Skip to main content

Recent Posts

1
General Audio / Re: Clipping audible when lossy encoding?
Last post by j7n -
I don't think that software should reduce the volume upon decoding to an unpredictable level (based on a few short high frequency peaks) unless specifically requested to perform normalization. When playing PCM floating-point format files, Winamp scans the whole fle for peak level, normalizes, and the normalization cannot be defeated. I believe it is incorrect, and a file should be replayed at the level it is recorded by default. (Or it would have been reduced in level.)

It is possible that clipping is audible in some cases, but I haven't ever heard it in music. Tracks subject to the loudness war usually contain enough distortion to effectively mask additional clipping noise. I've heard clipping in recordings of speech, at low bitrate and sample rate, where the clipping is longer in duration, and also due to speech signal being less busy than most music.

Integer overflows sound really nasty. An older version of the WavPack plug-in for Winamp had these (when playing floating-point files, this is now fixed) and also the latest official build of Speex command-line decoder (the Winamp plugin works correctly).
2
General Audio / Re: BBC Radio 3 lossless stream trial
Last post by probedb -
There's an article on medium that Mozilla just posted in their newsletter about this....

https://medium.com/mozilla-tech/mozilla-and-the-bbc-team-up-to-deliver-concert-quality-audio-from-royal-albert-hall-over-the-web-52366d38ab5

Although I believe it's more about a future broadcast :)
3
General - (fb2k) / Re: windows 10 and foobar2000
Last post by darkflame23 -
Yep, it works just fine here, Win 10 64 latest version, latest version FB2K, loads of plugins etc. Drop files from Explorer straight into FB2K to create a playlist. It has never not worked (Win 98SE, XP, 7 and now 10).
4
Opus / Re: Three new Opus releases
Last post by OrthographicCube -
Thanks!

I always check the Opus 1.2 alpha page to see if new compiled binaries are available and yesterday, when I posted this question, the latest beta was still not posted ^_^
5
The only thing I wouldn't like is an electric panel that made any bit of an audible hum/buzz.  However that might be indicative of electrical problems that need addressing before the fire department has to be called to put out an electrical fire.

I went to a school where this one circuit panel in the hallway was always buzzing.  They never fixed the damn thing and to my knowledge is probably still doing it to this day.

I have a UPS for my computer by a subwoofer and I have no problems with either device being by each other.  The UPS keeps taking the rumbles just fine and the subwoofer isn't distorted at all.  My problem is limited under the desk space.
6
General Audio / Re: Clipping audible when lossy encoding?
Last post by bennetng -
If you are really paranoid you should measure the analog output of each individual playback device for each song instead of at software level since DACs can introduce intersample peaks as well.

FYI:
http://archimago.blogspot.hk/2017/05/preview-oppo-sonica-dac-thanks-oppo-for.html
7
[Note - I'm not quite sure this is the correct section; mods please move if appropriate]

How bad a potential hum/RFI problem is an home electrical panel right within a few feet of a Class D subwoofer amplifier?''

Why should there be any at all?

Quote
We're doing some home upgrades. Unfortunately as part of these upgrades we must move our electrical panel. It currently sits in a stairwell, and that was unfortunately disallowed in a 2008 code revision. Even more unfortunately, the most practical location (i.e. doesn't involve cutting into a century-old plaster wall in a heavy-traffic room) is in the basement. Due to the HVACs vents in our unfinished basement restricting height in most locations to below the 6'6" required by code, placement is further limited. (Code requires a clear space zone that's 6'6" high, 30" wide, and 36" deep.)  Long story short, the electrician wants to put the panel in a spot in the basement - right where my subwoofer amp currently sits! 

The subwoofer amp is 4-channel touring/installation unit with SMPS and Class D output stages. The subwoofer amp and living room audio equipment share a 20A circuit, installed a few days after we closed on the house ca. 2014. The subwoofer amp is plugged into a Panamax 20A "power conditioner," because that was the lowest-effort way to effect a 12V trigger on the amp. The subwoofer amp connects to the DSP in the living room via an 8-channel balanced snake (Mogami 2932); four channels of the snake carry balanced audio, and one channel carries the 12V trigger signal. In any case, all of the electrical cables to current wiring would have to pass by the snake and subwoofer speaker wiring.

I can move the subwoofer amp to be perpendicular to the proposed panel location and about 5' away in a straight line.

Am I stressing out about a likely non-issue, or should I do whatever I can to find an alternate location for the panel?.
[/quote

Yes,]
8
As far as I understand that this would just mean transforming the input signal from the time domain to the frequency domain. I wouldn't have the hope that this can lead to a bitrate reduction comparable to that of lossyFLAC or wavPack hybrid.
9
[Right. So it does not (only) matter what can be reproduced to the LP format, but what a turntable setup can get out of the groove.

Correct
.
Quote
To balance out their desire for supersonic hiss they cannot hear and which is only noise anyway, audiophiles must certainly equip themselves with a laser turntable in order to listen to those subsonic signals that never were intended to make it to the medium.

Laser turntable doesn't help because the laser  system ends up containing an analogous mechanical system for tracking the disk.
10
For many lossless codecs, there's LossyWAV with it's variable reduction of bitdepth as an approach to near-losslessness.
For a time now I've been wondering, from a completely inexpert standpoint, about a different approach based on similar concepts as used in lossy codecs.
Instead of aiming to replicate a waveform down to the bits, the idea would be to encode the audible band (or a more limited range, if desired) in the same or similar fashion as lossy encoders do, with the exception that there wouldn't be any psychoacoustic evaluation.
The aim of this would be to reduce bitrate further than lossless and lossywav, but not raising the noisefloor, and also avoiding completely(?) any psychoacoustics-induced artifacts, avobe or under the threshold of audibility, even surviving further processing/DSP and other non-linearities in an audio system that might reveal otherwise inaudible artifacts as present in common lossy compression. For example, on my phone, through headphones I can tolerate very low bitrates without being annoyed by artifacts (or even noticing them), but the same files can become almost unbearably artifacted through the built-in speaker.
I imagine that this could also prove a good target for transcoding of existing lossy material for which there's no access to a better source than old/rare/unsupported formats and neither pure lossy or lossless targets seem appropriate, one introducing further distorsion and the other being a waste of bandwidth (in my limited

Of course, all of this is just hypotetical. All that remains is to answer these questions:
Does something like this exist?
Is it feasible to make an encoder that works like this for an existing lossy codec? Preferably something fully open, such as Opus
Could such an encoding method deliver on the goals of bitrate reduction (compared to lossless), and no artifacting even under harsh conditions (strong non-linearities, heavy use of DSP...)?
Does the concept have any merit or it's just me daydreaming?