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mp3 to wav to mp3 to wav same?
gts
post Feb 27 2003, 14:42
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If a file is encoded to mp3, then coverted back to a wav, and then that wav is convered back to mp3, will the both mp3s be the same?
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dreamliner77
post Feb 28 2003, 05:19
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QUOTE
I perceived the decay of plucked notes on an acoustic guitar and the startling snap of snare drum shots, and could even distinguish among the drums used. And there was no harshness whatsoever. (I typically listen at a sampling rate of 128 kbps, which is a pretty good comprise between compression and not).



Gee, when I hear something that wasn't there before, I call it an artifact.

QUOTE
In terms of its smoothness, it made me think I was listening to quality tube gear. That is a tough feat to pull off: "smooth detail."


Repeat with me now, "distortion"


--------------------
"You can fight without ever winning, but never win without a fight." Neil Peart 'Resist'
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makarov
post Jan 30 2005, 07:33
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An analogy to JPEG lossy image compression was made above. I have a curious fact about it.

It is true that successive decompress-compress cycles on the same image each reduce its quality further. However, it turns out that (with JPEG) the biggest information loss occurs when the original lossless image is first compressed into JPEG. If you do successive decompress-compress cycles (at the same JPEG quality setting) and check the information loss at each cycle (which is easily done by subtracting one image from another pixel-by-pixel and presenting the subtraction result as an image), you'll see that the magnitude of artefacts introduced at the second compression is much smaller than that introduced at the initial compression. Firthermore, the magnitude of artefacts introduced at the third and following compressions is still smaller than that at the second compression. The artefacts still do build up and eventually trash the image completely, but not nearly as fast as if you'd expect if each next compression threw away as much information as the first one. JPEG has a limited robustness against stupid users doing image editing and recompression cycles.

Now, I don't know whether MP3 has the same robustness or not.
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- gts   mp3 to wav to mp3 to wav same?   Feb 27 2003, 14:42
- - CiTay   No. MP3 encoding is a lossy process. The WAV that ...   Feb 27 2003, 14:46
- - gts   Well the first conversion from wav to mp3 removes ...   Feb 27 2003, 15:05
- - Xenion   QUOTE (gts @ Feb 27 2003 - 03:05 PM)Well the ...   Feb 27 2003, 15:15
- - X-Fixer   QUOTE (gts @ Feb 27 2003 - 09:05 PM)Well the ...   Feb 27 2003, 15:26
- - gts   QUOTE theoretically this could work this way. (sec...   Feb 27 2003, 23:30
- - gts   QUOTE original wav => mp3 =lossy agreed QUOTE m...   Feb 27 2003, 23:33
- - Messer   Codec does not remove anything. It rounds some val...   Feb 27 2003, 23:39
- - gts   Thank you. What search words will find the topic? ...   Feb 27 2003, 23:43
- - Mac   I'll chip in because it took me a few goes of ...   Feb 27 2003, 23:46
- - Messer   I'd try "reencoding". This is for e...   Feb 27 2003, 23:49
- - gts   Thank you!   Feb 28 2003, 00:01
- - CiTay   QUOTE Codec does not remove anything. It rounds so...   Feb 28 2003, 00:21
- - gts   QUOTE It doesn't care if the WAV was previousl...   Feb 28 2003, 00:30
- - Messer   QUOTE (CiTay @ Feb 28 2003 - 01:21 AM)QUOTE C...   Feb 28 2003, 00:35
- - gts   QUOTE that essential process in lossy compression ...   Feb 28 2003, 00:37
- - fewtch   There's a simple way to test this. Encode a ....   Feb 28 2003, 00:42
- - Artemis3   If you record a CD into a cassette tape, then use ...   Feb 28 2003, 02:14
- - gts   QUOTE If you record a CD into a cassette tape, the...   Feb 28 2003, 02:29
- - rjamorim   QUOTE (gts @ Feb 27 2003 - 08:30 PM)In the jp...   Feb 28 2003, 02:39
- - gts   QUOTE But reducing the amount of colors is only ON...   Feb 28 2003, 02:44
- - rjamorim   QUOTE (gts @ Feb 27 2003 - 10:44 PM)but the p...   Feb 28 2003, 03:05
- - andrew3199   I think we can all agree that there is some loss w...   Feb 28 2003, 04:29
- - rjamorim   QUOTE (andrew3199 @ Feb 28 2003 - 12:29 AM)fo...   Feb 28 2003, 04:36
- - dreamliner77   QUOTE I perceived the decay of plucked notes on an...   Feb 28 2003, 05:19
|- - makarov   An analogy to JPEG lossy image compression was mad...   Jan 30 2005, 07:33
- - NeoRenegade   gts, with regards to your JPEG analogy... you refe...   Mar 2 2003, 23:14
- - kdo   QUOTE (rjamorim @ Feb 28 2003 - 03:05 AM)Code...   Mar 3 2003, 00:37
- - aggies11   Not to resurrect a dead thread or anything, but it...   Aug 21 2003, 02:13
- - Doctor   aggies: no. Lossy sound encoding is not like you ...   Aug 21 2003, 02:54
- - phong   An interesting thought, but probably academic. MP...   Aug 21 2003, 02:58
- - AtaqueEG   QUOTE (dreamliner77 @ Feb 27 2003, 11:19 PM)R...   Aug 21 2003, 03:18
- - 2Bdecided   QUOTE (aggies11 @ Aug 21 2003, 01:13 AM)Could...   Aug 21 2003, 10:33
- - 2Bdecided   In reply to the original question, the simplistic ...   Aug 21 2003, 10:39
- - sld   (Redundant post, sorry)   Aug 21 2003, 10:40
- - Vietwoojagig   I remember long time ago, there was a technology c...   Aug 21 2003, 12:53
- - 2Bdecided   DCC used (what would become) MPEG-1 layer I. You ...   Aug 21 2003, 13:24
- - aggies11   Thanks for the quick replies. Very informative ind...   Aug 21 2003, 17:06
- - phong   The answer to the first question is "no...   Aug 21 2003, 19:29
- - Doctor   Yawn. phong: I think you are wrong on both counts...   Aug 22 2003, 03:29
- - phong   I think I mis-specified which questions I was answ...   Aug 22 2003, 03:46
- - Canar   QUOTE (2Bdecided @ Aug 21 2003, 01:33 AM)I do...   Aug 22 2003, 04:08
- - bexx   Isn't wavpacklossy/hybrid whatever its called ...   Aug 22 2003, 04:29
- - sublimelouie   easiest way to think of it, its like xeroxing a xe...   Aug 22 2003, 04:51
- - aggies11   Sublime: easiest way to think of it, its like xero...   Aug 22 2003, 05:26
- - 2Bdecided   This reply is in response to no one in particular....   Aug 22 2003, 11:05
- - Gabriel   QUOTE IIRC FhG looked at this. You could call it a...   Aug 22 2003, 11:23
- - smg   QUOTE (2Bdecided @ Aug 22 2003, 06:05 AM)This...   Aug 22 2003, 14:46
- - phong   QUOTE Do it enough, you can reduce the complexity ...   Aug 22 2003, 16:13
- - ErikS   QUOTE (Gabriel @ Aug 22 2003, 11:23 AM)Now, t...   Aug 22 2003, 16:50
- - Zilva   Cosine transformation is NOT LOSSY. After transofm...   Sep 10 2003, 10:06
- - tigre   QUOTE (Zilva @ Sep 10 2003, 01:06 AM)Cosine t...   Sep 10 2003, 10:35
- - 2Bdecided   QUOTE (Zilva @ Sep 10 2003, 09:06 AM)Cosine t...   Sep 10 2003, 11:11
- - MugFunky   wow.. old post. ("holy thread resurrection, b...   Jan 31 2005, 04:06
- - h.tuehn   I don't want to correct anything MugFunky or m...   Jan 31 2005, 07:16


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