Skip site navigation (1)Skip section navigation (2)

FreeBSD Manual Pages

  
 
  

home | help
MP4(3)			    MP4	File Format Library			MP4(3)

NAME
       MP4AddTrackEdit - Add an	edit segment to	a track

SYNTAX
       #include	<mp4.h>

       MP4TrackId MP4AddTrackEdit(
	    MP4FileHandle hFile,
	    MP4TrackId trackId,
	    MP4EditId editId,
	    MP4Timestamp startTime = 0,
	    MP4Duration	duration = 0,
	    bool dwell = false
       )

ARGUMENTS
       hFile  Specifies	the mp4	file to	which the operation applies.

       trackId
	      Specifies	the track to which the operation applies.

       editId Specifies	the desired position in	the edit list sequence for the
	      new edit segment.	If the value is	MP4_INVALID_EDIT_ID, then  the
	      edit segment is added at the end of the existing edit list. Note
	      editId's start with the value of 1, not 0.

       startTime
	      Specifies	the starting time of the edit  segment	in  the	 track
	      time scale.

       duration
	      Specifies	 the  duration	of  the	edit segment in	the track time
	      scale.

       dwell  If false,	the track media	should be played at its	 normal	 rate.
	      If  true,	 the  media  should be paused for the duration of this
	      edit segment. This is a mechanism	by which  one  can  delay  the
	      start of a media track.

RETURN VALUES
       Upon  success,  the  edit  id  of  the new edit segment.	Upon an	error,
       MP4_INVALID_EDIT_ID.

DESCRIPTION
       MP4AddTrackEdit adds an edit segment to the track edit list.

       The track edit list is a	feature	that allows creation of	 an  alternate
       timeline	 for  the  track,  typically  cutting out segments of the full
       track to	form an	shorten, cleaned up version. The  edit	segments  that
       form  the  edit list are	a sequence of track start times	and durations,
       they do not alter the track media in any	way. I.e. no data can be  lost
       via edit	list operations.

       To  read	 out  the  editted  version  of	 the track, use	MP4ReadSample-
       FromEditTime() instead of MP4ReadSample().

       To export the editted version of	the track to a new track,  potentially
       in a new	mp4 file, see MP4CopyTrack().

       Note  with many media encodings such as MPEG-4, AAC, and	MP3, care must
       be taken	when choosing the edit segment start  times.  E.g.  for	 video
       tracks a	reference or key frame should be selected as the starting sam-
       ple of any edit segment.	For audio tracks, an audio sample  start  time
       should be used.

SEE ALSO
       MP4(3)	MP4DeleteTrackEdit(3)	MP4ReadSampleFromEditTime(3)  MP4Copy-
       Track(3)

Cisco Systems Inc.		  Version 0.9				MP4(3)

NAME | SYNTAX | ARGUMENTS | RETURN VALUES | DESCRIPTION | SEE ALSO

Want to link to this manual page? Use this URL:
<https://www.freebsd.org/cgi/man.cgi?query=MP4AddTrackEdit&sektion=3&manpath=FreeBSD+12.0-RELEASE+and+Ports>

home | help