I am testing 4K MPEG-4 playing capability on MERLIN FALCON RX-421 platform. The film I tested is 4K-resolution with H.264 compressed format.
OS : Windows 7 SP1 64-bit
DRAM : 8GB
CPU : AMD MERLIN FALCON RX-421
MPEG4 media player for Windows : PotPlayer, KMPlayer, PowerDVD
Display interface : DisplayPort 1.2 LCD monitor with 4K display capability
Problem is that I saw video-lagging symptom during 4K mp4 film playing by PotPlayer or KMPlayer. Then I found CPU usage is 100% full load. It looks the MPEG-4 HW decoder didn't be enabled by these two player. The MPEG-4 film is decoded by software and not by hardware decoder.
Next I test on PowerDVD player. There is no video-lagging symptom and film playing is smoothly. The CPU usage is under 40% when playing film by PowerDVD.
Since our customer want us to prove MPEG-4 4K decode capacity of this CPU (we are mother board design company), I don't know if we just show customer the test result of PowerDVD.
How to explain another player cannot play smooth MPEG-4 4K video quality ?
I don't know why the hardware MPEG-4 decoder in CPU cannot be enabled by media player.