Video playback for image stacks #1771

Requested solution or feature

In silx view it's possible to slice through a dimension like a video. The user selects the frame rate and clicks play, and the viewer automatically plays the frames at the specified rate.

It has been a recurring request for H5Web, so I thought I'd open an issue for it. If this is of interest to you please feel free to upvote and share your use case (scientific domain, example file, myHDF5/VS Code/custom app..., etc.)

Alternatives you've considered

A similar feature was proposed in #1758 specifically for stacks of binary JPEG/PNG images. The implementation made the playback automatic, though (rather than opt in via UI elements) and the frame rate was hard-coded.

Additional context

The solution needs:

• to work for all providers, including server-based providers like h5grove, which rely on potentially slow HTTP transfers;
• to handle very large images and very big image stacks without causing the browser to lag (buffering, domain pre-computation, etc.);
• to work for all image visualizations (Heatmap, NX Image, RGB, JPEG/PNG);
• to not clutter the UI for users who do not need this feature.

This follows the work started in #1578 and #1667 to make slicing through a dimension more smooth.

Concerning stacks of binary JPEG/PNG images, it requires reworking the Raw visualization (work started in #1768 and #1770).