About structure for media (M)
M1
C1

M1
- Filetype (video or sound)
- Timeline Layout Color
(orange or purple)

« Color » : This is ALSO a dynamically computed method, with following formula
-If position of media M is even in timeline description: color is orange
- If position of media M is odd in timeline description: color is purple

As a consequence, when we do manipulation such as on previous slide, Media description does NOT change either !
Only timeline changes from (M1, M2, M3, M4) to (M1, M2, M4, M3)

M2

M1
C1

C2

M4

M3
C3

C4
M4

C5
M3

2.5 What about other objects ?
All other “visual” objects in Alexandra should also be “ported” to use relative time TR:
-

comments (“bubbles”)
“black cursors”
“sommaire” comments

reason is always the same, if a user has commented a video and you move the video, you
should move the comment with the video, and so on...



Seek (TA) -> seeks presentation at absolute time TA,
TRtoTA (Media, TR): this method returns TA,
TAtoTR (TA): this method returns Media and TR,
Possible way to do this. For each cursor C, store in database associated media M, relative time
TR, and absolute time TA as a “computed field” – when you call that field, a method is
actually started that returns the result of the computation: TA.
[I don’t know if mysql is object oriented enough to allow this, I am pretty sure that Flex
allows this and this is enough. That would be the best since such a structure allows almost
same syntax to sort on absolute or relative time. We need to sort on absolute time for things
such as comments in video HTML view above... ]

2.4.1 Structures for Media, Cursors, Timeline
Advantages of such method explained slide 25 and 26 of NewScreen.ppt (copy below)
Structures
M2

M1
C1

C2

C3

C4

C2

-TR1
-M1
-TA1

-TR2
-M2
-TA2

C5

Timeline description = (M1, M2, M3, M4) [ordered set of medias]

Initial cursor description
C1

M4

M3

C3

C4

C5

-TR3
-M3
-TA3

-TR4
-M3
-TA4

-TR5
-M4
-TA5
Move a media by drag and drop
(similar to « reorganizing slides »
in PowerPoint / Speechi)
Note that « sync points » come
with the media that is moved.

C1

C2

C5

C3
M4

C4
M3
Final timeline

Final cursor description: unchanged !
Final timeline description = (M1, M2, M4, M3) [ordered set of medias]

C1

C2

-TR1
-M1
-TA1

-TR2
-M2
-TA2

C3

C4

C5

-TR3
-M3
-TA3

-TR4
-M3
-TA4

-TR5
-M4
-TA5
TA is not value, but dynamically computed method
(according to formula TA = TR + (duration of all other media positionned “before” the cursor)