Audio file Bitrate

how do you determine whether an audio file was ripped at the same bitrate as its tags claim? I mean, you could always rip it at a low rate and re-encode it with a higher bitrate (of course the quality will be affected). So is it possible to find out whether a 320 kbps mp3 file was actually ripped at the claimed rate? (I am on a Linux platform)

finemann

Posted 2010-09-16T19:26:55.327

Reputation: 91

Just an observation, but when most people use the word "RIP" they mean getting a wav file from a CDDA file and then (maybe) re-encoding the wav as a WMA or mp3 or m4a file. In other words you will be using a lower bitrate when you down-sample from wav to mp3:320. You could of course take a wav and resample it upwards, but that's relatively unusual (larger file with same sound quality). – hotei – 2010-09-17T03:28:31.390

Answers

If you have the original flac/wav file and a tool like audacity you can load both waveforms (your suspicious 320-kbps mp3 and a re-encoded from scratch 320-kbps mp3) and visually and/or aurally compare them. It's not easy for most people to distinguish differences at those encoding rates but maybe you've got the ear for it.

If this comparison leads you to believe it was NOT ripped at 320 then you can decrease the from-scratch encoding until you get to a rate that matches the quality of the suspicious one. Somewhat subjective I admit, but it's a way to do it.

hotei

Posted 2010-09-16T19:26:55.327

Reputation: 3 645

If OP had the uncompressed/lossless source, he wouldn't bother determining real quality of encoded files. He would just encode them from source with desired bitrate. – Gepard – 2010-11-04T16:10:22.607

Take a look at EncSpot. It's no longer maintained but supposedly does the job. I've never personally used it, but found the reference here

James Mertz

Posted 2010-09-16T19:26:55.327

Reputation: 24 787

It's a nitpick, but he's asking what rate it was RIPPED at, not what rate it was ENCODED at (which is what EncSpot tells you - "ENCode Spot"). – hotei – 2010-09-17T03:21:05.370

OP seems to think that some "sleight of ear" may be going on so the last encoding rate is not the one of interest (unless it's the only one). – hotei – 2010-09-17T03:41:50.027

Once it is re-encoded, there is no way to know what the source bitrate was. Its better to find music in "Flac" uncompressed format and encode it yourself to the bit rate you want.

Moab

Posted 2010-09-16T19:26:55.327

Reputation: 54 203