Media Preparation

@shelby-protocol/media-prepare transcodes video into adaptive streaming formats like HLS and DASH. It handles multi-quality encoding, segment generation, and manifest creation—everything needed to prepare video for delivery from Shelby's decentralized storage.

Installation

npm install @shelby-protocol/media-prepare

Requires FFmpeg 7.0+ with libx264 support. Install via brew install ffmpeg (macOS) or your system package manager.

Quick Example

Create a transcoding plan and execute it:

transcode.ts

import {
  CmafPlanBuilder,
  videoLadderPresets,
} from "@shelby-protocol/media-prepare/core";
import { NodeCmafPlanExecutor } from "@shelby-protocol/media-prepare/node";

// Define the transcoding plan
const plan = new CmafPlanBuilder()
  .withInput("input.mp4")
  .withOutputDir("output")
  .withVideoLadder(videoLadderPresets.vodHd_1080p)
  .withVideoCodec({ kind: "x264", preset: "medium" })
  .addAudioTrack({
    language: "eng",
    bitrateBps: 128_000,
    default: true,
  })
  .withSegmentDuration(4)
  .withHlsOutput()
  .build();

// Execute the plan
const executor = new NodeCmafPlanExecutor();
await executor.execute(plan);

This produces HLS playlists and CMAF segments ready for upload:

output/
├── master.m3u8          # Master playlist (entry point)
├── 1080p/
│   ├── playlist.m3u8    # Variant playlist
│   └── segment-*.m4s    # Video segments
├── 720p/
│   └── ...
└── audio-eng/
    └── ...