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View Full Version : Lossy Source?


moebootz
2006-09-16, 11:01 AM
I'm putting together an srv show to seed. I'm trying to determine if it's mp3 source since an srv guru I know says one has to be careful because a lot of srv mp3 sourced shows are polluting the pool. So I opened all of the tracks in cool edit pro 2 and did a frequency analysis. The high ends have the signature mp3 look but I know this can't always be conclusive.

So I converted a track to mp3 @<hidden> I figure you can't get back what's been taken away and if it's been an mp3 at a lower bit rate then converting to 320 would yield the same result as say if it were a 128 mp3.

There was a change in the frequency analysis result between the wav and mp3. So I converted the mp3 to wav and the freq analysis result was the same for the mp3 and wav and different from the original wav.

So I decided to compare the original wav to the wav > mp3 > wav using eac. The error message eac generated says "Different Samples." Also says there was almost .06 difference in length.

So ya think this is ok to seed? I've attached a few screen shots which I'll include in my file set.

Thanks
Moe

Five
2006-09-16, 11:31 AM
EAC is not reliable for spotting lossy sources

the test of converting and comparing is moot, if you convert a wav to mp3 to wav to mp3 again there will be differences in the files as well!

can you upload a 10-20 second flac of what you want to seed to rapidshare.de / megaupload.com or similar and post the link here?

also check here
http://www.thetradersden.org/forums/showthread.php?t=4288

and here
http://www.thetradersden.org/forums/forumdisplay.php?f=47

moebootz
2006-09-16, 12:19 PM
OK I uploaded a 20 second flac to my web space:

http://home.comcast.net/~gotbootz/srv_test.flac

It's only 1.9 mb

Don't know how those other sites work and no time to f around there atm.

I know eac isn't good at spotting lossy. So I got to thinking :hmm: on the grounds that you can't get back what was taken away. Then compare the 2 wavs in eac. Seemed reasonable but of course not real hehe.

Let me know what ya think five. I'm heading out the door in a couple hours and was hoping to get this going before i leave.

Thanks!

btw, ANALFreq sounds like someone obssessed with, ahhhh, well imagine :lol
Or could be gay talk :lol but then I've never been to a gay bar hehehe.

moebootz
2006-09-16, 12:40 PM
I just followed the suggestion for setting the colors for the sprectral view in cep. Nice tip. Now I looked at a file from the questionable show and one I know isn't from a lossy source. I think I have my answer and will look for something else to seed. But would like a more experienced person to tell me if I'm correct.

Thanks!
Moe

ffooky
2006-09-16, 01:33 PM
Looks 100% losstastic to me, mate.

moebootz
2006-09-16, 01:56 PM
Looks 100% losstastic to me, mate.
Kinda thought so. Thanks fooks.

I got kicked out of an srv group because I jumped on a guy who had srv shows in mp3 on his site for download. He says it's to share with those on dial up and no burners. Of course I informed him that these people will now think they have a show to trade and the pool will get polluted. I told him it would be better if you did a bnp for them instead because it's more important to keep the trade pool clean than to share with everyone who knows how to turn a computer on hehe. Well, things got kinda nasty after that :lol Am I surprised? not in the least.

Five
2006-09-18, 12:45 AM
I got kicked out of an srv group because I jumped on a guy who had srv shows in mp3 on his site for download. He says it's to share with those on dial up and no burners. Of course I informed him that these people will now think they have a show to trade and the pool will get polluted. I told him it would be better if you did a bnp for them instead because it's more important to keep the trade pool clean than to share with everyone who knows how to turn a computer on hehe. Well, things got kinda nasty after that :lol Am I surprised? not in the least.
I totally agree with you

looks unquestionably lossy to me as well

enchantgy
2006-10-02, 11:33 AM
Actually, considering that the frequency analysis you originally posted has NOTHING beyond 12KHz, you would already know that it is mp3 sourced. The window should show you up to 22KHz