Show HN: I made an app that listens for a rapper's songs and raps along in sync | Hacker News Reader

Show HN: I made an app that listens for a rapper's songs and raps along in sync

thenextweb.com

119 pointsskattyadz31 comments

Do you know that many (terrestrial) radio stations do not play songs at their exact recorded speed?

Most are sped up a little (single-digit percentage), so they can fit more songs (or more commercials) in each hour.

I wonder what sort of time distortion the matching algorithm can handle?

Apparently very few of you read the article...

It's a smart way for a rapper to market his music. I chuckled as I watched the video, and learned about a rapper I hadn't heard of before.

Harmless fun.

It was interesting but the video kept cutting out for me. I figured I'd check out the music anyway and was greeted with a "This content is not available in your country" message. That was a first being in the US.

On this topic I guess. I recently used shazamm (or the other one) and it - in addition to finding the song - showed me the lyrics in real time, highlighting the current line in the song. Really impressive.

That was probably soundhound

Why do you say that? Shazam does it too, since 2011 when it acquired Tunezee to power that functionality.

http://gigaom.com/2011/06/15/shazam-makes-first-acquisition-...

Guy said "(or the other one)".

Soundhound was the likely candidate.

  Why? Why? Why the fuck?
  Nerdie homes must make a buck.
  Have a need? Scratch that itch.
  Take a break to hack that bitch.

  People hurt & need more meds,
  Hacker rather show his creds.
  Breakthrus needed by a sage,
  But iphone apps r all the rage.

  Enterprise really sucks
  Hackers never get those bucks.
  Web apps used to be the hack
  But mobile's got a "craftsman's" back.

  Analysis!
  Paralysis!
  Algorithms!
  Distillation!
  Interpretation!
  Compilation!
  
  Deployment to the cloud.
  Disruption now allowed.
  Users need a good solution
  But all they get is more polution.

  Something no one ever needed.
  HN front page: he succeeded.
  Nerdie homes must make a buck.
  Why? Why? Why the fuck?

It's not clear whether the above is intended as an impressive, rhyming, satirical tribute to the OP or if it is a creative, yet sarcastic, put-down attempt.

Regardless, I want to say that "Show HN" is my favorite type of HN post. If what is presented is useful or marketable, all the better, but the sheer fact that somebody built something (anything), usually in their spare time, and are proud enough to share it with the masses is something I applaud.

There is a lot of negativity on HN these days, but in most cases "Show HN" threads have respectfully been spared. I sincerely hope it stays that way.

It seems like a tongue-in-cheek stylistic parody of nerdcore on top of most rap music: bravado and aggression. ... but it's hard to tell whether it was a joke or not, but I'm leaning towards not.

Next music app idea: every time it hears The Grateful Dead or Iron Butterfly, a B-52 Westfalia bomber swoops in firing lolcat missiles and drops cluster bombs that grow dandelions. (Hippies seem to be the most antithetical to the topic to change the subject.)

Is it necessary to hijack the top comment in the discussion thread of OP's awesome app with your shitty, negative "rap" lyrics?

Cute! It's pretty much the same as the Cassius app from a few years back (https://itunes.apple.com/en/app/cassius-i-3-u-so/id399394777), but syncing to external audio instead. A nontrivial extension, but still very similar from the user's perspective.

Now, if the app was able to lipsync to any tune, that would be more impressive. It's certainly doable, see e.g. Tony Ezzat's "Mary 101" system from 10 years back: http://people.csail.mit.edu/tonebone/research/mary101/

This is totally awesome; way beyond my iOS knowledge. Any pointers or tips you learnt about audio processing along the way?

I'm doing FFTs at regular intervals using the Accelerate framework. Then a lot of rolling window comparisons of frequency data to try and determine which fingerprints these frequencies match closest.

Expect a blog post soon (Y)

Can't wait for the blog post !

I imagine it's similar to what Shazam do. I read the original algorithm paper years ago; it's very interesting and written clearly enough to be understood by people with zero background on the subject:

http://www.ee.columbia.edu/~dpwe/papers/Wang03-shazam.pdf

Cool! On the topic of tech and music: here's an app that lets you play your favorite YouTube music videos and SoundCloud songs by voice: http://youtu.be/cyS4TlBkTns

The linked page pegs one of my CPU cores to 100%. Anyone else get the same thing?

Fine for me - here's an App Store link if you can't click through from the article :D https://itunes.apple.com/gb/app/tinie-tempah-rap-demonstrati...

Yup. Locked up firefox for me for quite some time. Was compiling at the time, so didn't think too much of it..

Compiling, huh? http://xkcd.com/303/

This is clever. I can see so many different apps using a similar technology.

Do you have to record each song separately?

It's using a ton of videos we recorded with Tinie on one grey London afternoon

Off topic, but do TNW know that that page is impossible to scroll? (Safari, brand-new MBP)

Just opened Safari (latest OSX and latest updates installed) here to try it out: Works well here, can scroll without a problem.

This is an extremely cool app! I'm impressed. Good job.

Is this a "me, too" kind of thing? Or is it different than Sound Hound or Shazam in some way?

Edit: ah, now I see. It syncs up video, not just scrolling text lyrics.

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