Technical Q&As
QTW 72 - Live MIDI-input Sequences (07-Dec-95)
Q Is it possible to synchronize the playback of a QuickTime movie to incoming
time code of one sort or another? An example application might be to cause a
movie to speed up or slow down in response to a changing clock from a MIDI
sequence.
A Sounds like you're talking about a live MIDI-input sequence. While your
application processes the MIDI input, it can call MCDoAction/mcActionPlay and
adjust the playrate on the fly. This will adjust the playback speed of all
enabled tracks.
If you are only interested in synchronizing a video track to an external clock
source, you can make calls to MCDoAction/mcActionStep or /mcActionGoToTime.
This method, however, overrides QuickTime's intelligent frame-dropping
algorithm, which could be a problem if a system cannot handle the playing of
every frame at the current rate.
Technical Q&As
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