Dear all,
Those days I am always confused by one question that maybe is very simple in your mind. Here are two formulas for calculating NMR. One is NMR = Sum(abs(line^2 - requant_line^2)) / mask_energy, the other is NMR = sum((line - requant_line)^2)/mask_energy. Which one is correct? In my idea, from the conversation of energy law, noise energy should be the difference between original signal energy and re-quantized signal energy, so the former is correct. But according to my experiment the encoding result with the later NMR criteria is absolutely better than that with former NMR criteria. I also review many audio codes such as mp3Lame, EAQUAL, which all use the later NMR definition. Why? Could anyone help me to clarify this puzzle? Thanks in advanced. BR, Shine _______________________________________________ mp3encoder mailing list [email protected] http://minnie.tuhs.org/mailman/listinfo/mp3encoder
