[REQUEST] Find Low Quality MP3s

Arm-the-Homeless · 2010-03-06 14:58:06

Is there any script that can recursively check a folder for MP3 files that have lower quality than V0 or 320?

I understand this could be done with `mpg123 -t` but I have a lot of albums so... could take a long time.

bobdob · 2010-03-06 15:45:05

How about:

find . -name "*mp3" -type f -exec file '{}' \; | grep -v 320 | cut -d ':' -f 1

This should print the path name of all mp3 in or under the current directory not in 320kbps.

Ultraman · 2010-03-06 15:46:30

I don't have a solution for that one at the moment, but there is an additional problem. Simply checking the bitrate says nothing. A 320 CBR or V0 VBR MP3 could be a reencode of a 192 CBR MP3, which would result is a much lower quality but you would not spot it by just checking the bitrates...

tlvb · 2010-03-06 15:48:41

Finds mp3 files with <320kbps.

find . *.mp3 -print0|xargs -0 -n1 file|perl -e 'for(<stdin>){/(.*mp3).*?(\d+) kbps/;print "$1 $2\n" if ($2<320);}'

I don't know what V0 is, but if it does not list as \d+ kbps in the file output I would guess that both these solutions would give an error.
If you could tell us what the output for file x.mp3 is for a V0 mp3 the scripts could be altered to take that into account.

.:B:. · 2010-03-06 16:09:14

V0 is the heaviest VBR encode you can do with LAME .

Ultraman wrote:

I don't have a solution for that one at the moment, but there is an additional problem. Simply checking the bitrate says nothing. A 320 CBR or V0 VBR MP3 could be a reencode of a 192 CBR MP3, which would result is a much lower quality but you would not spot it by just checking the bitrates...

That is right. You need visual inspection for that - spectrals. If you have an excellent ear though, you might pick them like that, but I haven't met someone like that in person yet

You can switch to spectral view in e.g. Audacity.

rusty99 · 2010-03-06 16:23:05

Ultraman wrote:

I don't have a solution for that one at the moment, but there is an additional problem. Simply checking the bitrate says nothing. A 320 CBR or V0 VBR MP3 could be a reencode of a 192 CBR MP3, which would result is a much lower quality but you would not spot it by just checking the bitrates...

Do people really transcode a lesser bit rate to a higher bit rate?

.:B:. · 2010-03-07 07:35:02

That's the same question as: do people really transcode from lossy to lossy?

If people don't see any harm in it (and if they don't know anything about music formats, they mostly don't), then they'll do it. Simple as that.

Urfaust · 2010-03-07 09:29:24

rusty99 wrote:

Ultraman wrote:
I don't have a solution for that one at the moment, but there is an additional problem. Simply checking the bitrate says nothing. A 320 CBR or V0 VBR MP3 could be a reencode of a 192 CBR MP3, which would result is a much lower quality but you would not spot it by just checking the bitrates...
Do people really transcode a lesser bit rate to a higher bit rate?

Plus sometimes you have a bad source, e.g. someone burned an audio cd from 192kbps MP3s and then you grab it again in a higher bitrate...
Such a script would be nice, i recently noticed that Rhythmbox can display the "Quality" of a file but it doesnt work very well (lots of "unknown" and 32kbps entries which are definitely wrong).

Arch Linux

#1 2010-03-06 14:58:06

[REQUEST] Find Low Quality MP3s

#2 2010-03-06 15:45:05

Re: [REQUEST] Find Low Quality MP3s

#3 2010-03-06 15:46:30

Re: [REQUEST] Find Low Quality MP3s

#4 2010-03-06 15:48:41

Re: [REQUEST] Find Low Quality MP3s

#5 2010-03-06 16:09:14

Re: [REQUEST] Find Low Quality MP3s

#6 2010-03-06 16:23:05

Re: [REQUEST] Find Low Quality MP3s

#7 2010-03-07 07:35:02

Re: [REQUEST] Find Low Quality MP3s

#8 2010-03-07 09:29:24

Re: [REQUEST] Find Low Quality MP3s

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