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Working With Media Samples

This chapter describes the functions your application can use to determine information about a movie’s sample data, such as the size in bytes of the data in a movie, track, or media, or the number of samples in a media, or the media’s sample description.

• GetMovieDataSize

• GetTrackDataSize

• GetMediaDataSize

• GetMediaSampleCount

• GetMediaSampleDescriptionCount

• GetMediaSampleDescription

• SetMediaSampleDescription

• MediaTimeToSampleNum

• SampleNumToMediaTime

The Movie Toolbox provides a number of functions that allow applications to determine information about a movie’s sample data. This section discusses these functions. See “Adding Samples to Media Structures” for information about functions that allow you to retrieve sample data from a media.

Your application can use the GetMovieDataSizeMovie, GetTrackDataSizeMovie, and GetMediaDataSize functions to determine the size, in bytes, of the data stored in a media, movie, or track.

You can use the GetMediaSampleDescriptionCount and GetMediaSampleDescription functions to retrieve a media’s sample descriptions. The SetMediaSampleDescription function enables you to change the contents of a particular sample description associated with a media. The GetMediaSampleCount function determines the number of samples in a media. The SampleNumToMediaTime and MediaTimeToSampleNum functions allow you to convert from a time value to a sample number and vice versa. You can use the functions described in “Finding Interesting Times” to locate specific samples in a media.

Contents:

Adding Samples to Media Structures
Finding Interesting Times
Working With Movie User Data

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