1MP4(3)                      MP4 File Format Library                     MP4(3)
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NAME

6       MP4GetRtpTimestampStart - Get the RTP start time of a hint track
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SYNTAX

9       #include <mp4.h>
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11       MP4Timestamp MP4GetRtpTimestampStart(
12            MP4FileHandle hFile,
13            MP4TrackId hintTrackId
14       );
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ARGUMENTS

17       hFile  Specifies the mp4 file to which the operation applies.
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19       trackId
20              Specifies the hint track to which the operation applies.
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RETURN VALUES

25       Upon success, the RTP start time in the RTP time scale which is identi‐
26       cal to the hint track time scale. Upon an error, MP4_INVALID_TIMESTAMP.
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DESCRIPTION

29       MP4GetRtpTimestampStart returns the RTP timestamp start of  the  speci‐
30       fied  hint  track. Typically this is a random value that is chosen when
31       the first RTP packet is constructed by the  MP4  library.  However  the
32       value  can  be  set explicitly for the hint track and stored. Typically
33       this is used if it is desired that timestamps start at zero.
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35       An application will need this value in order to construct  RTCP  Sender
36       Reports  that  relate  the  hint  track time to an real time clock. The
37       mp4broadcaster test program provided with  the  MP4  library  gives  an
38       example of this.
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40       See IETF RFC 1889 for details regarding RTP timestamps and RTCP.
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SEE ALSO

43       MP4(3) MP4SetRtpTimestampStart(3)
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47Cisco Systems Inc.                Version 0.9                           MP4(3)
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