Help viewer in Qt version does not show movie

[Elaine Meng]

The Help viewer in the wx version of ChimeraX shows the movie in the Quick Start Guide, both an initial static image and a working "play" button, but in the Qt version it shows nothing. This is the second problem I've found in the Help viewer in Qt but not wx (see #370).

[Elaine Meng]

Now there are 2 movies in the documentation that won't play in the ChimeraX browser but will play in standard browsers:

(1) the one with "play" button in the Quick Start, about halfway down the page on the right:

https://www.rbvi.ucsf.edu/chimerax/docs/quickstart/index.html

(2) the immersive movie linked to the "virtual reality" page:

https://www.rbvi.ucsf.edu/chimerax/docs/user/vr.html#movie-details

[Greg Couch]

The problem is that the Qt viewer does not support h264 videos due to licensing issues. If we paid the appropriate licensing fees and compiled our own version of Qt, then we could have h264 videos.

So the workaround is to provide both h264 and webm (or Theora) videos. For example:

<video width="302" height="302" controls>
  <source src="images/spin.mp4" type="video/mp4">
  <source src="images/spin.webm" type="video/webm">
Your browser does not support the video tag.
</video>

That way, when viewed in a browser that does not support webm video (Safari, Explorer), it would use the h264 video, and in ChimeraX's help viewer, it would use the webm video.

To make that possible, I've enabled the webm and Theora (.ogg/.ogv) formats in the ChimeraX's movie command.

[Elaine Meng]

OK, but note that the movies in Quick Start and VR pages still can't be played in the ChimeraX browser. Somebody would have to create/add the additional format for them to work.

[Greg Couch]

Need webm versions of vr and quickstart movies in documentation.

[Tom Goddard]

The webm and theora movie recording you added do not work on Mac (probably other platforms too). It requires libvpx and libtheora dependencies and additional ffmpeg compilation options, none of which are currently in prereqs. Either that ffmpeg support should be added or those broken movie recording options should be taken out. Those are setup in Chimera 1 and if you wanted to add all that support you could look at Chimera 1 foreign/FFmpeg, although ChimeraX is probably using a newer FFmpeg so may have different build issues.

[Greg Couch]

Added OGG and WEBM codecs to ffmpeg on Linux and Mac OS X. This allows us to add a second video source to the <video> tag and support our internal browser.

Went ahead and generated the appropriate spin.ogv file for the quick start guide.

[Elaine Meng]

Thanks for checking the Quick Start and adding the movie.  I noticed it looks more dark and shadowy than it used to.  Maybe (although not shown in the Quick Start commands) originally it had been recorded after setting “light default”.

I may add that command and redo the movie at some point, but not urgent I guess.
Elaine