The emphasis bit is not normally stored on WAV, FLAC, MP3 or any other computer-format audio files. Therefore, you cannot scan your files to determine if any are pre-emphasized. The only place I know of where this infomation is available is on the cue sheet (either .CUE files or embedded in FLAC). I don't believe SqueezeCenter or any other player software pays any attention to emphasis. It assumes the sound file in "flat" (no pre-emphasis).
I believe the problem with most software that automatically applies de-emphasis is that it truncates the result to 16-bits. Since de-emphasis is an EQ operation, the calculations should be done at a higher bit-depth, so there will be useful "residue" from the calculations. Also, since the de-emphasis EQ results in lowering the levels above 1 KHz, it will lower the overall level of the program material by potentially a few dB. If you are going to reduce the bit depth back to 16-bits after de-emphasis, you may want to boost the level back up a bit. And certainly re-dither so that you don't introduce new quantization distortion. Of course, all of these problems can be avoided if the de-emphasis calculation residue is left > 20 bit depth. Note that, being an EQ operation, de-emphasis is a lossy operation. Maybe it would be good to use something process the results with something like lossyWAV before encoding to FLAC, which will make a better, dynamic choice as to how much calculation residue to retain. -- Timothy Stockman ------------------------------------------------------------------------ Timothy Stockman's Profile: http://forums.slimdevices.com/member.php?userid=8867 View this thread: http://forums.slimdevices.com/showthread.php?t=34336 _______________________________________________ audiophiles mailing list audiophiles@lists.slimdevices.com http://lists.slimdevices.com/lists/listinfo/audiophiles
