mh_PLAYer v2.12.4

High-Performance CGI/VFX Image Sequence & Video Player for Windows

Martin P. Heigan · anti-matter-3d.com

Proprietary software — free to download and use. Some production features require a license.

See Licensing below. Full terms in License_Agreement.pdf (included in the ZIP).

---

Download

⬇ Download mh_PLAYer v2.12.4 (Windows x64)

Or visit anti-matter-3d.com/mhplayer for release notes and licensing. GitHub mirror: Releases.

---

What is mh_PLAYer?

mh_PLAYer is a professional image sequence and video player built for CGI and VFX production pipelines. It handles multi-layer OpenEXR sequences, video dailies, HDR files, and everything in between — with full colour management, A/B compare, stereo anaglyph compositing, annotation tools, a pipeline CLI, and a three-level frame cache for sustained playback of large sequences.

Version 2.12 adds a complete EDL / Multi-Clip Timeline, frame-accurate ** Synced Remote Review** across machines, and Python plugin scripting — turning the player into a review and conform hub for the whole team.

v2.12.4 puts mh_PLAYer in Windows' Open with menu, makes A/B compare drag-and-drop and fullscreen, lets the sidebar follow what you do, and gives plugins text rendering. See CHANGELOG.md.

No Python. No dependencies. Extract the ZIP and run — or use the optional signed installer.

---

Features

Playback & Formats

• OpenEXR multi-layer — full AOV tree, all channel depths, float16/float32
• HDR / Radiance RGBE — .hdr support with Reinhard tone-map
• Video — MP4, MOV, MKV, MXF, AVI, WebM, WMV, MTS / M2TS, TS, FLV via bundled FFmpeg
• Linear video read-ahead — clips are decoded in order into RAM ahead of the playhead, so scrubbing over the cached span is instant and playback needs no further decoding; the span re-anchors wherever you scrub to
• R/G/B/A channel isolation — on all source types including video
• Frame stride — play every 2nd–5th frame at real-time speed
• Three-level cache — L1/L2 RAM + L3 SSD for large-sequence playback
• Onion-skinning — overlay adjacent frames for animation timing

Colour Management

• sRGB, ACES Filmic, Power Gamma, Linear display modes
• False Colour — exposure heat map keyed to 18% grey (GUI and CLI)
• CDL grade — slope / offset / power / saturation on the display image through a fast precomputed LUT; imports ASC-CDL .cc, .ccc and .cdl
• LUT support — .cube and .3dl
• OpenColorIO bundled — no separate install; auto-loads $OCIO
• Auto colour space detection from EXR header on load
• EV (±8 stops) and gamma — spinbox controls, live labels
• Aspect ratio correction — 13 presets from 1:1 to 4K Scope; transport bar combo + sidebar; saved per workspace

Stereo / Anaglyph (free)

• Two-sequence mode — load left and right eye sequences independently; any supported format
• Single stereo EXR mode — auto-detects left/right layer pairs in multi-camera EXRs (left.R/G/B + right.R/G/B and 10 other naming conventions)
• Colour modes — Red-Cyan Half-Color · Red-Cyan Greyscale · Amber-Blue · Green-Magenta
• Eye swap and gamma-correct options
• CLI anaglyph convert — headless \--anaglyph flag for batch pipeline use

Review & QC

• A/B Wipe compare — draggable divider or independent B sequence; drag a file onto the right half of the viewer to load it as B; fullscreen keeps A, B and the divider; B always shares A's exposure, gamma, display mode and channel view (license)
• Diff mode — |A−B| × amplify (1–32×) full-frame difference (license)
• Playlist — multi-clip queue with per-clip In/Out trim, drag-reorder, and ** M3U / M3U8 import/export**; SSD pre-caching between clips (license)
• Annotation tools — pen, line, arrow, rectangle, text + voice notes (license)
• HUD overlay — frame number, SMPTE TC (drop-frame-correct at 29.97/59.94), shot name (file / folder / custom)
• Stencil overlay — lay a PNG with transparency (a station ident, a scoreboard, a stats banner) over playback to keep the action clear of it; fit to frame or original size, nine positions, margin, opacity; S shows / hides it (free — baking it into exports follows the export licence)
• Remote Review (browser streaming) — built-in HTTP server; open http://LAN-IP:8765 on any tablet, phone, or second PC; follows playback frame by frame with frame number, timecode and shot name, and sends nothing while paused; no software install on the remote device (free)
• Remote Control — 127.0.0.1:7979 scripting port for Nuke, scripts and curl: open, go to frame, play, stop (free)
• Waveform / Parade scope — vertical RGB stack with solo buttons
• Pixel inspector — linear float readout, hex sRGB, clipboard copy
• Histogram — live RGB overlay
• Multi-View Compare — dailies-style grid of up to 9 stills with per-pane zoom/pan (kept as you change the selection), optional synced inspection and its own fullscreen; Grab Current Frame captures the canvas exactly as displayed (free)

EDL / Multi-Clip Timeline (Studio Pro)

• Assemble multiple sequences and clips into a single ordered cut for back-to-back review
• Per-clip trims, drag-to-reorder, edge trim handles, and a non-modal editor with a live playhead
• Loop playback, seamless next-clip pre-loading, and grade persistence across cuts
• CMX 3600 EDL import/export for round-trips with Premiere, Avid, Resolve, and Final Cut — drop-frame-aware at NTSC rates
• Build a timeline straight from the Playlist (Send Playlist to Timeline)
• Headless render — mh_player --convert cut.mhedl review.mp4

Synced Remote Review (Studio Pro)

• Frame-accurate playback synchronisation across multiple mh_PLAYer instances on a LAN
• Automatic session discovery — followers see hosted sessions and join with one click
• Host-authoritative timing with bi-directional transport control, auth token, and reconnect-on-drop
• Distinct from the free browser Remote Review above — this syncs full-quality playback between running players

Plugins (Studio Pro)

• Load small Python plugins that add menu commands and react to playback/export events
• Stable, versioned mh_player_api — state queries, playback control, status/log, event hooks, and text rendering (API 1.2: render_text, find_font, list_fonts)
• Six plugins ship in the box — Studio Watermark (logo, text, or both), Field Recorder, Contact Sheet, Colour Palette, Colour Theme, and Test Patterns — in the plugins/ folder next to the exe, nothing to install
• Drop your own .py file in the same folder; the bundled example_plugin.py shows the structure
• Full API reference in Appendix B of the user manual

Interface

• Quick-access icon toolbar — collapsible rows of icon buttons for display, HUD, guides, the stencil overlay, A/B compare, scopes, remote review, Playlist, EDL, Onion-skin, Multi-View, Export Video and Sync
• Sidebar anchors — toolbar icons bring the relevant sidebar section to the top; auto-expands if collapsed
• The sidebar follows what you do — channel keys, proxy, exposure, display mode, aspect ratio, compare, audio and layers open their section when used (switchable in Preferences)
• Windows integration — offered in Open with and Default apps for video and images without changing your defaults (Help → File Associations…); .mhplay / .mhedl open on a double-click
• Collapsible sidebar — Tab or click the ‹ strip for a clean full-canvas view
• Find Feature — Help → Find Feature… (F1): type a word (diff, wipe, * scoreboard*) to see where a feature lives — menu path, toolbar icon, sidebar section and key — and open it from the list
• Wheel-safe controls — the mouse wheel scrolls panels and zooms the canvas; it never changes a combo, spin box or slider value, so scrolling a dialog cannot alter a setting by accident

Pipeline

• CLI — viewer / convert (headless) / check (QC) modes
• Timeline & playlist inputs — open .mhedl and .m3u8 from the command line; render a timeline headlessly
• CLI PATH Setup — Help → CLI PATH Setup… adds the app to user PATH, no admin rights required
• Nuke flipbook integration — mh_PLAYer in Nuke's Flipbook dialog, plus Render → Open in mh_PLAYer for Read / Write nodes; mh_player_nuke.py + mh_player_nuke_Quickstart.pdf included
• Workspace save/load — complete session state in a .mhplay file
• Sequence gap detection — warns on open with exact missing frame ranges
• SMPTE timecode — configurable start, click frame counter to toggle
• Check for Latest Version — Help → Check for Latest Version… compares against the newest GitHub release; a manual check only, nothing contacts the network at startup

Export (license required)

• Frame export — PNG, TIFF, EXR; current / range / full sequence; optionally with the stencil overlay
• Video export — H.264, H.265, ProRes via bundled FFmpeg
• Slate & burn-in (video export) — shot, scene, take, artist, company, logo, watermark
• Stencil overlay baked into video, frames and Quick Save on request
• Display grade in exports — the CDL grade, invert and flip baked into video and frames on request (a tick box in each export window)
• Quick Save — current frame to PNG/TIFF/JPEG, one keystroke

---

Installation

1. Download the ZIP from anti-matter-3d.com/mhplayer or the Releases page.
2. Extract to any folder — no installer or admin rights required. (Prefer a managed install? The signed mh_PLAYer_Win_x64_v2_12_4_Setup.exe installs per-user, with shortcuts, PATH, Open with integration, and an offer to remove the previous version first.)
3. Run mh_PLAYer_Win_x64_v2_12_4.exe.
4. Use Help → Manage Shortcuts… to create Desktop and Start Menu shortcuts.
5. Use Help → CLI PATH Setup… to add mh_PLAYer to your user PATH for terminal access.

mh_PLAYer_Win_x64_v2_12_4.exe       Main application (digitally signed)
ffmpeg\                              Bundled FFmpeg
_internal\                           Application runtime files
plugins\                             Six bundled plugins + example_plugin.py
mh_PLAYer_v2_12_User_Manual.pdf      Full user manual
Nuke_Integration\                    Nuke flipbook integration:
                                       mh_player_nuke.py, mh_player_nuke_Quickstart.pdf
License_Agreement.pdf                End User License Agreement
README.txt                           Plain-text quick reference

---

Quick Start

1. Drop an EXR frame, image file, or video onto the window — or use File → Open Sequence.
2. Press Space to play. Use J / K / L for shuttle control.
3. Press Ctrl+Tab to collapse the sidebar for a clean full-canvas view.

---

EDL / Multi-Clip Timeline (Studio Pro)

Assemble shots into a single reviewable cut:

1. EDL → New EDL, or build one from the Playlist with Playlist → Send Playlist to Timeline (EDL)…
2. EDL → EDL Editor… opens a non-modal editor — drag clips to reorder, drag a clip edge to trim, watch the cyan playhead track playback live.
3. EDL → Activate EDL Playback to run the clips back-to-back; Loop EDL Playback to loop.
4. EDL → Export CMX3600 .edl… to round-trip with an NLE, or render headlessly:

mh_player --convert cut.mhedl review.mp4
mh_player --convert cut.mhedl review.mov --display aces --burnin --codec prores

---

Synced Remote Review (Studio Pro)

Keep several machines on the same frame, in sync, at full quality:

1. On the host, start a Sync session. Followers on the same LAN see it appear automatically and join with one click (or enter the host address).
2. The host drives transport; playback stays frame-accurate across all participants, with automatic reconnect if a connection drops.

For lightweight viewing on a tablet or phone, the free browser Remote Review (below) is still available and needs no second mh_PLAYer.

---

Remote Review (browser streaming) (free)

Start the server via Help → Remote Review or the antenna icon in the toolbar. A dialog shows the URL — open it on any device on the same network:

http://192.168.x.x:8765

The page follows playback frame by frame, up to the playback rate, with the frame number, timecode and shot name. Each new frame is sent once; if the network falls behind, frames are skipped rather than queued, so the page never lags behind the player. Nothing is sent while paused. The stream is a JPEG preview (quality 75%, up to 960 px wide) — for review, not colour-critical checks. No software installation required on the remote device. Works on iPad, phone, laptop, or a second PC with any modern browser.

---

Plugins (Studio Pro)

Six plugins ship inside the plugins/ folder next to the exe — Studio Watermark , Field Recorder, Contact Sheet, Colour Palette, Colour Theme, and Test Patterns — and appear in the Plugins menu with nothing to install.

Drop your own Python file in the same folder. Plugins load on startup and can add menu commands and react to events:

import mh_player_api as mh

def _note():
    mh.log(f"reviewing {mh.get_current_path()} @ {mh.get_current_frame_number()}")
    mh.notify("Review note logged")

mh.register_menu_item("Log Review Note", _note)
mh.on_export_complete(lambda out: mh.log(f"export done: {out}"))

Plugin API 1.2 adds text — mh.render_text("WORK IN PROGRESS", size=96, bold=True) returns a transparent image a plugin can stamp, scale or save.

See the bundled example_plugin.py and Appendix B of the user manual for the full API.

---

Stereo / Anaglyph (free)

Two-sequence workflow:

1. Open the left eye sequence via File → Open Sequence.
2. In the sidebar STEREO / ANAGLYPH section, click Load R Eye… to load the right eye.
3. Check Enable Anaglyph.

Single stereo EXR workflow:

1. Click Load Stereo EXR… — mh_PLAYer auto-detects the layer pairs and enables anaglyph immediately.

CLI headless anaglyph convert:

# Two separate sequences → anaglyph MP4
mh_player --convert --anaglyph left.####.exr --right-eye right.####.exr anaglyph.mp4

# Single stereo EXR sequence (auto-detects left.R/G/B + right.R/G/B)
mh_player --convert --anaglyph --stereo-exr camera_stereo.####.exr anaglyph.mp4

# ACES display + gamma correction for linear EXRs
mh_player --convert --anaglyph --display aces --anaglyph-gamma \
    left.####.exr --right-eye right.####.exr review.mp4

---

Pipeline CLI

# Viewer
mh_player beauty.####.exr
mh_player -s 1001 -e 1250 --display aces -n 2 beauty.####.exr
mh_player cut.mhedl --play             # open a saved timeline
mh_player review.m3u8 --play           # open a playlist

# Convert (headless, farm-safe)
mh_player --convert beauty.####.exr  review/beauty.####.png
mh_player --convert --display aces beauty.####.exr  out.mp4
mh_player --convert --ar 2.39 beauty.####.exr review.mp4
mh_player --convert cut.mhedl review.mp4          # render an EDL/timeline

# Check / QC (exit codes: 0=complete, 1=gaps/partial, 2=error)
mh_player --check beauty.####.exr
mh_player --help

---

Nuke Flipbook Integration

# %USERPROFILE%\.nuke\menu.py
import mh_player_nuke
mh_player_nuke.register()

Add the Nuke_Integration folder to NUKE_PATH (or copy the script to .nuke ). Then choose mh_PLAYer in Nuke's Flipbook dialog, or select a Read / Write node and use Render → Open in mh_PLAYer (no render; a Read opens with its own frame range). A Setup install is found automatically; otherwise point the script at the exe:

set MH_PLAYER_PATH=C:\App\mh_PLAYer\mh_PLAYer_Win_x64_v2_12_4.exe

See Nuke_Integration/mh_player_nuke_Quickstart.pdf for full setup including OCIO passthrough and exe discovery.

---

Verifying Your Download

Every release ships with verification artefacts.

File	Purpose
SHA256SUMS.txt	Plain-text SHA-256 hashes for all release files
SHA256SUMS.yaml	Machine-readable hashes for pipeline scripts
release_manifest.cat	Signed Windows catalogue — cryptographic proof of file integrity
manifest.yaml	Full release manifest (version, date, file list)

PowerShell:

Get-FileHash mh_PLAYer_Win_x64_v2_12_4.exe -Algorithm SHA256

Command Prompt:

certutil -hashfile mh_PLAYer_Win_x64_v2_12_4.exe SHA256

Compare the output against SHA256SUMS.txt. The exe is digitally signed and submitted to Microsoft WDSI and VirusTotal before every public release.

---

System Requirements

OS	Windows 10 / 11 (64-bit)
RAM	16 GB min; 32 GB+ recommended for large EXR sequences
Storage	SSD recommended for L3 disk cache
Display	1920×1080 min; 4K supported

Image formats: EXR, PNG, TIFF, JPEG, DPX, HDR

Video formats: MP4, MOV, MKV, MXF, AVI, WebM, WMV, MTS / M2TS, TS, FLV

Audio formats: WAV, MP3, FLAC, AIFF

---

Licensing

mh_PLAYer is free to download and use. The core viewer, all display and colour management tools, stereo anaglyph compositing, aspect ratio correction, browser remote review, the QC toolkit, and the pipeline CLI work without a license — with no time limit and no reduced quality.

Paid licenses add the production workflow features. Individual and Studio licenses unlock the same feature set and differ only in machine binding (single machine vs organisation-wide); Studio Pro adds the advanced collaboration and automation features on top.

Capability	Free	Individual	Studio	Studio Pro
Core viewer · colour management · aspect ratio · stereo anaglyph	✓	✓	✓	✓
Browser remote review · QC toolkit (scopes, inspector, histogram) · CLI	✓	✓	✓	✓
Annotations · A/B Compare · Playlist · Audio · Export · Slate & Burn-in	—	✓	✓	✓
EDL / Multi-Clip Timeline · Synced Remote Review · Plugin Scripting	—	—	—	✓
Licensed use across machines	—	Single (MAC-bound)	Organisation-wide	Organisation-wide

All paid licenses are perpetual — no subscription, no renewal fees. A Trial unlocks every feature, including Studio Pro, for 10 days on any machine.

License	Use across machines	Feature set	Expiry
Free (unlicensed)	Any machine	Core viewer, colour, AR, stereo, browser remote review, QC, CLI	None
Individual	Single machine (MAC-bound)	Free + production features	None — perpetual
Studio	Organisation-wide (floating)	Free + production features	None — perpetual
Studio Pro	Organisation-wide (floating)	Studio + EDL / Timeline, Synced Remote Review, Plugins	None — perpetual
Trial	Any machine	All features (including Studio Pro)	10 days

Video file audio plays without a license — only imported audio for image sequences requires one.

10-day full-feature trial available on request — no payment required.

Purchase and trial requests: anti-matter-3d.com/mhplayer

Or contact me at: anti-matter-3d.com/contact

This software is proprietary. Use is governed by the End User License Agreement included in the distribution (License_Agreement.pdf). By downloading or using mh_PLAYer you agree to its terms.

---

Keyboard Shortcuts

Key	Action
Space	Play / Pause
J / K / L	Shuttle reverse / stop / forward
← / →	Step one frame
Home / End	First / Last frame
R / G / B / A	Channel isolation
C	Full colour (RGB)
V	Invert display
P	Cycle proxy (Full → ½ → ¼)
F / 1	Fit to window / 1:1 pixel
Ctrl+Tab	Toggle sidebar
N	Annotation mode (license)
[	A/B compare (license)
Ctrl+G	Go to frame
Ctrl+S	Save workspace
Ctrl+E	Export frames (license)
Ctrl+Shift+E	Export video (license)
Ctrl+F	Fullscreen (keeps A/B compare; Esc or F11 to leave)
Ctrl+Shift+C	Quick save frame as displayed (license)
Shift+R	Reset EV and gamma
S	Stencil overlay show / hide
F1	Find Feature — where is it?

---

Digitally signed · Signed release catalogue (.cat) + signed SFX · WDSI + VirusTotal submitted before every release

anti-matter-3d.com/mhplayer

Copyright © 2026 Martin P. Heigan. All Rights Reserved.