ActiveFrame

ActiveFrame is a small pipeline and javascript library for turning a video into a single binary .af file and decoding it in the browser with the Web Codec API — without a <video> element and without third-party dependencies such as FFmpeg.wasm, Mediabunny, or other JS demuxers/decoders.

The file packs raw encoded samples (H.264 / H.265) plus a JSON manifest. The runtime loads the buffer, configures the decoder from the manifest, and exposes frame-accurate navigation via setFrame(index).

Why use this instead of “regular” video?

• Frame-accurate control and random access
• Feed the frame natively to WebGL/WebGPU and Canvas 2D
• Hardware accelerated**
• Optimized for interactive scrubbing, 3D, image-like control over which frame is shown

Why use this instead of “regular” spritesheet?

• Smaller file size, leveraging H.264 / H.265 intra frame compression
• Better memory management

Generating an .af file

node af.js <input video> <output.af> [maxWidth] [h264|h265] [gop] [crf]

Roadmap / ideas

• Surface codec support before loading (e.g. companion manifest or a tiny probe).
• Streaming or partial fetch (range requests), LOD, adaptive quality.
• Runtime tuning of hardware vs software decode based on performance.
• Benchmark suite to calibrate and fine tune performance and hw support.