问题
this question is just out of pure curiosity.
I noticed, that when I sync my phone with my Spotify playlists, music is transfered really fast, I haven`t benchmarked or something, but it just feels times faster than just downloading 20 or so mp3s.
How they do it ? Is it some kind of special audio format ? Or maybe they compress the data somehow when transfering ?
回答1:
This isn't really a programming question, but I'll bite.
Spotify uses OGG audio for its mobile clients. Depending on the quality you choose for offline syncing, it's either 96, 160 or 320 kbit/sec, and not really much different in size to the equivalent MP3 bitrate. However, the Spotify client and backend do have a very optimised network stack, so it's possible you're seeing this, but I'd be surprised if the latency benefits the network stack provides is enough to have a visible effect considering the vast majority of the time is spent actually downloading the track rather than requesting it.
回答2:
The funny thing is that Spotify uses OGG to stream music, but it can't play local OGG files.
http://community.spotify.com/t5/Spotify-Ideas/Local-file-support-OGG-Vorbis/idi-p/5451
来源：https://stackoverflow.com/questions/15613581/what-audio-format-spotify-uses-and-how-they-transfer-the-files-to-mobile-devices