IPB

Welcome Guest ( Log In | Register )

> Upload forum rules

- No over 30 sec clips of copyrighted music. Cite properly and never more than necessary for the discussion.


- No copyrighted software without permission.


- Click here for complete Hydrogenaudio Terms of Service

 
Reply to this topicStart new topic
opus echo sample
DonP
post Feb 20 2013, 22:12
Post #1





Group: Members (Donating)
Posts: 1469
Joined: 11-February 03
From: Vermont
Member No.: 4955



I know bitrate=35 isn't going to be hi fi, but I found this while playing with the speech/music theme. The first note of the tune has an echo to the point of being a whole extra note. Happens in both 1.1a and babyeater. The forum says opus isn't an allowed file type for upload, so I just did the flac file. At 40 its more like just a mushy attack on the first note.

edit: uploaded result opus file converted back to flac.

This post has been edited by DonP: Feb 20 2013, 22:17
Attached File(s)
Attached File  12_Sasha_s.flac ( 1.07MB ) Number of downloads: 70
Attached File  12._Sashas_opus35.flac ( 835.65K ) Number of downloads: 63
 
Go to the top of the page
+Quote Post
Garf
post Feb 21 2013, 07:49
Post #2


Server Admin


Group: Admin
Posts: 4853
Joined: 24-September 01
Member No.: 13



QUOTE (DonP @ Feb 20 2013, 22:12) *
The forum says opus isn't an allowed file type for upload


Fixed.
Go to the top of the page
+Quote Post
jmvalin
post Feb 22 2013, 15:08
Post #3


Xiph.org Speex developer


Group: Developer
Posts: 473
Joined: 21-August 02
Member No.: 3134



QUOTE (DonP @ Feb 20 2013, 16:12) *
I know bitrate=35 isn't going to be hi fi, but I found this while playing with the speech/music theme. The first note of the tune has an echo to the point of being a whole extra note. Happens in both 1.1a and babyeater. The forum says opus isn't an allowed file type for upload, so I just did the flac file. At 40 its more like just a mushy attack on the first note.

edit: uploaded result opus file converted back to flac.


OK, problem identified. What happens is that the speech/music detector is classifying the silence at the beginning of the file as speech (probably because the training set had too much silence in the speech). I'm working on fixing this. BTW, it seems ike this thread would belong to the Opus forum. Can someone move it?
Go to the top of the page
+Quote Post
C.R.Helmrich
post Feb 22 2013, 22:38
Post #4





Group: Developer
Posts: 681
Joined: 6-December 08
From: Erlangen Germany
Member No.: 64012



QUOTE (jmvalin @ Feb 22 2013, 15:08) *
What happens is that the speech/music detector is classifying the silence at the beginning of the file as speech (probably because the training set had too much silence in the speech).

I also heard similar issues on other items starting with a fade-in (the first half-second or so was apparently coded with SILK). It was either at 24 or 32 kbps, official v1.1 binary. Makes me wonder: which stereo tools are available for SILK? Can it do "true" stereo with a downmix+residual (or M/S) or just some kind of time-domain intensity stereo?

Chris


--------------------
If I don't reply to your reply, it means I agree with you.
Go to the top of the page
+Quote Post
jmvalin
post Feb 23 2013, 03:19
Post #5


Xiph.org Speex developer


Group: Developer
Posts: 473
Joined: 21-August 02
Member No.: 3134



QUOTE (C.R.Helmrich @ Feb 22 2013, 16:38) *
I also heard similar issues on other items starting with a fade-in (the first half-second or so was apparently coded with SILK). It was either at 24 or 32 kbps, official v1.1 binary. Makes me wonder: which stereo tools are available for SILK? Can it do "true" stereo with a downmix+residual (or M/S) or just some kind of time-domain intensity stereo?


SILK uses downmix+residual, aka MS stereo in the signal domain (unlike CELT and Vorbis that do MS after band normalization). That's what explains some of the stereo artefacts it sometimes causes. That being said, it usually sounds good on "normal" stereo speech that doesn't have too much channel separation. I recently checked in some changes to the detector in the exp_analysis branch that improves the decision code and adds the possibility of using look-ahead (up to 2 seconds) on that decision to make it better.
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: 17th April 2014 - 05:54