anycodec 0.1.0

Cross-platform audio/video codec engine for Dart and Flutter: platform-native codecs first (MediaCodec, Media Foundation, VideoToolbox, GStreamer, WebCodecs) with an always-available software fallback.

0.1.0

First release. A cross-platform audio/video codec engine for Dart and Flutter: the platform's own media framework is preferred, and a software fallback is always available and always reported.

Codecs

Video H.264, H.265, H.266, VP8, VP9, AV1; audio MP3, AAC, Vorbis, Opus, FLAC, ALAC.

Platform-native backends

• Android — MediaCodec through the ndk crate, with real avcC/hvcC to Annex-B conversion, flexible-YUV input layout, crop-rect-aware decoding, and hardware detection from the component name.
• Windows — Media Foundation, discovered by MFTEnumEx rather than by hard-coded CLSIDs. Synchronous MFTs only, so hardwareAccelerated is reported as false and says so, instead of claiming a GPU it does not use.
• macOS / iOS — VideoToolbox and AudioToolbox through the objc2 crates. Hardware use is read back off the live session (kVTCompressionPropertyKey_UsingHardwareAcceleratedVideoEncoder, VTIsHardwareDecodeSupported), never assumed.
• Linux — GStreamer through gstreamer-rs, with an explicit per-codec element table and hardwareAccelerated true only for the va*/nv*/v4l2*/ msdk* element that was actually selected.
• Web — WebCodecs, implemented in Dart (lib/src/runtime/runtime_web.dart).

Software fallback

Pure-Rust codecs, compiled in unconditionally, needing no C toolchain, no cmake and no nasm: MP3, AAC, FLAC, Opus and VP9 in both directions; H.265 and ALAC decoding; Vorbis through symphonia. A runtime-loaded libavcodec tier is probed and reported honestly when it is absent.

Knowing which one you got

CodecPath answers it: backend, implementation, hardwareAccelerated, detail (the concrete object in use) and fallbackReason (every backend that was skipped and why). AnyCodec.capabilityReport() renders the same information for every codec and direction, and BackendPreference lets a caller refuse a software fallback up front.

Dart API

• One unified Future-based API on every platform (package:anycodec/anycodec.dart).
• A pool of worker isolates owns every native handle, so no native call happens on the calling isolate and several sessions run in parallel. Frames and packets cross the boundary as TransferableTypedData.
• Platform-specific APIs in package:anycodec/anycodec_platform.dart, selected by conditional export, so dart:ffi never reaches a web build and dart:js_interop never reaches a native one.
• AnyCodecException / AnyCodecErrorKind map one-to-one onto the ABI's ANYCODEC_STATUS_* codes, preserving the Rust-side message.
• A diagnostic codec (diagnosticEncoder / diagnosticDecoder) for exercising the whole pipeline — timestamps, ownership, the isolate hand-off, flush — on a host with no media framework at all. The Dart implementation is byte-compatible with the Rust one, and a test proves it.