lossless normalization
Reply #3 – 2006-11-14 20:30:32
hi, i know that wav normalization isn't lossless, but is there normalization for other lossless formats (ape/flac/wv/wm/whatever) that is lossless? or is the only lossless normalization for lossy compression? No, it's not lossless if you apply the change to the audio in the file. The best approach is to use a ReplayGain compatible player to standardise (normalise) the perceived volume on playback - it then simply multiplies the sample values by a pre-determined factor, which usually make the songs quieter. Foobar2000 can do the scanning to determine the scale factor, apply the tags and play back the audio with your choice of making tracks the same loudness, albums the same loudness or making no change to the original CD. If your soundcard supports 24-bit output, the multiplication (done in 32-bit floating point then downconverted to 24-bit) is essentially lossless, because the noise floor of your 24-bit output is below that of your 16-bit CD source (if it is a 16-bit source).if so, then is wav normalization only lossy in the fact that it's irreversible, or does sound quality actually get deteriorated? It introduces a certain amount of extra noise including dither, but at a level that's almost certainly inaudible. It does mean that you probably can't recover the bit-exact data you originally had.i would love to be able to normalize lossless formats losslessly, so i don't have to convert all my lossless ripped vinyls to mp3 just so i can gain them and listen to them on my computer. i'd like to actually be able to listen to the lossless versions without having to crank my speakers to the max. alternatively, does anyone know any way to rip vinyls at a higher volume in the first place? (and i know how to up the line-in recording volume level, but even when this is maxed my records still come out unlistenably low.) First: Your vinyl rips will almost certainly have a noise floor above the noise floor inherent in 16-bit audio formats, so being precisely lossless shouldn't be an audible problem. Second: I notice you're hoping to increase the volume of your Vinyl rips using only normalization. One of the wonderful things about good quality recordings, particularly those on vinyl is that they have a wide range of musical dynamics and sharp transients. It's sharp transients like percussion hits or orchestral sforzando climaxes that tend to be where the voltage (or sample value on your rip) reaches the extremes (most positive or most negative values). Standard peak-value normalization will only take the most extreme of these values to the absolute extreme sample value available and it won't actually make the loudness the same. To get higher volume from the vinyl rip in the first place, you have to degrade the peaks using some form of limiting or dynamics compression either before sampling or using digital processing after sampling. This inevitably alters the sound to some degree and is certainly not lossless, but it's what is done in modern CD mastering, radio broadcasting and TV broadcasting. The better approach for preserving audio quality (and that which is recognised by ReplayGain) is to turn up the loudspeakers, leave nicely dynamic material nearly unchanged (like your vinyl rips) and make the heavily limited and dynamically compressed material quieter so that they end up at around the same loudness. You can even go so far as to take all you operating system sounds and (after backing them up!) replacing them with ReplayGained versions that are quieter so that your whole system sounds fine at the higher loudspeaker volume level. Search for ReplayGain in the knowledgebase for more info.