The Traders' Den  

  The Traders' Den > Where we go to learn ..... > Technobabble > Lossy or Lossless?
 

Notices

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

Reply
 
Thread Tools
  #1  
Old 2009-10-15, 03:32 PM
Kingbuzz Kingbuzz is offline
715.22 MB/1.20 GB/1.72
 
Join Date: Oct 2009
Having some doubts

Hello guys,

I have 3 samples here and I'm not sure if they are truly lossless.

1st example looks weird to me in FA also channels look different in SA.

2nd and 3rd example both peak all the way to the top but have black areas above 20khz in SA and some drop offs at 21khz in FA.
Attached Images
File Type: png 1994-06-29.png
( 1.51 MB, 22 views)
 
File Type: png 1995-01-11.png
( 1.73 MB, 16 views)
 
File Type: png 1995-02-09.png
( 1.69 MB, 13 views)
 
Reply With Quote Reply with Nested Quotes
  #2  
Old 2009-10-15, 05:28 PM
paddington's Avatar
paddington paddington is offline
please look after this bear
TTD Staff
83.17 GB/882.10 GB/10.61
 
Join Date: Jan 2005
Location: UK
Re: Having some doubts

What you have there doesn't show anything regarding lossy compression one way or the other. We can only guess with that. We'd need to see a 2-3 sec slice on the SA to view the blocks that are removed by the lossy data compression (if there are any).

What is DOES show, in #2, is an FM radio stereo pilot tone (19kHz) which could also explain the abrupt cut, depending on how it has been processed, post-receiver.

Also, in #3, the noise slightly below 16kHz is the flyback in a CRT video display that was likely picked up during analog recording or dubbing. Very common.
__________________
"There are some of these recordings where it is just a whirring, and you cannot hear the music. " - Jimmy Page, 2007 / JUL / 26
Reply With Quote Reply with Nested Quotes
  #3  
Old 2009-10-15, 05:58 PM
Kingbuzz Kingbuzz is offline
715.22 MB/1.20 GB/1.72
 
Join Date: Oct 2009
Re: Having some doubts

Thank you for your fast reply and here are 2 sec slices as you requested:
Attached Images
File Type: png 1994-06-29(2).png
( 1.27 MB, 15 views)
 
File Type: png 1995-01-11(2).png
( 1.46 MB, 12 views)
 
File Type: png 1995-02-09(2).png
( 1.45 MB, 13 views)
 
Reply With Quote Reply with Nested Quotes
  #4  
Old 2009-10-15, 06:00 PM
paddington's Avatar
paddington paddington is offline
please look after this bear
TTD Staff
83.17 GB/882.10 GB/10.61
 
Join Date: Jan 2005
Location: UK
Re: Having some doubts

pretty sure we happy

the recordings aren't flawless, but they aren't MP3.

recommend you wait for second opinion from Five as to whether they are some modern version of ATRAC3, which isn't as easy to spot (or as noticeable when listening) due to much less abrupt aliasing.
__________________
"There are some of these recordings where it is just a whirring, and you cannot hear the music. " - Jimmy Page, 2007 / JUL / 26
Reply With Quote Reply with Nested Quotes
  #5  
Old 2009-10-16, 03:15 PM
Five's Avatar
Five Five is offline
TTD Staff
186.65 GB/588.32 GB/3.15
 
Join Date: Oct 2004
Location: Canada
Re: Having some doubts

the first looks normal. the 21kHz drop in the 2nd and 3rd is strange. 256kbps cbr mp3 cuts off around here (see here) but your shows have some bit of distortion above the line (uncharacteristic) and I can't spot mp3 artifacts. perhaps it was pitch correction? not certain.

anyhow, I can't point to direct evidence so 'innocent until proven guilty...'

the 2nd and 3rd are a little suspicous for sure... perhaps see if there's any variant filesets for these two dates that might be free from the drop at 21kHz.
__________________
Checksums Demystified EAC Config MakeTorrent WinAmp Config

Modern social theory casts a highly skeptical eye on any declaration that a group of persons is without conflict, and insists, on the contrary, that conflict is natural to groups, and even more, is essential to them. -Patrick Henry
Reply With Quote Reply with Nested Quotes
Reply

The Traders' Den > Where we go to learn ..... > Technobabble > Lossy or Lossless?

Similar Threads
Thread Forum Replies Last Post
serious doubts if are lossy or lossless please help - inflicted Lossy or Lossless? 6 2007-08-09 11:10 AM


Thread Tools

Posting Rules
You may not post new threads
You may not post replies
You may not post attachments
You may not edit your posts

BB code is On
Smilies are On
[IMG] code is On
HTML code is Off

Forums


All times are GMT -5. The time now is 04:20 AM.


Powered by: vBulletin, Copyright ©2000 - 2017, Jelsoft Enterprises Ltd.
Copyright ©2004 - , TheTradersDen.org - All Rights Reserved - Hosted at QuickPacket
no new posts