1MP4(3)                      MP4 File Format Library                     MP4(3)
2
3
4

NAME

6       MP4FindTrackId - Find a track id
7

SYNTAX

9       #include <mp4.h>
10
11       MP4TrackId MP4FindTrackId(
12            MP4FileHandle hFile,
13            u_int16_t index,
14            const char* type = NULL,
15            u_int8_t subType = 0
16       )
17

ARGUMENTS

19       hFile  Specifies the mp4 file to which the operation applies.
20
21       index  Specifies which track is desired from matching tracks.
22
23       type   Specifies  the type of track to be matched. A NULL value implies
24              any type of track. See MP4GetTrackType() for predefined values.
25
26       subType
27              Specifies the subtype of the track to be matched.  Subtypes  are
28              only  defined  for audio and video tracks, see MP4GetAudioTrack‐
29              Type() and MP4GetVideoTrackType() for predefined values. A  zero
30              value implies any subtype.
31

RETURN VALUES

33       Upon  success,  the  track  id  of  the specified track. Upon an error,
34       MP4_INVALID_TRACK_ID.
35
36

DESCRIPTION

38       MP4FindTrackId gets the track id associated with the index'th track  of
39       the specified track type. For example, to get the track id of the first
40       video track:
41
42            MP4FindTrackId(hFile, 0, MP4_VIDEO_TRACK_TYPE);
43
44       For audio and video tracks, a subtype can be specified to find a  track
45       of a particular encoding. For example, to get the track id of the first
46       audio track encoded with MPEG-1 audio:
47
48            MP4FindTrackId(hFile,           0,           MP4_AUDIO_TRACK_TYPE,
49       MP4_MPEG1_AUDIO_TYPE);
50
51       Caveat:  The track id's do not imply anything about the ordering of the
52       track information within the mp4 file.
53

SEE ALSO

55       MP4(3) MP4FindTrackIndex(3)
56
57
58
59Cisco Systems Inc.                Version 0.9                           MP4(3)