1MP4(3) MP4 File Format Library MP4(3)
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6 MP4GetRtpTimestampStart - Get the RTP start time of a hint track
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9 #include <mp4.h>
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11 MP4Timestamp MP4GetRtpTimestampStart(
12 MP4FileHandle hFile,
13 MP4TrackId hintTrackId
14 );
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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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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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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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43 MP4(3) MP4SetRtpTimestampStart(3)
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47Cisco Systems Inc. Version 0.9 MP4(3)