Re: [MP3 ENCODER] SR Conversion.

1999-10-08 Thread Monty
> someone please correct me if im massively confused here... the first > thing you do to the input when encoding is convert it to frequency > spectra, right? so why not just treat 22khz input exactly the same > as 44khz, except half all computed frequencies and fft windows? why > ever convert b

Re: [MP3 ENCODER] SR Conversion.

1999-10-01 Thread Mark Gilbert
>> Does anyone have a GOOD quality Sample Rate conversion algorithm ? > >See any elementary discrete time audio processing book and look under 'integer >ratio rate conversion'. It's mostly an exercise in upsampling, lowpassing and >downsampling. The computational complexity is proportional to th

Re: [MP3 ENCODER] SR Conversion.

1999-09-30 Thread Ambrose Feinstein
> For example, going from 22050 to 44100, just make every other sample a zero, > then apply a lowpass (however you like) with a cutoff just below 11.025 kHz. > Now downsampling is needed in this case (well, the downsample factor is 1). someone please correct me if im massively confused here...

Re: [MP3 ENCODER] SR Conversion.

1999-09-30 Thread Monty
> There is a much better way to do SRC using polyphase filtering. It also allows > SRC between ANY two sample rates. This is a generalization of what I described done in the time domain (if one understands the MPEG audio polyphase subbander, this should be easy to work through). It introduces j

Re: [MP3 ENCODER] SR Conversion.

1999-09-30 Thread Mike Oliphant
On Thu, 30 Sep 1999, Mark Gilbert wrote: > Does anyone have a GOOD quality Sample Rate conversion algorithm ? The resample code in the *current* version of sox is pretty good. Make sure that you get the current version, though, because previous versions were not good at all Mike -- Mike Olipha

Re: [MP3 ENCODER] SR Conversion.

1999-09-30 Thread Erik de Castro Lopo
Monty wrote: > > > Does anyone have a GOOD quality Sample Rate conversion algorithm ? > > See any elementary discrete time audio processing book and look under 'integer > ratio rate conversion'. It's mostly an exercise in upsampling, lowpassing and > downsampling. The computational complexity

Re: [MP3 ENCODER] SR Conversion.

1999-09-30 Thread Monty
> For example, going from 22050 to 44100, just make every other sample a zero, Sorry, make that 'double the number of samples, making every other sample a zero'. Eg, 'A,B,C,D' becomes 'A,0,B,0,C,0,D,0'... Monty -- MP3 ENCODER mailing list ( http://geek.rcc.se/mp3encoder/ )

Re: [MP3 ENCODER] SR Conversion.

1999-09-30 Thread Monty
> Does anyone have a GOOD quality Sample Rate conversion algorithm ? See any elementary discrete time audio processing book and look under 'integer ratio rate conversion'. It's mostly an exercise in upsampling, lowpassing and downsampling. The computational complexity is proportional to the pro

Re: [MP3 ENCODER] SR Conversion.

1999-09-30 Thread Mark Gilbert
Does anyone have a GOOD quality Sample Rate conversion algorithm ? Please mail me if you have, Thanks Mark Gilbert >> >> > - resampling (sox) >> >> if this would just be added as a pipeline stage, ie part of reading the >> input file, i dont see a lot of point in integrating it. on the other