Date: Tue, 25 Oct 2005 09:14:03 +0200 From: "Fabrice Grattier" <grattier@digigram.com> To: "Per olof Ljungmark" <peo@intersonic.se>, "Ariff Abdullah" <skywizard@MyBSD.org.my> Cc: freebsd-multimedia@freebsd.org Subject: RE: uaudio and Digigram UAX220 Message-ID: <E15B45BD62FCA142AED96D290103FDBB222896@digiexch.digigram.com>
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Dear Per Olof, Indeed, the UAX220 feature you mention might have something to do with = the problem that is encountered with FreeBSD. By default, the UAX220 has a fixed internal clock, set at 48 KHz.=20 Under Windows (XP), Microsoft DirectSound allows "on the fly" sampling = rate conversion (processing being done on PC's CPU) if playback and/or = recording is performed at a different sampling frequency value. That = ensures that Analog-To-Digital and Digital-To-Analog Converters provide = the best possible quality with the UAX220, whatever actual = playback/recording sampling frequency value. Modifying this UAX220 feature requires a firmware change (to switch from = fixed-48Khz-firmware to free-frequency-firmware). Problem is that firmware updater program is not finalized yet, that is = why you cannot find neither the firmware, not the firmware updater = program on our site.=20 Is this UAX220 feature definitely a problem to make it work under = FreeBSD? Please let me know. With regards, Fabrice -----Original Message----- From: Per olof Ljungmark [mailto:peo@intersonic.se]=20 Sent: Sunday, October 23, 2005 10:50 AM To: Ariff Abdullah Cc: freebsd-multimedia@freebsd.org; Fabrice Grattier Subject: Re: uaudio and Digigram UAX220 > http://people.freebsd.org/~ariff/snd_RELENG_5_20051009_054.tar.gz >=20 > tar -zxf snd_RELENG_5_20051009_054.tar.gz -C /usr/src/ >=20 > Again, as I've stated in my previous post: >=20 > Your entire playback channel goes haywire by not returning appropriate > sound format. Nothing can be done, even with this patch. Perhaps you > can try replacing all your /usr/src/sys/dev/sound/usb/ sources from > HEAD/CURRENT branch instead. So I recompiled the kernel using http://people.freebsd.org/~ariff/snd_RELENG_5_20051022_055.tar.gz and as you foresaw, it changed nothing. UAX220 works as a native USB Audio device under Win2k, XP, Linux and OS = X. I found this statement in the manual for the adapter, perhaps relevant=20 to the problem? I looked at digigram.com/drivers but saw nothing relevant contrary to=20 the statement below, perhaps Fabrice could enlighten me? The manual only refers to Windows XPsp2 as OS so I assume with all=20 others the adapter will report that it supports 48kHz only? ###### From UAX manual: UAX220 operates by default at an internal sample rate of 48 kHz. In case = the files played back have a different sampling rate, the operating=20 system performs a real-time frequency conversion. Under Windows XP (=99SP2) only, it is possible to modify the embedded=20 firmware version of the UAX220 so that it accepts other internal sample=20 rates: 8 kHz, 11.025 kHz, 16 kHz, 22.05 kHz, 24 kHz, 32 kHz, 44.1 kHz,=20 48 kHz. That makes it possible to work with files at e.g. 44.1 kHz=20 without frequency conversion. To use this feature, please download the corresponding firmware update=20 application at www.digigram.com/drivers/index.htm. In the 'Firmware'=20 section, select 'UAX220'. Read the instructions on how to use this=20 application carefully. Attention: When using this firmware, UAX220 notifies Windows that it is=20 able to manage sample rates from 8 through 48 kHz. Nevertheless, UAX220=20 uses internally the same sampling rate for recording and playback. This=20 entails, that if an application plays a file at a given sample rate, and = then another application is launched in parallel to record at another=20 sampling rate, UAX220 will record at the sampling rate defined by the=20 playback application, whereas the recording application assumes to work=20 at another sampling rate. On the other hand, if a recording is already=20 in hand at a certain frequency and a playback is launched at another=20 frequency, the output will have the right frequency. To sum up, the=20 audio stream being recorded or played back first imposes the sampling = rate! With the firmware delivered by default, Windows detects that UAX220=20 supports only 48 kHz, and in consequence performs frequency conversions=20 automatically when it detects that the frequency required by the=20 application is different from 48 kHz. Digigram, networking your sound
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