Re: [Flac] FLAC: general question
Harry, Keep in mind that the processor load will be different for every processor model. PowerPC G4, G5, and then all the implementations of x86. Processor load does not depend upon clock speed - all that clock speed determines is how fast the operation can be done, and particularly whether it can be done in real time. Back to your question: The CPU load will be determined by the efficiency of the instruction set for the processor running the program, as well as how well the compiler maps the C source to those instructions. Any comparison table you might find could be irrelevant if your processor model was not tested, and if the compiler options are changed when you build FLAC, then that might change the efficiency as well. I point this out because FLAC is not always going to be better or worse than other formats. We're talking about several moving targets here, all of which influence each other. Brian Willoughby Sound Consulting On Jul 25, 2007, at 11:21, Harry Sack wrote: 2007/7/24, Ivo Emanuel Gonçalves [EMAIL PROTECTED]: On 7/24/07, Greg M. [EMAIL PROTECTED] wrote: Ivo, Harry is asking about CPU usage of the DEcoder, not the ENcoder. Sorry, my bad. I believe that FLAC's decoding is somewhat faster than most other lossless formats, as FLAC is a much less complex format. Maybe somebody knows some comparison tables with some measured values like the ones available for encoding times? (so now I'm looking for the decoding CPU power loads) thx ___ Flac mailing list Flac@xiph.org http://lists.xiph.org/mailman/listinfo/flac
Re: [Flac] FLAC: general question
Harry, Another thing to consider is the balance between CPU efficiency and disk speed. On some of my systems, decoding a FLAC file to AIFF (or WAV) uses 100% of the CPU. That's because the drive is faster than the CPU, so the CPU is constantly working. Moving to a 4-processor system, I can run 4 FLAC decodes at the same time. At first, that would not use 400% (100% of all 4 CPUs) because the disk was not fast enough to read 4 files and write 4 files at once. But as soon as I upgraded to a faster drive on a faster bus, I am back to 400% CPU usage when decoding. I use FLAC to back up original multi-track recordings. Then I burn the FLAC files to CD-R or DVD-R. Whenever a client needs the originals for a mixing session, I have to pull all the FLAC files from optical media and decode them, since nearly all mixing software uses AIFF (even the ones that allow FLAC will convert the files from FLAC to something else on disk). In order to respond to the client as fast as possible, I want to decode the FLAC files as fast as possible, so I have experimented with faster machines and faster drives. In other words, I'm not sure that you can make any solid conclusions from a comparison table, even if you could find one, because it would always be possible to recompile flac, or upgrade the CPU, or upgrade the disk, or add additional disks to spread the load. There is no single answer to your question. Brian Willoughby Sound Consulting On Jul 25, 2007, at 11:21, Harry Sack wrote: Maybe somebody knows some comparison tables with some measured values like the ones available for encoding times? (so now I'm looking for the decoding CPU power loads) thx ___ Flac mailing list Flac@xiph.org http://lists.xiph.org/mailman/listinfo/flac
[Flac] FLAC: general question
hi FLAC list! I have a general question about the FLAC decoder. Is it true the FLAC decoder requires less CPU power then a MP3 decoder? And if yes, is there somebody who can give me a comparison e.g. FLAC decoder uses 50% less CPU power then a MP3 decoder or is this difference only minimal? thx ___ Flac mailing list Flac@xiph.org http://lists.xiph.org/mailman/listinfo/flac
Re: [Flac] FLAC: general question
The amount of CPU the FLAC encoder uses is dependant on how much compression you will use. The less compression you need, the less CPU power that will be used. Of course, the whole point of FLAC is to get as much compression as possible without losing any audio fidelity. I don't know of any site that compares CPU power usage between FLAC and MP3. I have seen a few threads on HA comparing CPU usage between FLAC and other lossless formats, though. ___ Flac mailing list Flac@xiph.org http://lists.xiph.org/mailman/listinfo/flac
Re: [Flac] FLAC: general question
On 7/24/07, Greg M. [EMAIL PROTECTED] wrote: Ivo, Harry is asking about CPU usage of the DEcoder, not the ENcoder. Sorry, my bad. I believe that FLAC's decoding is somewhat faster than most other lossless formats, as FLAC is a much less complex format. ___ Flac mailing list Flac@xiph.org http://lists.xiph.org/mailman/listinfo/flac
