CAV Transcoder

The CAV Transcoder is a separate Windows-only application that converts media files into Composer's proprietary .cav (Composer Audio Video) format. Files in .cav support seamless video scrubbing via cue points, which can be triggered through the HTTP API or Connectors for live frame-accurate playback.

The transcoder ships at C:\Program Files\RealSprint AB\Vindral Composer\CAVTranscoder\ComposerCAVTranscoder.exe.

Important

Run the CAV Transcoder with administrator privileges. The application needs elevated permissions to write its working files; without them, transcoding fails or behaves unpredictably.

Transcode mode

Open a video file (.mp4 or .mov) via File → Open File, then click Start transcode. The resulting .cav saves alongside the source with the same base name.

CAV Transcoder transcode-mode interface

Note — supported codecs

For .mov files, the only supported video codec is QuickTime Animation in colour space RGBA (with alpha channel). Other .mov codecs are not transcoded.

Play / edit mode

Play / edit mode lets you add and manage cue points on an existing .cav file.

CAV Transcoder play / edit mode with cue point markers

Navigating

Single-frame step — Left / Right arrow keys.
10-frame step — Ctrl + Left / Ctrl + Right.
Playback — the on-screen play / pause / stop controls.

Adding cue points

Navigate to the desired frame, click Add CuePoint, and give the marker a name:

Cue point naming dialog with frame and name fields

Cue points can be edited, dragged, or deleted via the right-click context menu.

Cue-point behaviour options

Each cue point can carry one of four behaviours, which the CAV File Input honours during playback:

Behaviour	Effect	Minimum cue points
`None`	Continue normally past the cue point.	1
`ReplaySegment`	Replay between two cue points.	2
`ReplayNextSegment`	Replay between the next two cue points.	3
`PauseAfterNext`	Pause at the next cue point.	1

Note

The testing behaviour you set in CAV Transcoder is not saved into the .cav file. The actual cue-point behaviour at playback is controlled by the CAV File Input (its UI controls and Connector triggers). The transcoder's behaviour dropdown is for previewing only.

Command-line transcoder

A headless cavconverter.exe ships alongside the GUI application — useful for batch transcoding from scripts or scheduled jobs:

cavconverter.exe --source <sourcefilename> --target <targetfilename> [--quality <10-100>] [--cuepointfile <jsonfile>]

Parameter	Description	Default
`--source`	Path to the source `.mp4` or `.mov`.	required
`--target`	Path for the output `.cav`.	required
`--quality`	Quality preset from `10` (lowest) to `100` (lossless).	`80`
`--cuepointfile`	JSON file containing the embedded cue-point list (each entry has `VideoFrameIndex` and `Data` fields).	(no cue points)