Welcome Guest ( Log In | Register )

Reply to this topicStart new topic
Why have lossy files a peak over 1.0?
post Jan 25 2009, 19:25
Post #1

Group: Members
Posts: 19
Joined: 17-August 07
Member No.: 46287

So, out of some kind of curiosity, I had a look at the values for %replaygain_track_peak% in my collection, and it looks like only lossy files have a peak over 1.0. A lot of lossless tracks with 1.0, but not one over. Why is that? Have all of them been loudened or is it some kind of calculation problem due to interpolation used in lossy codecs? And doesn't a peak over 1.0 indicate clipping?

I'm sorry if this question has already been answered, I didn't really know what to search for.
Go to the top of the page
+Quote Post
post Jan 25 2009, 22:32
Post #2

Group: Members
Posts: 82
Joined: 3-February 08
Member No.: 51007

Artifacts due to the mathematics of the lossy encoding indeed might cause a decoded signal to have a peak beyond the full scale. And yes, this indicates clipping. A negative replaygain value might eliminate the clipping, though.

This post has been edited by chromium: Jan 25 2009, 22:32
Go to the top of the page
+Quote Post
post Jan 25 2009, 23:13
Post #3

Group: FB2K Moderator
Posts: 2359
Joined: 30-November 07
Member No.: 49158

QUOTE (fillip @ Jan 25 2009, 19:25) *
I didn't really know what to search for.
google.com: "peak over 1.0" site:hydrogenaudio.org
Replaygain clipping prevention, How does it work?

Additionally, if it's only a little bit over 1.0, it's only a slight error caused by the nature of lossy encoding and it is probably ~0.999 in the original.

Full-quoting makes you scroll past the same junk over and over.
Go to the top of the page
+Quote Post
post Jan 26 2009, 00:35
Post #4

Group: Developer
Posts: 1408
Joined: 27-June 07
Member No.: 44789

This is useful too:


TAK -p4m :: LossyWAV -q 6 | TAK :: Lame 3.98 -V 2
Go to the top of the page
+Quote Post

Reply to this topicStart new topic
1 User(s) are reading this topic (1 Guests and 0 Anonymous Users)
0 Members:


RSS Lo-Fi Version Time is now: 1st December 2015 - 13:47