Zeta
comes a selection of video capturing softwares, one of the is Scrubba.
The application begins capturing video immediately
as it starts up and will therefore quickly be able to fill up a
small disk partition.
From the File menu you can pause the capturing,
and you can change the size of the ring buffer and its file name
under the Options menu. The video input source is configured
from the Media Preferences
in Zeta, and can eighter be set to DV (IEEE-1394 or raw video (bt848).
Scrubba handles the streams as is, and does not
encode frames before they are to written to its ring buffer. It
is therefore important that your raw setting doesn't exceed your
fisk throughput. As mentioned in the article about the VideoRecorder,
this usually means resolutions no more than 352x240 at 16 bits per
pixel. When it comes to capturing DV Scrubba is capable of handling
resolutions up to 720x480 in realtime. This is because the DV format
has a lower data rate then 320x240 raw video.
If you have DV and you want to capture live TV
or an analog source, you can plug a VCR into your camera, have it
do the encoding, and pass the frames along to Scrubba through via
1394.
Scrubba can present the video in two different ways.
The online playback is displaying the live video frames as they
are being captured. If you choose to press the Pause button,
only the playback will be paused, not the recordings. The second
time you press the Pause button Scubba will perform a timelapse
playback beginning from where you earlier paused the playback of
the video recording. You can also press the Live button
here, that will bring the playback in sync (realtime) with what
is being captured.
Scrubba has two sliders:
- The first tracks the location of the capture
head in the ring bugger and is not interactive.
- The second slider tracks and controls the location
of the playback head.
When the playback head is paused, you can scrub
by dragging Scrubba's sliders (here is what got it's name from).
When the playback slider has the focus, use the left and right arrow
keys to get frame accurate scrubbing.
You can also export frames from a video in Scrubba.
This is done simply by scrubbing to the frame you want to take and
then pressing the Grab button.You can of course also export
parts of the video as a movie clip. To do this, simply hold down
the shift key as you scrub over a series of frames before you click
the Grab button.
Images and movies are named sequentially; GRAB0001.jpg,
GRAB0002.mov, GRAB0003.png, and so on.
The export file formats can be changed using the
Still and Clip submenus under the Options menu.
But when you are capturing DV clips, Scrubba
will not re-encode the frames from your camera (stills, of course,
always get re-encoded). Instead, it will feed them into the movie
as-is. This way your clips retain the audio. When grabbing clips
from a raw video source, be aware, some encoders are slow and your
clip may be overtaken by the capture head before it completes.
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