Download presentation
Presentation is loading. Please wait.
Published byMaxwell Chad Modified over 10 years ago
1
Concepts & Techniques for Accessible, Closed Captioned Web-Based Video 10th Annual Accessing Higher Ground: Accessible Media, Web and Technology Conference Boulder, Colorado November 7, 2007 http://disability.law.uiowa.edu/lhpdc/publications/kleinpubs.html David Klein K. “Fritz” Thompson
2
Interactive Who are you? Why are you here? What would you like to know? What are your expectations from this workshop?
3
Overview Introduction to accessible web-based video Compression Captioning (activity) (Break?) QuickTime (activity) Our Flash player (activity) Embedding content in a web page
4
Introduction Law, Health Policy & Disability Center Grant-funded research, technical support, & training
5
Our Needs Provide accessible web-based training Quality video with high quality audio Closed captions Transcripts Supporting documents (PowerPoints, Handouts, etc.) Different formats (QuickTime, Windows Media Player, Flash) Efficient production, development, and deployment Frustrated with “player wars”
6
Our Video http://disability.law.uiowa.edu/dpn/video/dpn_ 112004/dpn_112004_index.html http://disability.law.uiowa.edu/dpn/video/dpn_ 112004/dpn_112004_index.html http://disability.law.uiowa.edu/dpn/video/dpn_ 112004/dpn_112004_index.html Over 100 hours of online video for training Mostly talking heads
7
Feature Choices Player choice Flash player (default) QuickTime Windows Media Player Uncaptioned versions Embedded in web page vs. standalone Automatic play vs. user initiated Resizable Metadata, transcript, supporting documents
8
Overview of the Technologies
9
Players QuickTime Windows Media Player Flash Player
10
The Technologies Clients and servers Plugins or whatever Downloading Embedding video in web pages Captioning Flash
11
Clients vs. Servers Server Clients
12
Server vs. Client Server Stores HTML, video, caption text, other files Files can be stored on different servers Some dynamic content (e.g., databases) Client Displays content Interface to the user Dynamic Assembles files / content into a whole presentation
13
Client View Browser Window Embedded Player with Controls Video Captions Links to supporting documents
14
Embedded Captioned Video Embed in HTML File ServerClient Video File Caption File Combine Files in Player
15
Captioning Technologies XML Extensible Markup Language SMIL Synchronized Multimedia Integration Language SAMI Microsoft® Synchronized Accessible Media Interchange QuickTime caption file Apple DFXP Adobe Flash
16
Creating Accessible Video Start with video / audio of highest possible quality Acquire secondary audio source and/or CART (real- time caption) file if possible Capture, edit and compress video 3 output formats:.mov,.wmv, and.flv Attention to first frame Black Titling
17
Video Compression Examples Find folder “ahg2007CD” on desktop Open folder (double click) Double click “index.html” Select “Compare compression methods”
18
Web-Based Video Methods Download & play Video downloads completely; then plays Streaming Server sends packets of video to client “Progressive” download Video downloads, but starts playing as soon as possible
19
Download & Play Pros Reduces bandwidth issues Can play back without freezes Download and store for later play Cons Wait for file to download before playing Can be a long time No copy protection Archive only; not live video
20
Streaming Pros Short wait for start of video Can start in middle of video Cons High bandwidth required Freezes not uncommon Problems at client end (firewalls) Can be expensive Can copy protect Required for live video Useful for archived video
21
“Progressive” download Pros Short wait for start of video, depending on bandwidth Low bandwidth possible Store for later play Freezes possible but replay without freezes Copy resistance but no protection Archive only; no live video
Similar presentations
© 2025 SlidePlayer.com. Inc.
All rights reserved.