16 meters (about 52 ft) is quite long cable. Doesn't it need some sort of signal equalizer to maintain picture quality? I supposed your cable is of very good quality.
I have read this from the Oppo website:
Frequently Asked Questions
Q: Does the HM-31 HDMI Switch support long HDMI cables?
A: Yes. The HM-31 HDMI Switch has a built-in signal equalizer. The signal equalizer removes distortion from the input HDMI signal after it travels over long cables and restores the signal quality/strength. We have tested the HM-31 HDMI Switch passing 1080p signal successfully with a 50-foot cable between the source and the HM-31's input, and another 50-foot cable between the HM-31's output and the TV. The total cable length from the source to the TV is 100 feet. Of course, in any particular installation, the maximum cable length depends on many factors - quality of cables used, signal quality at the source, and the tolerance of the display device.
Q: What does the "built-in signal equalizer" do?
A: The signal equalizer is a key component to support long HDMI cables. It removes distortion from the input HDMI signal after it travels over long cables and restores the signal quality/strength. We have tested the HM-31 HDMI Switch passing 1080p signal successfully with a 50-foot cable between the source and the HM-31's input, and another 50-foot cable between the HM-31's output and the TV. The total cable length from the source to the TV is 100 feet. Of course, in any particular installation, the maximum cable length depends on many factors - quality of cables used, signal quality at the source, and the tolerance of the display device.