Conference hydra::amiga_v1

5309.0. "narrator, video problem?" by MKODEV::OSBORNE () Mon Dec 30 1991 11:41

In a program I am writing, I am attempting to use the narrator device with
a set of Bobs to show a character speaking. The narrator device will send
messages indicating mouth shapes while it is providing the "speech", such
as it is. I poll the narrator device while it is "speaking" as rapidly as
possible, and change the Bob image to reflect the mouth width/height when
appropriate. This process is similar to speechtoy, the old demo program.

However, I double-buffer the screen (to prevent flicker of the Bob drawing),
and something about switching between the two images causes a "click" in
the output speech, so that when I rapidly change the Bob images, there is
a staccato "tick" added to the audio output.

Since I can play sampled sounds while the Bobs are switching without any
apparent noise on the audio, I assume the narrator device is having some
problem with the bus while Agnus or Denise are flipping the image. I use a
call to the Intuition function RethinkDisplay to modify the image after the
gels list is sorted. 

Has anyone else encountered, and hopefully, solved, this problem? I can use
a group of hardware sprites to replace the Bobs, but it's a lot of work, if
there's a simpler solution.

Thanks
John O