Hello, my name is Craig Chapman, and I attempting to create
quick time movies from global motion stimuli I am running with
psychtoolbox.
While I have been able to produce a screen sized movie of my 8
frame stimulus, I am still struggling to determine what each of
the parameters mean while creating the movie. In addition my
movies are over 50 megs which seems a bit excessive
compared to the 2.6m movie created by the demo.
First, I don't really understand the purpse of the
'videoTrackCreate' function, especially the variable
'trackTimeScale'. I apologize in advance that I have no
experience with QuickTime, but I attempted to access the QT
documentation and could not find a function with the same
name.
Similarly, while I understand that each call to
'videoMediaSamplesAdd' adds another frame to the movie, I
don't get reliable times when I vary the frameDuration variable. I
guess I might not be sure of its units.
What I find most confusing is deciphering the ShowTimeDemo.
I am unclear how a single call to 'videoMediaSamplesAdd' on
line 80 can make a seamless multiple frame movie. I am under
the impression that each frame needs to be added separately.
I understand that I am doing and thinking many things
incorrectly, and what may be most helpful is another sample of
code that I could look at to see these functions in action. Any
answers, help or samples would be much appreciated,
Thanks in advance,
Craig Chapman
quick time movies from global motion stimuli I am running with
psychtoolbox.
While I have been able to produce a screen sized movie of my 8
frame stimulus, I am still struggling to determine what each of
the parameters mean while creating the movie. In addition my
movies are over 50 megs which seems a bit excessive
compared to the 2.6m movie created by the demo.
First, I don't really understand the purpse of the
'videoTrackCreate' function, especially the variable
'trackTimeScale'. I apologize in advance that I have no
experience with QuickTime, but I attempted to access the QT
documentation and could not find a function with the same
name.
Similarly, while I understand that each call to
'videoMediaSamplesAdd' adds another frame to the movie, I
don't get reliable times when I vary the frameDuration variable. I
guess I might not be sure of its units.
What I find most confusing is deciphering the ShowTimeDemo.
I am unclear how a single call to 'videoMediaSamplesAdd' on
line 80 can make a seamless multiple frame movie. I am under
the impression that each frame needs to be added separately.
I understand that I am doing and thinking many things
incorrectly, and what may be most helpful is another sample of
code that I could look at to see these functions in action. Any
answers, help or samples would be much appreciated,
Thanks in advance,
Craig Chapman