Media formats and limits
This page lists the kinds of files MultiTaction Canvus shows on a canvas, what happens to other files, and the limits you can configure.
How Canvus decides what a file is
When you drop a file on a canvas, Canvus identifies its type from the file name and contents (its MIME type), and creates an item to match:
| File type | Item on the canvas | More information |
|---|---|---|
Image (any image/... type) |
Image | PNG, JPEG, BMP, GIF, SVG and more. See below. |
Video (any video/... type) |
Video | Videos and 360 video |
PDF (application/pdf) |
PDFs | |
3D model, by extension: .glb, .gltf, .obj, .fbx |
3D model | 3D models |
| Anything else | File placeholder | See below |
Folders cannot be dropped on a canvas. Drop the files inside them instead.
Images
Canvus opens PNG, JPEG, BMP, GIF, SVG, TGA, DDS and ICO images on Windows and Ubuntu. A GIF shows its first frame as a still image. Canvus 26.11 cannot open WebP, TIFF or HEIC images. Convert them to PNG or JPEG before you add them.
Video files
Canvus decodes video files with FFmpeg. A file is treated as video when its MIME type is a video type. The FFmpeg version installed with Canvus 26.11 decodes H.264, HEVC (H.265, 8 and 10 bit), VP8, VP9, AV1, Apple ProRes, MPEG-2, MPEG-4 Part 2 and Windows Media Video. It reads MP4, MOV, MKV, WebM, AVI, MPEG-TS, MXF and WMV files. Audio in AAC, MP3, Opus, Vorbis, FLAC, AC-3 and PCM plays with the video. Smooth playback of high resolutions and frame rates depends on the computer, so test a sample of your largest files on the wall.
On a computer whose hardware video decoder misbehaves, set the environment variable VIDEODISPLAY_FORCE_SOFTWARE_DECODE=1 before you start Canvus to force software decoding. (From Canvus 26.06.)
For live video, see Video inputs and Video streams.
File placeholders
A file that Canvus cannot show, such as a Word, PowerPoint or Excel document, appears as a file placeholder: a card with the file name and a file-type icon. The file is still stored with the canvas, so you can:
- email it from the placeholder's sidebar;
- edit it over RDP, when an RDP connection is configured.
Mixed client versions
From Canvus 26.09.5, any 26.x client can open canvases from any 26.x server:
- A client that does not know an item type skips that item and loads the rest of the canvas. Before 26.09.5, the client dropped the connection instead.
- A client older than 26.07.4 shows 3D models as file placeholders.
- Features stored with an item, such as note Markdown mode, video looping and the 360 view, need a server new enough to store them. Each feature page says which version it needs.
Limits
Canvus does not enforce a maximum number of items on a canvas or a maximum file size for files you drop. The practical limits are the memory, graphics memory and network of your computers.
These limits apply. You can change each one in mt-canvus.ini, and all except the video background limits also on the settings page:
| Limit | Default | Setting |
|---|---|---|
| Canvas size for new canvases | 9600 px on the longer edge, no maximum | [canvas] size. See Canvas size and zoom. |
| Zoom in | 10x | Not configurable |
| PDF page image size | 2048 px | [pdf] raster-resolution. See PDFs. |
| Snapshot image size | 8192 px on the longer side (minimum value 256) | [system] max-snapshot-resolution |
| Snapshot scale | 1.0 | [system] snapshot-scale |
| Email attachment size | 32 MB | [mail] max-attachment-size, in MB |
| Preferred resolution range for live video sources | 800 x 600 px to 3840 x 2160 px | [video-stream] min-resolution, max-resolution |
| Preferred frame rate range for live video sources | 14 to 31 fps | [video-stream] min-fps, max-fps |
| Video canvas background (Canvus converts larger videos down to these) | 3840 x 2160 px, 30 fps, 20 Mbit/s | [system] background-video-max-width, background-video-max-height, background-video-max-fps, background-video-bitrate |
| Open files | 4096 | [system] max-open-files |
[system]
; Largest snapshot image, in pixels on the longer side. Values below 256
; are raised to 256.
; DEFAULT: 8192
; max-snapshot-resolution=8192
; Multiplier for the resolution of snapshot images.
; DEFAULT: 1.0
; snapshot-scale=1.0
[mail]
; Largest email attachment in megabytes.
; DEFAULT: 32
; max-attachment-size=32