Inside Macintosh: QuickTime /

Chapter 2 - Movie Toolbox / Movie Toolbox Reference

Functions That Modify Movie Properties / Working With Media Samples

SampleNumToMediaTime

The SampleNumToMediaTime function allows you to find the time at which a specified sample plays. This time is expressed in the media's time scale.

pascal void SampleNumToMediaTime (Media theMedia, 
                                    long logicalSampleNum, 
                                    TimeValue *sampleTime,
                                    TimeValue *sampleDuration);

theMedia

Specifies the media for this operation. You obtain this media identifier from such Movie Toolbox functions as NewTrackMedia and GetTrackMedia (described on page 2-138 and page 2-190, respectively).

logicalSampleNum

Specifies the sample number.

sampleTime

Contains a pointer to a time value. The MediaTimeToSampleNum function updates this time value to indicate the starting time of the sample specified by the logicalSampleNum parameter. This time value is expressed in the media's time scale. Set this parameter to nil if you do not want this information.

sampleDuration

Contains a pointer to a time value. The Movie Toolbox returns the duration of the sample specified by the logicalSampleNum parameter. This time value is expressed in the media's time scale. Set this parameter to nil if you do not want this information.

ERROR CODES

invalidMedia

-2008

This media is corrupted or invalid

SEE ALSO

You can find the sample for a specified time by calling the MediaTimeToSampleNum function, which is described in the previous section.