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Output and Recording

Manual for Hex Composer v0.19.0. This is an archived snapshot. Corrections can be suggested on the current version of this page.

Output is the app’s own composite: the last module in the chain, or the mixed result of both decks in Mixer Mode. Everything downstream, recording, NDI, Spout, Syphon, and the physical output window, reads from that same image.

Recording writes an MP4 straight to disk with no save dialog, at whatever quality, frame rate, codec, and audio-inclusion setting Settings > Recording holds at the time. The codec is H.264 or H.265. It captures the aspect-locked output image itself, not the window or its docked panels. Start and stop it from the REC pill in the toolbar, which Mixer Mode also shows, or with Ctrl+Alt+R.

The timer next to REC counts the length of the recording, and the saved file has that same length. Each frame is stamped with the moment it was captured, so the file plays back at real speed and stays in sync with the sound.

Encoding runs on the graphics card’s own video encoder when the computer has one for the chosen codec, and on the processor otherwise. An encoder running on the processor can fall behind at high resolutions or frame rates, H.265 in particular. When it does, the previous frame stays on screen a little longer instead of the video speeding up: the recording keeps its length and its sync, and motion looks less smooth. The message after saving then reads “Saved recording (some frames skipped) to …”, and Settings > Recording shows a note under Codec suggesting a faster choice, such as H.264 or a lower frame rate. If no encoder for the chosen codec can start on the computer, the recording doesn’t start and a message says so.

Stopping a recording doesn’t hold up the app. The file finishes writing in the background, and a message then names the saved file. When finishing takes more than a moment, the timer shows Saving... and REC is dimmed until the file is complete. Quitting while a file is still being written waits for it to finish.

NDI, Spout (Windows), and Syphon (macOS) each send the same output live to another program instead of, or alongside, a file. Each is enabled separately in Settings > Output, under its own sender name.

Parts of the picture that no module has drawn on are empty. The Output window, Dual Monitor Output, recordings and snapshots show them as black. NDI, Spout and Syphon send them as transparency. A receiving program that ignores alpha shows partly see-through areas at full strength, for example FEEDBACK echoes that are fading out.

Dual Monitor Output, also in Settings > Output, opens a second window carrying nothing but the output image, sized independently of the main window.

Display Fit controls how the output image sits inside whatever window or monitor shows it, when the two don’t share an aspect ratio: Fit Best, Fill, or Shrink.

Related: Signal Chain.