Ubuntu Wiki

• Launchpad Entry: screencasts-in-ubuntu

• Created: Date(2007-09-27T12:00:00Z)

• Contributors: AlanPope

• Packages affected:

• See also: https://wiki.ubuntu.com/UltimateScreencastingApplication

Summary

This spec describes Screencasts In Ubuntu whose aim is to develop an infrastructure to allow tutorial videos (screencasts) to be easily accessed from the Ubuntu desktop, and directly from within the online help for applications.

Rationale

The goal here is to make tuition video content directly available in Ubuntu. This content would be produced by the Ubuntu Screencasts team and it would be made available directly on the desktop using the standard help browser. The videos would be embedded directly in yelp, being streamed from a localized ubuntu screencast server (CC.screencasts.ubuntu.com/foo/bar/baz). The videos should be easily accessible to someone looking for help. It therefore could make sense for them to be embedded inside the online help. That way the user goes to one location for text based help, screenshots and videos.

Use Cases

• John buys a new Ubuntu system from Dell and wants to get started. When he logs in, a little notification bubble pops up telling him tutorial videos are available by clicking System->Tutorial Videos. He clicks the menu and a little program appears with a range of general purpose tuition videos.

• Paul wants to learn how to use OpenOffice.org Writer - he clicks Help->Tuition Videos and the window appears with a range of videos for different tasks in that application.

• Daniel is keen to learn how to contribute to Ubuntu. He clicks System->Contribute->Tuition Videos. Here the window appears and has a number of videos for packaging, bug triage, translations etc are available. He can now get started learning how to contribute easily.

• Sarah is installing Ubuntu. When she boots from the CD and the desktop starts, a small window appears offering her a video tutorial of how to install Ubuntu.

Scope

Due to the nature of the spec, the scope reaches into a number of distinct areas:-

Embedded in Help option

• Client
  • Yelp + Totem plugin

Common elements

• Server side hosting and management
  • Deployment of videos to server infrastructure
  • Streaming technologies

Design

Playback

A simple interface for playback should be used. Something similar to that used by other media players (such as Totem).

Application Integration

Individual applications should have their "help center" (most likely a menu item) modified to provide a link to start the screencast playback client. The application should pass to the client it's own name and version to allow the client to pre-filter the list of available screencasts and thus make it context sensitive.

Server hosting

We would need a means to store screencasts somewhere so that the client can request them. Launchpad seems a sensible place here, but any structured filesystem would also be suitable. Storing on

This would also require an investment from IS regarding serving and bandwidth. We would need to determine bandwidth requirements and affordability.

The server should host:-

• Screencasts in Ogg / Theora / Vorbis format for streaming by the totem plugin over http
• Screencast meta-data
  • Release of Ubuntu that each screencast pertains to
  • Application(s) and versions of, that each screencast pertains to.
  • Size, date created, popularity, duration, and availability of audio tracks and subtitles
    • Data can be gathered from standard web server log analysis

Implementation

Unresolved issues

• Localization
  • Subtitles - can they be shown in a video that is streamed? (we know that .srt files can be loaded from the local fs)
  • Alternate audio streams, dub audio on top of the video
  • language on the desktop when the recording is made.
  • Full localization is linear in the number of languages both in effort and diskspace.

Factors in size of vidoes

• resolution

  • currently 1024x768 -> 1280x720

  • make them the minimum size useful for driving the point down
• duration
  • currently 5 to 35 minutes
  • codec/bitrate video/audio
    • Flash is a possibility, but is a non-free format.

BoF agenda and discussion

The tools ========= * recording:

• we want only free tools
• xvidcap:
  • not in universe, because of legal problems with the parts we don't use (ffmpeg,...)
  • could motu package a clean version?

* all current apps have limitations * editing:

• avidemux: could motu package this with added ogg theora/vorbis support?

* documented in the wiki * possibility to use xnest and simplify

How to make it easier to contribute:

• xvidcap in universe/multiverse

• Extend existing screencasting applications like Istanbul or RecordMyDesktop

• avidemux to have ogg support

• Make this:- UltimateScreencastingApplication

Comments

[https://wiki.ubuntu.com/Daengbo Daengbo]: I think this would be most easily accomplished by having RSS feeds for each release and category. The video help system would then just be a simple RSS parser which listed, for example, the 8.04 videos tagged with Rhythmbox. If there is a specific order to the videos (basic to advanced), that could easily be set server-side. I guess mousing over the name of the video would bring up a short description, and clicking on it would just open a link to the video with Totem (or preferred player). This is a great idea!! My only complaint is that the screencast team now mispronounces Ubuntu, so the screencasts will need to be a little more professional. Bandwidth could be saved by integrating bittorrent into the download client, but I think that's too much for a Hardy release.

[https://wiki.ubuntu.com/Daengbo Daengbo]: One more thought about bandwidth. The videos could be packaged as part of the documentation, installed upon the first request to view the video. This would solve the problem of bandwidth, since the packages are already mirrored.

Related specifications and projects

CategorySpec