OMwiki:Tech


[edit] Recording devices

[edit] Known issues

[edit] Possibly fixable

  • Rework modcopy to avoid mmap calls on JFFS2 filesystems (e.g., the OLPC-XO). Ticket
  • Investigate audio ground loops and prevention techniques

[edit] Dreamlist

  • Find a portable camera or device that records footage from two audio sources (e.g., XRL mic + ambient mic) time-synchronized to a video track.
  • Migrate to open-firmware cameras that record directly to Ogg; also include simplified on-camera editing. Elphel has completely-open network cameras supported by the Apertus community.
  • Auto-balancing, wireless, golfball-sized mics that are mutable by the camera. Best for when push-to-talk mics are not available.
  • Have cameras set to blur-out individuals broadcasting a 'do not record my voice, person, or both' flag via iPhones, RFID, or colored stickers as mentioned in Yochai Benkler's keynote at OVC 2009.


[edit] Editing

[edit] Known issues

  • Cinelerra-CV is buggy and somewhat dated. Wait for Lumiera to mature.

[edit] Possibly fixable

[edit] Dreamlist

  • Theora encoding via hardware acceleration (TI C64x+ DSP or an Elphel card?)
  • Find a sensible audio compressor to avoid the time-intensive task of adjusting audio to comfortable listening levels.



[edit] Archiving

[edit] Known issues

  • FTP on the Internet Archive is only available for item download and initial upload; item editing is browser-based.
  • Video playback on Internet Archive description pages (inc. <video> fallback) requires the presence of a Flash-based derived file. These derived files are manually deleted post-upload.
  • OpenMeetings.org is not crawled by the Wayback Machine.

[edit] To-do

[edit] Dreamlist

  • Implement template support on the Internet Archive description pages.
  • Secure logins + strong item deletion-prevention.



[edit] Distribution

[edit] Known issues

  • Forgo Media RSS ver. 1.5.0 and start on a sensible ver. 1.6. Ver 1.4 is OK.

[edit] To-do

  • Implement content delivery network, which will involve site migration.

[edit] Dreamlist


[edit] OMwiki issues

[edit] Known issues

  • Find a way to add style="width:352px;" to embed code in 352×240 streams and fix aspect ratio for 352×240 thumbnails when in category view.
  • Google Chrome has buggy Theora support.
  • Edit MediaWiki:Common.js to download animated gifs only when 'show' is clicked to avoid long page loads.
  • Speaker labels work for annotations but not transcripts.
  • Search works but has a few issues (punctuation stripped, 'play inline' plays audio although video is paused, search-by-date not yet enabled for all videos)
  • White-on-black site design works well for focusing attention on video streams (right?), but fares poorly for text-heavy pages. Implement an automatic "turn down the lights" feature when video is in a 'play' state.

[edit] To-do

  • Add a Vorbis-only option on video streams for low-bandwidth connections.
  • Turn on OpenID logins. Need to figure out how to link non-PEAR libraries to non-recompilable PHP or upgrade web hosting.
  • Figure out AJAX auto-complete magic.
  • Fix Google search listing.
  • Start up project blogging, @openmeetings.org email addresses, and listing of similar projects.

[edit] Dreamlist

  • Ideas on MetaVid-l (e.g., Identi.ca integration)
  • Replace animated GIFs with low-FPS, enlargeable, jump-to-timecode Theora. Alternatively, use Pad.ma-style mouse-overs (see $(imagePoster).load(function() {...})). The thumbnails should cycle through the meeting in large time chunks when non-mouseover'd, and then display clickable frames according the how far the mouse is from the left edge when mouseover'd. Include ability to pause all animations and step-through lock-step upon mouse clicks.



[edit] Video post-processing

[edit] Known issues

  • No video post-processing is implemented.

[edit] To-do

  • Figure out best options to breakdown tons of video.
  • Fixup and advertise availability of echo.openmeetings.org for compute tasks.
  • Machine synchronization of known-good transcripts to video (i.e., match individual words to the exact timecode spoken).

[edit] Dreamlist

  • Identify a way to output time ranges generated from multi-speaker audio files, with each time range corresponding to the duration of how long a person spoke for (CMU Sphinx?). Hopefully add speaker identification based on the vocal profile, and maybe even facial recognition and emotional categorization (e.g., laughter).
  • Have individuals appear as virtual avatars in-video (i.e., Second Life or Avatar-esque), according to user preference.



[edit] External apps/reuse

[edit] Known issues

[edit] To-do

  • ffmpeg/mplayer seems to handle duplicate Theora frames poorly, breaking A/V sync and thus limiting video reuse. Submit bug report.
  • Draft a script to import MetaVidWiki clips from apps that can produce .srt or .cmml captions (e.g., Gnome Subtitles)
  • Figure out a easy way to integrate playback with blog platforms, including various commenting systems (i.e., plugins). Known hacks

[edit] Dreamlist


[edit] Minor things

  • USB headsets crash spontaneously (error message usb_set_interface failed in Debian Squeeze).



[edit] Communicate:



[edit] Non-technical development

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