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

NAME

6       MP4GetSampleIdFromTime - Get the sample id of a specified time
7

SYNTAX

9       #include <mp4.h>
10
11       MP4SampleId MP4GetSampleIdFromTime(
12            MP4FileHandle hFile,
13            MP4TrackId trackId,
14            MP4Timestamp when,
15            bool wantSyncSample = false
16       );
17

ARGUMENTS

19       hFile  Specifies the mp4 file to which the operation applies.
20
21       trackId
22              Specifies the track to which the operation applies.
23
24       when   Specifies the time in the track time scale that is desired.
25
26       wantSyncSample
27              Specifies  if the returned sample id must correspond to a sample
28              whose sync/random access flag is true.
29
30

RETURN VALUES

32       Upon success, the sample id that occurs at the specified time. Upon  an
33       error, MP4_INVALID_SAMPLE_ID.
34

DESCRIPTION

36       MP4GetSampleIdFromTime  returns  the  sample  id of the track sample in
37       which the specified time occurs.
38
39       The specified time should be in the track time scale. See MP4ConvertTo‐
40       TrackTimestamp() for how to map a time value to this time scale.
41
42       It is wise to use MP4GetSampleTime() with the returned sample id so one
43       can adjust for any difference between the specified time and the actual
44       start time of the sample.
45
46       If the calling application needs a sample that can be accessed randomly
47       then the 'wantSyncSample' argument should be set to true. This could be
48       the  case  for a player that is implementing a positioning function and
49       needs to be able to start decoding a track from the returned sample id.
50
51

SEE ALSO

53       MP4(3) MP4GetSampleIdFromEditTime(3)
54
55
56
57Cisco Systems Inc.                Version 0.9                           MP4(3)
Impressum