intel libva utils ( h264decode ) produced decoded output with green blocks all over

produces corrupted decoded output. This is easily reproducible with given stream

h264decode /uhome/media/big.h264 /tmp/b5.yuv
You need retry few times. first attempt may not produce the issue.

input stream is extracted h264 stream from Big_Buck_Bunny_1080_10s_1MB.mp4

You will see green blocks on produced decoded output when you play using ffplay
ffplay -f rawhide -pixel_foramt nv12 -video_size 1920x1080 -I b4.yuv

I can share input stream and produced decoded ouput (yuv)

Start by reproducing the issue with h264decode on the Big Buck Bunny H.264 stream, retrying as described, then inspect the generated raw NV12 output with ffplay. Compare successful and corrupted runs; done means decoding the supplied stream consistently without green blocks in the output.

Written by the indexing model from the issue text.