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iMX6 VPU Zero Buffer Decode

Question asked by Leonardo Sandoval Gonzalez Employee on Aug 1, 2013
Latest reply on Dec 11, 2014 by Ganesh R

Original thread is from a user's profile area, but placing on i.MX Community for wider audience:


We need to use the VPU decoder in a zero-delay mode, i.e. we give the decoder a frame of H.264 data and the decoder performs the decode and provides the framebuffer, immediately.  It looks like according to the documentation if we set reorderEnable in the DecOpenParam structure, the decoder should operated in this mode.  However we must feed 3 frames in before we get the first frame out. Previously we used iMX53 and this zero-delay decode worked fine.

Enclosed is a modified version of the mxc_vpu_test example.  The example was modified to read a .h264 files along with an index file that precisely feeds one frame per keystroke to the decoder.  The very first frame is made up of SPS, PPS and and I-Frame, all other frames are P frames.  A Readme file in the tgz file explains the changes.  You need to build this in the same directory as the original mxc_vpu_text.  You probably will have to modify the system directory and the example should build.  Also the binary is included see readme for launch instructions.


I guess we are missing setting some parm somewhere to get into this zero-delay mode????

Original Attachment has been moved to: mxc_vpu_test_single_frame.tgz