Automatic captions in YouTube
11/19/2009
Since we first announced captions in Google Video and YouTube, we’ve
introduced multiple caption tracks, improved search functionality and even
automatic translation. Each of these features has had great personal
significance to me, not only because I helped to design them, but also
because I’m deaf. Today, I’m in Washington, D.C. to announce what I consider
the most important and exciting milestone yet: machine-generated automatic
captions.
Since the original launch of captions in our products, we’ve been happy to
see growth in the number of captioned videos on our services, which now
number in the hundreds of thousands. This suggests that more and more people
are becoming aware of how useful captions can be. As we’ve explained in the
past, captions not only help the deaf and hearing impaired, but with machine
translation, they also enable people around the world to access video
content in any of 51 languages. Captions can also improve search and even
enable users to jump to the exact parts of the videos they’re looking for.
However, like everything YouTube does, captions face a tremendous challenge
of scale. Every minute, 20 hours of video are uploaded. How can we expect
every video owner to spend the time and effort necessary to add captions to
their videos? Even with all of the captioning support already available on
YouTube, the majority of user-generated video content online is still
inaccessible to people like me.
To help address this challenge, we’ve combined Google’s automatic speech
recognition (ASR) technology with the YouTube caption system to offer
automatic captions, or auto-caps for short. Auto-caps use the same voice
recognition algorithms in Google Voice to automatically generate captions
for video. The captions will not always be perfect (check out the video
below for an amusing example), but even when they’re off, they can still be
helpful—and the technology will continue to improve with time.
In addition to automatic captions, we’re also launching automatic caption
timing, or auto-timing, to make it significantly easier to create captions
manually. With auto-timing, you no longer need to have special expertise to
create your own captions in YouTube. All you need to do is create a simple
text file with all the words in the video and we’ll use Google’s ASR
technology to figure out when the words are spoken and create captions for
your video. This should significantly lower the barriers for video owners
who want to add captions, but who don’t have the time or resources to create
professional caption tracks.
To learn more about how to use auto-caps and auto-timing, check out this
short video and our help center article:
http://www.google.com/support/youtube/bin/answer.py?answer=100077
http://www.youtube.com/watch?v=kTvHIDKLFqc
You should see both features available in English by the end of the week.
For our initial launch, auto-caps are only visible on a handful of partner
channels (list below*). Because auto-caps are not perfect, we want to make
sure we get feedback from both viewers and video owners before we roll them
out more broadly. Auto-timing, on the other hand, is rolling out globally
for all English-language videos on YouTube. We hope to expand these features
for other channels and languages in the future. Please send us your feedback
to help make that happen.
Today I’m more hopeful than ever that we’ll achieve our long-term goal of
making videos universally accessible. Even with its flaws, I see the
addition of automatic captioning as a huge step forward.
* Partners for the initial launch of auto-caps: UC Berkeley, Stanford, MIT,
Yale, UCLA, Duke, UCTV, Columbia, PBS, National Geographic, Demand Media,
UNSW and most Google & YouTube channels.
Posted by Ken Harrenstien, Software Engineer
Source:
http://googleblog.blogspot.com/2009/11/automatic-captions-in-youtube.html