From mboxrd@z Thu Jan 1 00:00:00 1970 Received: from pigeon.gentoo.org ([208.92.234.80] helo=lists.gentoo.org) by finch.gentoo.org with esmtp (Exim 4.60) (envelope-from ) id 1MFTKk-00065D-T1 for garchives@archives.gentoo.org; Sat, 13 Jun 2009 13:31:47 +0000 Received: from pigeon.gentoo.org (localhost [127.0.0.1]) by pigeon.gentoo.org (Postfix) with SMTP id 3C420E03F2; Sat, 13 Jun 2009 13:31:40 +0000 (UTC) Received: from mail-gx0-f207.google.com (mail-gx0-f207.google.com [209.85.217.207]) by pigeon.gentoo.org (Postfix) with ESMTP id 1871CE03F2 for ; Sat, 13 Jun 2009 13:31:40 +0000 (UTC) Received: by gxk3 with SMTP id 3so12254273gxk.10 for ; Sat, 13 Jun 2009 06:31:39 -0700 (PDT) DKIM-Signature: v=1; a=rsa-sha256; c=relaxed/relaxed; d=gmail.com; s=gamma; h=domainkey-signature:mime-version:received:in-reply-to:references :date:message-id:subject:from:to:content-type :content-transfer-encoding; bh=0fojYqnHiJxkF8ceWYOPCHm8hA8whkZtIN2gtdLMIck=; b=ReTny3+DAflUR1MaLimleas0xf55xRLuiKrh7zsDftzFGYcThHTaBHSeF297J/J3X9 r6HSbaM/ZpRG4NVr35QFT/wO39+fdr8XYu66gAYEFuMIsl8MTcCKxH4mFZqNC5o4RF4M IoHVgjU3G9EPVfDvB/5nFZ1eaaWOS1aIacZiQ= DomainKey-Signature: a=rsa-sha1; c=nofws; d=gmail.com; s=gamma; h=mime-version:in-reply-to:references:date:message-id:subject:from:to :content-type:content-transfer-encoding; b=o+3XVNNha7mF5O7Cq4AmlvGb9XZdQAzWmxvaNznUhgaHN1cHZgGUvGZr/JtOAz5TIc Ec2IIL2X57fEkD1ueoijgsJhZjW65Fvh2NrNnNeoS8btjo88wer/KjZceqCEMx5Ov9Ec AQa13kwu04IJkZhWuDO2LbTHVPeHgtmUZ0SX4= Precedence: bulk List-Post: List-Help: List-Unsubscribe: List-Subscribe: List-Id: Gentoo Linux mail X-BeenThere: gentoo-user@lists.gentoo.org Reply-to: gentoo-user@lists.gentoo.org MIME-Version: 1.0 Received: by 10.90.81.11 with SMTP id e11mr4181701agb.110.1244899899768; Sat, 13 Jun 2009 06:31:39 -0700 (PDT) In-Reply-To: <20090613111155.6d042ee9@coercion> References: <49bf44f10906121602x6b0cf20rfe2731edfdf7d205@mail.gmail.com> <20090613103056.552dc565@coercion> <49bf44f10906122145k327c03c3jb99731ca1fe818cb@mail.gmail.com> <20090613111155.6d042ee9@coercion> Date: Sat, 13 Jun 2009 06:31:39 -0700 Message-ID: <49bf44f10906130631j187d0649vb4e479d576a32f18@mail.gmail.com> Subject: Re: [gentoo-user] Prioritizing mpd From: Grant To: gentoo-user@lists.gentoo.org Content-Type: text/plain; charset=ISO-8859-1 Content-Transfer-Encoding: quoted-printable X-Archives-Salt: be24bd6d-32fe-49cb-b263-17978b8b8c85 X-Archives-Hash: 3c38213a49b45c3deaf36a0966744996 >> renice -20 -p `pgrep mpd` >> >> but my Athlon 2.2Ghz still can't handle it for more than a few >> seconds. =A0I don't have SMP enabled because of a bug in madwifi, and >> I'm hoping when I get that fixed I'll be able to run the best >> libsamplerate resampler. =A0Any other ideas for making this work? > > AFAIK resampling is expensive operation that's only necessary when your > sound card can't handle native stream sample rate, furthermore, it's a > lossy operation (degrading quality). > > So, I'd look for the answer to the question "why mpd is doing it and > why I allow it to do that?". > For example, you might have enabled it to resample stream to 32 bits > depth, while your built-in card can only handle 16 and the stream has > also 16, so what happens is userspace-level conversion (with some loss > of quality) to 32, loading your CPU, then this stream goes to alsa, > and, provided that your card can't play this, driver or the card itself > converts it back to 16. > Note that the latter case would probably mean "card offloads conversion > to your CPU as well", so you'll get CPU load for both ways' conversion > anyway, only reducing sound quality, no matter how good converters are. > > To avoid any processing, try disabling resampling in mpd, since it'll > probably be done for you anyway, if necessary (you'll hear "white > noise" otherwise). > > And you can pre-convert all the streams to any given samplerate, but > note that you'll probably get far worse results if the target format > isn't lossless (flac, ape), even if the source one is lossy, than with > worst resampling. > And you can get worse CPU/IO load with lossless format in the end, > since it's harder to decode and the input data stream is much heavier > than with lossy mp3s or oggs. > > -- > Mike Kazantsev // fraggod.net I'm upsampling my 16/44.1 files to 24/96 because it sounds much better than letting the USB DAC do it. This was actually recommended by the manufacturer and it sounds much better. Pre-converting sounds interesting. I could convert all of my 16/44.1 files to 24/96 files? That way the CPU wouldn't be stressed at playback time. How can I do that? I use libsamplerate "Best" for resampling. - Grant