Displaying 17 results from an estimated 17 matches for "imperceptible".
2015 Oct 25
4
recommended opus bitrate / opusenc setting for general?
Hey.
I just wondered,... which is the recommended bitrate and further
settings of opusenc (like complexity and framesize) for general music
(e.g. including classical music) to achieve more or less transparency?
Talking about CD level audio (16bit; 44,1 kHz; Stereo)
The only source I could find regarding that was:
http://wiki.hydrogenaud.io/index.php?title=Opus#Music_encoding_quality
But that
2017 Oct 31
3
Antw: Re: OPUS vs MP3
Hi guys,
as MP3 and Opus have very similar objectives, I think the original poster's
question was a valid one: Why does Opus have more artefacts in the lower
frequency ranges than MP3 has? The spontaneous suspect that lower frequency
artefacts may be more noticeably than higher frequency artefacts seems
plausible, also. Is it a matter of energy (which is higher for higher
frequencies)?
When
2019 Apr 23
4
Sis to deduplicate attachments does not work?
Hi, I use sis to deduplicate attachments, here is my `doveconf -n`
------------
auth_cache_size = 10 M
auth_failure_delay = 5 secs
auth_mechanisms = plain login
auth_socket_path = /var/run/dovecot/auth-userdb
auth_ssl_username_from_cert = yes
auth_username_format = %Ln
default_vsz_limit = 512 M
lmtp_rcpt_check_quota = yes
mail_attachment_detection_options = add-flags-on-save
mail_attachment_dir =
2015 Nov 12
2
[cfe-dev] Propagating llvm.assume across function calls to enhance de-virtualization
...on in
which we
emit invariant.group.barrier.
4. Fix compile time regression caused by many assume instructions (after
constructor call). I don't remember which pass it was, but there was one
pice of code that had some huge complexity,
and we coudn't make it better enough to make this change imperceptible. I
am not sure what would be good solution to this - maybe there should be
some other assume like intrinsic for
doing this numbers assumes that we had problem.
5. Maybe add logic that will remove all invariant.group stuff when doing
LTO with module that was not compiled with -fstrict-vtable-pointer...
2004 Nov 24
5
HTB Script
2003 Feb 19
3
trying to get better ogg quality for this clip
...unnoticed unless using head phones. it sounds like the guitar pick
scratching against the strings.
using decent (but not top of the line) headphones for evaluation, i
found that wma and mp3pro did a very nice job of encoding the file where
the differences from the raw wav file were practically imperceptible to
me. however, when encoded with ogg q0-q2, the sounds is noticeably
altered and the "high frequency guitar pick noise" sounds like someone
walking through gravel. at q3 it starts to sound better and at q4 it is
about equal to the others.
by my ears, the 64k wma file does the best j...
2019 Apr 24
0
Sis to deduplicate attachments does not work?
...the comes to this.
mbox has potential use for long term read-only archives - I see no reason
to use it for live mailboxes.
maildir is undoubtedly the least susceptible to corruption. It's also the
slowest format for reading. How slow is "slow" depends on your hardware -
it may be imperceptible with enough RAM and SSD's - or it may result in
user complaints with large mailboxes.
dbox is Dovecot's preferred format. I know Timo has put a lot of effort
into it. sdbox is similar to maildir in that each mail is a separate file.
mdbox significantly reduces the number of files which...
2006 Jun 19
0
Re: Asterisk-Users Digest, Vol 23, Issue 135
...bsequent delay, pass the digital data
through various routers, each of which add additional delay, then
reconvert the digital data back into analog audio, which again adds
still more delay. The sum of all of these delays is more than the
threshold of 25ms, and as a result, what may have been an imperceptible
echo on the PSTN is now a very apparent -- and very annoying -- echo in
the VoIP call.
--Mike
> Subject: [Asterisk-Users] ECHO Tutorial
>
> Is there anyone that could explain to me the phenomenon of Echo or at
> least point me where I can learn more? Why is this affecting the VoIP...
2015 Oct 25
0
recommended opus bitrate / opusenc setting for general?
...ything above 96kbps on that table is speculative, as the highest
multi-participant listening testing done was at 96kbps. Here's the
results from that test, if you're curious:
http://listening-test.coresv.net/results.htm
As you can see, at that rate Opus ranged from slightly perceptible to
imperceptible. Also importantly, note how few of the donors were able to
give significant results on most tracks. This makes a 128kbps or higher
test impractical as there would not be enough listeners capable of
hearing a difference. The HydrogenAudio wiki should probably be updated
accordingly.
FWIW I cannot A...
2017 Nov 01
0
Antw: Re: OPUS vs MP3
...ir best possible condition, you may try
> a spectrogram, just to make sure you don't miss anything.
Actually, that's the wrong way. Especially when the spectrogram is
computed on a signal difference. For example, some codecs can alter the
phase (or add a small delay) in a way that's imperceptible, and yet
causes a large difference signal. At the same time, artefacts such as
pre-echo will not be noticeable on the spectrogram of the difference
signal -- even when it's audible and annoying.
The least bad way of estimating how good a codec is at very high bitrate
is to just measure the poi...
2017 Nov 04
1
Antw: Re: OPUS vs MP3
...on,
>> you may try a spectrogram, just to make sure you don't miss anything.
>
> Actually, that's the wrong way. Especially when the spectrogram is
> computed on a signal difference. For example, some codecs can alter the
> phase (or add a small delay) in a way that's imperceptible, and yet
> causes a large difference signal.
My favourite is what happens with ambisonics, and especially NFC-HOA.
You're simply not *allowed* to do time-coherent detection with that
stuff.
> The least bad way of estimating how good a codec is at very high
> bitrate is to just mea...
2015 Oct 26
2
recommended opus bitrate / opusenc setting for general?
...s speculative, as the highest
> multi-participant listening testing done was at 96kbps. Here's the
> results from that test, if you're curious:
>
> http://listening-test.coresv.net/results.htm
>
> As you can see, at that rate Opus ranged from slightly perceptible to
> imperceptible. Also importantly, note how few of the donors were able
> to
> give significant results on most tracks. This makes a 128kbps or
> higher
> test impractical as there would not be enough listeners capable of
> hearing a difference. The HydrogenAudio wiki should probably be
> updated...
2015 Nov 12
2
Propagating llvm.assume across function calls to enhance de-virtualization
Hi All,
I have a two-part de-virtualization enhancement that I'm considering working
on and am looking for any feedback on how feasible it is. The two parts
are:
1. llvm: Extending inter-procedural SCCP (or some other IPO module
pass) to propagate llvm.assume's across function calls. The basic idea
would be to collect the set of assumptions for each argument at each call
2007 Oct 24
5
OSLEC and zaptel-1.4.5.1
Hi all,
After reading great things about the OSLEC Echo Canceller
(http://www.rowetel.com/ucasterisk/oslec) and seeing the reactions of
people who have tried it on a recent Trixbox thread
(http://www.trixbox.org/forums/trixbox-forums/open-discussion/need-people-echo-problems),
it sounds like it is the "bees knees" for sorting out echo problems with
cards like the x100p.
Has anyone
2005 Oct 11
6
PRI echo issues: solvable?
Hello,
After solving the other "low hanging fruit" audio issues in our Asterisk
PBX, we are left with occasional cases of severe echo which we have not
found a solution for yet.
Our system:
- Asterisk 1.2.0-beta1
- TE110P on a PRI
- TDM04 and TDM40, but these are unrelated to current echo issues
- Fedora core 3
- Echo canceller KB1
Most calls have minimal, acceptable echo levels. But
2008 Apr 10
2
Phantom Rings
I'm having a major problem at one of my branch offices with "Phantom
Rings" on their asterisk-based phone system. The system was originally
built using 2 X100P cards and was recently upgraded to a Rhino R4FXO-EC
card. The upgrade severely increased the frequency of the phantom
rings. I've read everything I can find on-line about automatic testing
and noise on the line and
2020 Mar 21
9
Tasa variación diaria COVID-19
Hola:
Tengo los datos diarios del número de casos de coronavirus por comunidades
autónomas y quiero calcular el número diario de nuevos casos y la tasa
diaria de variación del número de casos y no se como hacerlo en R.
*fecha*
*comunidad*
*poblacion*
*casos_totales*
04/03/2020
Andalucía
8414240
13
05/03/2020
Andalucía
8414240
12
06/03/2020
Andalucía
8414240
21
04/03/2020
Aragón