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dhs0403
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John Marks - 24/96 resolution

Would someone please answer this question – How does the average user determine whether the “actual resolution" of the music in a file matches the “resolution capability” of the file format?

I ask because my ITUNES tool bar includes a utility named “Convert File to Apple Lossless”. When used with ITUNES download files, however, the utility simply transfers the MP3 resolution music stored in the Apple Compressed format – to the same MP3 resolution music stored in the Apple LossLess format. So, we start and end with the same MP3 music - even though the format of the file has changed.

Compounding the confusion, the ITUNES FILE DESCRIPTION changes to 16/44 even though the resolution of the music stored in the file remains unchanged at MP3.

JA notes that the term “compression” is misleading. Sponges that have been “compressed” to fit a smaller shape and volume can be restored to their original form. However, sponges that have been “trimmed” to fit a smaller shape and volume cannot. MP3 files have been irrevocably "trimmed" by the upstream processing, not "compressed".

So, how can the average user determine whether a music file has been “trimmed” beyond repair by any of the equipment that is used in the upstream processing?

A simple explanation in Business English would be appreciated. Thanks,

greenelec
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formats

It seems to me that you must know the source of the file. If you buy high res online from a dealer then they should state what resolution the files are, clearly. If they don't state clearly then, buyer beware. Some online dealers call cd res High Def and some others call 24/96 hi def.

You should be able to find out. But as you have stated, you can't take a low res file and make it hi def just by conversion.
I hear by way of the underground that there are some vinyl producers that are using cds for the source to cut vinyl.

I am not a total anti-Apple kind of PC user, but sometimes Apple does not make what they are actually doing very clear. I would be skeptical of files purchased from iTunes if they don't clearly state the resolution of the source (should be analog master tapes) and the resolution of the digital file, hopefully 24/96 or higher. You should be able to find out exactly what you are getting.

JasonVSerinus
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Trimming and Compression
dhs0403 wrote:

I ask because my ITUNES tool bar includes a utility named “Convert File to Apple Lossless”. When used with ITUNES download files, however, the utility simply transfers the MP3 resolution music stored in the Apple Compressed format – to the same MP3 resolution music stored in the Apple LossLess format. So, we start and end with the same MP3 music - even though the format of the file has changed...

So, how can the average user determine whether a music file has been “trimmed” beyond repair by any of the equipment that is used in the upstream processing?

A simple explanation in Business English would be appreciated. Thanks,

Explanation 1. Why would you convert an mp3 file to Apple lossless? The file is already shrunk, and cannot be expanded. This doesn't make sense to me. Leave it alone.

2. Any file that has been trimmed, that is, has had information permanently discarded, is "trimmed" beyond repair. Trying to convert it to compressed format can at best mask the problem; it cannot fix it.

struts
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Re: John Marks - 24/96 resolution

Great question dhs0403!

The simple answer is that there is only one way: analyze the musical waveform, but even that isn't conclusive.

If the waveform represents "full range music", i.e. program that contains a full range of orchestral dynamics (different loudnesses) which is approx 120dB and frequencies (pitches) for which the human ear is sensitive up to approx 22kHz then it will be apparent from the waveform if any clipping or cutting has taken place.

The full dynamic range of digital PCM (i.e. non-DSD) media is defined by the bit depth, one bit is approximately equivalent to 6dB. The frequency range is limited by the sampling frequency (the maximum reproducible frequency is half the sampling frequency).

Analyze the waveform using a suitable program like Audacity and you'll soon see if the dynamic or frequency range (use the FFT function to see this) are dramatically lower than the containing file reports.

However remember that the 'clipping' could always have taken place at recording or mastering stages as well as during encoding/re-encoding for playback. A file recorded at 16/44 will never contain more information even if it is burned onto a DVD at 24/96.

Good luck!

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