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Help. How to evaluate a Mp3's quality? Like noise existed in the f
MaiTiano
post Apr 16 2012, 12:00
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As mentioned in the title.

Now I am evolving into a project. In this project, we have a 128kbps mp3 library and we need to find which files have the inferior quality, such as noise existed, volume is too small etc.

Any advice? It would be better if someone know some open-source project which already has the ability to detect the mp3 files with bad quality.

many thanks.
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Dynamic
post Apr 18 2012, 13:22
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You've defined your problem a bit better.

You might want to look into SoX audio toolkit. It can be run from the commandline or a batch script, making it possible to deal with a whole bunch of files. It's also open source, like Audacity, which you used to plot that waveform.

It has switches to detect silences, which you could modify to make it detect or split that file:
http://sox.sourceforge.net/sox.html
... scroll down to the silence section.

You could either modify the source code to do what you want, or run Sox to decode an appropriate file and see if it produces more than one silence

Your use case is not normal, as few people who care about quality will have such bad files because they'll have chosen secure or database-verified ripping or listened to the output with their ears.

I'm sure you'll need to do some coding yourself.


--------------------
Dynamic the artist formerly known as DickD
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MaiTiano
post Apr 19 2012, 03:27
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QUOTE (Dynamic @ Apr 18 2012, 14:22) *
You might want to look into SoX audio toolkit. It can be run from the commandline or a batch script, making it possible to deal with a whole bunch of files. It's also open source, like Audacity, which you used to plot that waveform.

It has switches to detect silences, which you could modify to make it detect or split that file:
http://sox.sourceforge.net/sox.html
... scroll down to the silence section.

Many thanks, Dynamic.
I have a problem about your advice. As can be seen from the figure, actually, those horizontal wave which I highlighted in the red box is not on the 0 dB line. In other words, the sound track may not be silence in these area, right?
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saratoga
post Apr 19 2012, 03:33
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QUOTE (MaiTiano @ Apr 18 2012, 22:27) *
I have a problem about your advice. As can be seen from the figure, actually, those horizontal wave which I highlighted in the red box is not on the 0 dB line. In other words, the sound track may not be silence in these area, right?


Since you can't hear a DC level, that is still silence.
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MaiTiano
post Apr 19 2012, 03:44
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QUOTE (saratoga @ Apr 19 2012, 04:33) *
Since you can't hear a DC level, that is still silence.


Thanks. Actually, I think it is approximate DC tongue.gif
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Posts in this topic
- MaiTiano   Help. How to evaluate a Mp3's quality? Like noise existed in the f   Apr 16 2012, 12:00
- - halb27   Sounds like you don't have a reference to the ...   Apr 16 2012, 12:10
|- - MaiTiano   QUOTE (halb27 @ Apr 16 2012, 12:10) Sound...   Apr 17 2012, 02:35
|- - saratoga   Determining which will sound better to a person is...   Apr 17 2012, 02:53
|- - .alexander.   Robot will never replace man © Ogre   Apr 17 2012, 06:36
|- - Nessuno   QUOTE (saratoga @ Apr 17 2012, 03:53) Det...   Apr 17 2012, 07:42
|- - MaiTiano   Yes,I do think that there is a evaluation r...   Apr 17 2012, 08:44
||- - Nessuno   QUOTE (MaiTiano @ Apr 17 2012, 09:44) Yes...   Apr 17 2012, 09:11
||- - MaiTiano   For the simplicity, for the 1st step, at least I w...   Apr 17 2012, 10:01
||- - knutinh   QUOTE (MaiTiano @ Apr 17 2012, 11:01) For...   Apr 18 2012, 11:59
|- - pdq   QUOTE (Nessuno @ Apr 17 2012, 02:42) QUOT...   Apr 17 2012, 13:38
|- - Nessuno   QUOTE (pdq @ Apr 17 2012, 14:38) QUOTE (N...   Apr 17 2012, 17:38
|- - saratoga   QUOTE (Nessuno @ Apr 17 2012, 12:38) And ...   Apr 17 2012, 17:53
- - Nessuno   QUOTE (MaiTiano @ Apr 16 2012, 13:00) Now...   Apr 16 2012, 12:25
- - IgorC   Starting from previous knowledge will be somethin...   Apr 17 2012, 14:28
- - Dynamic   QUOTE (MaiTiano @ Apr 16 2012, 11:00) Any...   Apr 18 2012, 11:51
- - MaiTiano   I would like to add a more specific example to ill...   Apr 18 2012, 12:35
- - Dynamic   You've defined your problem a bit better. You...   Apr 18 2012, 13:22
|- - MaiTiano   QUOTE (Dynamic @ Apr 18 2012, 14:22) You ...   Apr 19 2012, 03:27
|- - saratoga   QUOTE (MaiTiano @ Apr 18 2012, 22:27) I h...   Apr 19 2012, 03:33
|- - MaiTiano   QUOTE (saratoga @ Apr 19 2012, 04:33) Sin...   Apr 19 2012, 03:44
|- - Dynamic   I'd assumed, perhaps wrongly, that you were di...   Apr 19 2012, 20:41
|- - MaiTiano   QUOTE (Dynamic @ Apr 19 2012, 21:41) I...   Apr 20 2012, 04:39
- - Dynamic   [1] - Yes, I think it's the whole song [2] - I...   Apr 25 2012, 20:44
- - MaiTiano   QUOTE (Dynamic @ Apr 25 2012, 21:44) [1] ...   May 22 2012, 02:24


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