Playback Display

The Playback display indicates the current state of the media player.

Each layer’s media player is an independent playback engine with it’s own set of controls:

Frames or time

From version 4.4, all playback controls by default work in Hours:Minutes:Seconds:Frames and work by frame number instead of time.

Previously, playback controls were defined by time: the outpoint for example was set to 34 seconds, and the corresponding frame number was deduced. If (as was common at 30 FPS) the calculation yielded a non-integer (not a whole number) then the frame displayed would be blended from the two adjacent frames. This approach made it very difficult to play a clip from specific frames: a workflow that is becoming more common.

To address this, the system has been changed to work from frames to derive time. The user specifies a frame number and the media player calculates time from it. In Zookeeper there is little difference as the calculations are carried out automatically and the displays can show either frames or time. For external controllers however this represents a significant change. All in and out-points are now defined by frame number instead of time on a single integer pin.

The frame rate of a clip is defined at encode; the media player will always play a clip back at its intrinsic frame rate independent of the frame rate of the engine, other media players or timecode received.

The time of the playback controls is a function of the frame rate of the clip; for example, at 25 FPS, a 1,000 frame clip would be 40 seconds long. The same 1,000 frame clip played at 30 FPS would be 33.33 seconds long. Setting the outpoint of these two clips to the same frame will correctly result in different lengths.

DMX and external controllers

In DMX, the out-point pin indicates frame number. The pin can either be controlled as a 16-bit pin yielding a maximum of 65,535 (18 minutes at 30 FPS) or 24-bit for a maximum value of 16,777,216 (or over 24 hours at 60 FPS).

For the out-point, and inner loop out-point setting the value to 0 moves the outpoint to the end of the clip.

Playback Controls

In-Point

The frame the clip will start from and loop to.

InLoop-Point

The frame the clip will start from in inner loop in Frame, and will loop to in inner loop play mode

Playhead

The current location of the play head.

Note: The play-head is somewhat unique in that it is a pin you should not control from DMX or any other external controller as by it’s nature it constantly changes. If a specific starting point for the playhead is desired, use in frame play mode and set the in point to that frame number.

OutLoop-Point

The frame the clip will return to the inner loop in-point when in inner loop playmode.

Out-Point

The frame the clip will stop playing on with play once, or loop on in play and loop.

Playbar

The playbar is a visual representation of the Playback controls. All controls in the playbar be dragged around as an alternative to setting values in the playback controls.