Creating a mp4 movie from IDL
For presentations or web-pages I often need to create movies
showing, e.g., the evolution of solar feature with time. This page
explains how I do this process. Please note that I make use of
QuickTime Pro for Macs.
The ideal format for a movie is mp4, but it must be created
with the h.264 codec. In this format the movie should play with any web
browser. There are many other codecs, but there is no guarantee that
these will work on all web browsers.
Although it's possible to create a mp4 movie directly from IDL
(see the IDLffvideowrite object below), they will not be created with
the h.264 codec and so the movies will not work with all browsers. (The
movie will be fine for personal use, such as presentations, though.)
QuickTime and iMovie (Mac)
Modern Macs come with QuickTime X pre-installed, but (as far as
I'm aware) it doesn't allow images to be combined into a movie. QuickTime Player 7
is an older version of QuickTime that Apple still distributes and is
compatible with old movie formats. It also does not allow images to be
combined into a movie. However,
it can be upgraded to QuickTime 7 Pro and this does allow you to make
movies. Unfortunately it seems it's no longer possible to buy the Pro
registration keys (they're not listed on the Apple site). You could check with your IT department or colleagues if they have an old registration key that you could use (note the keys don't expire).
option is to try using the iMovie software that comes with modern Macs,
but I haven't had any success in getting this to work.
My method (for a Mac)
My method for creating a good movie is to write out individual
frames from IDL using plot
objects. In particular note that any plot object, p, can be written
a png using:
The resolution=96 ensures the output image has the same size
as the image displayed on your screen.
After I've created a set of images (I usually call them
image0000.png, image0001.png, etc.), I then use QuickTime Pro (Mac) to
read the images into a movie. I do the following steps:
- Click on File -> Export...
- Select 'Movie to MPEG-4' option, and click on the
- Select File Format 'MP4', and Video Format 'H.264'.
- Data Rate should be set around 2000 kbits/sec.
- For 'Image Size' use 'Current'.
Embedding the mp4 in html
To embed the mp4 movie in a webpage, you need to use the html5
video container. I suggest going to one of my webpages
and viewing the page source for the video on this page to see how it
The option "controls" will display play and stop buttons when
the movie is played, while "loop" makes the movie automatically loop.
The IDLffvideowrite object
mp4 movies can be written directly from IDL, however not with
the h.264 codec so they are not useful for webpages. For information on
how to use the object, please check the information given at this location.
Page maintained by Dr Peter R Young.