My phone hates this wav in particular

May 10, 2019 12:10 PM

Why is a .wav file playing normally on my computer, but slow and distorted on my Android phone?

I have a series of files (audiobook chapters) in .wav format. On my computer, they play normally. However, when I transfer them to my phone (via Google Drive, if it matters), they play too slow - stretching a 32 minute file to an hour and a half.

I tried using Drive's own audio player and several other media apps on my phone - Same result each time. I tested a different wav file, and it played without distortion - but all the .wavs in this audiobook are messed up.

This is a Sony Xperia Z5 Compact, with Android 7.1.1

I tried cutting out a clip in Audacity to upload as a sample, but that file plays just fine. So there's some format issue with the original files, right?

I can probably import each file into Audacity and re-save them, or convert to mp3, but I'm curious about what is actually going on here. Any ideas?

(Also, this isn't my field, so please explain in small words)

posted by Gordafarin to Technology (3 answers total)

Best answer: I assume when they're playing slowly, they're also playing lower in pitch?

My guess is that it's a sample rate thing. The audio book files are recorded at a lower sample rate since the human voice doesn't have high frequencies in it that require a higher sampling rate to sound right. There's a header in the audio file giving some specifics about what the file is and either A. it's messed up but your computer is still figuring out what it should do, or B: the header is correct and your phone is misinterpreting it and playing it at the wrong sample rate.
posted by jonathanhughes at 12:17 PM on May 10, 2019

Best answer: WAV is a reasonably complicated file format with a lot of options for encoding, interleaving, sample format, sample rate, etc.
Not all players can play all possible WAV files correctly. If you re-encode the problem files with Audacity, as you say, they will probably work.
posted by w0mbat at 1:27 PM on May 10, 2019

Best answer: Yeah my guess is that it's a sample rate thing too. Probably the player on the phone is making assumptions about the sample rate of the file (which could be a poorly-designed player, or it could be the file is badly encoded somehow, hard to say).

I would reëncode the file to some other format. If you don't want to do them each individually, you can use Audacity in "Chains" or "Encode Multiple" mode or any number of other special-purpose programs that will do batch encoding. I'd just encode them all to MP3 and call it a day.
posted by Kadin2048 at 7:22 PM on May 10, 2019