Can I build audio peaks faster somehow?

Geoff_Wood wrote on 12/23/2014, 2:26 PM

Forgive if clarified elsewhere, but what is the scenario where it is taking so so to build paek files for (how many) tracks of (what type) and of (what size) ?

Is this a huge multi-track project coming from a multi-track recorder, or a (?)-channel single file coming as part of a a very long video ? If the latter, then I guess there is decoding the audio part of the, say, AVCHD file as a factor.

I routinely work with projects with tens of audio tracks and seldom have to wait for more than a minute for preak-building even when all the audio dumped new into a project. An for a single file of two, a few seconds at worst.

Clearly there is some variable factor involved here !

geoff

John_Cline wrote on 12/23/2014, 2:35 PM

A billion threads isn't going to make a bit of difference if the speed of the process is limited by how fast the hard drive can deliver the data. Personally, I think people spend way too much time looking at the CPU utilization readout, the process goes as fast as it goes. Building peaks is a relatively simple process and I'm pretty sure the code is written to be as efficient as possible.

One could write some horribly inefficient code and peg the CPU at 100% yet still not execute the task very quickly. Perhaps it would be more satisfying to have the peaks build at the same speed but see the CPU utilization at 100%.

NormanPCN wrote on 12/23/2014, 2:55 PM

I just ran a trivial "test" of sorts.

A 51MB stereo WAV file took about 5 seconds uncached and <1 second cached to compute peaks.

A 3.7GB MP4 file with AVC video and AAC audio too about 23 seconds uncached and about 5 seconds cached.

In both cases the cached test run got 70+ percent utilization.

4GHz i7 4770k, single 7200rpm HD with nothing else going on.

VidMus wrote on 12/23/2014, 3:53 PM

"The speed of building peaks is almost exclusively a function of how fast the file can be read from the disk, the CPU has relatively little to do with it."

While disk access has the greatest affect on building peaks, the type of file also has an affect. An ac-3 compressed file will take a bit longer than an uncompressed wav file. The higher the bit rate of the compressed stream, the longer it will take to decompress.

Sequence for spinner drive, disk drive moves heads to seek sample, disk drive reads sample, CPU decompresses sample and creates a portion of the peak data, disk drive seeks file to add peak data to, disk drive writes peak file data, repeat until done.

The seek times of the disk drive and its reading and then writing is what causes most of the delays and slowdowns. Decompression adds a little bit of time that varies with how much work is needed to decompress each sample of audio.

When I say samples, I am referring to the small amount of audio it gets each time while building the peaks.

So it is a combination of disk access time and decompression time of each little bit of audio it works with.

Would a super fast CPU and full utilization of it make a difference? Yes, but nowhere near as much of an improvement that the much faster access from an SSD drive makes.

So if you want the greatest speed increase while building peaks, use an SSD drive.

OK, break time is over and now I shall go back to editing.

I have theater, wedding and Church service videos to do. So guess what I get to do for Christmas?

Merry Christmas and a Happy New Year to all. See ya'll later...

https://vimeo.com/channels/cocnwp

LSBrewer wrote on 6/26/2016, 10:51 AM

Where do I find this option to build audio peaks while importing files? Where do I find the option to build only audio peaks that are used on the timeline?

Stringer wrote on 6/26/2016, 1:11 PM

I discussed in this thread, how peaks built faster for me if I had a 2nd instance of Vegas open..

It did vary depending on the type of file..

http://www.sonycreativesoftware.com/forums/showmessage.asp?forumid=4&messageid=944809

relaxvideo wrote on 8/18/2022, 6:26 AM

Every hard drive slows down significantly when reading and writing at the same time on the same drive. Thats why ssd helps a lot! Just my 2cents. Would be nice to have a user changeable peak files folder on different drive.