Kling 4.0 10-bit HDR at 1080p and 4K: what later edits keep
Kling says 4.0 outputs 10-bit HDR at 1080p and 4K. Sume's exact video_trim re-encodes to yuv420p; keyframe trims stream-copy. Verify before you grade.
Kling's post says Kling 4.0 produces 10-bit HDR output at 1080p and 4K, against 8-bit SDR for Kling 3.0. Sume's docs list kling-3, not Kling 4.0, and Sume's default video_trim re-encodes with libx264 and yuv420p, so an exact trim should not be assumed to carry 10-bit HDR through.
Vendor claims are from Kling's comparison post; Sume behavior is from the video trim docs, read 2026-10-01.
What does Kling say about HDR?
The comparison table lists dynamic range as 8-bit SDR for 3.0 and 10-bit HDR at 1080p and 4K for 4.0. The text says 10-bit HDR is designed to retain richer color information and smoother transitions between highlights and shadows.
| Item | Source says | What it means for your pipeline |
|---|---|---|
| Kling 4.0 output | 10-bit HDR at 1080p and 4K | Only on Kling's side |
| Kling 3.0 output | 8-bit SDR | Nothing to preserve |
| Sume Kling row | kling-3: 720p and 1080p | No Kling 4.0 id in the docs I read |
video_trim exact (default) | Frame-accurate re-encode (libx264, yuv420p) | A re-encode; not documented as keeping HDR |
video_trim keyframe | Stream copy; the cut may start a GOP early | Keeps the source encoding; re-base on actual_start_seconds |
Does Sume list Kling 4.0?
The public ids in the docs are seedance-2.5, seedance-2-mini, seedance-2, seedance-2-fast, kling-3, wan-3.0, grok-imagine-video-1.5, minimax-h3, minimax-h3-max and gemini-omni-flash-1.1. There is no Kling 4.0 id, so Kling's HDR claim does not apply to anything you can request today.
What happens to a 10-bit clip in an exact trim?
The docs name the output as libx264 and yuv420p. In ffmpeg, yuv420p is the 8-bit 4:2:0 format; 10-bit variants carry a p10 suffix. The docs do not mention HDR metadata either way, so treat an exact trim as an SDR step and inspect the output.
How do I trim without re-encoding?
Set precision to keyframe. It stream-copies, so the cut can begin earlier than your start; read actual_start_seconds to re-base. For what Sume outputs in HDR and EXR terms, see HDR and EXR video export on Sume.
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