LTX puts its VFX tools on the API: Alpha Gen mattes, SDR to HDR, Reframe and 8K Upscale, with ComfyUI partner nodes

What each one does, per LTX and the ComfyUI node descriptions. Alpha Gen returns a grayscale alpha matte (white is foreground) for clips up to 10 s and 4K, no green screen needed. SDR to HDR turns SDR video into 10-bit HDR (BT.2020, HLG) at the same resolution, up to 273 frames at 1080p or 65 frames at 4K. Reframe re-renders a clip into a new size and aspect ratio (1:1, 4:5, 5:4, 9:16 or 16:9 at 720p or 1080p) with the original placed center, top, bottom, left, right or at a custom position, and the scene extended around it, for clips up to 60 s. Upscale lifts footage to 1080p, 4K or 8K while keeping aspect ratio, frame rate and audio (up to 241 frames at 8K).

Where to run it. Direct through the LTX API console, through fal or Griptape, or as API (partner) nodes inside ComfyUI after PR #17664, billed to Comfy credits. ComfyUI's node price badges list rough per-second ranges: about $0.14-1.43/s for Alpha Gen and $0.57-2.29/s for SDR to HDR, with Reframe and Upscale priced by output resolution. Treat these as indicative and check the current rate card before batching a job.

Why it matters. These are the jobs that stop AI shots from getting into a real finish: mattes for compositing, HDR deliverables, platform cutdowns that don't lose the edges of the frame, and resolution for 4K timelines. LTX says these started as open-weight ComfyUI workflows and are now hosted endpoints for teams that would rather not run the GPUs. In LTX's launch video, its interviewees claim edits like getting 16-bit ACEScct EXRs from 8-bit SDR and pushing them several stops. That is LTX's marketing, not an independent test.

Signals (not hot by our rule). Official @ltx_io post (about 260k impressions, largely from promotion, but only ~40 likes when we checked) and ComfyUI partner nodes merged within the hour. No curator pick yet.

Our take: Reframe is the one most agencies will feel first. One 16:9 master turned into 9:16 and 4:5 versions with extended picture instead of a center crop is a weekly chore. Try it on a single client shot and compare it with your current crop-and-blur workflow before committing.