Closed Captions and Subtitles
This is Neil Hunt, Chief Product Officer at Netflix. We’ve had some
inquiries about why Netflix doesn’t yet provide closed captioning or
subtitles for streaming movies and TV episodes. Captioning is in our
development plans but is about a year away.
You might be asking how it could be so hard, since we already
subtitle foreign language streams with English subtitles. These
subtitles are “burned in” to the video stream at the time of encoding
– they are so-called “open captions” that cannot be turned on and off
by the viewer. The majority of viewers would object to English
captions on English content, so we have to figure out how to let
individual viewers turn them on and off.
Encoding a separate stream for each title is not an option – it takes
us about 500 processor-months to make one encode through the entire
library, and for this we would have to re-encode four different
formats. Duplicating the encoded streams is prohibitive in space too.
So we are working on optionally delivering the SAMI file
(Synchronized Accessible Media Interchange), or similar, to the
client, and having it render the text and then overlay it on the video
at playback time. Unfortunately, the tools for rendering SAMI files in
Silverlight, or in CE (Consumer Electronics) devices, are weak or
non-existent, and there is some technology development required.
I would expect to deliver subtitles or captions to Silverlight
clients sometime in 2010, and roll the same technology out to each CE
device as we are able to migrate the technology, and work with the CE
manufacturer to deliver firmware updates for each player.
Source:
http://blog.netflix.com/2009/06/closed-captions-and-subtitles.html