4 ms·

After using Shazam, I was kind of hoping there was more to it than just a time windowed frequency domain peak-pick algorithm. The algorithm itself is pretty bas

After using Shazam, I was kind of hoping there was more to it than just a time windowed frequency domain peak-pick algorithm. The algorithm itself is pretty basic from a signal processing perspective, but I think the key insight here was that the results are unique enough to store off and compare other samples against at some later point in time.

widdershins 13y ago
Yeah, this is the obvious implementation. As he said in his follow-up post: >And second, I’d like to know which patents are in play. Because I just couldn’t think that something this easy (music-fingerprint is a hash, and we do a lookup) can be patented.. Maybe in the States, but in Europe?
regularfry 13y ago
Yeah, the magic (if there is any) is doing the match across a silly amount of songs in a relatively short time. Not groundbreaking exactly, but operationally quite interesting.
- Jamiecon 13y ago
  I actually remember first using this by dialling 2580 about 10 years ago. At the time it felt truly magical.
kenshiro_o 13y ago
Well I'm sure they must be using a few tricks in their implementation. I've always been interested in knowing how Shazam actually works and had in mind that they must somehow split a song in intervals and "hash" every interval, then store them in some kind of indexed database for fast retrieval. Seems I was not too far off:)
jessedhillon 13y ago
Are there other uses for this algorithm/technique, when applied to signals other than audio? I mean apart from identifying a source from a small clip.
- bmohlenhoff 13y ago
  This type of analysis is commonly used in tons of things, like communications systems, image processing, radar, etc. I used a similar technique when trying to identify an underutilized wifi channel in the vicinity of my apartment.
- IanChiles 13y ago
  IIRC there have been a number of papers on using a similar technique with speech to text applications.

widdershins 13y ago

Yeah, this is the obvious implementation. As he said in his follow-up post: >And second, I’d like to know which patents are in play. Because I just couldn’t think that something this easy (music-fingerprint is a hash, and we do a lookup) can be patented.. Maybe in the States, but in Europe?

regularfry 13y ago

Yeah, the magic (if there is any) is doing the match across a silly amount of songs in a relatively short time. Not groundbreaking exactly, but operationally quite interesting.

Jamiecon 13y ago
I actually remember first using this by dialling 2580 about 10 years ago. At the time it felt truly magical.

kenshiro_o 13y ago

Well I'm sure they must be using a few tricks in their implementation. I've always been interested in knowing how Shazam actually works and had in mind that they must somehow split a song in intervals and "hash" every interval, then store them in some kind of indexed database for fast retrieval. Seems I was not too far off:)

jessedhillon 13y ago

Are there other uses for this algorithm/technique, when applied to signals other than audio? I mean apart from identifying a source from a small clip.

bmohlenhoff 13y ago
This type of analysis is commonly used in tons of things, like communications systems, image processing, radar, etc. I used a similar technique when trying to identify an underutilized wifi channel in the vicinity of my apartment.
IanChiles 13y ago
IIRC there have been a number of papers on using a similar technique with speech to text applications.