Lipsync (decl)

LipSync declarations define the associated visemes to use in order for a character to convincingly speak the given text.

Syntax

lipSync [lipSync Name]
{
description  [description]
text     [text]
visemes  [lang]  [data]
visemes  [lang]  [data]
visemes  [lang]  [data]
...
}

The first line begins with the text “lipSync” which defines this declaration to be of the lipSync type. This is followed by the name of the declaration.

The declaration is then opened with an opening bracket and closed with a closing bracket.

Inside the declaration is a series of fields and values. All values are strings enclosed in quotation marks.

• [description] - The spoken text.
• [text] - This field is in the form of a string reference. The value resolves to the translation of the spoken text as gathered from the coorisponding language file .
• visemes - Two values are assigned to this field…
• [lang] - The language for which the viseme data applies.
• [data] - The actual viseme data.

Visemes

According to wikipedia a viseme is…

A viseme is a facial position that articulates a certain sound in speech. A viseme is the visual
equivalent of a phoneme or unit of sound in spoken language. Using visemes, the hearing-impaired can
view sounds visually - effectively, "lip-reading" the entire human face. In computer animation,
visemes can be used as intermediate poses to give the illusion of speaking.

So in the case of Quake 4, the data field of a visemes line is comprised of a series of visemes. Each of which describes to the engine the state of the face of a character much like key frames in an animation. When these visemes are applied to a character in sequence it gives the apperance that the character’s facial movements are in sync with a given sound.

Visemes Syntax

As an example taken directly from Quake 4 source files, the viseme data for “On my way, sir.” looks like so…

"x12n <On> AA22z n3u <my> m3q AY3q <way> w8r EY7q x5g <sir> s3k ER17x x12o "

Some things to note…

• The use of <> to enclose words. These are markers to indicate comments. They are not interpreted by the engine. Their sole purpose is to make it easier for the end user to read.
• The use of phonemes as listed on Annosoft’s Phoneme Codes Webpage
• The use of a number directly following each phoneme. This defines the duration of a given phoneme. It’s currently unknown what unit of measure this is in. It could be frames, milliseconds, samples, ect…
• The use of a single lowercase letter directly following the duration. This defines the intensity of the phoneme for mouth movement, where a would be the lowest value and z would be the highest value.
• The use of spaces to separate both viseme groups and comments.

It is also possible to cue facial expressions by including the following modifiers in the visemes data field…

• {furrow}
• {idle}
• {confused}
• {puzzled}
• {scared}
• {happy}
• {pain}