dmTCToSeconds(3dm)                                          dmTCToSeconds(3dm)


NAME
     dmTCToSeconds, dmTCFromSeconds - digital media timecode mathematics

SYNOPSIS
     #include <dmedia/dm_timecode.h>

     DMstatus dmTCToSeconds
         ( const DMtimecode *tc,
           double *seconds )

     DMstatus dmTCFromSeconds
         ( DMtimecode * result,
           const int tc_type,
           const double seconds )


TYPES
     DMtimecode   A structure containing a representation of SMPTE time code
                  on which certain mathematical and utility functions can be
                  performed.  Can be used with:  dmTCAddTC(3dm),
                  dmTCAddFrames(3dm), dmTCToString(3dm), dmTCFromSeconds(3dm),
                  dmTCFramesPerDay(3dm), and dmTCFramesBetween(3dm).  Can also
                  be used with the dmLTC(3dm) and dmVITC(3dm) routines.  See
                  also DMtimecode(3dm).


ARGUMENTS
     result   The result of converting fractional seconds past midnight into a
              timecode value.


     tc       The timecode value to convert into seconds.


     seconds  The number of fractional seconds past midnight to convert, or
              the result of converting a DMtimecode into fractional seconds
              past midnight.


     tc_type  When converting from fractional seconds to a DMtimecode, the
              timecode format into which the seconds should be converted.  See
              tc_type(3dm).


DESCRIPTION
     These functions provide a simple means of converting between fractional
     seconds past midnight and DMtimecode timecodes.

     When converting from seconds to timecode, a valid tc_type must be
     supplied (see tc_type(3dm)). The tc_type of result will be the same as


     the tc_type that is passed to dmTCFromSeconds.

     For dmTCFromSeconds, the seconds value given will be rounded to the
     nearest frame.

     In order to convert to and from seconds, these routines need to assume
     some timecode rate in frames per second.  They will choose the rate given
     in the DM_TC_RATE bits of the specified tc_type.  For drop-frame
     timecode, this is not the rate of the underlying video signal, and over
     the long term there will be drift.  See tc_type(3dm) for more information
     on this.


RETURN VALUE
     If a DMtimecode operand (tc) contains an illegal timecode value (e.g., a
     negative entry, invalid frame number, etc.), dmTCToSeconds will return
     DM_FAILURE, and the contents of seconds will be undefined.

     If the number of seconds passed to dmTCFromSeconds is negative, or
     greater than the number of seconds in a 24-hour day, dmTCFromSeconds will
     return DM_FAILURE, and the contents of result will be undefined.

     If an invalid tc_type value is passed in to dmTCFromSeconds, DM_FAILURE
     is returned.

     dmTCToSeconds and dmTCFromSeconds return DM_SUCCESS upon successful
     completion.


SEE ALSO
     dmTCFromSeconds(3dm), dmTCToSeconds(3dm), dmTCFromString(3dm),
     dmTCFromString(3dm), dmTCFramesPerDay(3dm), dmTCFramesBetween(3dm),
     dmLTC(3dm), dmVITC(3dm)


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