Author Topic: Spotting transcodes, etc.  (Read 5124 times)

Offline Zevaka

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Spotting transcodes, etc.
« on: Dec 21, 2007, 03:11 PM »
Ok, many of you, ripping heads, were interested in this.
To say in short, transcode - is file ripped/encoded from lossy source. No exeptions
Examples: 192 kbps CBR MP3 -> 220 kbps V0 MP3, 320 kbps CBR MP3 -> 220 kbps V0 MP3, 320 kbps CBR MP3 -> FLAC
Examples of good mp3 rip, not a transcode: CD->mp3 320 kbps CBR, CD->Ape->FLAC->WAV->mp3 192 kbps

I've decided to post a tutorial from OiNK, music paradise of all music fans all over the world, which was closed by those fags from RIAA, IFPI, Interpol and so on. This tutorial is just perfect. Though it was not easy for me to recover it

==========================================================
What is a Transcode?
Put simply, a transcode is any audio file that wasn't encoded from an original lossless source, such as a retail CD (not created from lossy files) or a properly made lossless rip.

Why is transcoding bad?
Whenever you encode a file to a lossy format (such as mp3, m4a(AAC), ogg, or mpc) information is permanently lost. It doesn't matter what you do, it's impossible to get this information back without making a new rip from the original lossless source. If you reencode it to a different format or bitrate, all you're doing is reducing the quality. This applies to any lossy to lossy conversion, so even if you convert from 320kbps to 192kbps, the final file will still sound worse than if you had just ripped to 192kbps in the first place.

FhG VS. LAME
Most lossy encoders use a low-pass filter when encoding. The filter is set to cut frequencies above a certain point and leave those below. The reason they're doing it is, that high frequencies are more difficult to encode and hearing is less sensitive in higher frequencies. MP3 encoders at 128kbps will typically use a LPF at 16kHz. As you raise the bitrate, the frequency threshold raises. At 192kbps the LPF is usually set at 18kHz or higher.


How to view the Spectral Analysis of songs using Adobe Audition
To view the spectral analysis of audio files in Adobe Audition, first ensure you are in Edit Waveform View by pressing the number 8 on your keyboard.  Then, go to File > Open and select the file you wish to test.  Adobe Audition will open the audio file in the "Waveform View" by default each time, so you'll need to choose View > Spectral View or press F9 to switch to Spectral View. 

The following section contains a list of common bitrates and their audio spectrum.  The LAME were all done using dbpoweramp from a flac source, and they are all encoded using LAME version 3.97.  The shape of the screen-shots differ due to different screen resolutions.

128 LAME
   

160 LAME:


192 LAME:


VBR V2: preset standard


224 LAME


256 LAME


320 LAME


VBR V0: preset extreme

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Ok, here it is. It's done
Edit 1: No, one more thing

Edit 2: To find what codec/mode/bitrate/etc was use while ripping, use this great software: Mr. Questionman:
http://www.burrrn.net/download/MrQuestionMan.exe

Useful link: Ripping Guide / Creating quality rips with EAC (u just need it)

Edit 3: (i just can't stop, lol) Also, spectral view of the file can depend on mastering of the record. i mean old records/demos/unmastered files can cut off at lower frequences, it's not dangerous

If you have any questions, i'm open
CUZ THIS IS WEEEKEEEND!!!

« Last Edit: Dec 21, 2007, 03:26 PM by Zevaka »

Offline stu

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Re: Spotting transcodes, etc.
« Reply #1 on: Dec 24, 2007, 06:08 PM »
unless your going into audio production in about a year you'll go back to not really caring about it.

Offline Zevaka

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Re: Spotting transcodes, etc.
« Reply #2 on: Dec 24, 2007, 06:20 PM »
it's useful unless you care about your audio collection

Offline defTHE1s

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Re: Spotting transcodes, etc.
« Reply #3 on: Dec 24, 2007, 09:11 PM »
thanks, i've post you a question in other topic about how to compare between lossy and losless fromats, but now i've seen this tutorial. i'm going to chek it very close.. .thanks!

Yes yes, Deftones, yes yes, heavy metal, yes yes, nü metal, yes yes, fucking queer, yes yes...