Here's an interesting message I thought should be posted to the mp3encoder list: ------- Start of forwarded message ------- From: "Aleksandar Dovnikovic" <[EMAIL PROTECTED]> To: <[EMAIL PROTECTED]> Subject: MP3 and hi-frequences Date: Fri, 14 Apr 2000 21:00:41 +0200 Hello. First of all, congrats on a great job you guys are doing with LAME. I just wanted to point out the problem that all MP3s (more or less) have with high-frequencies (>16kHz). Interesting thing is that this problem is practically in the left channel - you can hear frequencies over 16kHz being "echoed", "swirled" in left channel. Now LAME indeed does the best job with these frequencies, FhG & Xing do pretty worse while Bladeenc is horrible. When I first discovered this, I thought it had something to do with joint stereo, but it didn't. I mean, if you can get proper hi-freq. encoding in the right channel, why can't you do it also in the left? Is it encoder using some intensity stereo for those frequencies? Why doesn't stereo mode help when the encoder then encodes channels separately (but with different bitrates). Maybe you should try adding an option in LAME that will encode everything in 16-20kHz range in dual mono...? FhG AAC doesn't have these problems with hi-freq. Also since LAME has worse pre-echo detection then FhG MP3 (the only thing in which FhG still holds the edge over LAME) have you thought of reverse engineering mp3enc31.exe - I know it can be pretty time consuming but most of you LAME guys are quite experienced so you might be able to extract what algorithm FhG uses... Your comments will be very much appreciated. Keep up the good work. ------- End of forwarded message ------- -- MP3 ENCODER mailing list ( http://geek.rcc.se/mp3encoder/ )
