mp4gettracktype.3

网络MPEG4IP流媒体开发源代码

.TH "MP4" "3" "Version 0.9" "Cisco Systems Inc." "MP4 File Format Library"
.SH "NAME"
.LP 
\fBMP4GetTrackType\fR \- Get the track type
.SH "SYNTAX"
.LP 
#include <mp4.h>
.LP 
const char* \fBMP4GetTrackType\fR(
.br 
	MP4FileHandle \fIhFile\fP,
.br 
	MP4TrackId \fItrackId\fP
.br 
)
.SH "ARGUMENTS"
.LP 
.TP 
\fIhFile\fP
Specifies the mp4 file to which the operation applies.
.TP 
\fItrackId\fP
Specifies the track for which the type is desired. 

.SH "RETURN VALUES"
.LP 
Upon success, a string that indicates the track type. Upon an error, NULL.

.SH "DESCRIPTION"
.LP 
\fBMP4GetTrackType\fR gets the type of the track with the specified track id. 
.LP 
Note: the library does not provide a MP4SetTrackType function, the track type needs to be specified when the track is created, e.g. MP4AddSystemsTrack(MP4_OCI_TRACK_TYPE).
.LP 
Known track types are:
.LP 
	MP4_OD_TRACK_TYPE		"odsm"
	MP4_SCENE_TRACK_TYPE	"sdsm"
	MP4_AUDIO_TRACK_TYPE	"soun"
	MP4_VIDEO_TRACK_TYPE	"vide"
	MP4_HINT_TRACK_TYPE		"hint"
	MP4_CLOCK_TRACK_TYPE	"crsm"
	MP4_MPEG7_CLOCK_TYPE	"m7sm"
	MP4_OCI_TRACK_TYPE		"ocsm"
	MP4_IPMP_TRACK_TYPE		"ipsm"
	MP4_MPEGJ_TRACK_TYPE	"mjsm"
.SH "SEE ALSO"
.LP 
MP4(3)