Message-ID: <41A5EDA2.60202@dark-reality.de>
From: Lars Grunewaldt <lgw@dark-reality.de>
MIME-Version: 1.0
To: bluez-devel@lists.sourceforge.net
Subject: Re: [Bluez-devel] more encoder stuff
References: <41A56774.1000308@xmission.com>	 <20041125071423.10e449c3.henryk@ploetzli.ch> <1101365484.7538.74.camel@pegasus>
In-Reply-To: <1101365484.7538.74.camel@pegasus>
Content-Type: text/plain; charset=ISO-8859-1; format=flowed
Sender: bluez-devel-admin@lists.sourceforge.net
Errors-To: bluez-devel-admin@lists.sourceforge.net
Reply-To: bluez-devel@lists.sourceforge.net
Date: Thu, 25 Nov 2004 15:35:14 +0100

-----BEGIN PGP SIGNED MESSAGE-----
Hash: SHA1

Marcel Holtmann wrote:
| Hi Henryk,
|
|
|>>you were saying the reference encoder runs faster. Is there
|>>any chance they are using vector processing like sse/sse2? Do projects
|>>like xine and mplayer detect and use a vector processor through a
|>>library?
|>
|>Nope, that was an error on my side. My file output was awfully slow. I
|>didn't test with large files since then, though. However, I_did_ profile
|>it and know that most of the encoding time is spent in sbc_analyze_audio
|>(no surprise there) in the matrixing, windowing and partial calculation
|>stages.
|>
|>I just tested it again with a -O3 compiled sbcenc:
|>
|>| time wine sbc_encoder.exe -o Uninvited.sbc Uninvited.wav
|>gives
|>| real    0m30.095s
|>| user    0m18.766s
|>| sys     0m0.686s
|>
|>| time ./sbcenc Uninvited.au > Uninvited.sbc
|>gives
|>| real    0m36.539s
|>| user    0m27.200s
|>| sys     0m1.500s
|>
|>That's not _too_ bad, especially since they are using dual channel while
|>we are using stereo (the latter gives smaller file size in this case).
|
|
| there exists a switch to sbc_encoder.exe to tell them to use stereo or
| joint stereo.
|
|
|>By using CC=icc CFLAGS="-O3 -tpp7 -march=pentium4" I can easily get it
|>down to
|>| real    0m19.122s
|>| user    0m11.272s
|>| sys     0m1.474s
|
|
| The MAD library (www.underbit.com/products/mad/) is using fixed-point
| integer computation. Do you think it is possible to do the same thing
| for SBC? Will it give us some extra performance?

just wanted to note that xine and mplayer definitly use mmx/sse in
different versions at least for video encoding/decoding, but I don't
know whether there are split-off libraries available.

The only audio encoding library I ever worked with was PWlib, the
hardware abstraction layer of the openh323 project.

Worked fine for playing/recording audio and decoding/encoding all this
gsm/mu_law stuff you use in VoIP, but I don't think it's well-suited for
the sbc encoder/decoder project.

Just wanted to mention it, though :)

- - Lars
-----BEGIN PGP SIGNATURE-----
Version: GnuPG v1.2.3 (GNU/Linux)
Comment: Using GnuPG with Thunderbird - http://enigmail.mozdev.org

iD8DBQFBpe2hQWC6DTWkDAoRAhCTAKCVOsTh7rc9DhM9aVuu1ryM+fnuqwCgnWSd
lYocn6vmLZG6mFgn+A8tr7g=
=KWh0
-----END PGP SIGNATURE-----


-------------------------------------------------------
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://productguide.itmanagersjournal.com/
_______________________________________________
Bluez-devel mailing list
Bluez-devel@lists.sourceforge.net
https://lists.sourceforge.net/lists/listinfo/bluez-devel