11 Oct
2011
11 Oct
'11
11:36 p.m.
On Tue, Oct 11, 2011 at 11:17:15PM +0200, Atte André Jensen wrote:
On 10/11/2011 11:07 PM, Fons Adriaensen wrote:
There are at least two good reasons why such a test is
not valid.
1. The difference signal doesn't tell you anything about
audible differences between two signals. It's fairly easy
to make a linear filter (no compression involved) with
a perfectly flat response and that nobody would be able
to hear. But when you take the difference between in and
out it is 3 dB higher than both.
2. Lossy compression is based on combined temporal and
spectral masking - some signals you can't hear in the
presence of others. Of course when you take away the
masking signal they become apparent...
Ciao,
--
FA
On Tue, Oct 11, 2011 at 10:57:38PM +0200, Atte
André Jensen wrote:
That's what my gut-feeling told me! My question is: is this really a fair way to
judge the artifacts
introduced by encoding?
No, it's completely invalid.