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Sneaking Past Heavy-Handed Audio Compression on YouTube

timothy posted more than 6 years ago | from the sine-language-for-the-hearing dept.

Google 234

niceone writes "Recently YouTube seems to have started applying extreme compression to the audio of uploaded clips. This is the type of compressions used by radio stations to make everything louder, but in this case applied extremely badly. In quiet passages, breathing and shuffling become overpoweringly loud. A gently plucked guitar chord becomes a distorted thud. Listen to an example here. And here's what it could sound like — still not perfect, but a whole lot better. The fixed version is thanks to a workaround proposed by Sopranoguitar — the idea is to turn down the audio and mix in a high frequency sine wave (I used 19kHz). The sine wave fools YouTube's compressor into thinking that the file is at a uniform level (and does not need the volume changing at all) but is filtered out by the encoding process (so, no need to worry about deafening any dogs)."

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haha (-1, Troll)

Anonymous Coward | more than 6 years ago | (#24360347)

trix are for kids mutherfucker!!

TROLL POST (-1, Troll)

Anonymous Coward | more than 6 years ago | (#24360355)

someone's been feeding me, fuck!

Re:TROLL POST (-1, Troll)

Anonymous Coward | more than 6 years ago | (#24360447)

Fuck you.
Everyone is an idiot.
Everything is stupid.
I know better than everyone about everything.
Fuck you.

Full?

This hurts (0, Troll)

Compuser (14899) | more than 6 years ago | (#24360375)

Can someone post an example I could possibly listen to for more than one second?

Re:This hurts (4, Informative)

_xeno_ (155264) | more than 6 years ago | (#24360411)

Sure, how about the given example? One second is really all you need.

In the heavily compressed one, you hear an annoying hiss and the sound of the microphone being moved for the first few seconds.

In the non-heavily compressed one, you don't.

That's really the complete example without having to listen to the song. Really, the first few seconds are the best example, because Google is apparently amplifying almost complete silence to noise. The song part really doesn't help much. (Or at least, as much as I was willing to listen to it, which was only a few seconds.)

Re:This hurts (5, Informative)

drspliff (652992) | more than 6 years ago | (#24360535)

The worst examples I've seen have been videos of a lecture/speech, and while the main speaker has a microphone it also picks up sound from around the auditorium or lecture hall.

Normally this is fine as we have all become accustomed to faint background noise, with this extreme compression the faintest cough or shuffling in the audience sounds is as loud as the person speaking and is thus very distracting.

Considering most of the lectures I view are 30+ minutes long this really pisses me off.

Brevity Required (5, Funny)

Tablizer (95088) | more than 6 years ago | (#24360489)

Can someone post an example I could possibly listen to for more than one second?

No
     

Re:This hurts (1)

niceone (992278) | more than 6 years ago | (#24360573)

Heh, yeah, I did consider that, but you do only need to listen to the first bar to hear the problem.

and who came up with it? (2, Insightful)

X0563511 (793323) | more than 6 years ago | (#24360379)

Who's the mentally... challenged... individual who decided that applying such compression in the first place was a good idea, and then proceeded to implement or accept such a shitty implementation?

Re:and who came up with it? (4, Interesting)

saxoholic (992773) | more than 6 years ago | (#24360403)

Well, it starts with the "Loudness War" Record companies/radio stations compete to make everything louder, because the louder the music is coming over the air, the more likely the listener is to notice it. I don't see how that would help youtube though, because we're not listening to youtube in the background like we are to the radio.

Re:and who came up with it? (1)

liquidpele (663430) | more than 6 years ago | (#24360477)

the louder the music is coming over the air, the more likely the listener is to notice it.

I was always under the impression that studies had shown that people, on average, rated music as "better" when it was the same thing but just increased in volume. Can't find such a study on google in the 30 seconds I looked though.

Re:and who came up with it? (5, Informative)

billcopc (196330) | more than 6 years ago | (#24360999)

Louder is one thing, compression is another.

Compression can help bring out the faint natural harmonics in a sound, making it "warmer", not unlike an overdriven tube amp. These harmonics are like ear candy to most people, subliminally making the sound more enjoyable.

Radio stations do it for various reasons, one is it helps them sustain peak output power. Another is that the average radio is a cheap chinese gadget that sounds like liquid ass, so the compression actually helps with the sound quality on those devices. When you also consider where radio is often heard, e.g. malls, outdoor venues, cube offices, you realize these are all substandard listening environments where high dynamic range really means you lose half the sound, so the compression again helps with perceived quality by driving most of the content above the noise threshold.

There are plenty of good reasons for sound compression, but its use should be toggled by the user, and for the love of god, give it some sane thresholds! For most content, anything above 4x compression is overkill!

Re:and who came up with it? (1)

Tablizer (95088) | more than 6 years ago | (#24360575)

I have to admit that I don't like it when some videos are blaring loud and others so quiet[1]. I have to keep jacking the knob up and down. However, perhaps rather than alter the original sound, they could have the volume knob (optionally) adjust to the appropriate volume for a given video.

[1] Is the youtube-side volume adjustment new? Many existing vids seem to be all over the place volume-wise.

Re:and who came up with it? (5, Funny)

Anonymous Coward | more than 6 years ago | (#24360647)

I have to keep jacking the knob up and down.

To YouTube videos? Sicko!

Re:and who came up with it? (4, Funny)

MightyYar (622222) | more than 6 years ago | (#24360737)

To YouTube videos? Sicko!

What can I say? Unrehearsed rants into webcams really turn me on...

Re:and who came up with it? (3, Informative)

daem0n1x (748565) | more than 6 years ago | (#24360905)

they could have the volume knob (optionally) adjust to the appropriate volume for a given video.

They do, it's called compression.

Re:and who came up with it? (1)

Tablizer (95088) | more than 6 years ago | (#24360929)

I meant without altering the encoded sound level in the *file*. In other words, client-side adjustment, but also client-side alterable.

Re:and who came up with it? (5, Insightful)

mdmkolbe (944892) | more than 6 years ago | (#24360657)

I don't think YouTube is trying to run a loudness war, but rather trying to fix up a lot of amateurish recordings that are uploaded with bad audio. I can't tell you how many recordings on the net are either way to quiet (e.g. I can't hear speech even at max volume) or too loud and that change in mid-video (e.g. person walks away from or closer to mic). Despite their good intentions, though, it seems to have fallen prey to the "Clippy" effect.

What YouTube needs to do is have a little check-box on uploads that indicates whether to apply the auto-balance. And in case an uploader asks for no auto-balance when they really shouldn't (e.g. they think they know but don't) there should be a side link to listen to the auto-balanced version.

Re:and who came up with it? (5, Funny)

billcopc (196330) | more than 6 years ago | (#24361007)

But what if you move away from the mic to breathe ?

Chocolate Rain
*whoooosh*
Youtube makes my breathing loud again
Chocolate Rain
*whoooosh*
My eardrums are whimpering in pain

Re:and who came up with it? (5, Funny)

archeopterix (594938) | more than 6 years ago | (#24361071)

This is just in. Studies have shown that on a popular site named Slashdot LOUD COMMENTS ARE MODERATED BETTER THAN QUIET ONES!!!

Re:and who came up with it? (3, Insightful)

larry bagina (561269) | more than 6 years ago | (#24360527)

youtube is a huge money sink. They probably can't afford to hire people that have experience in audio compression, test different algorithms, etc. As to why... video and sound quality varies a lot, so they probably are trying to make everything more equal, so the viewer doesn't need to adjust their volume for every video.

Re:and who came up with it? (1)

PopeRatzo (965947) | more than 6 years ago | (#24360901)

All they'd have to do is, as mdmkolbe says above, is put some checkboxes up for the uploaders, to choose from a few default compression algorithms, or a box to check if you just want them to leave your audio alone.

Was there really a big problem with inaudible YouTube videos before this, though? Is this a solution that really didn't have a problem?

Re:and who came up with it? (3, Insightful)

anotherone (132088) | more than 6 years ago | (#24361063)

The typical youtube uploader can't even manage to tag their videos properly. Giving them MORE options is just dangerous.

Re:and who came up with it? (3, Insightful)

daem0n1x (748565) | more than 6 years ago | (#24360897)

I guess they are trying to compensate for the huge differences between recording quality in the videos people submit. Some are loud enough, others are very low and you have to turn the level way up to understand what people are saying.
They could simply normalise the level, but if you have a speech with very low level and the guy drops the microphone in the middle, that one peak is so loud that will make the normalisation process useless.
But compression is such a complex and subjective issue that it should be performed by hand. I guess they have an automated process for that, and it doesn't have any intelligence, just steamrolls all the audio it finds, whether it's speech, music, or anything else.

Re:and who came up with it? (2, Insightful)

X0563511 (793323) | more than 6 years ago | (#24361001)

They need to allow a means of bypassing the compression, then.

Wouldn't it be easier (4, Insightful)

phantomfive (622387) | more than 6 years ago | (#24360391)

Wouldn't it be easier to set your gate [wikipedia.org] correctly? Cut out the background sounds BEFORE submitting to youtube; do proper editing and then it doesn't matter so much what they do. Here, in my opinion, is a good site for all such information [tweakheadz.com] .

Re:Wouldn't it be easier (4, Informative)

PetiePooo (606423) | more than 6 years ago | (#24360501)

Wouldn't it be easier to set your gate [wikipedia.org] correctly?

That would apparently help, but only in cutting out the quiet scrapes and shuffles before the actual (attempt at) music starts. During that silent period, YouTube's encoder would be cranking up the gain so much that, when the first guitar pluck occured, it would still be a highly clipped thud. This workaround keeps them from adjusting the gain at all.

In other words, prefiltering your audio stream with a gate would quiet down the quiet parts, but would not prevent YouTube's encoder from fiddling with the gain.

Re:Wouldn't it be easier (3, Informative)

4D6963 (933028) | more than 6 years ago | (#24360609)

During that silent period, YouTube's encoder would be cranking up the gain so much that, when the first guitar pluck occured, it would still be a highly clipped thud.

Well actually it really depends. It depends whether it's audio compression, or volume normalisation. If it's audio compression then things get amplified regardless of chronology, and therefore if you remove the ambient noise it won't get amplified to an audible hiss and it won't have a negative effect on anything else.

However what you were thinking about is "volume normalisation". In that case a quick change if volume would have the effect you described. I'm not sure which it is in this case but from the summary it looks like it's audio compression.

By the way, noise gating? There are more sophisticated things these days for that, like stuff based on STFTs and noise profiling.

Re:Wouldn't it be easier (1)

zalas (682627) | more than 6 years ago | (#24361131)

It depends on the parameters of the compressor used. If the compressor has a long attack time and no look-ahead, you'll get that the compressor doesn't have enough time to clamp down a sudden loud burst of sound.

Re:Wouldn't it be easier (0)

Anonymous Coward | more than 6 years ago | (#24361163)

No, it's the other way round. He is really is thinking of compression.

Normalising has no effect on the sound, other than an overall gain change. It's an offline process done by analyzing the entire length of the audio.

Compression is dynamic and constantly changing. It's done by doing an rms or peak average of a moving window of few milliseconds of audio.
The 'highly clipped thud' artifact petiepoo mentioned happens because of this short analysis window. The time constants of the compressor cannot respond fast enough after the gate opens and you get a thump.

As normalisation does not require calculating rms or have time constants, it does not create the same artifacts.

Re:Wouldn't it be easier (1)

Ethanol-fueled (1125189) | more than 6 years ago | (#24360655)

But a noise gate's pumping and breathing [harmony-central.com] may only aggrivate a compressor's worst attributes(which, coincidentally, just happen to be "pumping" and "breathing" since a comp is a dynamic effect like a noise gate).

Since many of the "you"-style(as in YOUtube) recordings like home-video style recorded lectures, performances, etc. are used with a mic, then the noise gate(especially in conjunction with a comp) will only amplify the imperfections.

In other words: slownewsday, stop whining. If it's that much of a hassle then rip the audio and master it yourself.

Re:Wouldn't it be easier (1)

Max Night (1221500) | more than 6 years ago | (#24360851)

Yeah but if you're posting something musical - this doesn't apply at all. It's not a matter of cutting out background noise, it's about screwing up the mix. :)

Re:Wouldn't it be easier (4, Interesting)

Anonymous Coward | more than 6 years ago | (#24360919)

It still matters what they do. This kind of high compression is unsuitable for most material, yet they're insisting on it. Not only does it completely kill the dynamic range - imagine going to see a classical music concert and the entire concert is played at the exact same volume, no crescendos or decrescendos - that lack of dynamic range also dramatically quickens ear fatigue. What they're doing is great if they want people to stop listening (and therefore likely watching) YouTube videos as much. Otherwise, it's a really dumb idea.

Using a noise gate to solve YouTube's poor decision is not very realistic - that's trying to get thousands and thousands of different people to fix something caused by YouTube trying to solve what wasn't really much of a problem. What's more, noise gate + high compression leads to Charlie Brown Special kinds of voice tracks and very limited musical choices - e.g., in a classical concert, instead of the quiet parts being just as loud as the loud parts, some of the quiet parts will simply be cut to silence. Noise gate + high compression can be cute for a bit in dialogue, and when done to a particular instrument - but not every instrument in a song - you can get some cool effects from it, but it's shitty thing for YouTube to require of people. It may be enough to force some users away.

Update (5, Informative)

niceone (992278) | more than 6 years ago | (#24360407)

After some more testing it seems that there is a problem with high quality mode. With the tone and sample rate I used (19kHz and 44.1k) at least the high quality encoder whistles at, some other frequency. Sounds like somewhere less than 10kHz to me.

I hope YouTube fix this soon.

Re:Update (1)

4D6963 (933028) | more than 6 years ago | (#24360479)

Any chance this would be due to a non-linearity like clipping? Someone correct me if I'm wrong but I think that with clipping with a strong 19 kHz component in a signal sampled at 44.1 kHz you'd get artifacts which base frequency would be 3,050 Hz.

Re:Update (0)

Anonymous Coward | more than 6 years ago | (#24360909)

Clipping typically isn't a problem at 19KHz... it's more likely to be another type of modulation artifact (e.g. bad re-sampling algorithm or a broken lowpass filter). Intermodulation would definitely distort down there to ~3KHz, but IM is an analog artifact, not (except in very rare circumstances) digital.

Re:Update (5, Interesting)

Anonymous Coward | more than 6 years ago | (#24360595)

It looks to me like Google have done this on purpose to stop people uploading high quality audio with a still image. A lot of the music I've been listening too recently has been from youtube, I'm sure I'm not the only one...

Re:Update (1)

pz (113803) | more than 6 years ago | (#24360867)

AWith the tone and sample rate I used (19kHz and 44.1k) at least the high quality encoder whistles at, some other frequency. Sounds like somewhere less than 10kHz to me.

Like, say, 3.05 kHz? That's what one would expect from a non-linear mixing of the sampling frequency and the signal you've injected. There are so many potential sources for non-linear mixing that it's hard to start a meaningful list, but here goes: gain control, compression, resampling, clipping, aliasing, unintentional digital-to-analog-to-digital conversions, non-idealities in the audio driver amplifier, etc. The problem could originate at your end when you created the audio stream, at the far end when they normalized it, at the near end during playback, etc. And that's just off the top of my head.

But, non-linear mixing between the signal and sampling rate is probably the culprit.

Just sneak past the entire recompression process? (4, Interesting)

4D6963 (933028) | more than 6 years ago | (#24360415)

Wouldn't another solution be to sneak past the entire recompression process by submitting a .flv video that meets YouTube's requirements to avoid recompression? Or would the compression on audio (not the same type of compression, the one this article is talking about) still be forced on these?

By the way to improve the trick, what you could do is detect the envelope of your sound, a modulate your 19 kHz sine with an envelope complementary so that the two envelopes would sum up to a flat line, so your 19 kHz envelope would be f(t) = 1 - original_sound_envelope(t).

Re:Just sneak past the entire recompression proces (2, Informative)

Not The Real Me (538784) | more than 6 years ago | (#24360805)

"...Wouldn't another solution be to sneak past the entire recompression process by submitting a .flv video..."

Last time I submitted a video, about six to eight months ago, Youtube did not accept .flv or .swf formats, even though that is the format that they use to stream. Youtube wanted mpg, divx or mov formats. That sucked because my original was done in swf. First I had to convert the swf to divx which I uploaded to Youtube. Converting from swf to divx resulted in a big quality degradation. Youtube then converted the divx back to flv which resulted in a second quality degradation with the audio being completely out of sync with the video.

Re:Just sneak past the entire recompression proces (2, Insightful)

4D6963 (933028) | more than 6 years ago | (#24360955)

Ha... however considered that .flv video is H263 (or is it H264 now?) I guess you could find a program that would change the container to an AVI-compatible one and thus avoid recompressing?

Re:Just sneak past the entire recompression proces (0)

Anonymous Coward | more than 6 years ago | (#24360861)

That would be a mess, though it couldn't be much different than what they currently do. They could simply accept finalized flv files and put out-of-spec flvs in the encoding chain with the rest of the uploads.

Or you could remodulate (-1, Offtopic)

Anonymous Coward | more than 6 years ago | (#24361135)

the sensor array and inverse the polaron field while refocusing the tachyon beam. Just watch out for the occasional transporter duplicating effect due to atmospheric interference. We know how that turned out last time.

Re:Or you could remodulate (1)

4D6963 (933028) | more than 6 years ago | (#24361203)

I didn't realise that what I said sounded impressive to the point of prompting a trekkie (or whatever it is you're referring to) to deblaterate nonsensical gobbledegook to try to sound as "cool".

Standards (5, Funny)

Dan East (318230) | more than 6 years ago | (#24360417)

YouTube is just trying to enforce a standard level of quality to the content. Everyone expects crappy video with lots of compression artifacts, so the audio might as well follow suite.

Re:Standards (0)

Anonymous Coward | more than 6 years ago | (#24361019)

that would be suit w/o the "e".

Compression (1)

retchdog (1319261) | more than 6 years ago | (#24360419)

I can understand why youtube does this (apart from the scream videos...) - a lot of people browse on laptops which have terrible audio. Thinkpads are especially awful; when I play video on VLC without headphones, I set the volume at 1600% and suffer the clipping - at least I can hear it over, say, a room A/C.

Is anyone aware of a lower-level playback compressor on Windows and/or Linux, perhaps a virtual device driver, which lets you mangle your sound this way? VLC doesn't work for everything after all.

Re:Compression (2, Informative)

AvitarX (172628) | more than 6 years ago | (#24360541)

I don't know about the practicality, but I read a tutorial of running all of your sound (In Linux) through Jackd.

You could then run your applications through the jack rack and tweak it however you wanted.

Re:Compression (1)

retchdog (1319261) | more than 6 years ago | (#24360871)

It sounds a bit more heavyweight than I'd like, but I've been curious about the network streaming of jackd. Interesting, maybe I'll get off my duff and set it up. Thanks for the tip.

Re:Compression (1)

4D6963 (933028) | more than 6 years ago | (#24360553)

Did you try VLC's "volume normalizer"? It's not compression but it makes more quiet passages louder. And if your ambient noise problem is that bad, it may damage your hearing in the long term depending on how loud it really is.

Re:Compression (1)

retchdog (1319261) | more than 6 years ago | (#24360837)

I live in a metropolitan area so there's only so much I can do about ambient sound. But seriously, it doesn't take much more than quiet background conversation or a standard room A/C to drown out my laptop. Thanks for the tip, I'll look through the miasma of VLC's options again - I guess that it preprocesses the whole file instead of doing it on-the-fly? That'd be better.

Re:Compression (1)

Mprx (82435) | more than 6 years ago | (#24360793)

ALSA supports LADSPA plugins. Example compressor/limiter setup here: http://alsa.opensrc.org/index.php/Ladspa_(plugin) [opensrc.org] I use this for watching movies at night without disturbing neighbors, works very well.

Re:Compression (1)

retchdog (1319261) | more than 6 years ago | (#24360953)

Very nice. I knew there had to be something like this; I'll check it out. Thanks.

Re:Compression (1)

Stormwatch (703920) | more than 6 years ago | (#24360951)

a lot of people browse on laptops which have terrible audio. Thinkpads are especially awful; when I play video on VLC without headphones, I set the volume at 1600% and suffer the clipping - at least I can hear it over, say, a room A/C.

That's a part of the loudness war... they make music more listenable with the most awful devices (cell phones, earbuds, car radios, laptop speakers), yet make it unbearably bad to anyone with a decent setup who expects quality.

If the game industry worked like the record one... every game would have GameBoy resolution, even if you ran it on a huge, hi-def TV set.

It's what viewers crave (0)

Anonymous Coward | more than 6 years ago | (#24360441)

Youtube, what bad audio compression you have!

All the better to hear the screams of yet another teenager lighting his farts (and himself) on fire, user.

Hans (1, Interesting)

Anonymous Coward | more than 6 years ago | (#24360451)

I upload already compressed FLV and find that the video has the same audio quality as I had encoded.

Brilliant idea though. hmm..I remember an episode of Batman Beyond where the Shriek used sound waves to destroy stuff and he even masked other waves. This is off-topic but maybe youtube compressor can be used as a weapon to increase the frequency to a point where glasses may break and dogs can be made deaf, hmm..

Re:Hans (1)

clang_jangle (975789) | more than 6 years ago | (#24360729)

I upload already compressed FLV and find that the video has the same audio quality as I had encoded.

That definitely seems like it would be the best solution, but that's assuming niceone isn't already using flv for his uploads clips. Does youtube do more processing on an flv, even if it's submitted as "ready"? If you can present your material in such a way that no conversion is necessary on youtube's end, that will always give you the most control over the end result.

I remember being unhappy with the sound I ended up with years ago when my recordings got mastered to CD, but then I learned the way to beat that is to record digitally and master it myself. If you fall in love with the sound of a format you will end up disappointed unless the format in question is ubiquitous.

Ruff ruff! (1)

Tablizer (95088) | more than 6 years ago | (#24360471)

mix in a high frequency sine wave (I used 19kHz) ... but is filtered out by the encoding process (so, no need to worry about deafening any dogs).

Ruff ruff rufff, and ruff rufff, you little bigoted ruff ruff ruffff.

-Tablizer's Dog
   

Re:Ruff ruff! (3, Funny)

4D6963 (933028) | more than 6 years ago | (#24360515)

Ruff ruff rufff, and ruff rufff, you little bigoted ruff ruff ruffff.

Translation : I'm ultrasound-deaf, you insensitive clod!

Re:Ruff ruff! (0)

Anonymous Coward | more than 6 years ago | (#24360891)

I say I say I say How does a dog feel the morning after the night before?

Ruff!

A simple recipe (0)

Anonymous Coward | more than 6 years ago | (#24360497)

1) Normalize sound around -15dBFS (RMS)
      (using the normalize-audio software)
2) Compress sound using the Dyson compressor
      (available in ecasound)

but is filtered out by the encoding process (3, Interesting)

NovaHorizon (1300173) | more than 6 years ago | (#24360509)

you mean that high pitched squeal that is driving me nuts in the example more then the audio compression? Yea.. that's filtered out all right...

Re: but is filtered out by the encoding process (0)

Anonymous Coward | more than 6 years ago | (#24361197)

Parent is rated "Funny", but...

I don't hear anything, but my ten-year-old daughter says that she can hear a high-pitched hum. She says it's especially noticeable before the music starts.

Warning from ccalam in the second video (5, Interesting)

Looce (1062620) | more than 6 years ago | (#24360543)

The high quality version of the audio will have the 19 (or up to 22.1) kHz sine wave you choose to use in your video upload. So this is a trade-off of quality (high-quality = eek!) versus lack of unwanted range compression (low-quality = listenable, for lack of a better word).

FWIW, I can hear 19 kHz waves. So this trade-off affects me.

Re:Warning from ccalam in the second video (0, Redundant)

4D6963 (933028) | more than 6 years ago | (#24360675)

Maybe they should try with infrasounds then?

Re:Warning from ccalam in the second video (3, Interesting)

pz (113803) | more than 6 years ago | (#24360821)

FWIW, I can hear 19 kHz waves. So this trade-off affects me.

You won't hear 19 kHz much longer. Seriously, not because of this or any other particular factor (although there are many), but because everyone experiences upper-range hearing loss as they get older, and it starts at an astonishingly early age.

Teen Buzz/Mosquito Ringtone (3, Interesting)

Looce (1062620) | more than 6 years ago | (#24360889)

I have indeed heard of such deterioration on the Teen Buzz website (which is currently down for excessive bandwidth usage?) - but this page [wikipedia.org] describes it as well.

Those little annoying sine-wave sounds are also used by TV advertisers such as Kentucky Fried Chicken [youtube.com] to grab teens' attention if adults are not their market. (For the record, if you can't hear the tone, it sounds off when the KFC bucket shows up.)

Re:Teen Buzz/Mosquito Ringtone (1)

flink (18449) | more than 6 years ago | (#24361123)

I'm 30 and I heard that loud and clear, and I have been to many, many extremely loud hardcore shows in small clubs with now ear protection. (In my youth of course, I'm a little more careful with my ears these days).

Re:Warning from ccalam in the second video (0)

Anonymous Coward | more than 6 years ago | (#24361115)

I'm 32 years old and i have no problems hearing very high frequencies. However the sound in the video does sound much lower than 19 kHz.

Re:Warning from ccalam in the second video (1)

cyclopropene (777291) | more than 6 years ago | (#24361127)

You won't hear 19 kHz much longer. Seriously, not because of this or any other particular factor (although there are many), but because everyone experiences upper-range hearing loss as they get older, and it starts at an astonishingly early age.

I'm 34, which is not astonishingly young, I've been to my share of loud music concerts (though I use earplugs for the obnoxiously loud ones), and I can hear that 19 kHz pitch painfully loud and clear when the volume is turned up enough to hear the guitar. Perhaps I'm just astonishingly lucky with my hearing so far, but for me this is not a worthwhile tradeoff.

It reminds me of the old remote control TV my grandfather had when I was a kid which used high pitched sound that sent me running for the other room every time he changed the channel...

Lack of Choices (2, Interesting)

Tablizer (95088) | more than 6 years ago | (#24360545)

It would be nice if YouTube offered some choices, such as volume adjustment, no volume adjustment, and also other things like stereo. The only way I know of to get stereo is to submit it in Adobe's proprietary formats. YouTube is pulling a Henry Ford: you can have any color you want, as long as its black.

Re:Lack of Choices (3, Funny)

4D6963 (933028) | more than 6 years ago | (#24360641)

It would be nice if YouTube offered some choices, such as volume adjustment

Yeah, I mean, who on YouTube would even think of abusing that?

Re:Lack of Choices (1)

Tablizer (95088) | more than 6 years ago | (#24361005)

Yeah, I mean, who on YouTube would even think of abusing that?

If they "abused" it, it would be quieter, not louder. Who'd want to do that? There is a situation whereby they might trick you into lowering the volume, and then blast you with noise, but this is technically detectable. Whether they want to check for such is another matter.

     

Re:Lack of Choices (0)

Anonymous Coward | more than 6 years ago | (#24360681)

Worked for Ford...

Re:Lack of Choices (1)

Tablizer (95088) | more than 6 years ago | (#24360899)

[black paint] Worked for Ford...

By some accounts it was a sound strategy early on, as people were happy enough just to have a car that they didn't complain about the color. However, as time when on, some say Ford grew stodgy and stuck in his ways. This is partly why he never was able to follow on with a similar success, becoming just another car company.
         

Choose better. (2, Interesting)

jbn-o (555068) | more than 6 years ago | (#24360879)

Host your video somewhere else [archive.org] , upload it in a high-quality format, and let the site make derivatives for you (including a Flash video and a player you can embed in your webpage if you insist on placating a proprietor). Some organizations do this daily and it works excellently. YouTube needs you more than you need YouTube.

Cheap asses (0)

Anonymous Coward | more than 6 years ago | (#24360549)

While this is more along the lines of aural compression, my guess is that they're figuring out a good way to save some bits on the backend as well. If you can cut down the size of an audio track by a couple of percent, that's thousands saved in bandwidth costs over the millions of videos viewed per day.

This is something that I really find at odds with the nature of technological progress. When quality should always be improving, the bean counters ratchet things down over and over again to eke out extra $$. Once in a while, you get lucky, and a new technology allows for increasing quality at a lower cost.

As a side note, that Youtube video gets some really odd resonance out of my sub.

Re:Cheap asses (2, Informative)

4D6963 (933028) | more than 6 years ago | (#24360661)

And how exactly would that help making smaller files?

Nomalization standard? (4, Interesting)

Waccoon (1186667) | more than 6 years ago | (#24360565)

It surprises me after all these years, audio formats don't provide recording information about the dynamics of the waveform.

Cameras write EXIF information into JPEG files, why can't we have something similar for audio so we don't have to adjust the volume all the time?

You don't have to be an audiophile to appreciate good audio. I have a custom amp next to my computer into which I've plugged headphones. Find anyone with a pair of headphones, and you'll find an amp, too. Either that, or a deaf person who's been tortured by a bad Flash file.

Re:Nomalization standard? (1)

4D6963 (933028) | more than 6 years ago | (#24360627)

It surprises me after all these years, audio formats don't provide recording information about the dynamics of the waveform.

Well what kind of things would you store that couldn't be obtained through analysis of the actual sound?

Re:Nomalization standard? (1)

tftp (111690) | more than 6 years ago | (#24360679)

All the things that you want to apply to the playback before the playback even starts, or even before the file is even fully downloaded.

Re:Nomalization standard? (1)

4D6963 (933028) | more than 6 years ago | (#24360761)

All the things that you want to apply to the playback before the playback even starts, or even before the file is even fully downloaded.

But in the case of YouTube they do all their processing on the entire file once and for all, so the point is moot.

Re:Nomalization standard? (1)

tftp (111690) | more than 6 years ago | (#24360791)

I was more thinking of YouTube doing no processing at all, and so that the client can apply its own if it wishes.

Re:Nomalization standard? (1)

Orestesx (629343) | more than 6 years ago | (#24360777)

Exactly, why do databases have indexes? All the information you need can be obtained by analyzing the data.

Re:Nomalization standard? (1)

4D6963 (933028) | more than 6 years ago | (#24361229)

Except that these have a use, and that their falsifiability isn't an issue.

It's called ReplayGain (2, Informative)

Anonymous Coward | more than 6 years ago | (#24360643)

Read more http://replaygain.hydrogenaudio.org/ [hydrogenaudio.org] .

Re:Nomalization standard? (1)

dabadab (126782) | more than 6 years ago | (#24360673)

There is such a thing (google for replaygain), but it's not about that, it's simple compression, i.e. making the really quiet sounds nearly as loud as the loudest ones.

Re:Nomalization standard? (0)

Anonymous Coward | more than 6 years ago | (#24360807)

It surprises me after all these years, audio formats don't provide recording information about the dynamics of the waveform.

You are mistaken. All of them do- it's the amplitude of the waveform as it is being sampled. The kind people at youtube just choose not to preserve those dynamics. Which is great for the umpteenth lip-sync video recorded on a handycam, of course- but not-so-great for those of us who actually provide reasonable quality audio.

Re:Nomalization standard? (3, Informative)

jimicus (737525) | more than 6 years ago | (#24360945)

There is, in MP3 at least. It's used by mp3gain:

http://mp3gain.sourceforge.net/faq.php [sourceforge.net]

However, not all audio players support it. I'm pretty sure the iPod doesn't, nor does iTunes. (For some reason iTunes does have a "normalise levels on all selected tunes" option but that works by decoding/re-encoding the audio, which is a lot slower because in addition to the audio analysis you have to re-encode the file and is likely to introduce further interference to the stream).

Having said that, I've only got a fourth gen ipod. For all I know, more recent models do make use of this tag and furthermore, for all I know if iTunes knows that it's being synced with an ipod which does support the tag then that's what it uses to adjust the gain.

Benefit of the doubt (0)

Anonymous Coward | more than 6 years ago | (#24360663)

To give YouTube the benefit of the doubt here--it's possible that the sound modification is being done with good intentions.

Most YouTube videos are uploaded by amateurs with respect to the details of A/V. As such, the audio quality in many videos is probably low. It's also likely that the sound level between different uploads are radically different. This means that unprocessed audio would sound bad for many videos. Moreover, switching from clip to clip on YouTube would involve annoying changes in audio level (e.g. you turn up the sound for one video, but then the next one is painfully loud).

So, they may be automatically recompressing all the audio to fix many of the mistakes of amateur uploaders. Again, it's important to remember that YouTube is not really meant for distribution of high-resolution content.

Having said all that, I'm also not an A/V expert, so I may wrong on this. Also, it would be nice if YouTube gave some advanced options for more experienced people to use, so that they could flag their content for "skip audio recompression" or whatever. Also, YouTube's introduction of the "watch in high quality" option shows that they want to expand beyond low-res clips... in which case they need to provide commensurate audio quality.

first harmonic is at 10khz (0)

Anonymous Coward | more than 6 years ago | (#24360705)

and humans can hear that ok
2nd is 5k and thats right in the mid band

or dont the geeks understand how sound works ?

first harmonic of what? (1)

unfunk (804468) | more than 6 years ago | (#24360853)

What you just said makes no sense.

The first natural harmonic of a 5kHz tone would indeed be 10kHz, but the second would be 20kHz, and so on.
Every sound has a whole raft of natural overtones and harmonics, individual to itself. A 1kHz tone's harmonics are at 2kHz, 4kHz, 8kHz, etc. It's therefore really quite disingenuous to just state that the "first harmonic is at 10kHz"

Why don't they just NORMALIZE instead of compress (1)

Latinhypercube (935707) | more than 6 years ago | (#24360713)

Why don't they just NORMALIZE instead of compress ? Compression changes dynamics, as in the thread descrription. Normalize would just raise the volume up to peak. No changing music, just increase volume...

The cat got my tongue (1)

darklich14 (1308567) | more than 6 years ago | (#24360875)

Brilliant! I've heard about problems with "normalizing" in the past. This is an excellent way to work around this problem!

reminds me of tape bias (2, Interesting)

stevetures (656643) | more than 6 years ago | (#24360957)

hopefully this wont date me much, but this reminds me of tape bias, the high-frequency signal applied to the magnetic frequencies used to record tapes (oh it did have unintended consequences). http://en.wikipedia.org/wiki/Tape_bias [wikipedia.org]

Thank the iPhone (2, Interesting)

wiredlogic (135348) | more than 6 years ago | (#24361013)

I would guess they are doing this to better "service" handheld devices like the iPhone and upcoming Android devices that have limited dynamic range in their speakers.

Kompressor crushes you (tube)! (1)

dzfoo (772245) | more than 6 years ago | (#24361113)

Sorry, couldn't resist.

        -dZ.

Recording vs Processing (3, Insightful)

rueger (210566) | more than 6 years ago | (#24361171)

Although I tend to think that Dan East [slashdot.org] summed it up best, I feel the need to point out that 95% of bad YouTube audio is the result of lousy recording quality, not subsequent processing.

Garbage In, Garbage Out.

The mics and electronics on most consumer camcorders (or that most people use with their Macs and PCs) are just plain crappy, and shouldn't be relied on for anything that you hope to distribute. And of course, some actual audio recording skills help too.
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