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Video input

C-Slice can use a video file as input instead of a numbered still image sequence. The rendering and output pipeline is identical — each selected SGCT window is still encoded into its own subfolder — but the source frames are decoded from a video file using MPV.

Switching to video input

In the Input sequence panel, change Input type from Image sequence to Video. The panel label changes to Video input and the file dialogs switch to video file filters.

Supported formats

The file browser filters for:

*.mp4 *.mov *.mkv *.avi *.webm *.m4v *.mpg *.mpeg

Any format that MPV can decode is accepted. The filter is a convenience; you can type a path directly into the Left/input field.

Reading metadata

After choosing a video file, press Read metadata. C-Slice probes the file with MPV and populates:

  • Start — set to 0
  • Stop — set to the last frame index derived from duration and FPS
  • Duration, FPS, and resolution shown in the status line

Use the reset buttons next to Start and Stop to restore the metadata-derived range after manual edits.

Frame range and step

Start, Stop, and Step work the same as for image sequences:

  • Start — first frame to process (0-based frame index).
  • Stop — last frame to process.
  • Step — skip frames when greater than 1. A step of 2 processes every other frame.

A short test range (for example, 10 frames) is recommended before a full render.

Stereo video input

Enable Use right-eye input to supply a separate right-eye video file. The two files must match in frame count, FPS, and resolution. Mismatches produce a warning in the sequence status line.

Example:

show_left.mp4
show_right.mp4

Video decoding mode

The Video decoding mode control is in the Performance section of the main settings panel. It sets how MPV decodes each input video:

ModeDescription
SoftwareCPU decoding. Compatible with all systems. Slower on high-resolution or high-bitrate sources.
HardwareGPU-accelerated decoding. Faster on supported hardware. Requires a compatible GPU and driver.
HybridHardware decoding for the left-eye video, software decoding for the right-eye video. Useful when the GPU cannot handle two concurrent hardware-decode streams in stereo mode.

Start with Hardware on a GPU workstation. Fall back to Software if you see decoding artifacts or errors in the log. Use Hybrid for stereo when hardware decode is available but causes issues with dual-stream playback.

Video Preview

Press the Video Preview button to open a preview window for the loaded video. Use it to verify the correct file is selected and that the expected content is visible before starting a render.

Differences from image sequence mode

Image sequenceVideo input
Input fileOne image from the sequenceThe video file itself
Index / metadataRe-index button scans the sequenceRead metadata button probes the file
Frame range sourceNumbered files on diskDuration × FPS from video metadata
Image error behaviorConfigurable (abort / pause / continue)Not applicable
PreviewImage Sequence Preview (frame stepping)Video Preview (MPV playback)