Can an L10 experiment use Xiph's derf test-video collection with a clear per-clip licence, and what do the per-clip notices say?

Not as a collection. The derf page says clips were publicly accessible or given to Xiph and are 'believed to be freely redistributable', that some may impose additional restrictions, and points to copyright or readme files. By my regex tally of the HTML, 118 clip entries, 85 with a copyright or readme link in the header and 32 with no link; 9 entries say login required at the original source. The notices I read differ: Fujitsu's Bowing notice grants use only for research purpose with conditions, the Hannover-path notice limits use to developing, testing and promulgating technology standards, and the twitch folder says public domain with a fair-use caveat. So derf clips need a per-clip read. Curator qualifications: twitch: 'These video game recordings are placed in the public domain. The recordings may contain copyrighted work which can only be used in compliance with fair use.' Bowing (Fujitsu 1997): permission to use, copy, modify and distribute under conditions incl. '3) The data shall be used, copied, modified, or distributed for research purpose only' and no charge. Hannover notice: 'These materials may only be used for the purpose of developing, testing and promulgating technology standards'; owners listed include ABC, NASA, Demografx, BBC, RWTH Aachen. Rights/verification notes are shown as limitations (L00 0019/ADR-0011): they restrict reuse of the cited material or record what was not verified; they are not cleared by this summary. Limitations: [rights_conflict_record] eligible_rights_conflict_preserved Evidence status: statements located in the cited sources by a correlated desk review (Claude); not executed; not independently reviewed.

{
  "citations": [
    {
      "url": "https://media.xiph.org/video/derf/",
      "note": "see curator disposition"
    },
    {
      "url": "https://media.xiph.org/video/derf/ftp3.itu.int/video-site/sequences/Bowing/Copyright.txt",
      "note": "see curator disposition"
    },
    {
      "url": "https://media.xiph.org/video/derf/ftp.tnt.uni-hannover.de/pub/svc/testsequences/copyright_notice_v1.04.txt",
      "note": "see curator disposition"
    },
    {
      "url": "https://media.xiph.org/video/derf/twitch/copyright.txt",
      "note": "see curator disposition"
    }
  ]
}