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Lossy or Lossless? Please use this forum to post spectral and frequency analysis posts about shows you have your doubts about.

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  #1  
Old 2006-01-16, 05:09 PM
taygan taygan is offline
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FM>HiFi VCR>VHS>WAV>EAC>FLAC but is it lossy?

I'm appreciating the dedication to good sources here, I've run into a lot of torrents that are not what they seem at 'other' sites.

Supposedly FM>HiFi VCR>VHS>WAV>EAC>FLAC It looks awfully blocky to me, but the blocks are before the analog generation, any ideas on how this happened?

The blocks look like they could be MD, but where? could a VCR do this? sat radio? hmmm...

imageshack.us is not working at the moment, I've attached the spec and freq.

Here's an 8 sec sample of the area analyzed.

http://s5.yousendit.com/d.aspx?id=09...326TXWXF8VC0LU

Thanks,

taygan
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Last edited by taygan; 2006-01-16 at 08:11 PM.
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  #2  
Old 2006-01-18, 01:47 PM
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Re: FM>HiFi VCR>VHS>WAV>EAC>FLAC but is it lossy?

I am thinking the same thing you are, it is certainly lossy and the shape looks MD. I'm pretty sure a VCR couldn't do this. you can also see the mirroring from a bad upsample job.

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  #3  
Old 2006-01-19, 04:16 AM
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range_hood range_hood is offline
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Re: FM>HiFi VCR>VHS>WAV>EAC>FLAC but is it lossy?

Could this be a satelliteFM capture? There's no carrier visible.
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  #4  
Old 2006-01-21, 06:41 PM
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Re: FM>HiFi VCR>VHS>WAV>EAC>FLAC but is it lossy?

Satellite isn't FM. it's broadcasted in MPEG 1 Layer II.

FM in itself is compressed, so that could be causing it-there is nothing else in that libneage that would make it 'lossy'
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  #5  
Old 2006-01-22, 12:16 PM
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Re: FM>HiFi VCR>VHS>WAV>EAC>FLAC but is it lossy?

I see some very cubic shapes in the SA

this sure doesn't look like a normal FM

I'm also wondering how/when it could have been resampled to cause the mirroring artifacts
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  #6  
Old 2006-01-23, 08:21 AM
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ssamadhi97 ssamadhi97 is offline
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Re: FM>HiFi VCR>VHS>WAV>EAC>FLAC but is it lossy?

Hmm, very odd one. Let me summarize what we're seeing so far (from my point of view )

FM
...somewhere around here, the following things must've happened:
1) lossy compression (from the looks of it I'd guess mp2)
2) resampling from 32 to 44.1kHz
In this order, too.

>HiFi VCR>VHS
...apparently caused lots of analog noise, which is fully preserved, so I'd say it's highly unlikely that any kind of lossy compression happened after this step

>WAV>EAC>FLAC
...yep, looks plausible to me when looking at the spectrum.


OK... now wtf? (where does the resampling come from?)
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  #7  
Old 2006-01-29, 11:34 AM
taygan taygan is offline
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Re: FM>HiFi VCR>VHS>WAV>EAC>FLAC but is it lossy?

Quote:
Originally Posted by ssamadhi97
Hmm, very odd one. Let me summarize what we're seeing so far (from my point of view )

FM
...somewhere around here, the following things must've happened:
1) lossy compression (from the looks of it I'd guess mp2)
2) resampling from 32 to 44.1kHz
In this order, too.
I'm not familiar with what mp2 looks like. the blocks look like MD to me, I assume mp2 is similar?

Maybe recorded on MD, or digital video camera at the show before FM broadcast?

I don't think that explains the resampling though.

taygan
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  #8  
Old 2006-01-31, 12:46 PM
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ssamadhi97 ssamadhi97 is offline
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Re: FM>HiFi VCR>VHS>WAV>EAC>FLAC but is it lossy?

Compared to md-sourced recordings, mp2 (an audio format commonly used in digital radio and tv broadcasts) generally doesn't exhibit those little spikes around the blocks.. eh, the difference is kinda hard to describe.

One thing most mp2 and atrac (md) encoders seem to have in common is relatively aggressive lowpassing even below 16kHz, so the skyline-ish features of the spectrum are often more pronounced with these, compared to mp3s.
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