Generating MPEG animations using DV
(last updated April 30, 2003)
Follow these 5 basic steps to generate MPEG animations using
From the Options menu of the DV local view
window, select Screen Capture as shown below
This should pop up the Screen Capture form:
Click on the Start capture button. The button label will
thereafter read Stop capture and every subsequent redraw of the
graphics output in local view will cause the viewing area
to be captured as a JPEG image located within the directory specified
in the directory widget (which you are free to
modify). Each such capture will be logged
to DV's standard output, producing diagnostic messages such as
refresh_gl_display: saving screen to file /tmp/scr_save_0.jpeg
refresh_gl_display: saving screen to file /tmp/scr_save_1.jpeg
refresh_gl_display: saving screen to file /tmp/scr_save_2.jpeg
refresh_gl_display: saving screen to file /tmp/scr_save_3.jpeg
The third and fourth numbers following vp: in the above messages
are the width and height, respectively, of the graphics area that is being
captured in the form of JPEG images.
It is crucial that the local view window be resized so that
the WIDTH of the JPEG images that are produced is a MULTIPLE of 16.
Currently, this resizing must be done intearactively by "trial-and-error",
that once Start capture has been enabled, interactive resizing
of the local view window will cause a graphics redraw and an
associated diagnostic message from which the width of the image can
be read off.
In the example shown above, the window has been sized to produce images
that are 256 pixels wide x 256 pixels high.
- Once you are satisfied with the size of the local view
drawing area, as well as the view of the data that you wish to recode,
click on the Stop capture button twice
in order to reset the sequencing of the captured JPEG images (i.e.
so that the first image in the recorded sequence of images will be
labelled via the entry in the first index widget).
- Click the Send to local view button of the main Data
Vault window to playback the data and generate a complete sequence
of JPEG images.
- Follow the instructions HERE
to convert the JPEG images to
an MPEG file.
- When you are done generating your movie(s), disable the screen
capture. Also note that the JPEG images that are produced
via the screen capture will need to be manually removed, and should
be so removed (once the MPEG generation is complete) in order
to conserve disk space.
Report any problems encountered to Matt.