| # EventActivityNet Annotations and Timing Metadata |
|
|
| These files cover the canonical 3,263-video Large release. Medium and Small use |
| the same annotation files, filtered by their video-ID lists. The 5-bin and |
| 9-bin representations share annotations and source timing. |
|
|
| ## Files |
|
|
| - `activitynet_captions.json`: ActivityNet Captions timestamped descriptions; |
| - `activitynet_actions.json`: ActivityNet v1.3 temporal action annotations; |
| - `eventactivitynet_alignment.json`: EventActivityNet-derived caption/action alignment using temporal IoU with midpoint-distance fallback; |
| - `annotation_issues.jsonl`: known source annotation quirks preserved without changing canonical values; |
| - `../metadata/video_metadata.jsonl`: shared source timing and per-representation tensor metadata. |
|
|
| ActivityNet Captions is the source of timestamped descriptions. ActivityNet |
| v1.3 is the source of temporal action labels and segments. EventActivityNet is |
| the source of the derived alignment. Captions are timestamped descriptions, |
| not instruction-tuning records. |
|
|
| ## Timing |
|
|
| For source frame count `N`, representation bin count `B` in `{5, 9}`, and |
| `frames_per_bin=1`: |
|
|
| ```text |
| T_B = ceil((N - 1) / B) |
| ``` |
|
|
| Voxel `i` groups adjacent-frame transition indices |
| `[B*i, min(B*i + B, N - 1))`. Its approximate source-frame interval is |
| `[B*i, min(B*i + B, N - 1)]`, and its approximate seconds interval is: |
|
|
| ```text |
| [B*i * fps_den / fps_num, |
| min(B*i + B, N - 1) * fps_den / fps_num] |
| ``` |
|
|
| Construction follows decoded frame order. Per-frame presentation timestamps |
| are not consumed, so seconds-level mapping is approximate for within-video |
| variable-frame-rate streams. Do not assume fixed 25 fps or 240 fps. |
|
|
| ## Known Source Annotation Quirks |
|
|
| Canonical source annotations are preserved as-is. Some timestamps or action |
| segments have minor ordering or boundary issues, including small floating-point |
| overshoots. Use a small numerical tolerance; `annotation_issues.jsonl` records |
| the observed cases. |
|
|
| ## Source Hashes |
|
|
| ```json |
| { |
| "activitynet_actions": "4c29d5b1561e1cbff9ac69816c159e60d417a18f16db8acc0fc254c377fa9ae3", |
| "alignment": "40a75cfd6a053011766e80e5a6d449b84a3ececf51b1f34cfa33eefba8729d36", |
| "captions_train": "704536b2779011c1a729c927ae30e39ea9c90c38557836bbe969499917243d69", |
| "captions_val_1": "466aaccb9ebe45c6db4c98488a4ddbeb5b22faffe62e1bbce81222c14fc29e1c", |
| "captions_val_2": "08fe56568bc92dd02a6150fe1094457a5f2ac72975b8778a922bc9a65aa7f0e9", |
| "class_mapping": "f15c7864abe012bd82b1df2c33beae8254acffc4b86a3dcbf6174c02a61eb400", |
| "large_manifest": "02468b7f301a85c5f3776b72b9b1ff83635bc99dd6b2ce42a7c7e5308007c96a", |
| "verify_all": "a5d17bcb508789c6e96747d3eac9ecee13b99dd683df995cd81e3179966bd7bc" |
| } |
| ``` |
|
|
