At what bitrate does Groove app play?

December 22, 2017 3:39 PM

I have an android smartphone. I play music files from my OneDrive, all ripped at different bitrates from CDs. Does the Groove app play at the bitrates I used, or convert down, and to what? Thanks.
posted by noelpratt2nd to Technology (9 answers total)

In order to provide a helpful answer to this question, it would be useful to know why you care about bitrates in the first place.

Just to start the ball rolling, though: in what format are the music files on your OneDrive? WAV, MP3, WMA, something else?

In any case, unless you've done something very unusual during the ripping process, the sample rate, sample depth and channel count for those music files are going to be the same as for the CDs they were ripped from. The intended playback bitrate of the original CD audio stream consumed by the ripping app will therefore be 44100 samples/second × 16 bits/sample/channel × 2 channels = 1411200 bits/second.

The output of a typical MP3 compressor is a bitstream something like 6 to 12 times slower than that, so if you look at the bitrate quoted in the file metadata for a format like MP3 or WMA you'll see numbers like 128 kbits/s or 192 kbits/s or similar.

Any player - not just the Groove app - will need to decompress those files on the fly to generate a stream of samples at the original speed (1411200 bits/second) for the digital-to-analog converter electronics. And in order to provide an output bitstream at that speed, the decompressor will need to consume compressed data from the audio file at the rate listed in its metadata.

Because some information is lost during compression, the content of the bitstream emerging from the decompressor will not be identical to that fed to the CD player's own DAC during playback of the original CD, even though the speed of the stream is the same; but if the compressor was any good, it should be very hard to pick audible differences.

As far as I know, OneDrive operates as straight file storage, so the input to Groove on your Android phone will just be audio files you've stored in your OneDrive exactly as stored; pretty sure there's no server-side transcoding going on. Therefore, the only bitrate conversion step will be the one inherent in the decompression that any player app must ultimately do, and the average network data rate during music streaming will be approximately that of the compressed audio file's listed bitrate plus a bit of overhead.

Does that help?
posted by flabdablet at 10:19 PM on December 22, 2017 [1 favorite]

Response by poster: Yes, if in the end I know what I'm hearing without having to go to a science lab or quiet corner. In other words, I know most of the above already, but don't know what Groove gives me -- and I'm not the only one. Trying to get an answer from the Microsoft community or Groovers is a dubious thing. I'd like to think my WMA-Lossless files on OneDrive aren't being heard at 192 or 256 bitrate without my knowledge, that's all.
posted by noelpratt2nd at 7:27 AM on December 23, 2017

I'd like to think my WMA-Lossless files on OneDrive aren't being heard at 192 or 256 bitrate without my knowledge, that's all.

I'm really not at all clear on what you mean by "being heard at 192 or 256 bitrate". What comes out of your speakers or earbuds doesn't have a bitrate.

Are you actually looking for confirmation that Groove streams your music files as stored, rather than transcoding them to some other low-bitrate lossy compressed format for network transmission?

I'm fairly convinced it does just stream them as stored. If it were transcoding to some intermediate format for streaming, I would expect the rules for which file formats Groove supports for streamed playback from OneDrive to be set by the server-side transcoder and therefore the same on all client platforms, which as far as I'm aware they are not.
posted by flabdablet at 11:13 AM on December 23, 2017 [1 favorite]

Response by poster: So you don't know either, although you're fairly certain, okay. Sansa non-internet mp3 players convert to 320, which is fine by me. I have a Cowon i9 that plays what you ripped it at only. You hear things online about what Groove does, and everyone's saying something different. If streaming internet = total accord with OneDrive, that would be great. If they wanna tell me some files change to lossier, just tell me.
posted by noelpratt2nd at 12:06 PM on December 23, 2017

Response by poster: Another thing. Is there any way my content on the cloud can exist unsupported, instead of actually residing also on my computers? Have a heavenly life of its own?
posted by noelpratt2nd at 7:59 PM on December 23, 2017

Most cloud providers give you a web interface as well as a desktop client. If you just use the web interface to upload stuff to your cloud account, and never install the desktop client, you effectively get cloud-only storage.

Most of the desktop clients also let you mark selected cloud folders as non-syncing on a per-device basis.
posted by flabdablet at 11:21 PM on December 23, 2017

Response by poster: If I unsync an album from my desktop OneDrive, it still has to be synced somewhere (another device) in order to play on Groove. Or have I forgotten how that works...
posted by noelpratt2nd at 6:58 AM on December 24, 2017

Best answer: it still has to be synced somewhere (another device) in order to play on Groove

If the mechanism by which your music reaches your player is file sync rather than actual online streaming, you can be virtually certain that it's not getting transcoded between storage and playback; there's simply no reason to do so.
posted by flabdablet at 8:28 AM on December 24, 2017

Response by poster: Thanks, I think I understand better now.
posted by noelpratt2nd at 12:39 PM on December 25, 2017