin@lists.sourceforge.net
Message-ID: <s5hhduc1zdo.wl@alsa2.suse.de>
References: <40AA2FF5.80700@superbug.demon.co.uk>
	<s5h3c5x3f5c.wl@alsa2.suse.de>
	<40AA33C5.6090808@superbug.demon.co.uk>
Mime-Version: 1.0 (generated by SEMI 1.14.5 - "Awara-Onsen")
Content-Type: text/plain; charset=US-ASCII
Return-path: <alsa-devel-admin@lists.sourceforge.net>
In-Reply-To: <40AA33C5.6090808@superbug.demon.co.uk>
Errors-To: alsa-devel-admin@lists.sourceforge.net
List-Unsubscribe: <https://lists.sourceforge.net/lists/listinfo/alsa-devel>,
	<mailto:alsa-devel-request@lists.sourceforge.net?subject=unsubscribe>
List-Post: <mailto:alsa-devel@lists.sourceforge.net>
List-Help: <mailto:alsa-devel-request@lists.sourceforge.net?subject=help>
List-Subscribe: <https://lists.sourceforge.net/lists/listinfo/alsa-devel>,
	<mailto:alsa-devel-request@lists.sourceforge.net?subject=subscribe>
List-Archive: <http://sourceforge.net/mailarchive/forum.php?forum=alsa-devel>
To: James Courtier-Dutton <James@superbug.demon.co.uk>
Cc: alsa-devel <alsa-devel@lists.sourceforge.net>
List-Id: alsa-devel@alsa-project.org

At Tue, 18 May 2004 17:03:17 +0100,
James Courtier-Dutton wrote:
> 
> Takashi Iwai wrote:
> > At Tue, 18 May 2004 16:47:01 +0100,
> > James Courtier-Dutton wrote:
> > 
> >>What would I need to change in the emu10k1 driver, to get alsa-lib to 
> >>send it 32bit audio samples.
> >>I tried just adding the SNDRV_PCM_FMTBIT_S32_LE to the playback options, 
> >>but that did not work.
> >>
> >>When I did that, everything just played at half speed.
> >>
> >>Can anyone give me any pointers as to where else I should change things 
> >>in order to get 32bit audio to the Audigy2 DSP.
> > 
> > 
> > AFAIK, emu10k1 engine processes only 16bit PCM.
> > or do you know the register (or anything else) to handle 32bit data
> > for audigy?
> > 
> > 
> > Takashi
> > 
> > 
> 
> The SB Live DSP can only handle 16bit PCM.
> The SB Audigy DSP can handle 24/32 bit PCM.
> 
> I am working from what someone has told me to get 24bit sound. Send it 
> to the Audigy inside a 32bit value: -
> For playback:
> You can use voice grouping - alloc 4 FX busses for 1 stereo stream
> or use TRAM.
> 
> Does this help you ?

if i understand the above correctly, audigy can assign 4 mono streams
as a stereo (interleaved?) 32bit stream.
it's similar as emu10k1 uses 2 mono streams for a single stereo 16-bit
interleaved stream.

in the case of 16-bit stereo, CPF_STEREO_MASK is used to toggle this
mode.  so, there must be a similar register switch for 32-bit mode.
otherwise it can't work...


Takashi


-------------------------------------------------------
This SF.Net email is sponsored by: SourceForge.net Broadband
Sign-up now for SourceForge Broadband and get the fastest
6.0/768 connection for only $19.95/mo for the first 3 months!
http://ads.osdn.com/?ad_id=2562&alloc_id=6184&op=click