HydrogenAudio

Lossless Audio Compression => FLAC => Topic started by: gandhi on 2008-10-03 17:01:39

Title: Is it possible to detect if the source was audio-CD or some lossy form
Post by: gandhi on 2008-10-03 17:01:39
I have some CDs that I'm not sure if I burned them from mp3 files or if I made a 1 to 1 CD-copy. Is there a way to find out if the source was mp3 or CD? I have the original CDs as well, ripped to FLAC, for reference.
Title: Is it possible to detect if the source was audio-CD or some lossy form
Post by: Bjossi on 2008-10-03 17:09:11
That could be a challenge, when making an audio CD all input will simply become CD audio. If the mp3s were very compressed you could just tell by bad sound quality.
Title: Is it possible to detect if the source was audio-CD or some lossy form
Post by: Goratrix on 2008-10-03 17:42:19
If you also have the original CDs in FLAC and just want to compare the copy to those, then the easiest way is to rip one track from the copy to FLAC (or WAV), open both FLACs in some audio editor and compare the frequency spectrums (there is a tutorial somewhere here on this topic). If the copy was made from mp3, there will be noticable differences in the high frequencies. If the copy was made as a 1:1 image, they will be identical.
Title: Is it possible to detect if the source was audio-CD or some lossy form
Post by: Tahnru on 2008-10-03 17:59:23
http://www.true-audio.com/ (http://www.true-audio.com/)

I have seen auCDtect and Tau Analyzer used to good effect.
Title: Is it possible to detect if the source was audio-CD or some lossy form
Post by: gandhi on 2008-10-04 09:38:13
Thanks, I tested Tau Analyzer and hopefully the results are trustworthy.

Goratrix: did you refer to this post?
http://www.hydrogenaudio.org/forums/index....mp;#entry380510 (http://www.hydrogenaudio.org/forums/index.php?showtopic=43451&st=0&p=380510&#entry380510)
Title: Is it possible to detect if the source was audio-CD or some lossy form
Post by: pdq on 2008-10-04 19:27:22
If you also have the original CDs in FLAC and just want to compare the copy to those, then the easiest way is to rip one track from the copy to FLAC (or WAV), open both FLACs in some audio editor and compare the frequency spectrums (there is a tutorial somewhere here on this topic). If the copy was made from mp3, there will be noticable differences in the high frequencies. If the copy was made as a 1:1 image, they will be identical.

You don't need to compare the spectra. Just use a bit comparison. Apart from a possible small shift in the data, they should be identical, or not.
Title: Is it possible to detect if the source was audio-CD or some lossy form
Post by: Mr. Molly on 2008-10-29 14:31:12
You might also want to check out Informer (http://www.neillcorlett.com/informer/)... But yeah, like Pdq says, just do a bit comparison if you have the original files.  Invert -> Copy -> Mix Paste