if use:

mpv --vo=vdpau --hwdec=vdpau --hwdec-codecs=all --fs --loop=yes /media/usb/*.mp4

hardware decoding work

 

 

if use mplayer

mplayer -stop-xscreensaver -ontop -quiet -fs -vo vdpau -vc ffmpeg12vdpau,ffh264vdpau, -loop 0 /media/usb/*.mp4

hardware decoding not work

 

Howto use mplayer with hardware decoding videoplaying on Orange PI PC v1.2?

Build-in mplayer2 doesn't work. I am receiving massage for missing h264 decoder even if it's present in system. You have to build it from source, but i see no point if you already have mpv and image quality is better in mpv for my taste. But if you are like me and want to have a backup or just to play around, this are the steps i do to build it from source:

wget http://www.mplayerhq.hu/MPlayer/releases/MPlayer-1.3.0.tar.xz
wget http://www.mplayerhq.hu/MPlayer/releases/codecs/all-20110131.tar.bz2
tar xjvf all-20110131.tar.bz2
sudo mkdir /usr/local/lib/codecs
sudo cp -v all-20110131/* /usr/local/lib/codecs
tar xJvf MPlayer-1.3.0.tar.xz
cd MPlayer-1.3.0
./configure
make -j4
sudo make install

Then execute mplayer once to create necessary directories and you can add your config - sudo nano /usr/local/etc/mplayer/mplayer.conf:

vo=vdpau
vc=ffmpeg12vdpau,ffh264vdpau
ao=alsa:device=hw=1.0
framedrop=yes

This is basic for hw acceleration, framedrop=yes is necessary because there is some a/v async without it, even if system is no more than 40% loaded. You can also add settings for subtitles encoding, i add ''subcp=cp1251'' for cyrillic, and  "fs=yes" to decrease a/v async a little if you using framebuffer version of mali driver.