Posted by Bernie Siegrist on 2001-04-17
Try GoldWave (http://www.goldwave.com) or any other wave editor; open the file, "Resample" it to 44100Hz, click "Save As..." and choose the new format (44100Hz 16bit stereo). That's all there is to it. :-) As for quality, the new file should sound exactly the same. In case you'd like to know, here is why: First thing to keep in mind is that a sound is stored as a (long) sequence of numbers giving the current "volume" (pro memoria, a sound is produced by constantly changing pressure, so these values are sort of "pressure" values). This might look like this (at 22050Hz)... 2 4 6 8 10 8 5 2... Now, when doubling the resolution (which is what we're doing by when converting it to 44100Hz), each of the above numbers is now represented by *two* numbers. Basically this would be... 2 2 4 4 6 6 8 8 10 10 8 8 5 5 2 2... See? The information is preserved. :-) Play this at doubled speed and you won't hear a difference. On a side note, GoldWave (and others) offer a function called "Interpolate"; this "smoothens" the waveform and gives you something like... 2 3 4 5 6 7 8 9 10 9 8 6 5 3 2 2... (Explanation: Every inserted value is the average of the surrounding values, e.g. "2 4" --> "2 *3* 4". Theoretically this should sound "smoother", altho I for myself can't hear a great difference.) Secondly, conversion from 8bit to 16bit (just so this essay is complete =): To simplify things, assume an 8bit sound is stored as an integer and a 16bit sound is stored as a floating point number; this would convert 2 4 6 8 10 8 5 2... to 2.0 4.0 6.0 8.0 10.0 8.0 5.0 2.0 ... So basically a 16bit sound is more "exact", but again, there's no loss of quality. You just don't use the increased precision. Last step, convert from mono to stereo - no big deal: you just take one copy of the mono track for each channel. :-) Having done all this, your original sequence "2 4 6 8 10 8 5 2..." looks something like "Left: 2.0 2.0 4.0 4.0 6.0 6.0 8.0 8.0 10.0 10.0 8.0 8.0 5.0 5.0 2.0... Right: 2.0 2.0 4.0 4.0 6.0 6.0 8.0 8.0 10.0 10.0 8.0 8.0 5.0 5.0 2.0..." Again, it's all there, it's just 8 times larger and 87.5% of the bytes are superfluous. :-) Other than that, it's ready for Nero. (Ofcourse it's not CD *quality*, but after all it's the CD *format* which is all Nero demands.) Hope this helps!
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