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-   -   Slow encoding on Mac OS X (https://forum.musepack.net/showthread.php?t=162)

krmathis 12 March 2005 08:51 pm

Slow encoding on Mac OS X
 
First of all I want to thank the developers for all the work placed into Musepack.
Imo its the best lossy encoder out there! :)

But I am disappointed with the encoding speed I get with the encoder for Mac OS X.
When I encode using the latest mppenc (1.15u) --standard I only get ~2.6x speed.
Really not sure if the encoder use AltiVec optimization, or if there are other ways to make it faster? (I know how to optimize using " ./configure > make", but not through Xcode as this software use).
Any hints are highly welcome! :idea:

By the way, I am running Mac OS 10.3.8 on a PowerBook G4 1.5GHz with 1GB ram.

kuniklo 16 March 2005 12:29 am

Musepack currently isn't optimized at all for PPC, so it will be slower.

I'm a little surprised that it's that slow on a 1.5Ghz machine.

You built the binaries yourself?

krmathis 16 March 2005 11:31 am

Yes I compiled the binary myself, from the 1.15u source code (since, afaik, there are no official Mac OS X binary for download).
Is it possible for me to use some optimization flags when I compile though Xcode? Something like "-O3 -faltivec -mcpu=7450 -mtune=7450"

kuniklo 16 March 2005 04:12 pm

Quote:

Yes I compiled the binary myself, from the 1.15u source code (since, afaik, there are no official Mac OS X binary for download).
Is it possible for me to use some optimization flags when I compile though Xcode? Something like "-O3 -faltivec -mcpu=7450 -mtune=7450"
We're not sure which compiler flags are appropriate for the mac build, although I'm working on it now. mppenc seems to be somewhat sensitive to compiler optimizations so be careful.

krmathis 16 March 2005 07:44 pm

kuniklo, great that you're looking into it.

I've done some testing myself and found something strange.
The encoding speed of 1.15u is only ~half of the 1.15s speed! :shock:
mppenc 1.15s:
Code:

100.0 197.7 kbps 5.17x 4:22.7 4:22.7 0:50.8 0:50.8
mppenc 1.15u:
Code:

100.0 185.8 kbps 2.79x 4:22.7 4:22.7 1:34.1 1:34.1
Both compiled with standard configuration, no additional compiler flags.
I dont know what changed between the two versions, but it certainly slow down the encoding process a LOT! :(


Note!
I've compiled 1.15s with these compiler flags "-fast -faltivec -mcpu=7450" and the resulting binary run a little bit faster.
Code:

100.0 197.7 kbps 5.42x 4:22.7 4:22.7 0:48.4 0:48.4

Pretzel 25 March 2005 01:27 am

Is there any Mac binaries for the more recent release of the mpc codec?

kuniklo 25 March 2005 02:10 am

Quote:

Is there any Mac binaries for the more recent release of the mpc codec?
I'm working on them but I've been pretty busy with some other stuff for the last week or two. Hopefully soon.


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