Broken in VLC
Display headroom read once, from the main screen
What you saw
Drag the window to a second display, HDR brightness stayed wrong.
What MacLC does
Re-measured on every screen, window-move and display-profile change.
MacLC
Everything VLC can play. Finally built like a Mac app.
Free and open source · Apple Silicon · macOS 13+
The Metal Compute Pipeline
SDR → HDR Highlight Expansion
Standard Dynamic Range (SDR)
Expanded Range (PQ / Metal)
Simulated on an SDR display. The real effect requires an HDR panel.
01
The problem
Your display can go six times brighter than SDR white. Almost nothing you own asks it to.
An XDR panel has up to 6.15× display headroom waiting. Yet 99% of your media library carries zero HDR signal, leaving the panel idle.
02
Why relabelling fails
Under PQ encoding, the same raw numbers mean roughly five times the luminance.
Relabelling the file blows out the entire mid-tone range. Skin tones wash out, faces turn chalk white, and shadow separation is lost.
03
The mathematical knee
Identity at and below half SDR white. Quadratic above it.
Value and slope match the identity curve exactly at the knee. Applied to the largest color component with the full triplet scaled, so hue and saturation never shift.
04
The payoff
“Shadows and mid-tones reach your eye at exactly the brightness they always did. Only the highlights move.”
A streetlight, a glint on metal, or a bright sky are lifted into spare headroom. The rest of the scene remains untouched.
Audit of VLC 4.0.0-dev on Apple Silicon
Six defects, fixed.
An audit of VLC 4.0.0-dev on Apple Silicon found 6 confirmed defects and 9 missing capabilities in the macOS HDR path. All six defects are fixed.
Broken in VLC
The HDR mode selector and brightness slider did nothing
What you saw
The settings were decorative.
What MacLC does
Both wired live — they take effect during playback.
Broken in VLC
No tone-mapping path to SDR
What you saw
HDR film on a normal display clipped to flat white.
What MacLC does
A real conversion, with a correct fallback on older macOS.
Broken in VLC
Subtitles untagged over HDR video
What you saw
White subtitles rendered at full HDR luminance — searingly bright over dark scenes.
What MacLC does
Subtitles pinned to SDR and scaled to the ITU-R BT.2408 203-nit reference white.
Broken in VLC
Video above 10-bit downsampled to 8-bit
What you saw
12-bit and 16-bit sources lost detail before reaching the screen.
What MacLC does
Full 10-bit path preserved; 16-bit 4:2:2 wired through.
Broken in VLC
Sub-4K HDR mis-tagged, zero-nit mastering volume emitted
What you saw
Wide-gamut content played through the wrong primaries.
What MacLC does
Correct tagging per stream.
Beyond the fixes
New capabilities in the macOS pipeline
Engineered specifically for Apple Silicon hardware decoders, display engines, and modern HDR formats.
Hardware AV1 on M3 & M4
VideoToolbox hardware decode gated on physical chip capability. Clean software fallback elsewhere.
HDR10+ Dynamic Metadata
Carried end-to-end through the filter pipeline without stripping frame-by-frame metadata.
Dolby Vision Extraction
Hardened bitstream parsers, resolving an upstream bug where Dolby Vision was dropped on frame one.
ARM64 NEON Conversions
Hand-written vector SIMD chroma routines replacing legacy scalar loops on CPU decode.
OpenGL 4.1 / 3.2 Core Profile
64-bit color support unblocking libplacebo shader stages previously failing on legacy profiles.
ST 2086 & CTA-861.3 Metadata
Mastering display color volume and content light levels forwarded directly to macOS display services.
Per-Window ICC Profiling
Color management reads the ICC profile from the current display surface rather than the primary monitor.
The Settings Philosophy
Settings that explain themselves.
VLC has thousands of unexplained controls scattered across an advanced tree. MacLC reorganizes preferences around human perception: every option tells you what you will see or hear.
What MacLC shows you
“highlights keep detail but the picture is dimmer overall”
Warm. Readable. Explains the perceptual consequence in plain English.
What software usually gives you
applies a BT.2390 EETF
Cold. Cryptic. Requires an engineering degree to adjust picture brightness.
General
Playback behavior, hardware decoding, interface preferences, and engine options.
Startup & Playback
Resume playback where you left off
Opens your recent file at the exact timestamp when the app starts.
Keep player on top while playing
Floats the video canvas above all other open application windows.
Automatic updates
Checks GitHub releases for verified updates without sending device identifiers.
Hardware & Media Engines
Hardware-accelerated video decoding
Routes AV1, HEVC, and H.264 streams directly through Apple Silicon media engines.
Fallback to software decode on bitstream errors
Handles damaged video streams but increases CPU temperature and battery draw.
NEON-accelerated chroma conversion
Replaces scalar loops with SIMD vector instructions on the software-decode path.
Interface & Control
Auto-hide floating HUD controls
Controls fade out when the cursor rests idle over the video canvas.
Monospaced-digit time labels
Numbers hold steady on the timeline so the layout does not jitter as seconds advance.
Advanced Engine Options 240 guarded options
All 240 configuration reads in the settings panes pass through guarded wrappers. Missing options no longer trigger engine assertions.
File caching buffer
Network and disk read-ahead window for smooth scrubbing.
Subtitle reference white luminance
Pins text to standard luminance to prevent blinding subtitles over HDR video.
Interface reconstruction.
Interface reconstruction.
Eight curated panes
General · Playback · Video · HDR & Colour · Audio · Subtitles · Interface · Shortcuts. Search filters across row labels, descriptions, and underlying keywords simultaneously.
Nothing decorative
Every single control is verified wired to a real engine option in the build. If an option is unsupported on your hardware, the row is omitted rather than drawn disabled.
The power user tree remains
Nothing was removed. The full upstream advanced module tree is untouched and still reachable when you need granular engine flags.
Startup Self-Check 8 panes, 8 ok, 0 failed
240 guarded config reads
Upstream, opening the Interface pane aborted the entire app on one build configuration when a missing option hit a hard assert().
MacLC routed all 240 configuration reads through defensive wrappers.
Native macOS Architecture
Built on the system.
VLC draws its own custom controls that mimic older platforms. MacLC adopts the system’s actual AppKit materials, translucency, and spatial hierarchy.
Interface reconstruction. Floating HUD on system material. Timecodes render in tabular-nums so numerals hold steady without layout jitter as playback advances.
Interface reconstruction.
Real source-list sidebar
Built with AppKit’s native source-list classes. It delivers genuine system vibrancy, spring-loaded dragging, and standard macOS collapse behavior rather than a simulated table.
Floating HUD transport
Hover playback controls float over video using Apple’s HUD material. Glyph weights, sizes, and padding strictly match macOS system media controls.
Monospaced-digit timecodes
Time labels use tabular-nums so the numbers stop shifting laterally on screen as the seconds tick forward during playback.
8-point grid & 32 pt targets
Six layout metrics moved onto the 8-point geometric scale. The small row height increased from 25 pt to 32 pt, restoring a comfortable, accessible click target.
Architectural Design System
Accessibility as architecture.
“It respects Reduce Motion, Increase Contrast and VoiceOver — because it never hardcoded around them in the first place.”
Upstream had eleven literal colour values in one file alone, font sizes typed at the call site, and corner radii that landed wherever they landed.
MacLC built MacLCDesign: a single token layer defining every colour, type style, spacing, radius, material, and animation duration — all mapped directly to macOS system semantics.
Reduce Motion
Animations do not merely slow down; transforms collapse immediately to their final state, and scroll scrubbers offer instant toggle buttons.
Increase Contrast
All text and hairline tokens adapt dynamically to system contrast settings, exceeding WCAG AAA standards across both light and dark appearances.
Reduce Transparency
HUD materials and translucent panels automatically switch to opaque, high-legibility surfaces without losing structural hierarchy.
VoiceOver & Keyboard
Every interactive control is fully keyboard-reachable with high-contrast focus rings and complete VoiceOver semantic roles.
App Identity
The details nobody asked for.
A superellipse, not a rounded rectangle
Standard circular corner radii look visibly out of place beside native macOS applications.
MacLC’s container is plotted using a Lamé superellipse curve (|x/a|^4.5 + |y/b|^4.5 = 1) on Apple’s 824-of-1024 grid.
At 16 points in the Dock, that mathematical curvature is what makes an icon look unmistakably native.
The bloom is the only color
The icon’s body is pure graphite and brushed metal. The radial amber bloom behind the play triangle is the single place saturated color appears anywhere in the artwork. Because the rest of the icon remains neutral, the bloom reads as pure illumination rather than simply orange paint.
Committed code, not an opaque asset
The icon geometry, gradients, and specular rims are defined by an executable program checked directly into the repository. Every contour can be inspected, tweaked, diffed in code reviews, and regenerated deterministically.
Its own bundle identifier
MacLC uses org.maclc.MacLC.
When upstream builds shared VLC’s bundle identifier, macOS resolved windows to VLC.app, causing Stage Manager and Dock menus to collide.
On first launch, MacLC safely copies your existing VLC preferences and defaults across — leaving your original install completely untouched.
Project Status
Where the project is.
The engineering is measured. Now it needs human eyes.
The mathematics is verified across the full signal range against an independently written CPU reference. Bit accuracy confirms true 10-bit output without padding noise, and frame execution clocks at 0.53 ms.
What has not yet happened is extensive human visual review. Two things need critical eyes: the interface redesign in daily use, and the aesthetic appearance of the SDR → HDR grade across different genres and masters.
Nobody has sat in front of an XDR display on five hundred films and confirmed every edge case looks natural. We are releasing this as early access to something being built properly, not as an apology. If you own an Apple Silicon Mac with an HDR panel, you can help test and refine the grade.
Get MacLC Everything VLC can play.
Everything VLC can play.
Finally built like a Mac app.
Full codec compatibility from libvlccore. Pure AppKit interface. A Metal pipeline tuned for Apple Silicon HDR displays.
Download MacLC
You can also download it for free.