--- Forwarded Message from eric eubank <[log in to unmask]> ---
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>In-Reply-To: <[log in to unmask]>
>References: <[log in to unmask]>
>Date: Thu, 12 Oct 2006 14:15:05 -0500
>To: Language Learning and Technology International Information Forum
<[log in to unmask]>
>From: eric eubank <[log in to unmask]>
>Subject: Re: #8338.1 (!) QT Streaming Problem
>Cc: waltje <[log in to unmask]>
Re: completely removing QuickTime and iTunes:
read section on "Completely Remove iTunes and QuickTime" in
http://docs.info.apple.com/article.html?artnum=93976
In general, yes, QuickTime can be quirky, even from one "dot" version
to another. e.g., the latest upgrade, v7.1.3 disables Flash tracks by
default (a possible security issue, although Apple has not formally
declared why they did this. You now have to actively enable Flash
tracks in QT Prefs for them to work).
No idea why the "white video" track appears now (all computers?) but
that does possibly indicate some version incompatibility (e.g. trying
to play H.264 video on QT6 will yield a similar result); but that
really shouldn't have occurred just as a consequence of reinstalling
the same version you had before.
You are correct in your instinct to try to remove all traces of QT
and start over - that is the typical last ditch effort. On Windows,
"things" do get stepped on, and I wouldn't necessarily think that QT
is even the prime suspect, in that type of occurrence.
---
As to QT streaming itself, you mention transport negotiation. Does
your server stream on HTTP/80 in addition to default UDP/554? Do some
of your computers have different firewall settings .. or are they on
different subnets with different routers?
An easy, if not totally ideal way to address this situation is to
enable streaming via HTTP (port 80) and set all of your clients to
either auto-negotiate streaming transport or to be fixed on port 80.
HTTP isn't as "pushy" as UDP (thus theoretically, not as well
performing), but it is more ubiquitous and doesn't necessitate any
client port manipulation.
You'd be surprised how many times QT streaming "problems" are due
simply to the fact that QT streaming ports are blocked by default on
routers and firewalls. On my little Linksys router, for example,
while it isn't rocket science to enable the streaming ports, you do
have to do something actively .. which is a step that many end users
just won't take.
In addition to the UDP/HTTP streaming issue: we've had relatively
predictable results by sticking to relatively predictable
implementations. You do need to be consistent in your methods of
preparing files; by avoiding more esoteric implementations you can
avoid some possible conflicts.
Examples of such "esoterica": combining streaming tracks with text,
chapter, sprite, and Flash tracks .. but that's not going to occur on
a streaming server, anyway. But even in the streaming context, you
can ensure more consistent results by starting with and sticking with
consistently proven file formats.
Start with good source video, output in well-tested formats, and the
rest typically takes care of itself.
Having said that, QT version changes --esp major ones .. v6 to v7
pretty dramatically broke some things-- do tend to be problematic.
But I do not think that kind of change describes whatever problems
you are experiencing now. Good luck.
--
Eric Eubank <[log in to unmask]>
Liberal Arts ITS, Texas Language Technology Center
University of Texas at Austin
1 University Station B3500
Austin, TX. 78712-0191
At 2:28 PM -0400 10/12/06, LLTI-Editor wrote:
>--- Forwarded Message from waltje <[log in to unmask]> ---
>
>>Date: Thu, 12 Oct 2006 09:45:21 +0200
> >From: waltje <[log in to unmask]>
> >To: Language Learning and Technology International Information Forum
><[log in to unmask]>
>>Subject: Re: #8338 QT Streaming Problem
>>In-Reply-To: <[log in to unmask]>
>>References: <[log in to unmask]>
>
>
>Dear All:
>
>First of all, thank you to Otmar, John Stewart, Hans Gilde, Karen Tusack,
>Doug Worsham, Ginny White, Jeff Magoto, and Sharon Scinicariello for
>offering valuable hints and insights re: our QT streaming conundrum.
>
>I have to report, though, that the problem still persists. I have a
>feeling, both from the feedback I received and since the problem seems to
>appear randomly on both Mac and PC, that Quicktime just happens to be
>quirky. In the meantime, after I tried to remove and re-install Quicktime,
>even files that used to work (converted .asf and .avi files) suddenly do
>not display the video track anymore, but rather a white screen while the
>audio plays just fine. ??? I made it worse, methinks. I could see other
>people's streaming files (e.g. the ones Ginny and Jeff supplied from the
>YLC) but not my own, then those stopped working on my G4 PowerBook and my
>MacBook, but still work on my Toshiba Laptop.
>
>To cut a long story short: How do you uninstall/remove Quicktime 7 and
>start again with a clean install? Does anybody know? Should I just stop
>being obsessive and wait for QT 8 to come out...? Or are there other QT
>experts out there who have not responded yet? (Paging Derek Roff and
>Christopher Jones :-)
>
>All the best for now, Jorg
>
>
> *****
>
>--On Wednesday, September 27, 2006 1:48 PM -0400 LLTI-Editor
><[log in to unmask]> wrote:
>
>> --- Forwarded Message from waltje <[log in to unmask]> ---
>>
>>> Date: Wed, 27 Sep 2006 09:34:39 +0200
>>> From: waltje <[log in to unmask]>
>>
>> Dear Listlers:
>>
>> Here is an interesting conundrum that has been puzzling us for a while:
>> We stream from an OS X / QT Streaming Server, and it works like a charm
>> on MOST of our computers, but not all, although they are all set up the
>> same way (mostly eMacs in the lab, but the problem occurs on other
>> machines, both Mac and Windows XP as well -- read on...)
>>
>> On most machines the computer connects, streams, and everybody is happy.
>> On a handful of machines it connects, negotiates, switches transports,
>> and then just hangs there with the little blue bubbly line going back
>> and forth. It obviously receives some info (the slider on the timeline
>> can be moved back and forth and does display the correct length of the
>> video file that should appear), yet the video does not appear. So, what
>> is going on here? Has anybody run into the same problem and can offer a
>> solution/explanation?
>>
>> Here is a link for you to try out a file or two.
>>
>> <http://oak.cats.ohiou.edu/~kelley/entrevistas/>
>>
>> Any insights you can offer will be appreciated.
>>
>> Best from Jorg
>>
>> ---------------------
>> Dr. Jorg Waltje
>> Director LRC
>> Ohio University
>> ---------------------
>
>
>>
>***********************************************
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>Join IALLT at http://iallt.org.
>Otmar Foelsche, LLTI-Editor ([log in to unmask])
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