[AG-DEV] Re: [AG-TECH]too much Bitrate in RAT
Robert Putnam
putnam at tonka.bu.edu
Fri Jul 21 11:54:23 CDT 2006
Reading recently about RAT crashes under MS Windows, I am reminded that
when I was developing my positional audio / window highlighting code, RAT
would routinely crash. The error message often looked like this:
Unhandled exception at 0x00430e5f in ratmedia.exe: 0xC0000005: Access
violation reading location 0x00000018.
I was able to track down what appeared to me to be a race condition whereby
the waveInProc Windows callback could try to access a data structure that
already been freed in w32sk_audio_read. Since fixing the bug [knock on
wood], I have not seen RAT crash in this way.
I don't know if other people's RAT crashes have the same cause, since I
only saw it when 3D audio was enabled. At any rate, I'd like to make the
fix available to the community. Source is here:
http://scv.bu.edu/~putnam/ag-audio/source-2.4/ag-media-positional/rat/auddev_win32.c
And an AG 2.4 AudioService with the fix is here:
http://scv.bu.edu/~putnam/ag-audio/ratfix-2.4-windows/AudioService.zip
Robert Putnam
putnam at bu.edu
617-353-8295
X-Envelope-From: putnam at scv.bu.edu
From: "Andrew A Rowley" <Andrew.Rowley at manchester.ac.uk>
Reply-To: "Andrew.Rowley at manchester.ac.uk" <Andrew.Rowley at manchester.ac.uk>
Date: Fri, 21 Jul 2006 10:28:26 +0100
Organization: University of Manchester
X-Sent-Folder-Path: Sent Items
X-Authenticated-Sender: Andrew Rowley from rosie.mvc.mcc.ac.uk (mvc.mcc.ac.uk) [130.88.1.73]:4195
X-Authenticated-From: Andrew.Rowley at manchester.ac.uk
X-UoM: Scanned by the University Mail System. See http://www.itservices.manchester.ac.uk/email/filtering/information/ for details.
X-Virus-Scanned: by amavisd-new-20030616-p10 (Debian) at mailgw.mcs.anl.gov
X-MIME-Autoconverted: from quoted-printable to 8bit by mcs.anl.gov id k6L9SVW104100
X-Spam-Status: No, hits=0.5 required=5.0
tests=FORGED_MUA_OUTLOOK,IN_REP_TO,QUOTED_EMAIL_TEXT
version=2.55
X-Spam-Level:
X-Spam-Checker-Version: SpamAssassin 2.55 (1.174.2.19-2003-05-19-exp)
X-MCS-Mail-Loop: ag-tech
Sender: owner-ag-tech at mcs.anl.gov
X-Score-Level: 0
X-UID: 32443
X-Keywords:
Hi,
Note that to be compatible with InSORS IGAudio, I think we are restricted to L16-16K-MONO (256kbps), PCMU-16K-MONO (128kbps) and PCMU-8K-MONO (64kpbs). Of the PCMU codecs, the 16K Mono one should be of the same quality as L16.
This depends on how important this interoperability is in your meetings - presumably if there was a move to another codec in general, I would guess that InSORS would consider implementing this in IGAudio too, but I wouldn't like to speak for them on this.
Andrew :)
============================================
Access Grid Support Centre,
RSS Group,
Manchester Computing,
Kilburn Building,
University of Manchester,
Oxford Road,
Manchester,
M13 9PL,
UK
Tel: +44(0)161-275 0685
Email: Andrew.Rowley at manchester.ac.uk
> -----Original Message-----
> From: owner-ag-tech at mcs.anl.gov [mailto:owner-ag-tech at mcs.anl.gov] On
> Behalf Of Colin Perkins
> Sent: 20 July 2006 18:54
> To: John Hodrien
> Cc: ag-tech
> Subject: Re: [AG-TECH]too much Bitrate in RAT
>
> On 20 Jul 2006, at 17:05, John Hodrien wrote:
> > On Thu, 20 Jul 2006, Robert Olson wrote:
> >> It may be historical. When we started out the compressed codecs
> >> seemed to be much less stable.
> >
> > I'm not sure that's not still the case. We had no end of problem
> > using GSM
> > under windows with rat crashing.
> >
> > There's also the other bonus. If you compress, you always
> > introduce a 1 frame delay to the audio.
>
> The way rat works, you always get that delay, no matter what codec is
> selected.
>
> Colin
>
More information about the ag-dev
mailing list