Which colour-pipeline outputs does Runway's API document for generated video (ProRes, 10-bit Rec.709, HDR, ACEScg EXR) and what does that say about AI plates in a graded timeline?

Problem. Default AI video is an 8-bit H.264 MP4, which is thin for grading; which vendors deliver more? Conditions. Runway Dev API docs, fetched 2026-10-23; applies to models gen4.5 and aleph2 as stated. Method (documented fields). outputFormat on the generation request: mp4 (default, H.264), prores (.mov; proresProfile 422 Proxy, 422 LT, 422, 422 HQ, 4444, 4444 XQ; default 4444), png_sequence (.zip of PNG frames plus a .wav when there is audio); these stay SDR. sdr_rec709_10bit gives HEVC Main 10 Rec.709 .mp4 for Gen-4.5 and Aleph 2.0 'when a grade needs more precision than 8-bit H.264'. HDR is Gen-4.5 only: hdr10 (HEVC Main 10, BT.2020 + PQ), hlg, hdr_pq_12bit_master (12-bit 4:4:4 BT.2020 PQ .mov), hdr_prores, hdr_png_sequence (16-bit PNG plus colorimetry sidecar), hdr_exr_sequence (half-float OpenEXR, linear BT.2020 light, 1.0 = 100 nits) and two ACEScg EXR options for ACES 1.3 and ACES 2.0. The ACEScg EXRs are scene-referred by inverting the picture through the ACES Output Transform (for 1.3: Rec.2100 PQ, 1000-nit) so that the stock 'ACES - ACEScg' input transform followed by your ACES view reproduces the delivered picture; a colorimetry.json sidecar names the ACES version and the inverted transform. A separate Ruby model converts an existing SDR video (at most 30 seconds, up to 4K) to HDR. Interpretation [inference]. The ACEScg files are an inverse-rendered display picture, not captured scene light: they reproduce what the model rendered and are not evidence of extra highlight latitude; treat grading headroom as unproven until you test it. Prefer ProRes, PNG or EXR deliveries over MP4 when a vendor offers them, to avoid a second lossy encode. Failure modes. Extra formats carry per-second surcharges (not recorded here); HDR/EXR options are model-specific, so a request with another model should fail validation. Limitations. Vendor documentation only; no file was generated or inspected, and the quality of the 'true HDR renders' claim is the vendor's. Version/date. Runway Dev docs 2026-10-23. Curator qualifications: All cited documentation excerpts located on the live pages by curator GET; no video sources. Limitations: Whether generated HDR/EXR holds more usable highlight detail than the SDR render is not demonstrated by the documentation. Format names may change; dated 2026-10-23. Evidence status: statements located in the cited sources by a correlated desk review (Claude); not executed; not independently reviewed.

{
  "citations": [
    {
      "url": "https://docs.dev.runwayml.com/guides/professional-outputs.md",
      "note": "Editorial containers; Editorial containers; Generate HDR video; HDR and high bit-depth table; ACEScg paragraph; ACEScg paragraph; image_to_video model gen4.5 outputFormat; ACEScg paragraph"
    },
    {
      "url": "https://docs.dev.runwayml.com/api.md",
      "note": "Editorial containers; Editorial containers; Generate HDR video; HDR and high bit-depth table; ACEScg paragraph; ACEScg paragraph; image_to_video model gen4.5 outputFormat; ACEScg paragraph"
    }
  ]
}