Video players

[Len Ovens]

On Mon, June 3, 2013 8:02 am, edmund wrote:

> What are you calling "uncommon" sample rates? Ubuntu Studio is for
> multi media and in my case High res audio. Here we use 96 kHz and 192
> kHz sample rates.
> VLC player, seems to play these formats too but it doesn't!
> When I play a 80 kHz sine it is audible as - something very different.
> It is far below 20 kHz and clearly audible on 10 Euro loudspeakers,
> so it is definitely not 80 kHz.
> I would say ditch it or use it for things that doesn't matter but not
> for playing high res or quality audio.
> Oh and yes it does so under windows too.

Whatever rate you use, the input and the output of any of the audio
interfaces people have tested has been 20-20000Hz. This has been a
disappointment to those studying bats who have been unable to find any
computer audio interface that supported any higher frequencies. So I am
wondering where you would be getting an 80kHz sine wave from that is
output from a computer. A higher sample rate than 48000 does give a
smoother bandpass frequency response and allow a simpler HF roll off
filter to be used. However it also introduces the very real possibility of
high frequency foldover into the audible pass band.

Yes many studios use "high res audio", but it is not because it is
measurably better. It is because the clients demand it because bluray
supports it. Many studios record at 48000 (the standard BTW) and upsample
to meet whatever format the client demands. The higher rates are IMO
gimmicks to sell new versions of old movies and of course the equipment
needed to support it. There are some audio cards that do sound better at
these higher rates, but they still do not include higher audio frequencies
than the low 20000 Hz range. It is merely a matter of the roll off filter
being designed for that rate and it not working quite so well at the lower
rate. A card designed for the lower rate can sound just as good.

A good video to watch with real analogue measurement inputs and outputs is:

http://www.xiph.org/video/vid2.shtml

-- 
Len Ovens
www.OvenWerks.net