Re: [PATCH] emu10k1: add 96Khz support and setting sample rate for direct SPDIF output

[Takashi Iwai <tiwai@suse.de>]

At Sun, 06 Feb 2005 16:12:43 -0500,
Lee Revell wrote:
> 
> This patch should add support for 96Khz "direct SPDIF" aka "SPDIF
> Bypass" (not P16V) playback mode available on the Audigy1 and 2 and
> newer SBLives (?).  It lets you bypass the 48khz DSP resampling when
> using the card in digital mode.  It also adds 96khz analog playback
> support, good for testing but less interesting because it's downsampled
> to 48khz.  A new mixer control "Audigy SPDIF Output Sample Rate" is
> created, you can choose 44100, 48000, or 96000.  Standard SPDIF
> playback, AC3 passthrough (real 96khz playback), and analog playback
> (96khz is resampled to 48khz in the DSP) all work with a 16 bit,96khz
> wav file.  Only the last was tested due to lack of any SPDIF hardware.

What happens if you play in a non-matching sample rate or a strange
rate like 45000Hz?

> This was derived mostly from the opensource.creative.com driver.  All
> that was needed for 96khz playback to work in analog mode was changing
> the format to 8000_96000 (looks like the creative driver supports 192khz
> too).

192kHz results in pitch_target=0x10000, so needs a correction to
0xffff?   Just a guess.  I'll need to take a look at creative driver.


Takashi


-------------------------------------------------------
SF email is sponsored by - The IT Product Guide
Read honest & candid reviews on hundreds of IT Products from real users.
Discover which products truly live up to the hype. Start reading now.
http://ads.osdn.com/?ad_id=6595&alloc_id=14396&op=click