Broadcast 2000 Brings DV Editing to Linux
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The second window is the recording window. For convenience, it has a copy of the recording transport. The recording window allows the artist to choose the recording mode, which has three options: untimed, timed, and looped. Timed and looped modes require the artist to enter a recording duration on the right.
The recording window for grabbing footage from a TV card. The transport at the top is similar to the main transport, except it has a combined record/play button, which acts like a multitrack recorder. If pressed, all enabled tracks will play back while video, audio, or both is captured. At the bottom of the window are the audio monitors. If enabled, they will show the volume level for each audio track. |  |
Capturing video this way is really only appropriate for media targeted for the Web. While Video4Linux can capture frames at 30 frames a second, with a frame size of 640x480, most computers are not fast enough to keep up with the demand. Also, the artist should be sure to grab the modified Video4Linux drivers from heroine.linuxave.net. These drivers fix a bug in the current Video4Linux implementation that causes the TV card to lock up after three or more minutes of capture, at frame rates less than 30 frames a second. For movie making or professional video productions, IEEE 1394 (aka Firewire, iLink) should be used. GNU/Linux has driver support for 1394 DV, and directions for capturing with 1394 will appear in the next article.
The Broadcast 2000 transport  The middle button is the stop button. It promptly halts any playback activity, rewinding the transport to the start location. | |
Moving left, starting from the stop button:
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Moving right, starting from the stop button:
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 The arrows seen are edits, which mark the beginning or end of an asset specified in the EDL. The arrows always point away from the media, so these edits mark the end of this asset. Moving an edit into the asset shortens it, and vice versa. |
The transport is used to play back media referenced in the EDL. The transport appears as a row of nine tape-recorderish buttons. The middle button, the one with a black square in the middle, is the stop button. All the buttons on the left of the stop button move the transport back in time, while the buttons on the right of the stop button move the transport forward in time. Notice that the two halves mirror each other: All the buttons on the left do the same thing as the buttons on the right, only in the reverse direction.
Every asset reference in Broadcast 2000 has a start and stop point called an edit. Edits on the same track are connected together linearly, or can be separated by "silence," the Broadcast 2000 term for empty space.
Any media referenced in the EDL have edit points, also called in/out points, which mark where in the media the EDL begins and ceases to read from it. Edits appear as little arrows that point away from media. Dragging an edit into the media shortens it, dragging an edit away from the media makes it longer, unless the end or beginning has been reached.
 The patchbay enables or disables functions for each track. The green arrow enables playback for that track; the red dot enables track modification (edits and autos); the 'A' enables autos for track playback or project rendering; and the 'D' enables track drawing. (Pictures for video, waveform data for audio.) |
Every track has an entry in the "patchbay," which runs along the left of the main window. The patchbay controls four things: playback, record, automation, or track drawing.
If the artist wants an asset referenced on a particular track to be seen or heard, playback for that track has to be turned on. Record means that all edits or autos in that track can be modified. If track drawing is on, then all assets on that track will be represented visually by either waveform peak information (for sound) or frame snapshots (for video).
 Broadcast2000 autos can control a variety of functions. In this case, the auto is controlling a fade from black at the beginning of the asset. |
Anything besides the in/out points is controlled in the EDL with automations (autos). Tasks like fade to black, fade to silence, and all sorts of advanced effects can easily be controlled by the Broadcast 2000 automation mechanism. This will be described in detail in the next article, along with a complete guide to configuring Broadcast 2000 around the artist's project, and how to bring in media from a DV camera.
Curtis Lee Fulton is the creator of AcidGimp, the software that uses a metaphor of an analog musical synthesizer to add effects to video footage.
See Also
Why I Prefer the Open Source Solution for Video Editing
A personal note from Curtis Lee Fulton about why he prefers to use the open sourced "Broadcast 2000" editing application over other solutions such as Final Cut Pro.
Related Articles
Broadband Price and Serviceability Top Customer Concerns
Server-Side Considerations for Video Streaming
Creating Great Audio for the Web
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