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Informed rebuttal of VBR disadvantages appreciated, VBR always rocks, when it comes to lossy compression, right?
Moon
post Oct 16 2008, 09:54
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As already mentinend in this thread some fanboy over at the offical Pioneer forums is making claims that VBR sucks (here and here) in that it needs more processing power compared to CBR and for various other reasons.

I would like to have a well written rebuttal of that statment based on facts so Pioneer might reconsider putting VBR support into their upcoming DJ equipment. I've ripped all my 1000+ CDs to VBR and I wouldn't want to reencode them just because Pioneer doesn't get it right. Thanks!
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DJRyanJ
post Oct 17 2008, 20:59
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I actually know Pulse personally and he's not nearly as much of an ass as he seems to be on the forums. Unfortunately for us, we get a lot of people who don't read the rules (it's Pioneer's forum and it's their rules, some of which people don't like), so Pulse deals with a bit of a heavy hand.

Anyway, back on topic here...

QUOTE
About 80% are my own CD collection. The rest is MP3 mixes by different DJs, friends, my own.
MP3gain can tell you if the file has an issue (it won't be able to process it).


Excellent. Thanks! I've heard of MP3gain but never used it; I'll check it out. Obviously since you did your own encoding, you wouldn't have come across the types of files I'm referring to (which I've been told via a nice PM that I can't do; sorry for the violation and I hope this isn't also crossing the boundary) which tend to be broken. But trust me when I say, they're abundant.

@xmixahlx - excellent info, thanks for that. Nice to see some concrete numbers.

QUOTE
You're mixing things in a way that it piles up according to your expectations and without any kind of sense. "Eyes blur, the ears (...) less" has nothing to do with VBR. Why do you think that?


You are correct sir. I was trying to justify it and ended up deleting it because I clearly had not thought it all the way through. I gotta stop doing that.

QUOTE
I was (possibly falsely) making the assumption that an audio CD would already be at least partially buffered to memory by such a player to allow tricks in real-time (you can't physically play a CD backwards... can you?) and that the MP3 data would be using the same buffer in the same way once decoded to an equivalent linear digital format and still using the same "trick" hardware/DSPs.


It's no secret that the CDJ's use a buffer to be able to manipulate the audio. I actually tried one time to make a CD play backwards in a player (I turned the motor around - and it WASN'T a CDJ that I paid $1200 bucks for) - it didn't work. LOL. As to what digital magic is happening internal to the player, that's a trade secret, I'd assume. There may be a valid reason for why VBR is not as supported as CBR - but I'm not privy to it.

Pioneer was one of the last hardware DJ companies to support MP3. It was a major point of contention for a lot of people for a long time. We never found out why it took them so long, but eventually support was released. Perhaps the reason they don't support VBR "properly" is similar to the argument around Wavelab - Pio's products are aimed at "professionals" and for a long time it was assumed that they wouldn't use MP3's. I'm not sure I agree with that, and it's speculation anyway, but it's an easy speculation to have I'd say. The other possible reason it's not supported properly is because their support for it is so new, it's suffering from the same problems reported by many VBR implementations - lack of seek, difficulty reading it correctly, etc. etc. Again, just speculation, and IMHO if VBR is as good as you're claiming (which I'm starting to believe), then there's no excuse for the lack of support. Then again, the same could be said for their initial lack of support for MP3's at all.

QUOTE
The encoder is "starving" bits in complex parts and "wastes" bits in easy to encode parts. VBR simply aims to maintain a constant level of quality throughout the encoding.


I'd say that's true of VBR encoder settings that use the full range vs. CBR settings below 320kbps; it's NOT true of 320kbps, which is the max anyway and is what I use. While at 320 it might be "wasting bits" on the uncomplex parts, the same could be argued for an uncompressed file - do we REALLY need all those bits to describe some minutia of the sound that we probably can't distinguish anyway? Isn't the sonic quality presented by MP3 "good enough" for "most people"? I'm sure you'd say no, but then we're right back to the same argument.

QUOTE
PS Apologies to DJRyanJ for the dig earlier. I got the impression that you weren't prepared to listen to logic or partake in reasoned debate. How wrong I was biggrin.gif


Don't worry about it. I can see how easy it is to make these kinds of assumptions; thanks for the warm welcome.

-r-

This post has been edited by DJRyanJ: Oct 17 2008, 21:10
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kornchild2002
post Oct 17 2008, 21:21
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QUOTE (DJRyanJ @ Oct 17 2008, 13:59) *
I'd say that's true of VBR encoder settings that use the full range vs. CBR settings below 320kbps; it's NOT true of 320kbps, which is the max anyway and is what I use. While at 320 it might be "wasting bits" on the uncomplex parts, the same could be argued for an uncompressed file - do we REALLY need all those bits to describe some minutia of the sound that we probably can't distinguish anyway? Isn't the sonic quality presented by MP3 "good enough" for "most people"? I'm sure you'd say no, but then we're right back to the same argument.


You are right that a VBR mp3 file, when compared to a 320kbps CBR mp3 file, is not true 320kbps. That doesn't mean anything though as you are kind of arguing against yourself here. 320kbps is wasting bits on most samples for most people and you are somewhat right about uncompressed audio. There aren't many people out there that benefit from uncompressed audio. That is why we have lossless though. Lossless formats such as FLAC and Apple Lossless are able to shave off 10MB or more from the file size (when compared to uncompressed WAV) while retaining track tag information and still being bit-for-bit identical. The main reason behind having lossless/uncompressed audio is so that someone can have a perfect backup of their music. They can then use only lossless files or use a lossy format. You are right that mp3 is normally good enough for most people. However, mp3 is normally good enough for most people at much lower bitrates. 320kbps is a "safe bet" but you don't need that high of a bitrate when encoding audio even for DJ purposes. The environments where DJs often play are not really optimal for music. The rooms are often not acoustically tuned, the positioning of the speakers are not optimal (studies have shown that even with small speakers, moving them by 1 cm can change the perceived quality), and people absorb and reflect the sound waves while adding to additional noise influences by talking and whatnot. That is why one doesn't really need 320kbps.

So go ahead and argue that 320kbps is a safe bet (or that you need it as your ABX tests have shown that). However, I wouldn't argue that that uncompressed audio uses more bits that needed and make that look bad and then come back saying that 320kbps uses more bits than needed and that is alright.

Edit: It is nice to see someone who will listen to logic and not come off as a butt hole. I am sure that Pulse isn't like that in real life and I know that maintaining a forum can add to daily headaches. However, he was coming off as someone who refused to listen to logic and would just ban people who disagreed with them.

This post has been edited by kornchild2002: Oct 17 2008, 21:22
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kwanbis
post Oct 19 2008, 19:25
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QUOTE (kornchild2002 @ Oct 17 2008, 20:21) *
Lossless formats such as FLAC and Apple Lossless are able to shave off 10MB or more from the file size (when compared to uncompressed WAV) while retaining track tag information and still being bit-for-bit identical.

Lossless compress to about 60% of a WAV size on average (iirc). Some things compress to 50% (half the size of the original WAV).


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Posts in this topic
- Moon   Informed rebuttal of VBR disadvantages appreciated   Oct 16 2008, 09:54
- - Raiden   Don't waste your energy. Self-absorbed people ...   Oct 16 2008, 10:51
- - halb27   It's all up to whether an encoder works well. ...   Oct 16 2008, 11:27
- - JensRex   Yes, don't waste your time. That guy is comple...   Oct 16 2008, 11:43
- - Slipstreem   As the other guys have already said, you're wa...   Oct 16 2008, 12:56
|- - add   QUOTE (Slipstreem @ Oct 16 2008, 13:56) C...   Oct 16 2008, 16:40
|- - Lyx   QUOTE (add @ Oct 16 2008, 17:40) QUOTE (S...   Oct 16 2008, 17:19
- - probedb   No point with some of these people....I've giv...   Oct 16 2008, 12:59
- - Canar   These threads are really old. I created an account...   Oct 16 2008, 16:59
|- - Synthetic Soul   QUOTE (Canar @ Oct 16 2008, 16:59) I resp...   Oct 16 2008, 17:08
- - Canar   No, I think I'm going mad. That post I made is...   Oct 16 2008, 18:10
|- - uart   QUOTE (Canar @ Oct 16 2008, 09:10) No, I ...   Oct 16 2008, 20:01
- - Slipstreem   Well, we have an answer of sorts over there from a...   Oct 16 2008, 18:18
- - Soap   Mind, if you do decide to argue: The argument that...   Oct 16 2008, 18:59
- - Slipstreem   I'm specifically not joining that forum as I...   Oct 16 2008, 19:39
- - Canar   Who is BDX?   Oct 16 2008, 20:03
|- - DJRyanJ   Alright guys, I'm the guy who did the wall of ...   Oct 16 2008, 20:49
|- - halb27   QUOTE (DJRyanJ @ Oct 16 2008, 21:49) ...S...   Oct 16 2008, 21:29
|- - kwanbis   QUOTE (DJRyanJ @ Oct 16 2008, 19:49) 5) W...   Oct 16 2008, 21:36
- - uart   I dont know, it's not me. Does anyone have a t...   Oct 16 2008, 20:06
- - Slipstreem   It wasn't me either, and I don't have a tr...   Oct 16 2008, 20:12
- - kornchild2002   I will post just to be ballsy. I don't see Pu...   Oct 16 2008, 20:48
- - Canar   I don't have the time right now to get more in...   Oct 16 2008, 21:13
- - m0rbidini   Pioneer should support VBR and stfu. If using VBR ...   Oct 16 2008, 21:57
- - DJRyanJ   OK, I have a brief moment here before my midterm s...   Oct 16 2008, 22:00
|- - Ron Jones   QUOTE (DJRyanJ @ Oct 16 2008, 14:00) Why ...   Oct 16 2008, 22:59
|- - m0rbidini   QUOTE (DJRyanJ @ Oct 16 2008, 22:00) QUOT...   Oct 16 2008, 23:32
|- - kwanbis   QUOTE (DJRyanJ @ Oct 16 2008, 21:00) I...   Oct 17 2008, 03:09
- - [JAZ]   I guess most it said already but I'd like to c...   Oct 16 2008, 23:01
- - Axon   What MP3 decoding library does Wavelab use? It...   Oct 16 2008, 23:02
- - DJRyanJ   QUOTE About 0.01% had issues. Most where CBRs. Di...   Oct 17 2008, 04:39
|- - kwanbis   QUOTE (DJRyanJ @ Oct 17 2008, 03:39) Did ...   Oct 17 2008, 05:06
- - xmixahlx   1. regarding the difficulty of decoding VBR it...   Oct 17 2008, 05:52
- - m0rbidini   QUOTE I've seen this in my very limited video ...   Oct 17 2008, 11:00
- - Lyx   Why have a long discussion when it all can be summ...   Oct 17 2008, 13:21
|- - halb27   QUOTE (Lyx @ Oct 17 2008, 14:21) Why have...   Oct 17 2008, 14:33
|- - lvqcl   QUOTE (halb27 @ Oct 17 2008, 17:33) QUOTE...   Oct 17 2008, 14:49
|- - Lyx   QUOTE But maximum bitrate for LAME VBR (i.e. lame ...   Oct 17 2008, 15:13
- - pdq   I am guessing (and I don't really know anythin...   Oct 17 2008, 13:50
- - Slipstreem   Won't the part of the audio stream being worke...   Oct 17 2008, 13:57
|- - pdq   QUOTE (Slipstreem @ Oct 17 2008, 08:57) W...   Oct 17 2008, 14:48
- - Synthetic Soul   DJRyanJ, kudos for making the effort to partake in...   Oct 17 2008, 14:04
- - Slipstreem   I'm gonna have to go and read more about how t...   Oct 17 2008, 15:01
- - Slipstreem   The only problem I can see with that is that some ...   Oct 17 2008, 15:43
|- - Lyx   QUOTE (Slipstreem @ Oct 17 2008, 16:43) T...   Oct 17 2008, 15:56
- - halb27   IMO the old --preset scheme or a similar one addre...   Oct 17 2008, 15:59
- - greynol   Now we're just going around in circles. There...   Oct 17 2008, 16:05
|- - Lyx   QUOTE (greynol @ Oct 17 2008, 17:05) Now ...   Oct 17 2008, 16:21
- - Synthetic Soul   We're also going way off-topic...   Oct 17 2008, 16:53
- - Slipstreem   A quick heads-up (not that I've been spying). ...   Oct 17 2008, 19:25
- - DJRyanJ   I actually know Pulse personally and he's not ...   Oct 17 2008, 20:59
|- - kornchild2002   QUOTE (DJRyanJ @ Oct 17 2008, 13:59) I...   Oct 17 2008, 21:21
|- - Canar   QUOTE (kornchild2002 @ Oct 17 2008, 13:21...   Oct 17 2008, 21:48
||- - kornchild2002   QUOTE (DJRyanJ @ Oct 17 2008, 14:40) Gene...   Oct 17 2008, 22:27
|- - kwanbis   QUOTE (kornchild2002 @ Oct 17 2008, 20:21...   Oct 19 2008, 19:25
- - Neasden   On the switch subject, I just would like to add th...   Oct 17 2008, 21:34
- - DJRyanJ   QUOTE (kornchild2002 @ Oct 17 2008, 13:21...   Oct 17 2008, 21:40
|- - Slipstreem   QUOTE (DJRyanJ @ Oct 17 2008, 21:40) What...   Oct 17 2008, 21:59
- - DJRyanJ   QUOTE (Slipstreem @ Oct 17 2008, 13:59) O...   Oct 18 2008, 01:11
|- - Synthetic Soul   QUOTE (DJRyanJ @ Oct 18 2008, 01:11) I...   Oct 18 2008, 10:00
- - Moon   Well, I'm sorry but after finding out about Pi...   Oct 18 2008, 11:11
|- - Synthetic Soul   QUOTE (Moon @ Oct 18 2008, 11:11) Well, I...   Oct 18 2008, 19:04
- - Slipstreem   With reference to your last paragraph, have you tr...   Oct 18 2008, 13:04
- - Moon   I'm gonna try em tonight. I've also conver...   Oct 18 2008, 16:36
- - pdq   If even a single frame uses 320 kbps then the enti...   Oct 18 2008, 22:16
- - Moon   QUOTE (Synthetic Soul @ Oct 18 2008, 20:0...   Oct 19 2008, 09:24
- - DJRyanJ   QUOTE (Moon @ Oct 18 2008, 03:11) a) a fu...   Oct 19 2008, 10:33
|- - Synthetic Soul   QUOTE (DJRyanJ @ Oct 19 2008, 10:33) I su...   Oct 19 2008, 11:54
|- - Moon   QUOTE (DJRyanJ @ Oct 19 2008, 11:33) QUOT...   Oct 20 2008, 09:50
- - shadowking   Dj's of the world please stop bothering us wit...   Oct 20 2008, 12:50
- - DJRyanJ   I'm trying to do some comparisons, and I'm...   Oct 21 2008, 19:58
|- - Canar   http://ff123.net/samples.html is a good place to s...   Oct 21 2008, 20:16
- - halb27   On problemSamples folder you'll find those sam...   Oct 21 2008, 20:25
- - DJRyanJ   QUOTE (Canar @ Oct 21 2008, 13:16) Howeve...   Oct 21 2008, 20:58
|- - halb27   QUOTE (DJRyanJ @ Oct 21 2008, 21:58) .. f...   Oct 21 2008, 22:06
|- - Moon   QUOTE (DJRyanJ @ Oct 21 2008, 21:58) I...   Oct 21 2008, 22:28
|- - Slipstreem   QUOTE (DJRyanJ @ Oct 21 2008, 20:58) I...   Oct 22 2008, 00:52
- - lvqcl   QUOTE It refers to the LAME problem samples page f...   Oct 21 2008, 21:09
|- - Canar   QUOTE (lvqcl @ Oct 21 2008, 13:09) http:/...   Oct 21 2008, 21:26
- - DJRyanJ   That's the plan, slipstreem. Moon, I'll s...   Oct 22 2008, 04:31


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