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*dJ*
2005-12-02, 01:54 PM
I just did a check for a show I got some time ago...

This is the result:

SA
http://img527.imageshack.us/img527/7148/sat1nu.th.jpg (http://img527.imageshack.us/my.php?image=sat1nu.jpg)
FA
http://img527.imageshack.us/img527/604/fat3cf.th.jpg (http://img527.imageshack.us/my.php?image=fat3cf.jpg)

From the SA, I would say it's lossy, but what are those vertical stripes going to max. frequency?

I was told this was first recording of the taper and the microphone level was set to high, so the show has distortion, but could that explain the (abscence of?) stripes??? Maybe FA can tell more, but don't know really how draw conclusions form a FA.

Lineage:
aud>mz-r909>ecm-ds70p>cdr1

I have a flac copy of a cdr (think gen 1 or 2)

edit:- I can post some samples if needed
- There aren't real blocks???

Five
2005-12-02, 11:36 PM
the fa here is displaying incorrectly... try clicking the cursor around after you open the fa window next time.

this was recorded on minidisc and the sa looks about right

altho md is lossy it is acceptable to most traders (and okay to seed here)

*dJ*
2005-12-06, 08:54 AM
the fa here is displaying incorrectly... try clicking the cursor around after you open the fa window next time.

this was recorded on minidisc and the sa looks about right

altho md is lossy it is acceptable to most traders (and okay to seed here)

If I understand it correct the [almost] absence of the frequencies above 13 kHz doesn't make it real lossy [as opposed to MD lossy], so how can I/you tell this (or in general any) show is mp3 sourced?

Is it, not mp3 sourced, because the purple spikes going >20 kHz? does the FA give this information? Do you trust the line-age given and conclude from there on? -- I am a bit puzzled about this (and wouldn't mind to learn a bit more about it).

Also made a new FA from the same show (different track) it has a steep[er] drop-off... should I worry?
http://img210.imageshack.us/img210/9019/sa21dh.th.jpg (http://img210.imageshack.us/my.php?image=sa21dh.jpg)

Five
2005-12-06, 11:51 AM
well what is fairly easy to tell is lossy vs lossless sources. the steep cutoff in the fa and blocks visible in the zoomed in sa are the giveaways. pure black in the high frequencies of the sa is also an artifact of lossy encoding in the lineage.

when it comes to md it can be difficult to really tell the diff since it is lossy just like mp3 et al. the blocks often look a little more hyphen-like.

it is possible sometimes that an md recording has also been converted to mp3 this is one of the most difficult things to spot. your zoomed in sa is 2ms would be better if that was 2sec ( 0:02.000 in the view/length stat). If you want to upload a sample via yousendit.com post the link here and I can download it and have a look on my end.

One thing that is unfortunate about the show in question here is that it seems to have been recorded at a quite low quality setting and as a result the sound will be worse than the average mp3, which cuts off at 16kHz :eek:

*dJ*
2005-12-06, 01:10 PM
well what is fairly easy to tell is lossy vs lossless sources. the steep cutoff in the fa and blocks visible in the zoomed in sa are the giveaways. pure black in the high frequencies of the sa is also an artifact of lossy encoding in the lineage.

I got that, but often the SA/FA aren't that clear-cut..

when it comes to md it can be difficult to really tell the diff since it is lossy just like mp3 et al. the blocks often look a little more hyphen-like.

I think this show is more hyphen-like, but that is more based on my feeling, but then why is MD sourced okay to most traders. Isn't it as lossy as mp3?

I know Hi-MD's do support less compressed and uncompressed (?) PCM formats, but I assume you are talking about the older generation of MD's?

it is possible sometimes that an md recording has also been converted to mp3 this is one of the most difficult things to spot.

that sucks..

your zoomed in sa is 2ms would be better if that was 2sec ( 0:02.000 in the view/length stat).

I see, must have been sleeping :rolleyes:

If you want to upload a sample via yousendit.com post the link here and I can download it and have a look on my end.

I made 3 for you:
http://s46.yousendit.com/d.aspx?id=1Y0ZGAA538U6902TXCEBF0CKD1
http://s46.yousendit.com/d.aspx?id=28NZA1RSWWN3J1IJN6D82XZ1D4
http://s46.yousendit.com/d.aspx?id=16RXTWRWR7R0U0EYWKKIGC2NG

Freq's of the las one go up on the end & beginning of the sample (If you make an SA you will see what i mean), those are the spikes I was talking about.



One thing that is unfortunate about the show in question here is that it seems to have been recorded at a quite low quality setting and as a result the sound will be worse than the average mp3, which cuts off at 16kHz :eek:

True, the sound isn't great..

As I said microphone level set to high and show is distorted. I just don't know what to do with it.

Should I consider this as lossless format, but note that a mp3 recording of this show had been better (although the higher freq's would have been more smoothed out in FA?)

ssamadhi97
2005-12-06, 01:50 PM
I know Hi-MD's do support less compressed and uncompressed (?) PCM formats, but I assume you are talking about the older generation of MD's?
Yes.



I made 3 for you:
http://s46.yousendit.com/d.aspx?id=1Y0ZGAA538U6902TXCEBF0CKD1
http://s46.yousendit.com/d.aspx?id=28NZA1RSWWN3J1IJN6D82XZ1D4
http://s46.yousendit.com/d.aspx?id=16RXTWRWR7R0U0EYWKKIGC2NG

Freq's of the las one go up on the end & beginning of the sample (If you make an SA you will see what i mean), those are the spikes I was talking about.
Seems the beginning and the end of the last sample are from an entirely different source and recording.


Should I consider this as lossless format, but note that a mp3 recording of this show had been better (although the higher freq's would have been more smoothed out in FA?)
Actually, looking at the beginning of sample 1, this 1) clearly looks upsampled from 11025Hz sampling frequency (note the slight vertical mirroring), and 2) I suspect it was mp3 compressed before (note the blocky holes in the spectrum).

Relevant SA screenshot attached.

Five
2005-12-07, 12:57 PM
^what he said

*dJ*
2005-12-10, 06:29 AM
Damn!! That sucks.. (although I am still very happy to have this show!)

I remember the guy who send this show to me ripped it from CDR to Flac (using NERO) and he was a bit surprissed he could rip whole show in 4 minutes. Don't know if it matters (possible not), but maybe it wasn't ripped secure and that's reflected in FA/SA :confused:

Another member of this board also has this show (not from me), maybe he has a better version. Will send him a PM asking if he could post some samples as well, so we can find out more about this one (maybe I can upgrade)

*dJ*
2005-12-12, 09:56 AM
While in wait for some more samples I decided to play around with some other shows I got.

I found this show, I am almost sure it's lossy (big drop and really blockish SA), but I was wondering where the missing parts of the carrier did go.. is this just due to the compression used?

http://img512.imageshack.us/img512/4978/fakarmapolice3gg.jpg (http://imageshack.us)
http://img444.imageshack.us/img444/9984/sakarmapolice1yr.jpg (http://imageshack.us)

Five
2005-12-12, 11:51 AM
that is weird... it is lossy for sure, & sourced from tv/fm

perhaps somebody here can come up with a theory about what happened to the missing bits of the carrier

range_hood
2005-12-13, 12:38 PM
Lossy encoding of an FM signal of a common tuner. The carrier is strong enough to be encoded. Some better tuners fade out that stripe so you get weaker ones that would get dropped entirely by the encoder.

ssamadhi97
2005-12-14, 05:13 PM
perhaps somebody here can come up with a theory about what happened to the missing bits of the carrier
Considered inaudible by the encoder and discarded.

Probably because the pilot tone was a little bit weaker for a bit, or because the encoder decided that it's temporarily masked (drowned) by a stronger music signal in the frequencies below.

*dJ*
2005-12-21, 05:23 PM
Considered inaudible by the encoder and discarded.

Probably because the pilot tone was a little bit weaker for a bit, or because the encoder decided that it's temporarily masked (drowned) by a stronger music signal in the frequencies below.

music is indeed strong in that area, didn't noticed that before, thanks!!

I got another one:

lineage:
Core Sound Binaurals(Bass Rolloff @<hidden> 90Hz) Sony MZ-R37 MD DAT Fostex D5(Optical) m-audio DiO 2496 CD Wave 1.94.4 beta .FLAC Goldwave(Convert to .wav(16 bit), normalize, split tracks) FlacFrontend (Encode Level 6 and align sector boundries) YOU!

http://img447.imageshack.us/img447/64/muse12mt.th.jpg (http://img447.imageshack.us/my.php?image=muse12mt.jpg)
http://img447.imageshack.us/img447/9195/muse25ay.th.jpg (http://img447.imageshack.us/my.php?image=muse25ay.jpg)

The drop can that be due to MD?
Or the transfers? e.g. why wav>flac>wav>flac ?
Also i don't get the DAT (maybe taper means data??)

*dJ*
2005-12-21, 05:34 PM
additional info:

Special shoutout to <edit name> for the digital MD transfer.

Five
2005-12-21, 07:25 PM
yes, that looks exactly like a digitally-transferred MD recording. this is very distinctive spectral signature, with lego building-like "skyline", very much like I get when I transfer from my own MD recorder.

*dJ*
2005-12-22, 08:12 AM
Ok thanks (again!), but are those types of digital transfers considered lossy..ok (this type) md is already lossy, but let's say is it allowed to share such a show here?

Five
2005-12-22, 09:55 AM
yes, it is okay to share minisisc recordings here and also at similar sites so long as it was taped originally to minidisc (as is the case here).

if it was, for example, taped to dat then copied to minidisc then to wav to flac that would be not okay if you see what I'm saying.

*dJ*
2006-01-06, 11:26 AM
It's me again with another question..

http://img287.imageshack.us/img287/5463/track03ma4jy.th.png (http://img287.imageshack.us/my.php?image=track03ma4jy.png)
http://img204.imageshack.us/img204/2311/fa2ky.th.png (http://img204.imageshack.us/my.php?image=fa2ky.png)

I was wondering if it's mono (upto 14-16 kHz both channels look the same..) and also if it's upsampled around 15 kHz it seems slightly mirrored.

Linage i have is CDR>EAC>WAV (I think the cdr is max 3 generation).

Sample[s] on request

Five
2006-01-06, 02:50 PM
go to analyze > show phase analysis

set it to mid/side and you can use the "normalize" button to make it easier to see (in this case normalize is just for display).

for mono you will see a little skinny line up the centre that bounces with the sound:
http://img446.imageshack.us/img446/4777/mono17hd.th.jpg (http://img446.imageshack.us/my.php?image=mono17hd.jpg)

for stereo, you will see something like a ball of string bouncing all over the place eg:
http://img446.imageshack.us/img446/9813/stereo12tj.th.jpg (http://img446.imageshack.us/my.php?image=stereo12tj.jpg)

easier to understand when you see it in motion. the phase analysis shows differences between the channels, so if its a perfectly thin line up the middle its mono.

*dJ*
2006-01-06, 03:35 PM
This is what I got (hope i picked a good number of samples):

http://img223.imageshack.us/img223/8074/pa24po.th.png (http://img223.imageshack.us/my.php?image=pa24po.png)

.. so this is stereo? if show how can it be the FA of both channels (the two different colours in the FA are the channels -- right?) or so similair, especially upto 14-16 kHz?

Five
2006-01-08, 01:35 PM
that is stereo

the image isn't all that wide compared to some shows which means that the L and R channels are almost the same, but not exactly the same.

*dJ*
2006-02-07, 01:51 PM
Was wondering about this one, especially because it's know to be circulating in mp3. It can (therefore) be some tracks are ok and some not..

Track 01
FA: http://img146.imageshack.us/my.php?image=evtrack1fa3gi.png
SA: http://img66.imageshack.us/my.php?image=evtrack1sa4vi.png

Track 12
FA: http://img141.imageshack.us/my.php?image=evtrack12fa5fd.png
SA: http://img149.imageshack.us/my.php?image=evtrack12sa4py.png

Track 18
FA: http://img91.imageshack.us/my.php?image=evtrack18fa3uc.png
SA: http://img91.imageshack.us/my.php?image=evtrack18sa9mi.png

The given lineage:
THIS IS AN EXCELLANT QUALITY DEMO TAPE THAT I RECEIVED IN A TRADE
FROM CD - FLAC

..which seems strange on his own. Got a tape and conversion says cd>flac :confused:

-----

Also got another show, which claims to be FM sourced:

Track 03
FA: http://img92.imageshack.us/my..image=strokesulufatr033jn.png
SA: http://img261.imageshack.us/m..image=strokesulusatr039ia.png

Track 11
FA: http://img145.imageshack.us/my.php?image=strokesulufa3xu.png
SA: http://img145.imageshack.us/my.php?image=strokesulusa4lq.png

I was wondering how can it be the carrier is 16 kHz? How can it be the drop at track 3 is reanoable (?) bigger comparing with track 11?
Track 03 seems to miss some blocks in ther carrier?

As usual any help is appreciated!!

ssamadhi97
2006-02-07, 02:36 PM
Was wondering about this one, especially because it's know to be circulating in mp3. It can (therefore) be some tracks are ok and some not..

Track 01
FA: http://img146.imageshack.us/my.php?image=evtrack1fa3gi.png
SA: http://img66.imageshack.us/my.php?image=evtrack1sa4vi.png

Track 12
FA: http://img141.imageshack.us/my.php?image=evtrack12fa5fd.png
SA: http://img149.imageshack.us/my.php?image=evtrack12sa4py.png

Track 18
FA: http://img91.imageshack.us/my.php?image=evtrack18fa3uc.png
SA: http://img91.imageshack.us/my.php?image=evtrack18sa9mi.png

The given lineage:
THIS IS AN EXCELLANT QUALITY DEMO TAPE THAT I RECEIVED IN A TRADE
FROM CD - FLAC

..which seems strange on his own. Got a tape and conversion says cd>flac :confused:
All of these look mp3 sourced -typical blocking and lowpassing, though the encoder picked a pretty high lowpass on some of the tracks (probably Blade at fairly high bitrate, which is iirc known to do that. It's also known to suck. :P)

Also got another show, which claims to be FM sourced:

Track 03
FA: http://img92.imageshack.us/my.php?image=strokesulufatr033jn.png
SA: http://img261.imageshack.us/my.php?image=strokesulusatr039ia.png

Track 11
FA: http://img145.imageshack.us/my.php?image=strokesulufa3xu.png
SA: http://img145.imageshack.us/my.php?image=strokesulusa4lq.png

I was wondering how can it be the carrier is 16 kHz? How can it be the drop at track 3 is reanoable (?) bigger comparing with track 11?
Track 03 seems to miss some blocks in ther carrier?

As usual any help is appreciated!!
This source exhibits typical signs of an analog tv recording - the audio bandwidth, the structure of the noise floor in the treble range (especially in the left channel), and especially the "tone" which apparently is at the line frequency of NTSC (~15750 Hz) or PAL (~15625 Hz), just below 16kHz - no, that's not a "carrier" signal of any kind.

*dJ*
2006-02-07, 02:37 PM
About last show:

I know there exists a digital broadcast from BBC's interactive feed, can this be an audio rip of that one?

Although I remember some talking by a presentator (going to re-check)

*dJ*
2006-02-07, 03:07 PM
I am puzzled:

The intro says: This is Lamac live [..] Recorded exclusively for Radio One last thursday, live in london this are the Strokes.

As I said can this be from an interactive (web/online) feed?