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Show HN: Entire concerts algorithmically "reconstructed" from YouTube videos

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Re: Show HN: Entire concerts algorithmically "reconstructed" from YouTube videos

#71

Post by lloeki »

brettwelch wrote: post #31
autrefoius wrote: post #29

Maybe it's just me, but the site rick-rolled me on each concert I tried to check out.

Sorry about that. It only happens when the JS borks out completely (which is rare), when JS is turned off, or when you're using a really old browser (which i assume you're not). If you're inclined (I completely understand if not) can you tell us the error that the console in Chrome or Firebug gives you?

It does it too when on uses ClickToFlash/ClickToPlugin Safari extension. Selecting Flash in the source selector makes it work.

Re: Show HN: Entire concerts algorithmically "reconstructed" from YouTube videos

#72

Post by fat0wl »

chartley wrote: post #21
fat0wl wrote: post #16

Does anyone believe that this is done algorithmically? All the examples I checked seemed to be really poorly sync-ed, & as a DSP engineer I don't believe this task to be incredibly difficult... would also be cooler to have a seating chart to click around to make sense of perspectives

It's all algorithmic but the flash player only seeks to the nearest key frame (every 2s) so that's why it isn't flawless. This can be overcome ... but I'd prefer to work on the seating chart thing - thanks!

Ah, didn't realize the flash / keyframe limitation. Best of luck! very cool idea.

Re: Show HN: Entire concerts algorithmically "reconstructed" from YouTube videos

#74

Post by Natsu »

VladRussian wrote: post #66
antimatter15 wrote: post #13

Earlier quoted context omitted.

Courts ruling on fair use are supposed to take into account "the amount and substantiality of the portion used in relation to the copyrighted work as a whole". Automated copyright detection schemes in YouTube may try to do some semblance of fair use by allowing snippets of copyrighted content under 30 seconds.

just a sidenote - if bittorrent software ensure that no peer-to-peer interaction exceeds 30 sec. for any given title, would MPAA/RIAA/etc... still be able to claim "illegal dowload"?

When they take into account fair use, they take the entire case into account, rather than following any hard and fast rules saying that using X% is "fair."

In other words, no, there's pretty much no way they'd buy any attempt to game the system so transparently. That's why you need a lawyer.

Re: Show HN: Entire concerts algorithmically "reconstructed" from YouTube videos

#77

Post by jackpirate »

nitrogen wrote: post #68
baddox wrote: post #54

Earlier quoted context omitted.

The idea I'm talking about should provide a single consistent audio signal. I know nothing about audio processing, but it seems like it should be possible to take multiple bad audio signals and combine them into one signal that's better than any constituent audio source. Perhaps one audio source captured low frequencies well, while another captured higher frequencies better.

This seems unlikely to be possible. If you haven't captured any frequencies above 15kHz (which an average cell phone mic is unlikely to do), no amount of averaging, filtering, or combining will get them back. There will also be a considerable amount of distortion, since concerts tend to be so loud that even one's ears are distorting. Good luck separating physical distortion in the mic, limiter distortion in the analo…

If you haven't captured any frequencies above 15kHz (which an average cell phone mic is unlikely to do), no amount of averaging, filtering, or combining will get them back.

I think this is technically not quite true. If two cell phones right next to each other are both sampling at 15kHz, in the best case you could combine their samples to get an equivalent sampling of 30 kHz. (Best case meaning phone 1 samples exactly half way between phone 2's samples.)

In practice, however, you would have to account for positioning and the fact that the phones' samples aren't perfectly offset from one another. It would require an amazing engineering feat to overcome this challenge, but I think it's within the realm of physically possible.

Re: Show HN: Entire concerts algorithmically "reconstructed" from YouTube videos

#78

Post by wingerlang »

Nice. However - the timeline should be default. I was pretty meh'd until I found it, works great.

Now it would be nice with an underlying concert-track or / per song mp3. I don't like the crappy cellphonesound. I guess the syncing will be hard though, with the videos lag not very constant (most often, seems to work good now but I have a nice broadband connection)

Re: Show HN: Entire concerts algorithmically "reconstructed" from YouTube videos

#79

Post by SandB0x »

nitrogen wrote: post #68
baddox wrote: post #54

Earlier quoted context omitted.

The idea I'm talking about should provide a single consistent audio signal. I know nothing about audio processing, but it seems like it should be possible to take multiple bad audio signals and combine them into one signal that's better than any constituent audio source. Perhaps one audio source captured low frequencies well, while another captured higher frequencies better.

This seems unlikely to be possible. If you haven't captured any frequencies above 15kHz (which an average cell phone mic is unlikely to do), no amount of averaging, filtering, or combining will get them back. There will also be a considerable amount of distortion, since concerts tend to be so loud that even one's ears are distorting. Good luck separating physical distortion in the mic, limiter distortion in the analo…

In some cases you will have a good prior on the clean signal from studio recordings. Of course, "registering" a recording (or parts of a recording) to the video would be a formidable task in itself.

Re: Show HN: Entire concerts algorithmically "reconstructed" from YouTube videos

#80

Post by allbutlost »

jackpirate wrote: post #77
nitrogen wrote: post #68

Earlier quoted context omitted.

This seems unlikely to be possible. If you haven't captured any frequencies above 15kHz (which an average cell phone mic is unlikely to do), no amount of averaging, filtering, or combining will get them back. There will also be a considerable amount of distortion, since concerts tend to be so loud that even one's ears are distorting. Good luck separating physical distortion in the mic, limiter distortion in the analo…

If you haven't captured any frequencies above 15kHz (which an average cell phone mic is unlikely to do), no amount of averaging, filtering, or combining will get them back. I think this is technically not quite true. If two cell phones right next to each other are both sampling at 15kHz, in the best case you could combine their samples to get an equivalent sampling of 30 kHz. (Best case meaning phone 1 samples exactl…

This is unfortunately so unlikely to as to be practically impossible (currently!).

If the microphones, ADCs etc on both phones are incapable of capturing frequencies of above e.g. 15Khz below a certain range, combining those signals definitely won't bring you any closer to the original signal. You may be able to cancel out a fair bit of noise given enough processing but you won't get back what hasn't been originally captured by either device.

That's before you get into phase problems from trying to combine two signals. A likely outcome is that the amplitude of some signals are increased whilst some are decreased due to phasing issues.

/fuzzily remembered music tech degree. May be too fuzzy though!

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