[alsa-devel] Juli@ ICE1724 and 24 bit audio

[Vedran Miletić]

The plughw part is what makese it resample to 16-bit. You should just use hw.

On Mon, Feb 9, 2009 at 10:29 PM, Demian Martin <demianm_1 at yahoo.com> wrote:
> Pavel:
> Thanks for all your help and work on this project.
>
> I'm using the Juli@ card because it supports 176.4KHz. The only other
> candidates are much more expensive and bring their own problems.
>
> I'm using Xine set for dolby/dts passthrough which seems to send the audio
> data at its native rate. The resampling is bypassed (Dolby Digital would be
> trashed otherwise).
>
> I will try playing the files from the command line when I am next in front
> of the system, tomorrow.
>
> This is the Asound.conf:
> Asound.conf  (/etc)
>
> pcm.asym_spdif {
>
>       type asym
>
>       playback.pcm "plughw:0,1"
>
>       capture.pcm "plughw:0"
>
> }
>
>
> pcm.!default asym_spdif
>
> Demian Martin
> PDS
>
>> -----Original Message-----
>> From: Pavel Hofman [mailto:pavel.hofman at insite.cz]
>> Sent: Monday, February 09, 2009 12:27 PM
>> To: Demian Martin
>> Cc: alsa-devel at alsa-project.org; pavel.hofman at insite.cz
>> Subject: Re: [alsa-devel] Juli@ ICE1724 and 24 bit audio
>>
>> Demian Martin napsal(a):
>> > I have the driver working fine for sample rates from 44.1K to 196K
>> however
>> > it seems to be truncating the data to 16 bits. I wasn't sure until I
>> started
>> > testing with the HRx 176.4K 24 bit files that have an embedded HDCD flag
>> in
>> > the LSB. The files work OK on Windoze systems (with a lot of low level
>> > settings tweaked) and they play fine but the flag isn't detected by a
>> system
>> > that can detect them. Further looking at the data stream with a scope it
>> > seems the last 8 bits aren't changing. Is there anything I can do to
>> control
>> > the driver to confirm this problem or change the playback settings to
>> make
>> > it work?
>> >
>> >
>>
>> How do you play the files? Do you use the hw or plug:hw device? IIRC,
>> the standard-setup dmix resampler is 16-bit only.
>>
>> I did tests with SPDIF OUT/IN and found it bit-perfect, for 24bit too.
>>
>> Regular ICE1724 cards do not output 176.4kHz SPDIF, only 88.2kHz. But
>> Juli is not affected by that bug.
>>
>> Regards,
>>
>>
>> Pavel.
>
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-- 
Vedran Miletić