Media (Intel® oneAPI Video Processing Library, Intel Media SDK)
Access community support with transcoding, decoding, and encoding in applications using media tools from Intel. This includes Intel® oneAPI Video Processing Library and Intel® Media SDK.
Announcements
Welcome to the Intel Community. If you get an answer you like, please mark it as an Accepted Solution to help others. Thank you!
2905 Discussions

NAL head after use Encoder indicaate: Access unit delimiter

zheng_s_
Beginner
102 Views

I use the same code to design a transcode app  which inlcude  Decode/VAPP/ Encode functions.

then I try to test the h264 video generated from Intel encoder and it is not playable by VLC.  I dump the header of each frame and  found follwoing interesting:

The orignal  H264 frame:

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

And here is the output from Intel Encoder:

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

 

I didn’t copy the full buffer, since it is huge. The first 4 bytes is 0001 which is h264 NAL start prefix code, then followed by 0x09, indicate access unit delimiter. But I don’t know why the header/NAL type could be different after encoder. Anyone get experience in h264  format? And how to make the output from encode is playable

0 Kudos
1 Reply
Anthony_P_Intel
Employee
102 Views

Hi, 

Is your source video an "elementary" stream (without audio, etc.)?

Do you reproduce the issue by using  sample_multi_transcode.exe application?  If so, can you provide the parameters you are using?

Reply