Specifying
Time Formats
Multimedia
data types typically can use time to identify significant positions within
their content. Common time formats are milliseconds, tracks, and frames; other
less common time formats, such as SMPTE (Society of Motion Picture and
Television Engineers) 24, also exist. Time is the format and reference system
for waveform-audio, MIDI, and CD audio data. Video supports time even though it
is recorded as a sequence of frames (stream) that is typically played at a
specific speed. Several macros are available for designating time format.
You can
retrieve the current time format for a file or device by using the MCIWndGetTimeFormat macro. You can change the
current time format to any other time format supported by a device by using the
MCIWndSetTimeFormat
macro. Or you can the set the time format to milliseconds or frames by using
the MCIWndUseTime
or MCIWndUseFrames
macros.
Note Noncontinuous
formats, such as tracks and SMPTE, can cause the toolbar to behave erratically.
For these time formats, you might want to turn off the toolbar by specifying
the MCIWNDF_NOPLAYBAR window style when creating an MCIWnd window.