@mcap/support

MCAP is a modular container format and logging library for pub/sub messages with arbitrary message serialization. It is primarily intended for use in robotics applications, and works well under various workloads, resource constraints, and durability requirements.

The @mcap/support package provides utilities for working with MCAP files that use well-known compression formats, from Node.js and browsers.

Usage examples

Reading MCAP files in a browser

import { loadDecompressHandlers } from "@mcap/support";
import { BlobReadable } from "@mcap/browser";
import { McapIndexedReader } from "@mcap/core";
import { open } from "fs/promises";

async function onInputOrDrop(event: InputEvent | DragEvent) {
  const file = event.dataTransfer.files[0];
  const decompressHandlers = await loadDecompressHandlers();
  const reader = await McapIndexedReader.Initialize({
    readable: new BlobReadable(file),
    decompressHandlers,
  });
}

Reading MCAP files in Node.js

import { loadDecompressHandlers } from "@mcap/support";
import { FileHandleReadable } from "@mcap/nodejs";
import { McapIndexedReader } from "@mcap/core";
import { open } from "fs/promises";

const decompressHandlers = await loadDecompressHandlers();
const fileHandle = await open("file.mcap", "r");
const reader = await McapIndexedReader.Initialize({
  readable: new FileHandleReadable(fileHandle),
  decompressHandlers,
});

License

@mcap/support is licensed under the MIT License.

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