wxQtMovie playback issue

wxPython Dev
1

Hi all,

I have been unable to resolve the QT MPEG playback issue where any MPEG loaded after the first video loads plays back slowly. I have, however, found a potential workaround. If you create a new wxFrame each time you load a new video (in other words, each frame only ever loads one video), then you don't run into this problem. In short, the problem only occurs when two or more videos are loaded into the same TLW, and furthermore this is only the case with long MPEG videos.

The hard part about tracking this down is that pretty much every QT sample app I've seen on the web loads each video into a new TLW, including of course the QT Player. So at this point there are two options:

- The Quick Fix: Clean up the wxQtMovie code to enable loading multiple videos at the same time (by being a bit more careful about how we call ExitMovies) and fix a couple bugs with loading multiple videos in multiple windows. (It works, but it sometimes crashes so I need to hunt that down)

- The Real Fix: Track down exactly what's happening by modifying some QT samples to load multiple videos into the same window. Then debug from there. Note that I don't have an ADC select membership, so if there is an issue at the QuickTime level that was simply never caught because none of their own apps (including samples) try it, then we're pretty much stuck.

What I'm going to do for the moment is get the "Quick Fix" out the door, sometime within the next couple days. I'd like to get this issue completely resolved, but that could take quite some time, and if most apps could workaround with the Quick Fix, then I'd much rather prefer to be spending my time on things that can't be worked around. (Like getting wxMozilla 2.5 packages out the door! :slight_smile:

Thanks,

Kevin

2

Kevin,

Really interesting. I should be able to work out a way to create a new
Video Window with each movie load. That seems like a reasonable
compromise, given the problem as you describe it. Transana needs to be
able to play clips out of numerous videos sequentially, but destroying
and recreating the video window shouldn't be too disruptive, as long as
I'm careful to make it visually smooth. Once the new wxQtMovie is out,
I'll give it a try and let you know.

Thanks for your work on this,
David

From: Kevin Ollivier [mailto:kevino@tulane.edu]
Sent: Sunday, October 24, 2004 12:29 PM
To: wxPython-dev@lists.wxwidgets.org
Subject: [wxPython-dev] wxQtMovie playback issue

Hi all,

I have been unable to resolve the QT MPEG playback issue where any

MPEG

loaded after the first video loads plays back slowly. I have, however,
found a potential workaround. If you create a new wxFrame each time

you

load a new video (in other words, each frame only ever loads one
video), then you don't run into this problem. In short, the problem
only occurs when two or more videos are loaded into the same TLW, and
furthermore this is only the case with long MPEG videos.

The hard part about tracking this down is that pretty much every QT
sample app I've seen on the web loads each video into a new TLW,
including of course the QT Player. So at this point there are two
options:

- The Quick Fix: Clean up the wxQtMovie code to enable loading

multiple

videos at the same time (by being a bit more careful about how we call
ExitMovies) and fix a couple bugs with loading multiple videos in
multiple windows. (It works, but it sometimes crashes so I need to

hunt

···

-----Original Message-----
that down)

- The Real Fix: Track down exactly what's happening by modifying some
QT samples to load multiple videos into the same window. Then debug
from there. Note that I don't have an ADC select membership, so if
there is an issue at the QuickTime level that was simply never caught
because none of their own apps (including samples) try it, then we're
pretty much stuck.

What I'm going to do for the moment is get the "Quick Fix" out the
door, sometime within the next couple days. I'd like to get this issue
completely resolved, but that could take quite some time, and if most
apps could workaround with the Quick Fix, then I'd much rather prefer
to be spending my time on things that can't be worked around. (Like
getting wxMozilla 2.5 packages out the door! :slight_smile:

Thanks,

Kevin

---------------------------------------------------------------------
To unsubscribe, e-mail: wxPython-dev-unsubscribe@lists.wxwidgets.org
For additional commands, e-mail: wxPython-dev-help@lists.wxwidgets.org

3

Hi all,

I have been unable to resolve the QT MPEG playback issue where any MPEG
loaded after the first video loads plays back slowly. I have, however,
found a potential workaround. If you create a new wxFrame each time you
load a new video (in other words, each frame only ever loads one
video), then you don't run into this problem. In short, the problem
only occurs when two or more videos are loaded into the same TLW, and
furthermore this is only the case with long MPEG videos.

The hard part about tracking this down is that pretty much every QT
sample app I've seen on the web loads each video into a new TLW,
including of course the QT Player. So at this point there are two
options:

- The Quick Fix: Clean up the wxQtMovie code to enable loading multiple
videos at the same time (by being a bit more careful about how we call
ExitMovies) and fix a couple bugs with loading multiple videos in
multiple windows. (It works, but it sometimes crashes so I need to hunt
that down)

- The Real Fix: Track down exactly what's happening by modifying some
QT samples to load multiple videos into the same window. Then debug
from there. Note that I don't have an ADC select membership, so if
there is an issue at the QuickTime level that was simply never caught
because none of their own apps (including samples) try it, then we're
pretty much stuck.

What I'm going to do for the moment is get the "Quick Fix" out the
door, sometime within the next couple days. I'd like to get this issue
completely resolved, but that could take quite some time, and if most
apps could workaround with the Quick Fix, then I'd much rather prefer
to be spending my time on things that can't be worked around. (Like
getting wxMozilla 2.5 packages out the door! :slight_smile:

Thanks,

Kevin

Kevin,

If you load the Quicktime Player and choose Preferences > Player
Preferences, you'll see a checkbox for the "Open movies in new players"
option, which is checked by default but which CAN be turned off. Then,
multiple MPEGs can be loaded sequentially in the same Quicktime window, and
they do not show any lag on repositioning or positioning-then-playing.

As far as the "Real Fix" goes, I suspect you've already looked into checking
the various status methods before you start playing, right? We had a
somewhat similar issue on Windows until we made sure to confirm that the
video was done loading before we tried to reposition or play it. Just a
thought.

Any chance you'll have a new release, even an improved but not yet perfect
one, of wxQtMovie within the next couple of weeks? I should have my Beta 2
release of Transana 2.0 for Windows out by November 19 (I hope) and hope to
be able to begin the final push in getting Transana for Mac finished once
the Windows Beta is released.

Also, it looks like the percentage of my appointment at work devoted to
Transana may be going up from 50% to 90% in January, which should allow me
some time to work on converting VideoWindow.py into a wxVideoWindow
component for Windows and Mac platforms. But the funding Gods work in
mysterious ways here, so I'm not counting on it yet. But it gives me hope.

David

4

Hi David,

Sorry I've been rather quiet. To get further in debugging some of these issues, I really need to get this building and running from C++ and creating a C++ demo, which has been taking a bit of time because I'm not really familiar with autoconf / Unix build system. I've now got the basic project building and creating a wxQTMovie library file (and wrote a little script for generating Bakefile/autoconf projects so that I don't have to remember how I did it =) but from here I still need to make a C++ demo. I don't think I'll make November 19, unfortunately, but I am still working on this, it's just taking time due to the complexity as well as some other issues. I'll be sure to take a look at the issues you mentioned, but I've also come across some weird crashes that happen when loading and playing multiple videos in their own windows and I need to track that down before releasing a new version.

Thanks as always for your help and feedback!

Kevin

[snip]

···

On Oct 29, 2004, at 1:10 PM, David Woods wrote:

Kevin,

If you load the Quicktime Player and choose Preferences > Player
Preferences, you'll see a checkbox for the "Open movies in new players"
option, which is checked by default but which CAN be turned off. Then,
multiple MPEGs can be loaded sequentially in the same Quicktime window, and
they do not show any lag on repositioning or positioning-then-playing.

As far as the "Real Fix" goes, I suspect you've already looked into checking
the various status methods before you start playing, right? We had a
somewhat similar issue on Windows until we made sure to confirm that the
video was done loading before we tried to reposition or play it. Just a
thought.

Any chance you'll have a new release, even an improved but not yet perfect
one, of wxQtMovie within the next couple of weeks? I should have my Beta 2
release of Transana 2.0 for Windows out by November 19 (I hope) and hope to
be able to begin the final push in getting Transana for Mac finished once
the Windows Beta is released.

Also, it looks like the percentage of my appointment at work devoted to
Transana may be going up from 50% to 90% in January, which should allow me
some time to work on converting VideoWindow.py into a wxVideoWindow
component for Windows and Mac platforms. But the funding Gods work in
mysterious ways here, so I'm not counting on it yet. But it gives me hope.

David

---------------------------------------------------------------------
To unsubscribe, e-mail: wxPython-dev-unsubscribe@lists.wxwidgets.org
For additional commands, e-mail: wxPython-dev-help@lists.wxwidgets.org