MP4FindTrackId - Find a track id
const char* type = NULL,
u_int8_t subType = 0
hFile Specifies the mp4 file to which the operation applies.
index Specifies which track is desired from matching tracks.
type Specifies the type of track to be matched. A NULL value implies
any type of track. See MP4GetTrackType() for predefined values.
Specifies the subtype of the track to be matched. Subtypes are
only defined for audio and video tracks, see
MP4GetAudioTrackType() and MP4GetVideoTrackType() for predefined
values. A zero value implies any subtype.
Upon success, the track id of the specified track. Upon an error,
MP4FindTrackId gets the track id associated with the index’th track of
the specified track type. For example, to get the track id of the first
MP4FindTrackId(hFile, 0, MP4_VIDEO_TRACK_TYPE);
For audio and video tracks, a subtype can be specified to find a track
of a particular encoding. For example, to get the track id of the first
audio track encoded with MPEG-1 audio:
MP4FindTrackId(hFile, 0, MP4_AUDIO_TRACK_TYPE,
Caveat: The track id’s do not imply anything about the ordering of the
track information within the mp4 file.