No idea about lossy or lossless

[darkside02]

Hi there,

I use Gspot to make sure a dvd is a real dvd (not wmv or avi sourced), to check the format, and all that stuff, and I kinda understand the rest of the info.

A few weeks ago I started trading and downloading FLAC and SHN shows, but I got NO idea how to know whether a show is mp3 sourced or not.

Ive read something about a spectral test or something, but I dont understand, so I´m asking for help. Would anyone please tell me step by step how to find out if the discs I just got are lossy or lossless?

thanks in advance

[Five]

open a few of the threads in this forum, especially the ones stuck at the top with links included. you can upload FLAC samples here, just go to an ftp replacement site like rapidshare or megaupload or one of the gazillion others & post the download link here. choose smaller tracks or if you're able create 10-20 second samples. After we look at a few together you'll start to get the idea.

[jaygs]

I assume you have a tool that can show things in spectral mode. If so, just take a wav file and encode it in MP3 at 128 kbps. Then open them both in spectral mode. The mp3 file will have no "color" at the top of the spectrum -- higher frequencies. Old, low quality, but lossless files will have some color at the top, but it will be "faded" because it's just the hiss. It looks a little like old fashioned television "snow"

[JGH1]

I believe I have an easier fix for this problem rather than looking at "snow" -

Audacity can do the job easily (free program...go to audacity.sourceforge.net). Open the file, highlight a section and go to the "analyze" pull-down menu, and select "Plot Spectrum". A window plotting the frequency response will pop up. If the file is mp3 sourced, it will have nothing above approx. 15kHz. If there IS frequency response plotted above that point, it's not an mp3.

John

[darkside02]

it was like 1am when I left the message so I guess I forgot a few things.

I have NO IDEA about how this works, I received three audio cds, so do I have to first convert them to wav? or to flac? with which software? I have Adobe Audition, Nero, Windows Media PLayer, FLAC Frontend (Which I still don´t know how to use very well), and Trader´s Little Help. After doing that, what´s next?

sorry, I´m still learning and trying to understand "encoding", "decoding", the "khz thing", etc.

[Five]

first you need EAC (exactaudiocopy.de) to get a secure rip off the audio cdrs. the other ripping progs don't check for errors, at least not the ones you've got listed.

[darkside02]

done, I´ve ripped wav files using EAC. Now..should I make a 10-15 sec sample and uploading it to a free host?

thanks for the help y´all

[Five]

yup. just be sure not to do anything funky to it when you make the sample (if you use audacity you have to check the settings are 16bit/44.1kHz first), encode to FLAC, upload it and post up a link here. if you're uncertain just choose the smallest track.

[darkside02]

the smallest file is 38mb..I´m uploading it at the moment, just wondering: For ripping a cd I´ll always use EAC from now on. Is Trader´s Little Helper any good at encoding to FLAC? What level should I use? 0 is Fast, 5 is Default, and 8 is Best.

I don´t have audacity btw

[darkside02]

http://rapidshare.de/files/38846710/Unknown_Artist_-_Track07.wav.html

here it is

thanks a lot really

[jaygs]

I believe I have an easier fix for this problem rather than looking at "snow" -

Audacity can do the job easily (free program...go to audacity.sourceforge.net). Open the file, highlight a section and go to the "analyze" pull-down menu, and select "Plot Spectrum". A window plotting the frequency response will pop up. If the file is mp3 sourced, it will have nothing above approx. 15kHz. If there IS frequency response plotted above that point, it's not an mp3.

John

Not true about having nothing above 15KHz. If it was MP3'd at 320kbps it will have content all the way to 20KHz!

[darkside02]

as I have nothing to do I played a bit with adobe audition and here´s what I did:

http://img170.imageshack.us/img170/3236/spectc0.jpg

[JGH1]

My mistake, jay...forget my comment.

[Five]

from what I can see in that pic darkside it is lossy & not dvd-quality at all. lower than average mp3 encoding setting to boot! :disbelief

I'll download the wav from work tomorrow where I've got a faster net connection. also next time would be better to compress to FLAC, which keeps all the audio data identical but brings the size (and upload/download time) down to 50-60% ;)

ps small note to any audacity users you have to set the spectral to dispaly to 22050 as the upper limit in the settings to see something similar to what audition produces.

[darkside02]

damn it, I knew something wasn´t rite

thanks for all your help :)