Re: old burned cd file in wav

Excellent Summary by Stephen Kilburn!

I’ll add to that by saying that there are two kinds of CODECs, lossy and lossless.  

Lossy CODECs, like MP3, MPEG-4 AAC, and Ogg Vorbis do what is technically known as data reduction.  They make the file smaller, but they do so with audio degradations, hopefully of the variety that will be inaudible or at least acceptable given the reduction in file size.  Once you convert to one of these formats, you can never reverse the process to get the original file back.  If you convert a WAV to MP3 and then back to WAV, the file you end up with will be different than the one you started with.  It will be degraded (as to whether the degradation is audible depends on the source material, your hearing, your audio gear, and the MP3 bitrate and quality settings).  Most lossy CODECs are designed for a single conversion from a lossless source.  

Lossless CODECs, like FLAC, Apple Lossless, and APE, do data compression which, unlike data reduction, do not impose a degradation in quality.  You can take a WAV file and compress it with one of those and then uncompress it, recovering the exact same WAV file you started with.  It’s like the audio equivalent of a ZIP file.  

You can freely transcode between lossless CODECs and WAV files with no loss of fidelity.  If your friend gives you tracks in FLAC format and you need them in Apple Lossless for your iPhone, you can just transcode (convert) them with no degradation in quality.

It’s also fine to transcode from lossless to lossy; it doesn’t impose any additional degradation over starting with an uncompressed WAV file.  What you want to avoid is starting with a lossy source (an MP3, AAC, etc.).  That’s why many people store their music in FLAC or Apple Lossless files on their computers, converting the tracks to smaller, lossy files for use in portable devices (smartphones, tablets, music players, USB thumb drives, etc.).

— Fred M.

> On Sep 27, 2020, at 4:04 PM, 'Stephen Kilburn' [email protected] [EAC] <[email protected]> wrote:
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> Sound degradation in digital is a function of format conversion, particularly to lossy formats (e.g. MP3). If you’re extracting WAV from the compilation CD then you should have an exact digital copy of what was there – no degradation (trusting the read of information from the CD is 100% bit for bit accurate). If you slice and dice the WAV and create another CD from parts of it again there should be no degradation. You’re just manipulating pieces of PCM data without changing them.
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> This sets aside the question of how the compilation CD was created in the first place. If it was created by somebody from some other source like MP3 that was ripped from WAV then the signal will have been degraded in the ripping from WAV to MP3. It won’t get any worse if you slice and dice it as WAV but clearly you can’t “un-degrade” it back to the original source quality. 
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> From: [email protected] <mailto:[email protected]> [mailto:[email protected] <mailto:[email protected]>] 
> Sent: September 27, 2020 2:07 PM
> To: [email protected] <mailto:[email protected]>
> Subject: RE: [EAC] Re: old burned cd file in wav
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> Thank you Jank.  Shazam works great to identify songs. It is a tedious process but I have no choice.
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> I have another question for the group. If I have a compilation music cd that was extracted in Wav format and then I use that cd to extract again (to create different combinations of songs) using easy audio copy, is there any sound degradation of the songs. I ask this because we all know that if you burn a video to lets say a dvd and then use that same dvd to burn another one there will be degradation. Wondering if that holds tru for audio. Thanks
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> From: [email protected] <mailto:[email protected]> [mailto:[email protected] <mailto:[email protected]>] 
> Sent: Sunday, September 20, 2020 7:50 PM
> To: [email protected] <mailto:[email protected]>
> Subject: [EAC] Re: old burned cd file in wav
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> I use Shazam to identify songs I hear on radio or untitled wav files.. It usually comes through.
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> JANK
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