Multimedia Video
Captions, accessibility and web multimedia
Captions, accessibility and web multimedia
Video content is more prevalent on the web than ever. Users are demanding that the content of the web be more exciting, interactive and useful.
As the functionality of the web increases people are finding more and more uses for using the Internet and accessing its content. Video in particular is being increasingly popular for distance learning, promotional interests, and entertainment and is now a significant part of overall web content offering. For those users who are deaf or hard of hearing, accessibility to video and audio content remains an issue. Captions and transcripts are used to give these users access to the material within the videos.
Open and Closed Captions
Captions can be either open or closed. Open captions are those which are part of the encoded media itself, they cannot be disabled and are always shown when the video is played. Closed captions may be optionally displayed and are not part of the media visual media itself. There are advantages and disadvantages to both types.
Because closed captions are not a separate part of the media, they can be accessed and indexed by the search engines separately. Currently the search engines are not able to index video media itself and so having the content captured in a separate data files in the form of closed caption text allows access allows the search engines to index the material which would not otherwise be possible. Closed captioning however places a burden of responsibility on the viewer for accessing the captions. In addition the capabilities of the software that is used to display the video may all may not permit the showing of captions.
Open captions however are always displayed when the video is shown so this burden of responsibility is taken away from the user. However because the captions form part of the media itself they will not be indexed in the search engines. A further disadvantage of open captioning is that it does suffer from a reduction in quality when the encoded video is compressed.
Captioning Guidelines
Wherever captions are used there are guidelines on the format that should be followed. These include:
1 The captions should be synchronised with the text content audio content
2 The caption should provide equivalent content and convey the same meaning as the audio
3 The captions should be readily accessible to the user.
Multimedia technologies and captioning
The primary technologies for online video today include Macromedia flash, Windows media player, QuickTime from Apple and RealPlayer from RealNetworks. Regrettably there is no fully standardised format used across each of these technologies however there are many similarities. The formatting and presentation of captions used in these multimedia technologies includes a file to control the layout and presentation of the caption and another to hold the captions themselves while some technologies may use both others combine the two functions into the one file.
QuickTime
QuickTime uses two files. A synchronised multimedia integration language (SMIL) file controls the layout and presentation while a separate text track file stores the captions themselves together with their timings.
RealPlayer
Similar to QuickTime, RealPlayer uses and SMIL and a separate text file to store the captions and timings.
Windows media player
Windows media player incorporates captioning into one file called synchronised accessible media interchange (SAMI)
Macromedia flash
Macromedia flash uses a timed text file that details the captions, timing and presentation.
About the Author
James Evanns
Articles, Captions, Transcripts for Web Accessibility and SEO
http://www.seotranscript.com
james.evanns@seotranscript.com
What is Multimedia?
|
|
Diamond Multimedia VC500 One Touch Video Capture Device-NEW IN SEALED BOX!! $39.00 |
|
|
Multi Media Movie Home HDTV RMVB AVI Video JPG GIF Photo MP3 Aduio Player Center $24.40 |
|
|
Sony VPL-ES1 Multimedia Video Projector WITH REMOTE & CABLES $499.95 |
|
|
Theater Multi Media Home HDTV TV Video Photo Aduio Player w/ Remote Controller $24.40 |
|
|
Diamond Multimedia AGP video card $4.95 |
|
|
Diamond Multimedia AGP video card $4.95 |
|
|
3.2 INTEL QUAD CORE I7 Pro Multimedia and Video Editing PC $1,055.18 |
|
|
Diamond Multimedia AGP video card $4.95 |
|
|
Diamond Multimedia VC500 One Touch Video Capture Device – 2Q29111 $44.95 |
|
|
MS Project 2003 CBT Video Multimedia Trainings 7+hours $9.95 |
|
|
Digital Video: An introduction to MPEG-2 (Digital Multimedia Standards Series) b $25.00 |
|
|
MPEG Video Compression Standard (Digital Multimedia Standards Series) (Digital M $59.00 |
|
|
Envizen Digital Emc01 Digital Multimedia Player Audio Player, Video Player, $50.52 |
|
|
SMP MOD-V6-S2G 6 WAY 2GHZ MULTIMEDIA VIDEO SPLITTER NIB $9.95 |
|
|
NEW Diamond Multimedia Radeon HD6670 PCIE PCI-e/Express Video Card $99.99 |
|
|
LEVITON TELCOM 41292DVW MULTIMEDIA OUTLET SYSTEM 3 RCA COMPONENT VIDEO $30.00 |
|
|
Ideal 33-856 (NO REMOTE) VDV Multimedia Voice, Data ,Video Cable Tester $36.99 |
|
|
NEW LOGITECH 5.1 MULTIMEDIA VIDEO GAME CONSOLE ADAPTER $18.95 |
|
|
Portable Eyewear 72″ 16:9 Widescreen Multimedia Player Portable Video Glasses Vi $328.00 |
|
|
Multimedia Music Video Editing Website Design Software Program Bundle $38.95 |
|
|
Multi Media Movie Home HDTV RMVB AVI Video JPG GIF Photo MP3 Aduio Player Center $24.40 |
|
|
Theater Multi Media Home HDTV TV Video Photo Aduio Player w/ Remote Controller $24.40 |
|
|
New! NERO 11 Multimedia Suite software Photo Music Video Burn CD/DVD Retail Box $29.97 |
|
|
Digital Multimedia 7 Inch Photo Frame w/ Remote (Music and Video Playback) $65.00 |
|
|
iLuv 8.5″ Multimedia Player for you iPod and DVD Video Play back from DVD & iPod $149.00 |
|
|
Portable Eyewear 72″ 16:9 Widescreen Multimedia Player Video Glasses 4GB $199.90 |
|
|
Dynamic Video Glasses 72 Inch Virtual Screen multimedia $123.99 |
|
|
MULTIMEDIA VIDEO EDITING PRESENTATIONS MOVIE MUSIC SOUND CLIPS CLIP ART PUBLISH $4.95 |
|
|
6 Touch Screen 4GB Multimedia”music/videos” Players $250.00 |
|
|
Multimedia Communications and Video Coding (The Language of Science) – Hardcover $19.84 |
|
|
Cyber Acoustics CA-3090 Multimedia Speaker System 2.1-channel Video Game Adapter $31.31 |
|
|
Hauppauge 1344 MediaMVP-HD Digital Multimedia Player,USB,HDMI,S-Video,S/PDIF NEW $88.08 |
|
|
Video Card, Multimedia Card, Modem, Network Card, Lot of 5 $0.99 |
|
|
Diamond Multimedia BizView 195 USB Video Card DVI VGA $63.61 |
|
|
Multimedia Media Player Music Video Editing Software Program Collection $38.99 |
|
|
Video Frame plus…Audiovox DPF711K Multimedia Message Center Audio+Video $3.99 |
|
|
Diamond Multimedia Vc500 Best Data Vc500 One Touch Video Capture Device – Usb - $37.35 |
|
|
Screenplay Tv Link Digital Multimedia Player – Audio Player, Photo Viewer, Video $113.11 |
|
|
REFURBISHED Optoma EP761 XGA DLP Multimedia Data Projector VGA DVI S-Video USB $794.74 |