How to know whether a audio file is CBR or VBR?

linux ubuntu audio bitrate

9,721

Solution 1

Install Checkmate first (the .deb file) by double clicking it and selecting Install in Ubuntu Software Center.

Then, open up a terminal with CtrlAltT and call:

mpck input.mp3 | grep "bitrate"

This will tell you precisely whether a file is CBR or VBR. If it's CBR, you'll just see the bitrate, and if it's VBR, after the average bitrate label you'll see (VBR).

I tested this on Ubuntu 12.04, but packages for Checkmate are available for Windows as well.

Solution 2

This is my trick, it works only if you have a directory containing multiple mp3 files, and you know that they have the same encoding (VBR or CBR): If the files show different bitrates then you know they are VBR encoded.

You see the bitrate indication in the file properties, or use exiftool *.mp3 | grep Bitrate.

9,721

kev

Updated on September 18, 2022

Comments

kev over 1 year
File size of an CBR(Constant bitrate) audio recording can be calculated using a formula:
```
File Size (Bytes) = (sampling rate) × (bit depth) × (number of channels) × (seconds) / 8
```
E.g., a 70 minutes long CD quality recording will take up 740880000 Bytes, or 740MB:
```
44100 × 16 × 2 × 4200 / 8 = 740880000 Bytes 
```
But it doesn't work if the audio is VBR(Variable bitrate). How to know whether a audio file is CBR or VBR?
- kev about 12 years
  
  I'm running on Ubuntu 12.04
slhck about 12 years

Not entirely true. That may hold for Winamp, but the OP is using Ubuntu. Even VLC doesn't properly show whether an audio file is CBR or VBR.
chmod about 12 years

@ slhck You are right about VLC, they don't display it correctly. Under Windows, I also check with dBpoweramp and it does display it correctly including the encoder name as well. I don't use linux so I don't know will do the job.
slhck about 12 years

See my answer on how to reliably check it in Linux. Given that it's command line, it could even be batch-scripted for multiple files or an entire MP3 collection. (By the way, you shouldn't put a space between @ and username, otherwise people won't get a notification).
Iain Samuel McLean Elder almost 9 years

Appears only to work for MP3 files. Do you have a solution for M4A? I tried mpck *.m4a and got output like no MP3 file.
slhck almost 9 years

You could try with MediaInfo maybe — not on a PC right now but it outputs a lot of information.
Ryan over 5 years

+1. Thanks. Here is how I installed: wget http://checkmate.gissen.nl/mpck_0.12-1_amd64.deb, then sudo dpkg -i mpck_0.12-1_amd64.deb, then sudo apt-get install -f, then mpck my_storage/my.mp3 | grep "bitrate"