@mediaway/decoder

Automatic hardware video decode + Opus audio decode over Mediaway's C ABI. Split out of @mediaway/encoder (previously buried as an undiscoverable decode.ts) into its own peer package — decode and encode are siblings, mirroring the Rust mediaway-decoder/mediaway-encoder crate split.

Windows is the verified platform for DecodeSession (WMF backend). Opus audio decode (AudioDecodeSession) is cross-platform — mediaway-sw, no OS dependency.

Install

npm install @mediaway/decoder

Example

import { DecodeSession, DecoderUnavailableError, type DecodedVideoFrame } from "@mediaway/decoder";
import type { Rational } from "@mediaway/container";

const TIME_BASE: Rational = { num: 1, den: 30 };

let session;
try {
  session = await DecodeSession.open({
    codec: "h264",
    width: 640,
    height: 480,
    timeBase: TIME_BASE,
    extraData: avccBytes, // AVCC / SPS-PPS, required at open time
  });
} catch (err) {
  if (err instanceof DecoderUnavailableError) {
    console.log("no hardware decoder available on this machine");
    process.exit(1);
  }
  throw err;
}

for (const packet of compressedPackets) {
  await session.pushPacket(packet);
  let frame: DecodedVideoFrame | null;
  while ((frame = await session.pollFrame()) !== null) {
    // consume frame.data (frame.pixelFormat, width, height)
  }
}
await session.flush();
session.close(); // always safe — no consumption trap

API

| Member | Notes | | --- | --- | | DecodeSession.open(config) | resolves a hardware video decoder or throws DecoderUnavailableError | | DecodeSession.pushPacket(packet) / pollFrame() | may produce zero or more frames per pushed packet | | AudioDecodeSession.open(sampleRate, channels, timeBase) | Opus only today; cross-platform |

License

MIT OR Apache-2.0. Part of the Mediaway project — pre-1.0, APIs may change.