| MP4/Animated GIF/JPEG woes....(Windows, IDL 8.1) [message #76872] |
Mon, 11 July 2011 08:59  |
Daft Pict
Messages: 8
Registered: March 2007
|
Junior Member |
|
|
I've just started collaborating with some planetary astronomers who
tend to use very different tools compared to us traditional
observational astronomers :-) It's fun but I'm trying to generate
products that they use (and I typically don't) and having some teeth-
gnashing moments and screaming at the IDL help pages....
1). Creating an MP4 file from a stream of images - seems easy
according to the help pages and I duplicated the example code. The
resulting file is playable on my windows box using media player, but
not when using QuickTime on either windows or their Mac systems.
2) Animated GIFs again seem straightforward, except that write_gif
appears to reset my color table so I lose the color in overlays over
images. I pass in the current RGB values from the common block after
setting my tables but the gif file is B&W and the RGB arrays are all
reset!
3) Even tried animated JPEG since the help pages describes how to do
it, but the sample code doesn't work as I get an error when trying to
use the unit option even though it is described in the help....
Venting over - if anyone has some suggestions as to what causes any of
these problems or have solved these issues, are please let me know
cheers - Brian
|
|
|
|
| Re: MP4/Animated GIF/JPEG woes....(Windows, IDL 8.1) [message #76935 is a reply to message #76872] |
Wed, 13 July 2011 12:52  |
chris_torrence@NOSPAM
Messages: 528
Registered: March 2007
|
Senior Member |
|
|
On Wednesday, July 13, 2011 12:29:43 PM UTC-6, Kenneth P. Bowman wrote:
> That is not a limitation of Quicktime. Quicktime Player 7 can create movies from still images with
> frame rates from 60 fps to 10 spf (seconds per frame). Other programs like GraphicConverter
> allow you to set arbitrary frame rates. I believe Quicktime is very flexible in this regard.
Sorry, what I meant to say is that the Quicktime player (at least that we tried) cannot play *MP4* files with slow frame rates.
-Chris
|
|
|
|
| Re: MP4/Animated GIF/JPEG woes....(Windows, IDL 8.1) [message #76940 is a reply to message #76872] |
Wed, 13 July 2011 11:29 |
Kenneth P. Bowman
Messages: 585
Registered: May 2000
|
Senior Member |
|
|
In article
<3ee0f01b-9f84-4fdc-9ee8-2b9d4c462c10@glegroupsg2000goo.googlegroups.com
> ,
Chris Torrence <gorthmog@gmail.com> wrote:
> Hi Brian,
>
> I think what Andrew meant is that it is a fundamental limitation of Quicktime that it can't
> play movies with less than 5 fps. I don't think there is anything we can do. But perhaps you
> could use Paulo's suggestion of writing out each frame multiple times.
>
> Thanks.
> -Chris
> ITTVIS
That is not a limitation of Quicktime. Quicktime Player 7 can create movies from still images with
frame rates from 60 fps to 10 spf (seconds per frame). Other programs like GraphicConverter
allow you to set arbitrary frame rates. I believe Quicktime is very flexible in this regard.
I think it might be a limitation of Windows media or MPEG files. I have had so many
problems converting Quicktime movies on my Mac to .wmv or .mp4 files in order to give
a presentation on a Windows machine at a conference that I have completely given up.
It is not worth fighting to make Windows compatible presentations. (Microsoft "wins" that one.)
Ken Bowman
|
|
|
|
| Re: MP4/Animated GIF/JPEG woes....(Windows, IDL 8.1) [message #76942 is a reply to message #76872] |
Wed, 13 July 2011 08:49 |
chris_torrence@NOSPAM
Messages: 528
Registered: March 2007
|
Senior Member |
|
|
Hi Brian,
I think what Andrew meant is that it is a fundamental limitation of Quicktime that it can't play movies with less than 5 fps. I don't think there is anything we can do. But perhaps you could use Paulo's suggestion of writing out each frame multiple times.
Regarding the WRITE_GIF problem, can you provide a simple reproduce case? I'm trying to reproduce it here, but I can't seem to get it to fail.
Thanks.
-Chris
ITTVIS
|
|
|
|
| Re: MP4/Animated GIF/JPEG woes....(Windows, IDL 8.1) [message #76950 is a reply to message #76872] |
Tue, 12 July 2011 18:02 |
penteado
Messages: 866
Registered: February 2018
|
Senior Member
Administrator |
|
|
On Jul 12, 9:46 pm, Daft Pict <brianjmcl...@gmail.com> wrote:
> Yes - that was the problem. Like you I got solid green in QT but 5fps
> makes it work. THANKS!
> However, being realistic I really need to have a slower frame rate.
> I'm displaying a sequence of observations taken from a NASA probe and
> I typically only have ~20 frames taken over a couple hours. To get the
> best visualization of the changes we see I was writing the mp4 at 1
> fps otherwise it's over in 3-4 seconds and hard to see! What are the
> odds of a fix for the QT issue?
One way would be to make it a 5fps with the frames replicated 5 times.
It would probably not make the file size different, since the
compression algorithm would detect that the frames are the same.
|
|
|
|
| Re: MP4/Animated GIF/JPEG woes....(Windows, IDL 8.1) [message #76951 is a reply to message #76872] |
Tue, 12 July 2011 17:46 |
Daft Pict
Messages: 8
Registered: March 2007
|
Junior Member |
|
|
Yes - that was the problem. Like you I got solid green in QT but 5fps
makes it work. THANKS!
However, being realistic I really need to have a slower frame rate.
I'm displaying a sequence of observations taken from a NASA probe and
I typically only have ~20 frames taken over a couple hours. To get the
best visualization of the changes we see I was writing the mp4 at 1
fps otherwise it's over in 3-4 seconds and hard to see! What are the
odds of a fix for the QT issue?
The alternative approach I tried was an animated gif since my mac
colleagues are ok with that. My problem was that write_gif resets the
color table (see original post) and I lose all my color annotation/
overlays highlighting the features. Suggestions to get that working
would be just as good :-)
Thanks again! Glad that folks are trying to help.
cheers - Brian
|
|
|
|
comp.lang.idl-pvwave archive
Members
Search
Help
Login
Home
