Growing Book -> SMIL
- The Growing Book -> SMIL translator is implemented in C and takes two parameters: a time limit L, and
file containing the MAWC tag structure. It then creates a SMIL presentation of length L in the file "presentation.smil." Each level in the original tag structure receives
equal time in the presentation. Appropriate media object elements for any text, image, video, and audio objects are created, and any text, image, video, and audio objects of the
same level are played simultaneously for the length of time allotted to the level. The image for the level is displayed
in the top left hand corner of the presentation window, the video in the top right hand corner, the text across the bottom
of the window (with a scroll bar in case the text does not fit into the window), and the audio is played simulatneously.
- Because SMIL expects text objects to be stored in a text file, rather than in
an html file as in the Growing Book structure, the lynx program was first used to
create plain text files from the original html sources.
- In order to preserve the values of the parameters of the tag structure in the SMIL presentation:
- the "subsection" value is stored as the "abstract" value in the media object elements in the SMIL presentation
- the "name" vaue is stored as the "title" value in the media object elements in the SMIL presentation
- the "keywords" value is stored as the "alt" value in the media object elements in the SMIL presentation
- the level of the object is stored within the "id" value in the media object elements in the SMIL presentation
- the "url" value is naturally stored in the "src" value for audio, image, and video objects in the SMIL presentation. However, because the src of any text objects is
the file created by lynx and not the url, the "url" value is stored in the "alt" value
of a text object along with any keywords.
- The following assumptions were made about the Growing Book MAWC tag structure:
- all media objects of a particular type are arranged in order of their level
- a video, image, or audio object only exists for a particular level if a text
object exists for the level.
- The following errors are looked for in the Growing Book MAWC tag structure:
- an invalid tag is used
- a closing tag does not match its opening tag with the appropirate tag type, or level or an opening tag has no closing tag
- a tag parameter does not have a value
- an invalid parameter type is used
- The source code for the translator, tagstoSMIL.c, is available here. tagstoSMIL.c uses tagtostruct.h, which is available here.