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Detect MPEG4/H264 I-Frame (IDR) in RTP stream

Asked 2009-12-24T08:42:33.720
30

I need to detect MPEG4 I-Frame in RTP packet. I know how to remove RTP header and get the MPEG4 frame in it, but I can't figure out how to identify the I-Frame.

Does it have a specific signature/header?

rtp rtsp
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2 Answers

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Actually, you was correct for h264 stream, if the NAL value (first byte) is 0x7C it means that the I-Frame is fragmented. No other frames (P and B) can be fragmented, so if there is packetization-mode=1 in SDP, then it means that the I-Frames are fragmented, and therefore if you read 0x7C as first byte, then it is I-Frame. Read more here: http://www.rfc-editor.org/rfc/rfc3984.txt.

answered 2010-05-15T19:47:37.990
0

0x000001b6: vop_start_code (keyframe, if the next two bits are zero) this is correct way for MPEG-4

answered 2012-01-13T04:20:37.340

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