search for: impercept

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

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

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 =

...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-poi...

...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 be...

...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 wh...

...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...

...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 cann...

...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...

...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...

...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 > upd...

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

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

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

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

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