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MP4(3)			    MP4	File Format Library			MP4(3)

NAME
       MP4AddRtpVideoHint - Add	an RTP video specific hint

SYNTAX
       #include	<mp4.h>

       bool MP4AddRtpVideoHint(
	    MP4FileHandle hFile,
	    MP4TrackId trackId,
	    bool isBFrame = false,
	    u_int32_t timestampOffset =	0
       );

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

       trackId
	      Specifies	the hint track to which	the operation applies.

       isBFrame
	      Specifies	if this	hint will contain packets for a	video B	frame

       timestampOffset
	      Specifies	a positive offset to add to the	RTP timestamp for this
	      hint. Caveat: the	value is in the	hint track timescale.

RETURN VALUES
       Upon success, true (1). Upon an error, false (0).

DESCRIPTION
       MP4AddRtpVideoHint is an	extended version of MP4AddRtpHint specifically
       to handle MPEG video frames.

       The  isBFrame parameter allows the packets in the RTP hint to be	marked
       as belonging to a video B frame.	This can  be  useful  to  a  streaming
       server if packets must be dropped due to	system load or network conges-
       tion. No	other video frames are dependent on the	contents of B  frames,
       so they are least damaging type of frames to drop.

       The  timestampOffset  parameter allows an offset	to be added to the RTP
       timestamp of the	packets	in the RTP hint. This is  necessary  for  MPEG
       video that contains B frames since the video frames are transmitted out
       of order	with respect to	when they should be  rendered.	I.e  I	and  P
       frames are transmitted before any B frames that depend on them. The RTP
       timestamp must represent	the rendering time of the data in the  packets
       hence an	offset must be added.

       Note:  The timestampOffset is equivalent	to the sample rendering	offset
       of a video media	track. See MP4GetSampleRenderingOffset().

SEE ALSO
       MP4(3) MP4AddRtpHint(3) MP4AddRtpPacket(3) MP4WriteRtpHint (3)

Cisco Systems Inc.		  Version 0.9				MP4(3)

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

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