Spotting Lossy Sources--links inside

Five · #1 02-28-05, 10:43 AM

Hey all now we've got a forum dedicated to "questionable" sources (i.e. lossy/lossless). I moved all the previous threads on the topic in here.

I'm gonna stick this old thread at the top because it has the links to software. I'll come up with something a little cleaner in the next while.

-Five

---------

1st off, EAC is not always reliable for spotting lossy sources, based on discussion in this thread:
http://www.thetradersden.org/forums/...ead.php?t=1331

The freeware program AnalFreq works well, but is difficult to find these days. Try these links:
http://ftp.sunet.se/pub/simtelnet/wi...nd/afreq18.zip
http://www.simtel.net/product.downlo...s.php?id=17151

The best tool is Adobe Audition/Cool Edit Pro. If you just want the SA functionality, download the old Cool Edit Pro 2.1, the Frequency Analysis and Spectral Analysis will still work even after the demo version expires (thanks to dorrcoq for this tip):

It is useful to add a "Black & White" preset for spectral analysis, to do this:

Quote:

Originally Posted by range_hood

Cool Edit pro 2.00
options > settings >

"colors" tab > "spectral" tab
Spectral High energy: black (highlight > change color)
Spectral Low Energy: white

Gamma: 0.4

thanks to range_hood for showing me this useful setting.

Cool Edit Pro 2.0:
http://www.softpedia.com/progDownloa...load-2076.html

Audacity is excellent for FA and pretty good for SA:
http://audacity.sourceforge.net/

to use Audacity for FA, decompress to WAV, open the file with Audacity, select up to 23 seconds and go to view > plot spectrum. They say spectrum, but it's a Frequency Analysis you get. update: Audacity 1.3.10 (Beta) supports FLAC files with no need to decompress to wav first.

to use Audacity for SA, first go to Edit>Preferences>Spectograms and change the Maximum Frequency to 22050 (it only needs to be set once). close preferences, then drag and drop your FLAC (or WAV etc) file into the audacity window. in the top left corner of the new window that appears you will see a triangle, left-click it and select 'spectrum'. zoom in by selecting about 2 seconds (left-click and drag to highlight a selection, then click the 2nd-last magnifying glass icon on the upper-right).

Here's the classic guide to spotting lossy sources:
http://www.audiohub.org/get/fa/fa.htm
http://www.audiohub.org/get/fa/sa.htm

Check the stickys and some of the old discussions in the Lossy or Lossless? forum to learn more. Don't hesitate to start your own thread if there's any doubt in your mind about the "purity" of any audio you're considering seeding. Please include screenshots and/or rapidshare.de / yousendit.com / megaupload.com etc link to 10 or 20 second FLAC sample.

U2Lynne · #2 02-28-05, 10:45 AM

Thanks, Five! It's always good to have this all in one place.

Five · #3 02-28-05, 10:48 AM

you're fast!

you're welcome!

U2Lynne · #4 02-28-05, 11:03 AM

It's the morning here when I drink my coffee and go through all the threads.

RainDawg · #5 03-01-05, 07:39 AM

Thanks for compiling these Fiver

. I personally like AnalFreq (aside from the name, it's a really handy little program). I'm not sure who the author is or why the program has seemed to start drying up though. Anyone who needs it and has no luck downloading from those links can contact me personally, as I keep a copy of the original zip file stored just in case this program goes completely underground.

Five · #6 03-01-05, 04:46 PM

you're welcome!

the author has created a new shareware program called "spectrascope". It's AnalFreq with a few more bells and whistles added:

http://www.spectrascope.com/

#7 03-23-05, 11:49 AM

Does no one here use auCDtect?

http://www.true-audio.com/site.download

Five · #8 03-23-05, 07:48 PM

ack...

this program is not reliable for verifying lossless pedigree. when it detects mp3-sourced audio it is quite accurate the trouble is it doesn't always detect it. so if it helps you spot lossy sources go for it but just because auCDtect says it's clean doesn't mean that it is.

Lou · #9 03-24-05, 08:57 PM

I think a subforum should be made that's specifically for threads asking, "Is this show lossy" or any other questions about whether something's digitally wrong. Additionally, this subforum could be used to house threads asking if a particular show has a quirk, and if everyone's copy of that show also has that quirk.

Lou · #10 03-26-05, 09:07 PM

There's already now two more "Is this mp3" threads since this thread...I think an "Is this mp3" subforum would clean things up.

#11 03-26-05, 09:26 PM

i havent had time to go through any of the threads, so i apologize if my suggestion has already been handled.. but..

i think it would be very handy if someone could come up with a webpage that shows what the different frequency analysis responses or whatever look like for different equipment. IE, such as a minidisk recording will look similar to mp3 sometimes, as well as some DAT recordings depending on the settings, etc. I know it would help me out a lot if someone could really explain the differences and what to look for (if anything)..

jcrab66 · #12 03-26-05, 09:39 PM

i think based on previous discussion its kind of a consensus that analfreq is best for FA while Audition/CEP is best for SA. Am i right?

Five · #13 03-27-05, 01:22 AM

Quote:

Originally Posted by Lou

There's already now two more "Is this mp3" threads since this thread...I think an "Is this mp3" subforum would clean things up.

Thanks so much for the great suggestion, we're taking it very seriously! Stay tuned...

Quote:

Originally Posted by mint_clay

i think it would be very handy if someone could come up with a webpage that shows what the different frequency analysis responses or whatever look like for different equipment. IE, such as a minidisk recording will look similar to mp3 sometimes, as well as some DAT recordings depending on the settings, etc. I know it would help me out a lot if someone could really explain the differences and what to look for (if anything)..

This is a big project which has been in the works since before STG crashed. We have to be very careful because there's no single authority on the subject and we don't want to post anything which is misleading. This thread and and Lou's suggested forum are steps in the right direction.

Quote:

Originally Posted by jcrab66

i think based on previous discussion its kind of a consensus that analfreq is best for FA while Audition/CEP is best for SA. Am i right?

ffooky has shown me that Audacity is sometimes even a little better than analfreq for FA, and yes CEP/Audition is still the best for SA.

brainysod · #14 05-26-05, 01:03 PM

So what exactly do you have to spot to see it for yourself manually? I am real interested in finding this out...

Five · #15 05-26-05, 01:45 PM

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