FastPlay is a Windows video player built for the parts of playback people actually notice: opening a file, reaching the first frame quickly, resuming where you left off, scrubbing without friction, adjusting the picture easily, and getting out of the way while you watch.

It is intentionally focused on local playback. No media library. No plugin maze. No feature sprawl. Just fast open, clean playback, responsive controls, and a tighter Windows-native experience.

Download FastPlay v0.3.0 for Windows x64 • All releases • Report an issue

Current status: early release, actively improving playback speed, seek feel, and UI polish on Windows x64.

Why FastPlay exists

Most of the time you open a video player, you are not managing a library or transcoding a stream. You are opening one local file and watching it. FastPlay is built around that single moment: how fast the file opens, how quickly the first frame appears, whether it resumes where you left off, and how cleanly it scrubs and gets out of the way.

The mainstream players are excellent and do far more than this. FastPlay deliberately does less, so the path from double-click to watching stays short and the controls stay responsive. It is a focused tool for local playback on Windows, not a replacement for a full-featured media suite.

Compared to VLC and MPC-HC

VLC and MPC-HC are mature, capable, and the right choice for most people when they need broad format support, streaming, playlists, deep configuration, and years of hardening. FastPlay is not trying to compete on breadth.

Where FastPlay differs is scope and intent:

Use VLC or MPC-HC when you need format coverage, streaming, or platform reach. Reach for FastPlay when you want a snappy, no-friction window for the local file in front of you.

Controls

Timeline scrubbing is available by hovering near the bottom of the window and clicking or dragging.

In / Out range

Press I to mark where playback starts and O to mark where it ends. The range adapts to however many points are set:

Press R while a range is active to loop it continuously. Use Shift+I / Shift+O to clear individual points. In/out points reset when a new file is opened.

Features

Playback

• Ctrl+O file open dialog and drag-and-drop file open
• recent-files overlay with automatic per-file resume playback
• quick open and first-frame path
• responsive keyboard seek with accelerated hold behavior
• timeline scrubbing overlay with playback position
• in/out point range with loop and auto-replay
• replay at end of playback
• playback metrics such as open-to-frame latency, seek latency, and dropped frames

Video and audio

• FFmpeg-based demux and decode
• hardware video decode on the preferred D3D11 path
• software video decode fallback with D3D11 upload and present
• WASAPI shared-mode audio playback
• audio-master playback timing when audio exists
• generation-safe seek and reopen behavior
• device-loss and resize recovery paths

Viewing controls

• borderless fullscreen
• cursor-centered zoom and drag-to-pan
• 90-degree view rotation with auto-rotate from stream display matrix metadata
• fit-to-screen window sizing with no black padding
• half native resolution window sizing
• volume control with on-screen overlay
• hold-to-show keybind reference overlay

Subtitles

• external .srt subtitle overlay
• runtime subtitle toggle
• accepts both comma and period millisecond separators in SRT timestamps
• UTF-8 with BOM support and Windows-1252 fallback encoding
• strips common formatting tags (<b>, <i>, <u>, <font>)

Platform

• per-monitor DPI awareness (Per-Monitor V2 with system-aware fallback)
• minimum window size enforcement (640×360)

Goals

FastPlay prioritizes:

• low open-to-first-frame latency
• responsive seek behavior
• GPU-resident presentation on the normal hardware path
• bounded queues and explicit ownership
• narrow, maintainable architecture
• Windows-specific performance rather than broad platform support

Non-goals

FastPlay does not currently aim to provide:

• playlists or media library management
• streaming support
• plugin support
• browser or web UI
• advanced subtitle styling or embedded subtitle track selection
• HDR or tone mapping
• extra hardware backends beyond the current D3D11-first design

Known limitations

These are current real-world caveats, separate from the deliberate non-goals above:

• Windows x64 only. No macOS, Linux, or ARM builds.
• Common formats, not exhaustive. Decoding depends on the FFmpeg build in use; uncommon or exotic codecs may not play. Software decode is the fallback when hardware decode is unavailable.
• External .srt subtitles only. Embedded subtitle tracks and other subtitle formats are not loaded, and styling is intentionally minimal.
• Single-file playback. No playlists, queue, or "next file" yet. Opening a new file replaces the current one and resets in/out points.
• No streaming or network sources. Local files only.
• Audio is WASAPI shared-mode. No exclusive mode, no multi-track/audio-track switching.
• HDR is not tone-mapped. HDR content plays but is not color-managed.
• Early release. Behavior, shortcuts, and metrics are still changing between versions.

Requirements

• Windows 10 or later
• Rust toolchain
• FFmpeg development headers and libraries available locally
• D3D11 / DXGI / WASAPI-capable system

FFmpeg setup

build.rs supports these FFmpeg discovery patterns.

Preferred

Set FFMPEG_DIR.

Or set explicitly

• FFMPEG_INCLUDE_DIR
• FFMPEG_LIB_DIR
• optional: FFMPEG_BIN_DIR

Fallback search locations

• %VCPKG_ROOT%/installed/x64-windows
• %USERPROFILE%/vcpkg/installed/x64-windows
• C:\tools\vcpkg\installed\x64-windows

The build expects the usual FFmpeg development layout with include/ and lib/. Runtime DLL staging works when a bin/ directory is available.

Build

Run

Normal playback:

cargo run --release -- <path-to-media>

Or drag and drop a media file onto the FastPlay window.

Force software decode fallback:

cargo run --release -- --force-sw <path-to-media>

External subtitles

FastPlay supports external sidecar .srt files only. Place a subtitle file next to the media file with the same basename:

The subtitle sidecar will be auto-loaded if present.

Architecture

Preferred path

FFmpeg -> AV_PIX_FMT_D3D11 -> D3D11 video processor -> DXGI present

Software fallback path

FFmpeg demux -> software decode -> D3D11 upload -> D3D11 video processor -> DXGI present

Audio path

FFmpeg decode -> WASAPI shared-mode sink

Subtitle path

• external .srt sidecar only
• CPU parsing and layout
• GPU alpha composition during present

For the full implementation charter, see ARCHITECTURE.md.

Project structure

src/
  app/        # session coordinator, commands, events, state
  audio/      # audio sink abstractions
  ffi/        # FFmpeg / D3D11 / DXGI / WASAPI interop
  media/      # source, video, audio, seek, subtitle
  platform/   # Win32 window/input
  playback/   # clock, metrics, queue policy, generations
  render/     # presenter, swapchain, surface registry, timeline overlay

License

MIT