#77017 - GizmoTheGreen - Mon Mar 27, 2006 2:52 pm
now fr another question, what source of sound is recommended when converting with sox to raw?
also, could someone explain the transfersounddata parameters a little deeper for me?
thanks in advance, i still need helpin my other post though :P
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#77052 - ProblemBaby - Mon Mar 27, 2006 7:54 pm
| GizmoTheGreen wrote: |
now fr another question, what source of sound is recommended when converting with sox to raw?
|
Do you mean format? In such case 8 or 16 bit not greather then 32khz cause it wont make any difference if you dont want to replay the sounds with a lower frequency.
But the most important thing is memory, try to use 8bit and a low frequency, be sure to normalize the sound before saving it as 8bit else if its a low volume sample you will get a lot of noise.
#77055 - GizmoTheGreen - Mon Mar 27, 2006 8:19 pm
i use windows internal soundrecorder to convert between formats before i sox the wav to raw, and i cant find anything under 8000khz? :\
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#77057 - ProblemBaby - Mon Mar 27, 2006 8:23 pm
I think thats low enough for most samples.
#77124 - GizmoTheGreen - Tue Mar 28, 2006 2:10 pm
ive tried, can only get it to sound like sh*t
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#77204 - melw - Wed Mar 29, 2006 9:31 am
8000hz sounds generally like shit, especially with high pitching samples. 16khz or 22khz is something I prefer to use as a sfx sound quality - if you have to cut somewhere, just use mono (first thing) and 8-bit (second) - with DS' speakers one can't really hear a big difference unless the sample rate gets too low.
If you really have to go as low as 8khz, apply first a lowpass filter or use antialiasing when resampling. Pretty much all the audio editors around can do these tricks.
#77224 - Chris Holmes - Wed Mar 29, 2006 4:41 pm
Just to be technically accurate, an 8000 hz sample sounds great for any sound below 4000 hz in frequency. As long as you're sampling at twice the frequency, then you should be able to reproduce the sound fairly accurately (See the Nyquist Sampling Theorem: http://www.cs.cf.ac.uk/Dave/Multimedia/node149.html ).
Of course, ironically, even if you're sampling at twice the frequency, you have to sample at the right time, which is why sampling at 4+ times the frequency will result in a better quality.
If you're using a quality audio editting program, it should be able to tell you what the maximum frequency of the sound clip is, so you can use that to determine how high the sampling rate really needs to be in order to reproduce the sound properly.
When in doubt, 44.1 khz is a pretty solid standard. Human hearing only extends up to about 20 khz, and 44.1 will give you a solid double sampling rate on the highest frequencies and, well, it's pretty much a standard.
Chris
#77246 - tepples - Wed Mar 29, 2006 7:25 pm
| Chris Holmes wrote: |
| Just to be technically accurate, an 8000 hz sample sounds great for any sound below 4000 hz in frequency. |
Except the Nintendo DS sample playback hardware uses nearest-neighbor resampling. If you have a sound at 3000 Hz and you're playing it back at 8000 Hz using hardware, you'll get audible aliases at at least 5000 Hz, 11000 Hz, and 13000 Hz, unless you use a software low-pass filter to smooth out the stairsteps.
| Quote: |
| When in doubt, 44.1 khz is a pretty solid standard. Human hearing only extends up to about 20 khz, and 44.1 will give you a solid double sampling rate on the highest frequencies and, well, it's pretty much a standard. |
The Nintendo DS itself can't do higher than 32768 Hz.[1]
[1] MoonShell has a bug in rate calculation.
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#77250 - Chris Holmes - Wed Mar 29, 2006 7:36 pm
| Quote: |
| Except the Nintendo DS sample playback hardware uses nearest-neighbor resampling. If you have a sound at 3000 Hz and you're playing it back at 8000 Hz using hardware, you'll get audible aliases at at least 5000 Hz, 11000 Hz, and 13000 Hz, unless you use a software low-pass filter to smooth out the stairsteps. |
Wow, that's crazy. The solution to that seems to be that you should
just record all your samples at whatever the native frequency the DS plays sounds at. Otherwise, yeah, you'll get crazy aliasing.
Chris