GoogleVideo

A collection of modules for handling YouTube's custom UMP format and SABR streaming protocol. Use it to build custom clients and downloaders, or integrate with existing media players (e.g., Shaka Player).

API Reference →

Installation

# NPM
npm install googlevideo

# JSR / Deno
npx jsr add @luanrt/googlevideo
deno add jsr:@luanrt/googlevideo

# GitHub
npm install LuanRT/googlevideo

Basic Usage

Below is a basic example using the UMP modules to create a buffer, write parts, and then read them:

Note

More advanced usage examples can be found in the /examples directory.

import { MediaHeader, UMPPartId } from 'googlevideo/protos';
import { CompositeBuffer, UmpReader, UmpWriter } from 'googlevideo/ump';
import { concatenateChunks } from 'googlevideo/utils';

const umpReader = new UmpReader({
  onPart: (type, data) => {
    switch (type) {
      case UMPPartId.MEDIA_HEADER: {
        const mediaHeader = MediaHeader.decode(concatenateChunks(data.chunks));
        console.log('Media Header:', mediaHeader);
        break;
      }
      case UMPPartId.MEDIA: {
        const headerId = data.getUint8(0);
        console.log(`Media Part (Associated Header ID: ${headerId}):`, data.split(1).remainingBuffer.getLength(), 'bytes');
        break;
      }
      case UMPPartId.MEDIA_END: {
        const headerId = data.getUint8(0);
        console.log(`Media End Part (Associated Header ID: ${headerId}):`, data.split(1).remainingBuffer.getLength(), 'bytes');
        break;
      }
    }
  }
});

function mockUmpData(): CompositeBuffer {
  const buffer = new CompositeBuffer();
  const writer = new UmpWriter(buffer);

  const audioHeaderId = 0;

  const partsToWrite: [UMPPartId, Uint8Array][] = [
    [
      UMPPartId.MEDIA_HEADER,
      MediaHeader.encode({
        itag: 141,
        videoId: "sOa4VVlI9tE",
        headerId: audioHeaderId,
        segmentLengthBytes: "963966",
        segmentByteRangeStart: "5463800",
        isInitializationSegment: false,
        lmt: "1645502668395260",
        segmentNum: 1,
        durationMs: "4000",
        formatId: {
          itag: 141,
          lastModified: "1645502668395260",
          xtags: ""
        },
      }).finish()
    ],
    [UMPPartId.MEDIA, new Uint8Array([audioHeaderId, ...new Uint8Array(827609).fill(0)])],
    [UMPPartId.MEDIA, new Uint8Array([audioHeaderId, ...new Uint8Array(136357).fill(0)])],
    [UMPPartId.MEDIA_END, new Uint8Array([audioHeaderId])]
  ];

  for (const [type, data] of partsToWrite)
    writer.write(type, data);

  return buffer;
}

umpReader.feed(mockUmpData());

Expected output:

Media Header: { ... }
Media Part (Associated Header ID: 0): 827609 bytes
Media Part (Associated Header ID: 0): 136357 bytes
Media End Part (Associated Header ID: 0): 0 bytes

License

Distributed under the MIT License.

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