How to extract IDR frames from H.264 elementary bitstream?

zoeliu · 9th February 2012, 15:54

Here is what I did:

Given an H.264 elementary bitstream, use a parser to extract all the SPS/PPS/IDR nalus (judging from nal_unit_type 7/8/5), add starting code 0x00000001 at the beginning of each nalu, and write to a file.

The result however cannot be decoded correctly. What am I missing here? Great thanks!

Dust Signs · 10th February 2012, 08:22

The start code is 0x000001, not 0x00000001. I assume that this is the problem. However, two questions:
* What error do you get exactly when trying to decode the stream?
* Did you escape 0x000001 sequences within the NALUs to 0x00000001 (unlikely that they appear, but nonetheless possible)?

Best regards
Dust Signs

9th February 2012, 15:54	#1 \| Link
zoeliu Registered User Join Date: Aug 2005 Posts: 2	How to extract IDR frames from H.264 elementary bitstream? Here is what I did: Given an H.264 elementary bitstream, use a parser to extract all the SPS/PPS/IDR nalus (judging from nal_unit_type 7/8/5), add starting code 0x00000001 at the beginning of each nalu, and write to a file. The result however cannot be decoded correctly. What am I missing here? Great thanks!

10th February 2012, 08:22	#2 \| Link
Dust Signs Registered User Join Date: Jun 2004 Location: Salzburg, Austria Posts: 220	The start code is 0x000001, not 0x00000001. I assume that this is the problem. However, two questions: * What error do you get exactly when trying to decode the stream? * Did you escape 0x000001 sequences within the NALUs to 0x00000001 (unlikely that they appear, but nonetheless possible)? Best regards Dust Signs __________________ The number you dialed is imaginary. Please turn your phone by 90° and try again

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