16 Apr
2009
16 Apr
'09
2:44 p.m.
Dear Linux Audio Developers,
as indicated by Stéphane in his presentation [1] he gave at LAC2009 today, I
finally handed in my diploma thesis, which I announced here [2]. You can
download the full text of the thesis here:
<http://www1.inf.tu-dresden.de/~s3418892/diplom.pdf> [3].
If you want to take a glimpse at the code, you can get a (still very dirty)
snapshot of the code here [4].
The abstract of the thesis:
Several available free software audio solutions were
analyzed, and
Jackdmp—a C++ reimplementation of the renowned JACK Audio Connection
Kit—was selected as the most appropriate solution for a real-time audio
architecture on DROPS. The JACK sound architecture provides the lowest
processing latency possible on a desktop computer for a given set of sound
card parameters. It reduces the latency jitter caused by software to zero
and synchronizes streams at sample accuracy.
A real-time admission scheme for JACK clients is
proposed.
The execution time of different typical JACK clients was analyzed with
measurements to validate the assumptions the proposal is based on,
but also to gain further knowledge about their timing behavior.
The measurements showed that the condition set by Paul Davis—the
time to process a client must be a linear function of the buffer size—holds
for all tested clients.
Jackdmp was ported to DROPS. The developed design
of the port and its
implementation is documented here. Measurements showed that—although
the real-time performance of the Linux kernel is continously being improved
in the mainline and on special external branches—DROPS can provide a
signaling latency that is two times lower on average than the values that
can be achieved on the same machine running with a low latency patched
Linux kernel. Thus, it can be stated that DROPS is well-suited for
real-time audio processing and that the pursued path to use it as the
foundation of a truly real-time capable audio workstation should be
followed.
As of the project's future: I will try to get the ALSA driver and the
connection with L4Linux working until the presentation of the project (no
date set so far, but probably in 2--4 weeks or so). If all works well, we
will consider releasing a demo disc and / or a Youtube demonstration for
interested developers and power users of the system then. And then we'll
see :).
Kind regards --- and those of you who are in Parma: Have an interesting
conference and a great time in Italy! ---,
micu
===============================================================
[1]<http://linuxaudio.de/lac2009/JACK2_LAC_2009_slides.pdf>
[2]<http://lists.linuxaudio.org/pipermail/linux-audio-dev/2008-July/02138…
[3]<http://www1.inf.tu-dresden.de/~s3418892/diplom.pdf>
// This is only a temporal location, I will inform you about the final
location here as soon as the document is published there.
[4]<http://www1.inf.tu-dresden.de/~s3418892/code_snapshot_(still%20dirty).tar.gz>
--
GnuPG: https://www1.inf.tu-dresden.de/~s3418892/micuintus.asc
Fingerprint: 1A15 A480 1F8B 07F6 9D12 3426 CEFE 7455 E4CB 4E80
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https://wiki.c3d2.de/Benutzer:Micuintus