mrv2 is an open-source media player and review tool for visual effects, animation, and computer graphics on Windows, macOS, and Linux. It plays movies, image sequences, and multichannel audio while providing comparison, color controls, feedback, and timeline editing. Its OpenGL build and Vulkan-based vmrv2 share feature licenses.
Loading a review
The viewer accepts movie files, camera RAW images, and sequences such as OpenEXR or DPX. Dropping a folder searches its subfolders for media. The Files panel selects the active clip and can load a separate audio file alongside it.
Playback controls move forward or backward, step through individual frames, and set a speed. In and out points define a range for repeating, ping-pong playback, or a single pass. Each clip or playlist retains its playback state. The cache reads frames ahead, and a timeline bar shows its progress. Settings control memory allocation or the time to read ahead and behind.
Reference images
The Compare panel assigns reference clips alongside the active image. Wipe, overlay, difference, horizontal, vertical, and tiled views combine them in different ways. A wipe reveals portions of each image, while a difference view displays their differences. OpenEXR layer selection and separate red, green, blue, or alpha views expose individual image components.
Color inspection
OpenColorIO controls select the input color space, display, view, and look from a configuration. Exposure, contrast, saturation and tint operate after the input transform to linear space, before the display transform. Exposure, contrast, saturation, tint, and gamma change the preview, and LUTs can run before or after the color controls.
A rectangular selection supplies pixel statistics, including minimum, maximum, and mean values. Histogram, vectorscope, and waveform panels inspect image regions. The OpenGL viewer tone-maps HDR material; the Vulkan variant also provides HDR display output.
Comments on frames
Drawing tools place vector strokes, shapes, and text directly over the image. Notes attach written comments to a frame, and timeline markers locate them again. Feedback can cover one frame or the entire clip. Ghosting extends drawings across nearby frames, while laser strokes fade away.
Brush hardness, fonts, erasing, and undo controls adjust the annotations. Voice annotations use microphone input for frame-associated audio comments. Link annotations attach file paths or URLs. These feedback tools depend on the feature license.
Building a timeline
Dragging clips from Files into a playlist creates an OpenTimelineIO sequence. Each entry can use its own in and out points, including repeated portions of the same source. Playlists accept different resolutions and frame rates, with matching video and audio track structures.
Editable timelines let users rearrange clips, slice them at the current frame, and insert or remove audio gaps. Frame cut, copy, paste, and insert operations change animation timing. Undo reverses edits. The playlist supports one video track and one audio track.
Shared playback
Network sessions connect a server viewer with client viewers. WebRTC rooms synchronize remote playback and drawing controls. Path mappings translate remote file locations into local ones. When a peer cannot locate media, another participant can transfer it through an encrypted data channel.
NDI input selects an audio-video source from the network. NDI output sends the viewer’s playback to compatible software or devices. The beta builds omit NDI.
Spatial views
Environment mapping projects an image onto a sphere or cube, with rotation and field-of-view controls. Stereo viewing combines two clips or OpenEXR eye layers into anaglyph, checkerboard, scanline, or horizontal output. The OpenGL build also loads USD assets. Its USD panel sets rendering quality, lighting, and drawing mode before loading.
Review files
Movie export controls resolution, encoding profile, pixel format, and audio codec. Image-sequence output includes OpenEXR compression and half-float or float pixels. An export option includes annotations, although movie output only retains drawings inside the image boundaries. PDF export places frame images and notes into a review document.
Session files preserve media references, annotations, and viewing settings for reopening. OpenTimelineIO output preserves the playlist’s edit structure.
Python integration
The Python panel runs all code or a selection through the viewer API and displays its output. Plugins add menus and actions. A ComfyUI integration receives images through a socket connection.
Feature licenses
The base download includes playback, image and movie saving, and limited remote review. Solo unlocks full annotations and color-area selection. Standard adds Python, and Edit adds editing and OpenTimelineIO saving. Pro includes voice and link annotations plus unlimited WebRTC review. Pro+ makes the license transferable between machines.
