Originally posted by Frank KlemmSubband coding is NOT patented. Read patents very very carefully or don't read it.Perceptional noise substitution is also NOT patented.When reading patents it is necessary to find out what is EXACTLY patented.
Subband coding is NOT patented---Philips subband patent can be removed
Originally posted by Gecko Now I'm confused. I'm sorry if I didn't use the proper, exact terminology.Way back in third grade a guy once said: "I didn't spit at her, and besides, I missed!"
Originally posted by wkw I tested MP3Pro on the castanets clip and it seemed to contain some irritating artifacts. I would not classify MP3Pro as a Hi-Fi / CD level encoder.
Originally posted by niktheblak Now that I'm at it, why does everyone keep saying that codecs using DCT are the only "transform" codecs whereas codecs like MPC (using FFT) are "subband" codecs with nothing to do with transforms at all?"Subband" encoding does use discrete Fourier transform. "Transform" encoding uses discrete cosine transform. Mathematically speaking, these transforms are nearly identical, with cosine transform being nothing but a cosine-termed (is this the correct english expression?) Fourier series (Fourier transform without the cosine, or ImX, part). Cosine transform just makes energy representation a little easier than Fourier transform.
Originally posted by JohnV Because the FFT in subband coders like MPC is done in psychoacoustics calculations which is a separate process. Psychoacoustics defines the masking threshold which is used in the quantization phase. With subband codecs transform coefficients are not used in actual encoding/quantization. Transform codec like MP3 also uses FFT (normally) for psychoacoustics, but as I said it's a separate process...MPC quantizes the time-domain samples (based on the masking threshold given by psychoacousic analysis), not any frequency transform co-efficients like transform coders.
Originally posted by Ivan Dimkovic wkw,AAC has very efficient mode of grouping of 8 short blocks into groups which in most cases reduces necessary bits by a significant margin.