I’m in the process of creating a slideshow containing 170 or so photos (each imported as a still frame), most of which are displayed for only a second or two before transitioning to the next photo. The photo durations are set to correspond to changes in the corresponding audio track. Everything plays nicely in perfect synchronization from within the application on my iMac (27" 2013 model). This is unfortunately not the case after the project has been exported as a QuickTime movie, where the video begins lagging the audio after playing for only a few seconds. As the video continues to play the lag between the audio and video increases.
Quite a number of my frames are marked with the warning “Insufficient time to load next slide”, which is understandable since the display and transition times are typically squeezed very close together to achieve the visual effect my project requires (a photo is displayed for a second or so, then immediately dissolves to the next photo). I can see where this would be a problem when building a slideshow and previewing the work in realtime within the application. What I don’t quite understand is why the lag appears only in the exported movie where you would think that the rendering process would either duplicate precisely what is seen when previewing in the app, OR with the exported video leading (rather than trailing) the audio since the process of rendering is not realtime.
Is there a secret to keeping the video and audio tracks in sync when the slide durations need to be very short?
If you time the transitions visually to the music by trial and error, it might seem right during live playback because you already compensated for the loading delay. As soon as you export there is no more loading delay as the FotoMagico engine doesn’t have to render in realtime. To make sure the export is perfectly in sync, always use audio markers to sync audio and video.
Thanks Bastian, that makes a lot of sense. If I spread out my audio markers at various points within the audio track, is there a way to tell FotoMagico to automatically set the durations of the slides that fall between a set of audio markers? I can, of course, calculate this myself if I know that one marker is at 3:48 and the next is at 4:08, but I’m hoping the application can do this for me with a high degree of precision.
One additional question… Is there a way to have live playback mimic the timing syntonization I’ll see for an exported slideshow?
By using audio markers I’m now able to precisely set slide transitions for export. However, past the first couple of markers, the live playback within the application UI becomes far out of sync (due, as expected, to the burden of loading media in realtime). With the UI not matching the export it becomes nearly impossible to use the UI as an authoring tool for synchronized output. I was hoping this problem could be averted by locking the audio track, but sill experience the visual lag dying live playback.
Is there a way to basically simulate WYSIWYG for exported slideshows within the UI?
Audio Marker sind unlogisch für den Export. Das ist ein Bug. Wenn bei der Live Wiedergabe Audio und Bild synchron sind, ist das auch nach einem Export synchron - nur ist mittlerweile ein Bug bekannt, dass Die Audiowaveform vom gehörten Ton öfter abweicht. Deshalb muss nach Gehör eingestellt werden und nicht nach Waveform. Dann stimmt auch die Synchronisation nach einem Export.
P. S.:
Ich warte immer noch auf eine Korrektur des Quicktime Bugs.