I played around with hardware acceleration on an RPi0 a while back - it was quite slow.
The vlc in the repo should use hw acceleration if available, those vlc instructions referenced above are using the old closed source omx and neon - I'm not sure neon is available on RPi0 and RPi1.
You could try ffplay: ffplay -i /mnt/mmcblk0p2/media/video/jellyfish-3-mbps-hd-h264.mkv [I think this would use hw acceleration]
or
ffplay -codec:v h264_v4l2m2m -i /mnt/mmcblk0p2/media/video/jellyfish-3-mbps-hd-h264.mkv
Note that you may need dtoverlay=vc4-kms-v3d and dtoverlay=rpivid-v4l2, check that /dev/video* exist.