PLAYBACKPlayback sets various parameters for audio playback. Since Broadcast 2000 is a full featured audio editor, it's audio support gets a distinct section from video.RECORDINGYou should read the Installation to read about various sound driver incompatibilities that can be overcome by configuring these settings.
Broadcast 2000 uses a pipeline for rendering audio. The first stage is reading large chunks of audio from disk. The second stage is rendering small fragments through the console to the sound driver. This gives virtually uninterruptable audio playback.
Preload size determines the minimum number of bytes in a seek before switching to a sequential read. A typical value is 2000000. For playing movies, the preload buffer allows audio and video to play back without seeking back and forth. This eliminates seeking on slow CD-ROM drives while increasing latency, big time. Set to 0 to eliminate prebuffering. To eliminate the latency you should really use XMovie.
During parts of the timeline which don't have any footage, Broadcast 2000 can either render silence or not render the track at all. Selecting Disable tracks when no edits causes tracks to be turned off when they have only silence. This speeds up video rendering considerably, allows more scenes to be viewed without alpha channels, but can cause transitions and plugins to turn off when they should be on.
Recording audio is also performed using a pipeline. Fragments are rapidly read from the sound driver but only committed to disk in large chunks.PERFORMANCEThe duplex device is what Broadcast 2000 uses to play audio while recording in duplex mode. This is useful if you're using one of the free sound drivers or want the playback synchronized. The commercial sound driver allows playback from the timeline to start and stop while a recording is in progress.
If you intend to record audio and video simultaneously turn off Record in realtime priority. Most modern processors don't need this option anyway.
Every time you load an audio file, Broadcast 2000 decides whether drawing an index of it would be faster than reading every sample from disk. The larger the index size, the faster the drawing will be for large files and the slower it will be for small files.INTERFACEOnly a certain number of index files are maintained on disk. Every time you quit Broadcast 2000, the index files in excess of this limit are deleted. Change index files to keep to reflect the number of index files to keep.
Caching is used to speed up video and audio rendering. During playback and drawing, Broadcast 2000 keeps a certain number of assets opened. When compositing video Broadcast 2000 actually stores a certain number of uncompressed images. These all count toward the total cache item count and increase your memory usage accordingly.
The number of CPUs option optimizes certain functions for a multiprocessor system instead of a single processor system. While this option can double and triple performance of multiprocessor systems, selecting it on a single processor results in tremendous speed degredation.
The time format displayed can be altered here. The frame base when using hours:minutes:seconds:frames is the frame rate of the project.VIDEOBroadcast 2000 not only allows you to perform editing by dragging in/out points but also defines three seperate operations which occur when you drag an in/out point. For each mouse button you select the behavior in this window. The usage of each editing mode is described in editing
Video operations have a seperate section from audio. Like audio, video is recorded in a pipeline but unlike audio, the video device has a configurable buffer size. Frames to buffer in device determines how many frames ahead of the current capture position the device should buffer but not write to disk. Setting this to a large number and capturing below the maximum framerate of the device will cause video to be delayed. This is only available when using a Video4Linux 2 driver. Unfortunately for most purposes Video4Linux 2 has never achieved usable functionality.Frames to record to disk determines the number of frames to read from the device and compress to disk at a time. This number doesn't cause a delay.
The rendering speed can be improved by selecting one of the 4 rendering modes: fastest, alpha channels, floating point, and interpolated The quality improves and speed decreases as you go down. Alpha channels without floats is lossy. Fastest rendering is lossless and should always be used when you have no scaling or alpha channels.
The record driver selects which driver to capture video from. When Video4Linux is selected Broadcast 2000 automatically determines what variant is installed and tries to match it.