Slide show time in / time out bug

[dvpaassen]

Hi Mike,

While playing with 11.2 rc1 i noticed something strange with
the time in time out of the picture Slide show.

Is it correct that the crossfade time cannot be more than half of the time
the picture is shown.

For example:
If I take 4 seconds as display time and i give 3 as crossfade time SCS gives 1 second fade time when playing the cue
when i fill in 2 it plays correctly.

Same thing with other times.

greetings,
Dennis van Paassen

[Mike Daniell]

Sorry for the delay in replying.

What you've said is basically correct but the algorithm is a bit more complicated, and hopefully you can see the reason for this overriding of the cross-fade time.

When SCS analyzes a slide show cue to work out fade-in/fade-out times it looks at the playlist fade-in time, the individual slide transitions, and the playlist fade-out time. Using this information it populates internally the fade-in time and the fade-out time for each slide. Now consider the cross-fade between slides 1, 2 and 3, assuming all 3 slides are set to display for 4 seconds each and you have set cross-fade times to 3 seconds. Assume the playlist fade-in time is blank (0). So we have:

• Display slide 1 for four seconds, with fade-out starting three seconds before the end, ie after one second.
• Start fading in slide 2 three seconds before the end of slide 1. However, because the cross-fade from slide 2 to slide 3 is three seconds, start fading out slide 2 just one second through the fade-in of that same slide (slide 2).

So slide 2 never gets fully faded in - it starts fading in for one second, gets to 1/3 of the fully displayed state, and then fades out over three seconds.

To allow slide 2 to get to the fully displayed state, SCS uses this algorithm for cross-fades, using slide 2 as an example:

1. Set slide 2's fade-in time to the calculated fade-out time of slide 1.
2. If this fade-in time is greater than the slide's 'Display Time' minus the 'Transition Time' then set the fade-in time to the slide's 'Display Time' minus the 'Transition Time'. This is to make sure the fade-in is completed by the time the fade-out is required to start.

SCS should probably display a warning message if the cross-fade time is overridden.