1MP4(3)                      MP4 File Format Library                     MP4(3)
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NAME

6       MP4GetNumberOfTracks - Get the number of tracks
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SYNTAX

9       #include <mp4.h>
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11       u_int32_t MP4GetNumberOfTracks(
12            MP4FileHandle hFile,
13            const char* type = NULL,
14            u_int8_t subType = 0
15       )
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ARGUMENTS

18       hFile  Specifies the mp4 file to which the operation applies.
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20       type   Species  the  type of track for which a count is desired. A NULL
21              value implies any type of track. See MP4GetTrackType() for  pre‐
22              defined values.
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24       subType
25              Specifies  the subtype of the tracks to be counted. Subtypes are
26              only defined for audio and video tracks,  see  MP4GetAudioTrack‐
27              Type()  and MP4GetVideoTrackType() for predefined values. A zero
28              value implies any subtype.
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RETURN VALUES

31       The number of tracks of the specified type and subType in the mp4 file.
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DESCRIPTION

34       MP4GetNumberOfTracks returns how many tracks of the specified type  and
35       subtype  exist in the mp4 file. This can be used to determine if an mp4
36       file contains a track of a given type of media, for instance  audio  or
37       video.  It  can  also  be  used to determine if multiple options may be
38       available. For instance multiple audio tracks in different languages.
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40       For audio and video tracks, a subtype can be specified  to  only  count
41       tracks of a particular encoding.
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SEE ALSO

44       MP4(3)
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48Cisco Systems Inc.                Version 0.9                           MP4(3)