rewrite README — NASA only (Pexels excluded for license)

README.md

@@ -1,26 +1,32 @@
 ---
-license: cc-by-4.0
+license: cc0-1.0
 tags:
   - mirce
   - video-editing-benchmark
   - source-videos
-size_categories:
-  - 10B<n<100B
+  - public-domain
 ---
 
-# MIRCE Bench Sources
+# MIRCE Bench Sources — NASA (Public Domain)
 
-Raw source videos for the **MIRCE benchmark** (paired with `Lando0/mirce-meta` for indexes).
+NASA public-domain source videos for the **MIRCE benchmark**.
+
+Paired with `Lando0/mirce-meta` for the candidate-pool indexes.
 
 ## Contents
 
 | Subset | Files | Approx size | License |
 |---|---|---|---|
-| `hq_long/` | HQ themed videos (euro_city, inca, rainforest, sigiriya, tropical, yacht, etc.) | ~18 GB | CC-BY |
-| `nasa/` | NASA public-domain documentary clips | ~11 GB | Public Domain |
+| `nasa/` | NASA documentary / Apollo / Earth-from-space clips | ~11 GB | Public Domain (NASA) |
+
+## What's NOT here (intentional exclusion)
 
-Pexels stock content is **NOT** included due to redistribution license restrictions.
-The full 974-window candidate pool definitions live in `Lando0/mirce-meta`.
+- **HQ themed videos** (`sources_hq_long/`): 100% Pexels-sourced. Pexels content
+  is free to USE individually, but its license forbids **redistribution as a
+  dataset**. Excluded for compliance. Researchers can re-download from Pexels
+  using the IDs preserved in `Lando0/mirce-meta` window indexes.
+- **UltraVideo long clips** (`datasets/ultravideo_long/`): subject to its own
+  research-license; not redistributed here.
 
 ## Usage
 
@@ -35,4 +41,4 @@ snapshot_download(repo_id="Lando0/mirce-bench-sources", repo_type="dataset",
 - `Lando0/mirce-demos` — 87 rendered demo MP4s
 - `Lando-C/Yin-Edit` (GitHub) — code
 
-License: source-by-source (mixed). Each video carries its original license; aggregate is CC-BY-4.0.
+License: Public Domain (NASA original content).