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File:White noise.ogg

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White_noise.ogg(Ogg Vorbis lydfil, længde 10 s, 161 kbps)

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Beskrivelse
Українська: Файл випадкового білого шуму із середнім рівнем -18 dBFS, 160 кбіт/с, моно. Створено за допомогою «Cool Edit Pro» як файл формату «*.wav», стиснений до формату «*.ogg» за допомогою «Blaze Media Pro».
English: Random white noise file with average level at -18 dBFS. 160 kbps, mono. Generated with Cool Edit Pro as a WAV file, compressed as OGG with Blaze Media Pro. Binksternet (talk) 22:46, 3 April 2010 (UTC)
Previous version
10 seconds of uniformly distributed white noise with an RMS value of -4.8 dB.
Histogram
Frequency analysis
Dato
Kilde

Generated with GNU Octave's random number generator rand(), which generates uniformly distributed random values in the interval [0,1). The wavwrite() function expects values in [-1.0, 1.0), so we multiply by 2 and shift down by 1. So to generate 10 seconds of noise sampled at 48 kHz:

white=rand(48000*10,1)*2-1;

I'm not sure about the inner workings of /dev/urandom, but I used the "reseed" command to feed it data from random.org, so this should be pretty random. To export this to a 16-bit, 48 kHz .wav file in our home directory, the command is:

wavwrite(white,48000,16,'white noise uniform.wav');

Then I converted the .wav file to a FLAC-encoded Ogg (.oga) file:

flac --ogg "white noise uniform.wav"

(The "compressed" FLAC file is actually larger than the .wav file.)  :) Then I generated a lossily-compressed .ogg Vorbis file:

oggenc "white noise uniform.wav"

This allows the pristine, lossless file to be downloaded directly from File history, while the smaller lossy file is the one included in articles.

RMS value derived from:

sox "white noise uniform.wav" -e stat

and then in dB is

Histogram derived from

hist(white,100,1)
Frequency analysis in Audacity.
Forfatter Omegatron
Tilladelse
(Genbrug af denne fil)
Dette billede kan ikke ophavsretsbeskyttes og er offentlig ejendom (public domain), fordi det udelukkende består af information som er almindelig ejendom og ikke indeholder noget originalt forfatterskab.

Vurdering[redigér]

Media of the day This file was selected as the media of the day for 30 April 2023. It was captioned as follows:
English: At the end of a certain month, we will listen to a piece of noise. Let's listen to white noise today.
Other languages
Čeština: Na konci měsíce přinášíme obvykle ukázku nějakého zvuku. Dnes jde o bílý šum.
English: At the end of a certain month, we will listen to a piece of noise. Let's listen to white noise today.
Italiano: Alla fine di ciascun mese, ascolteremo un brano contenente rumore. Oggi ascoltiamo il rumore bianco.
Эрзянь: Течи кунсолотанок ашо виев гайть.
Slovenščina: Govorjena različica članka Wikipedije v kitajščini o Williamu Shakespearu
Українська: Файл випадкового білого шуму із середнім рівнем -18 dBFS, 160 кбіт/с, моно. Створено за допомогою «Cool Edit Pro» як файл формату «*.wav», стиснений до формату «*.ogg» за допомогою «Blaze Media Pro».

Filhistorik

Klik på en dato/tid for at se filen som den så ud på det tidspunkt.

Dato/tidMiniaturebilledeDimensionerBrugerKommentar
nuværende3. apr. 2010, 22:4210 s (197 KB)Binksternet (diskussion | bidrag)Better quality sound, higher bit rate, more suitable average level of -18dBFS, better HF response, monophonic, lower file size.
21. apr. 2008, 03:2410 s (88 KB)Omegatron (diskussion | bidrag)Lossy Ogg Vorbis version of the same file
21. apr. 2008, 03:2310 s (957 KB)Omegatron (diskussion | bidrag)Lossless, FLAC-encoded version generated from GNU Octave

Transcode status

Opdater transcode status
Format Bitrate Download Status Encode time
MP3 129 kbps Gennemført 24. dec. 2017, 12:32 1,0 s

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