Video transforms

Stored video files in Convertly Storage, or video fetched from a configured HTTPS or private-bucket origin, use the same CDN URL pattern as images. Pass poster or image-format params to extract a frame, video output formats to trim and transcode, or spritesheet/VTT formats for timeline hover previews. Use Image CDN → Transform Lab in the dashboard to preview posters, clips, and GIF output against stored files or library paths before you ship URLs to production.

Video poster frame example — Poster frame. `?t=3.5&w=800&format=webp`.

Video to GIF example — Animated GIF. `?format=gif&so=1&du=3&w=480&fps=12`.

Video spritesheet example — Spritesheet grid. `?format=spritesheet&w=140&cols=4&interval=3&du=20`.

Trimmed video clip example — Trimmed clip preview. `?format=mp4&w=1280&so=0&du=30`.

Poster frames

Extract a raster frame, then run the normal image pipeline (resize, format negotiation, smart crop):

https://cdn.convertly.sh/{endpointNamespace}/{videoFileId}?t=3.5&w=800&format=webp
https://cdn.convertly.sh/{endpointNamespace}/{videoFileId}?poster=1&w=1200&format=auto

Param	Purpose
`t` or `time`	Timestamp in seconds for the frame to extract.
`poster=1`	Explicit poster mode (useful with presets).
`w`, `h`, `format`, `gravity`, …	Same image params as raster sources.

Without poster, spritesheet, VTT, GIF, or video-format params, bare video URLs redirect to a signed download (302).

Animated GIF

Transcode a clip segment to an animated GIF on the CDN edge:

https://cdn.convertly.sh/{endpointNamespace}/{videoFileId}?format=gif&so=1&du=3&w=480&fps=12

Param	Purpose
`format=gif` or `gif=1`	GIF output mode.
`so` / `start` / `ss`	Clip start time in seconds.
`du` / `duration`	Clip length in seconds (max 300).
`w`	Output width in pixels (height follows aspect ratio).
`fps`	Frame rate (`4`–`24`, default `12`).

Spritesheets and trick play (VTT)

Generate a contact-sheet grid of sampled frames for scrub-bar hover previews:

https://cdn.convertly.sh/{endpointNamespace}/{videoFileId}?format=spritesheet&w=160&cols=6&interval=2
https://cdn.convertly.sh/{endpointNamespace}/{videoFileId}?format=vtt&w=160&cols=6&interval=2

Param	Aliases	Purpose
`format=spritesheet`	`format=sprite`, `spritesheet=1`	Single grid image of sampled frames.
`format=vtt`	`vtt=1`	WebVTT file mapping timestamps → `#xywh=` regions on the spritesheet URL.
`w`	`spriteW`, `video-spritesheet-w`	Thumbnail tile width in pixels (default `160`).
`h`	`spriteH`, `video-spritesheet-h`	Optional fixed tile height.
`cols`	`columns`, `spriteCols`, `video-spritesheet-columns`	Grid columns (`auto` ≈ square grid).
`interval`	`spriteInterval`, `video-spritesheet-interval`	Seconds between sampled frames (default `2`).
`frames`	`spriteFrames`	Max frames in the grid (default `36`, max `120`).
`spriteFormat`	`video-spritesheet-format`	Spritesheet image format: `jpg`, `webp`, `png`.
`so`, `du`, `eo`		Optional clip window (same as clip delivery).

Point a <video> metadata track or player thumbnail plugin at the VTT URL. Each cue references the spritesheet image at the same transform params with a #xywh=x,y,w,h fragment:

<video controls src="https://cdn.convertly.sh/{endpointNamespace}/{videoFileId}?format=mp4&w=1280">
  <track kind="metadata" src="https://cdn.convertly.sh/{endpointNamespace}/{videoFileId}?format=vtt&w=160&cols=6&interval=2" />
</video>

For one-off contact sheets without VTT, the Media API POST /api/media/storyboard remains available. CDN spritesheets use the same FFmpeg tile engine with interval-based sampling.

Clip delivery

Use video output formats (mp4, webm, mov, gif) to trim, resize, and transcode:

https://cdn.convertly.sh/{endpointNamespace}/{videoFileId}?format=mp4&w=1280&q=80
https://cdn.convertly.sh/{endpointNamespace}/{videoFileId}?format=webm&so=5&du=15&mute=1
https://cdn.convertly.sh/{endpointNamespace}/{videoFileId}?format=gif&so=2&du=4&w=480&fps=12

Param	Purpose
`format` / `f` / `fm`	Output container: `mp4`, `webm`, `mov`, `gif`, `spritesheet`, or `vtt`.
`so` / `start` / `ss`	Clip start time in seconds.
`du` / `duration`	Clip length in seconds (max 300).
`eo` / `end`	Clip end time in seconds.
`w`, `h`	Scale output (maintains aspect ratio).
`q`	Encode quality hint (`20`–`100`).
`mute=1` / `an=1`	Strip audio track.
`fps`	GIF frame rate (`4`–`24`, default `12`).

<video src="https://cdn.convertly.sh/marketing/demo-clip?format=mp4&w=1280&so=0&du=30" controls />

For full async video pipelines (audio extract, streaming packaging), use the media tools API or video streaming product.

Getting Started

Image CDN

Media Platform

SDKs & Integrations

Resources

Poster frames

Animated GIF

Spritesheets and trick play (VTT)

Clip delivery

​Poster frames

​Animated GIF

​Spritesheets and trick play (VTT)

​Clip delivery

Poster frames

Animated GIF

Spritesheets and trick play (VTT)

Clip delivery