[Music]
Hello, my name is Alejandro Rodríguez Ascaso.
I am a professor at the Department of Artificial Intelligence at UNED.
This video is entitled "Audiovisual accessibility, sound information".
We know that the video is not only a sequence of
images, but also sound content synchronized with it.
Can everyone perceive and understand the sound information of a video?
Well, no. There are people, deaf, whose way
of communicating is through the sign language.
Other deaf people prefer to read subtitles.
There are also those who do not master
the original language of the video or are
in a noisy environment. Other people watch the video without
being able to activate the audio.
By the way, did you know that most of those who watch
videos on social networks do it without volume and using subtitles?
If we analyze how the information of
the video is perceived by the person,
the image is perceived through the eye and
the sound is perceived through the ear.
Now that we know that not everyone uses videos in the same way and
that we agree that the idea is that our video
reaches as many people as possible, what can we do?
Subtitles or sign language offer visual information that is equivalent
to the sound content of the video and that is synchronized with it.
That information is perceived by the sense of sight.
These adaptations do not replace the sound content.
They are contents that can be shown simultaneously to the audio.
In fact, many people prefer to have
both types of information at the same time.
To adopt our sign language video, we must have an expert in
its interpretation. To ensure that it
reaches adequately to those who need it,
interpretation in sign language must meet certain requirements, including
being located at the bottom right of the video, having a sufficient size,
and that the clothing of the person who
interprets contrasts with their skin color,
and an adequate quality of the image.
Another adaptation of sound information is that of subtitles.
It is text that is shown on the screen, equivalent
to the relevant sound information of the video.
For the subtitles to really reach people with hearing disabilities,
they must meet certain characteristics.
Subtitles appear centered at the bottom of the screen,
occupying two lines and only exceptionally up to three.
There is also a limit to the width of each
subtitle, measured in number of characters.
Subtitles must be literal and be well synchronized with the audio.
Voices in off must be subtitled, that is,
the voices of characters that do not appear on the screen.
Subtitles must describe sounds such as music, background noise,
animal or thing sounds, etc., that are relevant
to the message transmitted by the video.
When there are different voices, the speaker must
be identified to the one that corresponds to each subtitle.
Sometimes, instead of labeling, the technique
of assigning a different color to each character is used.
But some deaf people complain that, as
there are colors that are always assigned
to important characters in the plot, if
at the beginning of a suspense film a guy
with a bad face appears to whom they put
the subtitles in yellow, which is usually
the main character, will he be the killer?
Well, maybe yes, maybe no.
Do you think it is difficult to subtitle your own video?
You would be surprised how easy it is to do it.
You just have to take your video and upload it to YouTube.
YouTube automatically generates subtitles that
do not meet the minimum quality conditions that we have seen above.
But we can use them as a base.
We edit them and improve them in a reasonably simple and fast way.
Be careful, you already know that if you upload the video
to the Internet, it is possible that your
video is available worldwide and beyond.
If you don't want that to happen, you must
properly configure the distribution of your video.
Let's go over some more technical questions about subtitles.
Subtitles should not be embedded in the video as an image.
They must be in a separate file, a text file.
If we have a subtitle file and we feel curious...
you already know what happened to the cat
with this curiosity, but hey, go ahead.
If we open a subtitle file to see what it
contains, we will check that it contains
the text of our subtitle and also some
time codes that are the ones that indicate
to the player that each subtitle appears
and disappears when it is his turn.
Luckily we don't have to write that file,
the program we use to generate the subtitles
already does it, whether it's YouTube or any other.
But it is interesting that these programs
allow us to download the file or the subtitles
to reuse it as many times as we want.
In addition, having the subtitles in a separate
file and therefore not embedded in the video has many advantages.
Subtitles can be shown or hidden, it is
possible to have them in different languages,
they contribute to our video being better
indexed in search engines, that is,
it is easier to find it on the Internet.
In addition, so whoever uses our video can
choose the type, size and color of the subtitles,
as well as the contrast with the background.
And even more, the text can be converted
to other perception channels, for example
Braille, useful for some deaf and blind people.
In short, let's make our videos meet
the needs derived from human diversity.
Let's make sure that subtitles and
sign language interpretation meet the
accessibility criteria, in order to enjoy all the advantages.
A final tip, think about accessibility from the
beginning, from the moment you write your script.
When designing how your video will look
visually, reserve space to show the
subtitles and sign language interpretation.
You will do great!
Until the next video!