62 lines
6.1 KiB
Markdown
62 lines
6.1 KiB
Markdown
# Player
|
||
|
||
A personal native macOS player whose playback code is small enough to own and modify. FFmpeg reads and decodes media; our C++ worker owns playback. SwiftUI owns the controls, Core Audio owns audio output, and Metal presents video.
|
||
|
||
## Build and run
|
||
|
||
Requires macOS 15+, Xcode's command-line tools with Swift 6, and Homebrew FFmpeg/pkg-config:
|
||
|
||
```sh
|
||
brew install ffmpeg pkg-config
|
||
make
|
||
make run
|
||
```
|
||
|
||
The local app is `.build/Player.app`. It links the installed FFmpeg libraries; it is not a standalone distributable bundle. After upgrading FFmpeg, rebuild with `make -B`.
|
||
|
||
Open a local file with **⌘O**, drop it onto the window, or use Finder's **Open With**. Files open paused. **⇧⌘W** closes the file; closing the window quits and joins the worker.
|
||
|
||
## Playback UI
|
||
|
||
The layout follows [IINA's video-first window](https://iina.io/img/screenshot.png) and the supplied screenshots: a 32-point frosted titlebar with native traffic lights and file icon, plus a dark frosted 440 × 68-point floating controller. AppKit materials blur the video beneath the chrome; muted icons, an orange volume track, a narrow seek thumb, and zero-padded time labels follow the reference. The controller starts centered with a four-percent bottom inset and keeps its relative position when the window changes size.
|
||
|
||
Opening video fits the window to its display aspect ratio, including non-square pixels, and constrains subsequent window resizing. Fullscreen retains the normal letterboxed renderer; audio-only playback and close release the aspect constraint. Extreme ratios that cannot fit both the screen and usable controls keep a freely resizable letterboxed window.
|
||
|
||
- **Space:** play/pause. **←/→:** seek five seconds. The timeline slider seeks on release.
|
||
- **↑/↓:** adjust volume by five percent. **M:** mute/unmute, restoring the previous audible level.
|
||
- **Double-click video**, **F**, or **⌃⌘F:** toggle native fullscreen. **Esc:** leave fullscreen.
|
||
- **Single-click video:** hide controls. Mouse movement reveals them; they fade after 2.5 seconds, including while paused. Hovering the titlebar/controller, dragging, seeking, an inactive window, errors, or VoiceOver keep them visible.
|
||
- Click the right-hand time label to switch between total and remaining time. The titlebar pin keeps the window on top.
|
||
|
||
Only implemented actions have controls; there are no placeholder playlist, subtitle, picture-in-picture, or settings buttons. Layout and interaction references: IINA v1.5.0's [floating controller](https://github.com/iina/iina/blob/v1.5.0/iina/OSCFloatingView.swift), [preferences](https://github.com/iina/iina/blob/v1.5.0/iina/Preference.swift), and [titlebar](https://github.com/iina/iina/blob/v1.5.0/iina/Titlebar.swift).
|
||
|
||
## Where to change things
|
||
|
||
- `Sources/Core/player.h`: the C interface and authoritative state snapshot. Playback commands enqueue work; poll state for completion. Volume set/get is synchronous and uses a lock-free target gain. Callers own the opaque handle and must stop using it before destruction.
|
||
- `Sources/Core/player.cpp`: single demux/decode worker, bounded buffers, timestamps, audio-master synchronization, paused previews, decoder/resampler drain, seeking, errors, and shutdown. A seek stops output and flushes all old timeline state before resuming.
|
||
- `Sources/Core/output.hpp` and `Sources/macOS/Output.mm`: native output contract, allocation-free/nonblocking Core Audio callback and bounded audio ring, latency-aware presentation clock, retained frame mailbox, and Metal YUV conversion. The view can outlive the player safely.
|
||
- `Sources/App/PlayerApp.swift`: MainActor state polling, file panel/Finder/drop handling, video host, AppKit glass and native slider cells, floating controls, visibility, video-fitted sizing, and native window integration.
|
||
- `Makefile`: compiler/linker commands and app bundle construction. No generated Xcode project or additional build dependency.
|
||
|
||
## Runnable check
|
||
|
||
```sh
|
||
make check
|
||
```
|
||
|
||
Generates short fixtures and exercises the real playback interface and native outputs: audio/video, video-only, audio-only, non-square-pixel display aspect, pause, paused/playing seek, completion, replay, close, HDR rejection, failed-open recovery, and destruction while playing. It initializes the actual Metal shaders and uses an offscreen native window. It requires a working audio device and graphical macOS session, and plays short sine-wave audio. It is a runtime smoke check, not a mocked clock/device test.
|
||
|
||
`make check-audio` runs just the audio-quality check. A check-only hook captures actual Core Audio callback PCM into preallocated storage and compares every sample against FFmpeg's reference output for PCM/AAC, 44.1/48 kHz, and coarse container timestamps. It checks fractional gain, silent muted startup, smooth live volume changes, and unchanged playback completion. A separate gapped fixture verifies that real timestamp gaps remain silent. Release builds contain no capture hook.
|
||
|
||
Continuous audio uses resampled sample counts for its output timeline; packet timestamp quantization and rounded resampler delay must not insert silence or drop samples between blocks.
|
||
|
||
Volume persists across open, seek, and close. Live gain changes ramp over five milliseconds without callback allocation or locking; a stopped output adopts the requested gain before playback starts, so muted startup cannot leak audio.
|
||
|
||
Visual correctness, perceived A/V synchronization, and control usability still need a check in the visible app.
|
||
|
||
## Current limits
|
||
|
||
Local regular files, automatically selected best audio/video tracks, software decoding, and SDR output. PQ/HLG HDR is rejected rather than rendered incorrectly. No subtitles, selectable tracks, VideoToolbox decoding, rotation/deinterlacing, or network playback yet. Mid-track audio format changes report an error.
|
||
|
||
Audio buffering is bounded to one second plus one decoded block (up to four seconds); video is bounded to 64 frames/128 MiB. Extremely interleaved files can drop far-future video frames to avoid starving audio; the ceiling and upgrade path are marked at `queueVideo()`. Device/stream latency is accounted for, but device changes during playback are not handled yet.
|