A User Guide To Scrubba

Use the BeOS Media preferences application to configure the video input source. Scrubba supports either DV (IEEE-1394) or raw video (bt848).

Scrubba does not encode frames before writing them to its ring buffer so your raw settings must not exceed your disk throughput. Usually, this means resolutions no more than 352x240 @ 16 bits per pixel.

Capturing DV rather than raw video gives Scrubba the advantage of receiving compressed data. DV, at 720X480, has a lower data rate than 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.

Launch Scrubba. It begins capturing video immediately and can quickly fill a small disk partition. Fair warning to you Free BeOS users: If you increase the ring buffer size beyond a few seconds, Scrubba may quickly use up all the free space on your disk. Under the File menu is an item allowing you to pause capture and you can change the size of the ring buffer and its file name under the Options menu.

Scrubba has two playback modes: online and offline. By default Scrubba begins with online playback, displaying the live video frames as they're captured. Clicking the Pause button will take the playback head offline, pausing playback but not capture. Once paused, you can click the Play button to perform time-lapse playback beginning where you paused. Clicking the Live button will bring the playback head back in-sync with the capture head.

Scrubba has two sliders. The first slider simply tracks the location of the capture head in the ring buffer 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 its slider. When the playback slider has focus, you can use the left and right arrow keys for frame-accurate scrubbing.

To export a still frame, simply scrub to the frame you want and click the Grab button. To export a movie clip, 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.

You can change the export format using the Still and Clip submenus under the Options menu. However, when 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.