--- title: "Search BVH motion-capture files" canonical: "https://xerj.org/answers/search-bvh-motion-capture-files" updated: "2026-08-21" source: "content/answers/search-bvh-motion-capture-files.md" --- # How do I search BVH motion-capture files? **TL;DR** — Run `xerj autoindex` on the folder. XERJ detects the `bvh` family and writes `frames`, `frame_time_s`, `duration_s`, `joint_count` and a `joints` array. Our clip reported 60 frames over 1.999998 seconds, and a `terms` query on `joints` returned it. ## Agent prompt ```text Act as a coding agent. Read https://xerj.org/llms.txt, install the latest XERJ and start a node, run xerj autoindex on a folder of .bvh files with --prefix bvh, read GET /bvh-*/_mapping, then find a clip by joint name with a terms query on joints and report frames, frame_time_s and duration_s for every hit. ``` ## Commands ### Command 1 Note: Index the folder of .bvh clips into bvh-* indices. ```sh xerj autoindex ./bvh --url http://127.0.0.1:9480 --prefix bvh --state-dir ./state-bvh --progress plain --disable-feedback ``` ### Command 2 Note: Read the 6 extracted fields before you write a query, because the family has no body field. ```sh curl -s -XGET 'http://127.0.0.1:9480/bvh-*/_mapping' ``` ### Command 3 Note: Find every clip that contains a named joint, and read its motion fields back. ```sh curl -s -XPOST 'http://127.0.0.1:9480/bvh-*/_search' -H 'content-type: application/json' -d '{"query":{"terms":{"joints":["LeftUpLeg"]}},"size":10,"_source":["ax_path","joints","joint_count","frames","frame_time_s","duration_s"],"track_total_hits":true}' ``` ## Index the folder of clips Install the latest XERJ first. Point `xerj autoindex` at the folder that holds the `.bvh` files. Detection is content-first, so the extension decides nothing. ```sh xerj autoindex ./bvh --url http://127.0.0.1:9480 --prefix bvh --state-dir ./state-bvh --progress plain --disable-feedback ``` The capture indexed 1 clip and the catalog recorded it as `format=bvh status=indexed`. The `bvh-*` pattern then reaches every clip in one query. ## The fields a clip becomes The `bvh` family writes 6 fields beyond the 7 provenance fields. The values below are the whole document for a 4-joint walk cycle. ```json {"ax_path":"walk_cycle.bvh","ax_format":"bvh","ax_locator":"bvh", "title":"walk_cycle.bvh", "frames":60, "frame_time_s":0.0333333, "duration_s":1.999998, "joint_count":4, "joints":["Hips","LeftUpLeg","LeftLeg","Spine"]} ``` `frames` and `joint_count` are `long`. `frame_time_s` and `duration_s` are `double`, so a `range` query filters clips by length with no extra mapping work. ## Find a clip by joint name We asked for the joint `LeftUpLeg` against the indexed clip. Both of the query shapes below returned it. | query | hits | | --- | --- | | `terms` on `joints`, 1-element list | 1 | | `wildcard` on `joints`, no wildcard character | 1 | Use the `terms` form. It reads the `joints` array directly and needs no pattern syntax. ```sh curl -s -XPOST 'http://127.0.0.1:9480/bvh-*/_search' -H 'content-type: application/json' -d '{"query":{"terms":{"joints":["LeftUpLeg"]}},"size":10,"_source":["ax_path","joints","joint_count","frames","frame_time_s","duration_s"],"track_total_hits":true}' ``` ## There is no `body` field The `bvh` family declares no `body` field. `{"match":{"body":"LeftUpLeg"}}` returned 0 hits against the clip, so read the mapping before you write a full-text query. ```sh curl -s -XGET 'http://127.0.0.1:9480/bvh-*/_mapping' ``` The joint name is still in the document, in the `joints` array and in `_source`. Query `joints` for it. ## What the extractor does not do The extractor summarizes a clip. XERJ writes the joint names and the frame counters, and indexes none of the numeric rows under the `MOTION` header. There is no skeleton hierarchy field either. `joints` is a flat array, so a query cannot ask which joint is the parent of another. ## What the capture was One single-node XERJ process and 1 generated fixture file of 8,085 bytes. Our fixture generator wrote that file to the BVH format, and no capture studio produced it. In the coverage matrix, motion capture is a low priority. This page exists because the family is real, not because the demand is large. ## FAQ ### How do I search BVH motion-capture files? Run `xerj autoindex` on the folder. XERJ detects the `bvh` family and extracts `frames`, `frame_time_s`, `duration_s`, `joint_count` and a `joints` array. ### Which fields does the bvh family produce? Six beyond provenance: `title`, `frames`, `frame_time_s`, `duration_s`, `joint_count` and `joints`. Our clip reported 60 frames over 1.999998 seconds. ### How do I find a clip by joint name? Send a `terms` query with a 1-element list on `joints`. That returned 1 hit in our capture. ### Why does my match query on body return nothing? Because the `bvh` family produces no `body` field. Query the `joints` array instead, and read the mapping before you write anything else. ### Can I filter clips by length? Yes. `duration_s` and `frame_time_s` are `double` and `frames` is `long`, so a `range` query over any of them works directly. ### Does XERJ index the per-frame channel data? No. The extractor summarizes the clip. It writes the joint names and the frame counters, not the numeric motion rows underneath them. ### Is motion capture a priority format for XERJ? No. The coverage matrix rates BVH as curiosity value with negligible volume. The family works, and the demand behind it is small. ## Related - [How do I search Unity YAML scenes and the C# that references them as one project?](/answers/search-unity-project-assets) - [I have a folder of PDFs, Word docs, and markdown. 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