Clarify metadata-only scope and YouTube raw media requirement

README.md

@@ -2,6 +2,19 @@
 
 Full-set metadata for lmms-eval task `vggsound`.
 
+## Dataset Contents
+
+This repository contains **annotations and metadata only** (YouTube IDs, start seconds, labels, and splits).
+Raw audio/video media files are **not hosted here**.
+
+## Raw Media Requirement
+
+To run media-backed evaluation, download original clips from YouTube using metadata fields.
+If local media is missing, full evaluation for `vggsound` cannot run.
+
 - Annotation source: https://raw.githubusercontent.com/hche11/VGGSound/master/data/vggsound.csv
-- Raw media location: VGGSound YouTube-derived clips, audio not embedded here.
-- Expected local media root for evaluation: `$VGGSOUND_AUDIO_DIR` or `$HF_HOME/vggsound`.
+- YouTube URL template: `https://www.youtube.com/watch?v=<youtube_id>`
+- Expected local media root: `$VGGSOUND_AUDIO_DIR` or `$HF_HOME/vggsound`
+- Download guide: https://github.com/EvolvingLMMs-Lab/lmms-eval/blob/main/docs/raw_media_download.md
+
+Media availability depends on YouTube and per-video licensing constraints.