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Topic: Why is LAME so much slower than MPC? (Read 2671 times) previous topic - next topic
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Why is LAME so much slower than MPC?

Why is it that LAME is so much slower at encoding -aps than other variable bitrate encoders such as MPC, which is lightning fast by comparison?

It seems to me (which is obviously wrong) that a more transparent encoding scheme, like MusePack, that also reduces bitrate quite significantly would be more processor intensive than a format such as LAME which encodes at lesser quality at comparitively higher bitrates.

Thanks for the info.

 

Why is LAME so much slower than MPC?

Reply #1
Well, I've always figured that LAME is basicly squezing out all the possible quality from a comparitivly old scheme that wasn't really designed with transperency in mind. MPC was designed with nothing but transperency in mind, so the compressor doesn't have to even worry about things like pre-echo.

I.E., what's the fastest way to drive 140 mph? Buy a VW Bug and mod it like crazy hell, or just buy a Porche to begin with? 

Why is LAME so much slower than MPC?

Reply #2
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I.E., what's the fastest way to drive 140 mph? Buy a VW Bug and mod it like crazy hell, or just buy a Porche to begin with? 

Hey, if you get a Beetle Turbo S, it's top speed is already 130 mph (and I think that's simply because it's electronically limited).

Why is LAME so much slower than MPC?

Reply #3
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I.E., what's the fastest way to drive 140 mph? Buy a VW Bug and mod it like crazy hell, or just buy a Porche to begin with?  

Hey, if you get a Beetle Turbo S, it's top speed is already 130 mph (and I think that's simply because it's electronically limited).

hehe I knew some car guy would rip apart my analogy. You can also find POS Porches that won't do 140, I believe.

Why is LAME so much slower than MPC?

Reply #4
Eh.. the main reason that LAME is so slow is simply because it's not optimized for speed very well, and if I must say, it's not coded particularly well in general either (code is quite messy/hackish/etc)

There are some other factors that theoretically could be issues, including the fact that LAME is a transform coder, while MPC is a subband coder (transforms are more expensive).. but the fact that an optimized SSE2 compile of oggenc (Vorbis is a transform coder also, and more complex than LAME) can pretty much match the current mppenc (which isn't SSE2 optimized) in speed shows that LAME is nowhere near this threshold.  LAME could be very fast if certain things were handled differently.....

AFAIK, the Nero AAC encoder is faster than LAME also (and again, not only is the psymodel of this encoder much more complex than that of LAME's, but the format is also much more complex), though I haven't tried it so I'm not quite certain on that.

Why is LAME so much slower than MPC?

Reply #5
Thanks Dibrom. That is interesting. I thought, perhaps naively, that since LAME has been around as long as it has that the code was optimized for modern processors as well as the "younger" formats such as ogg and mpc.

Why is LAME so much slower than MPC?

Reply #6
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Quote
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I.E., what's the fastest way to drive 140 mph? Buy a VW Bug and mod it like crazy hell, or just buy a Porche to begin with?  

Hey, if you get a Beetle Turbo S, it's top speed is already 130 mph (and I think that's simply because it's electronically limited).

hehe I knew some car guy would rip apart my analogy. You can also find POS Porches that won't do 140, I believe.

I knew one guy... (it's one of those urban legends)

He had a beetle going 200 mph and the Benz it overtook couldn't believe it got overtook.

Long story short, it turns out the guy is an engineer working for Porsche and modified his beetle.

Hey, at least his car is less likely to get stolen.

Why is LAME so much slower than MPC?

Reply #7
Lame is lacking some assembly optims. As an exemple SSE fft or mdct would speed things quite a bit.

MPC is SSE optimized.

 
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