H264 (the decompression standard implemented by VLC/ffmpeg and CoreAVC/MPC) has well defined output in YUV space, and up to +/-1 pixel values in RGB space.
The differences you have captured here indicate that at least one of them is applying non-standard filters of some sort. Perhaps it's just a matter of the right settings (though I cannot offer help in determining what they are)
The differences you have captured here indicate that at least one of them is applying non-standard filters of some sort. Perhaps it's just a matter of the right settings (though I cannot offer help in determining what they are)