Working in FLAC. Too CPU intensive or not?

[Ice]

Certainly, the power of our computer can change this result wildly.

I'm just curious how much harder than .WAV is it to use FLAC as a native format?

I know I know, disk space is cheap, use .WAV I'm just curious.

[serr]

Best performance is wav files on a SSD.

I'll archive my projects to FLAC and put them on a 7200rpm HDD. If I open one up in a pinch in that state and just hit play, it just works. If I were to try seeking around wildly like you might do when in an editing frenzy, NOW I get the little half second lags here and there. Especially if you zoom in past the range of the peak images!

When I first started running live sound with Reaper it was on a C2D machine. A SSD was required if I wanted to record multitrack at the same time while running the live sound. 95% CPU use on that last generation machine. FLAC would not have been an option in that scenario.

Editing/seeking or doing anything that's already pushing your system would make FLAC a poor choice. You'd be none the wiser with mundane projects.

[cassembler]

I asked same question a while back, and ended up doing some testing.

TL;DR - no, the only real disadvantages to flac are:
1) Limited to 24 bit depth (meaning clipping is a risk)
2) If you collaborate or work with folks who can't handle flac

Otherwise, literally no material difference in performance (*except drawing the initial waveform image). I'm still surprised, but I welcome anyone to validate the results.

See Post#15:

https://forum.cockos.com/showthread....72#post2062972

[Ice]

Originally Posted by cassembler

I asked same question a while back, and ended up doing some testing.

TL;DR - no, the only real disadvantages to flac are:
1) Limited to 24 bit depth (meaning clipping is a risk)
2) If you collaborate or work with folks who can't handle flac

Otherwise, literally no material difference in performance (*except drawing the initial waveform image). I'm still surprised, but I welcome anyone to validate the results.

See Post#15:

https://forum.cockos.com/showthread....72#post2062972

Cool thanks for pointing out the other thread and the tests!

[phNord]

Would recording 16 tracks to FLAC on a relatively well-powered cause a ton of CPU overhead during the process, or should I not worry about it?

Context:

I have a residency I run & perform in every Sunday night. It's a big jam session, I end up at times using almost every channel on the Behringer X Air X18 Mixer. I've been recording the shows for archival purposes, and to be safe I tend to record every channel of the 16, in case people pop-in later so I can set-and-forget REAPER until the show is over

I'm currently recording in 44.1K 24-bit wav. After the shows, sometime during the week, I end up loading up the project file and batch-processing them all down to 24-bit FLACS, getting rid of the wavs

Problem is this is taking up a lot of space on my SSD until I get around to archiving it, and that's not great as I sometimes forget to. Moreover, last week I managed to eat-up my whole free-space on my SSD and lost the end of the show

The reason I haven't just been recording straight to FLAC as of yet:

I am *ALSO* using my computer to stream the video of the show. I do so through OBS, and it hogs a lot of CPU. It also archives the video locally, just in case, so it's writing to the disk as well

I haven't hit any CPU or RAM issues... at this point. My computer is a 2017 MBP with a 3.1 Ghz Quad-Core i7, 16 GB of 2133 MHz RAM, an internal 1TB SSD, etc.

But I'd like to start making my process more efficient by recording straight to FLAC in REAPER.

I imagine that *should* be fine? I can't imagine FLAC taking a ton more CPU overhead to encode in real-time than recording in WAV; I imagine it will be negligible on my computer?

But if I am wrong about that, I don't want to lose a show to my computer stuttering, and I won't really have an opportunity to test-run it outside of a gig...

... so I'd love advice / insight

[serr]

If you're just recording with Reaper and not running the live sound with it - using the XR18 instead for the live mix - the computer is only idling. There's no performance to even consider.

If you were running the live mix with Reaper, now you might have to consider the extra CPU hit. It's live sound in front of an audience. So that would lead me to avoid inviting trouble and just flac the files after the show. Use an app like XLD and it's a quick drag/drop.

Live sound usually gets into low latency settings and pushing a couple bigger plugins through that. Don't want to take extra risks in front of live audiences! The computer isn't really doing anything when just recording. (With 'don't care' high latency settings and no plugins.)

[MiddleC]

Originally Posted by Ice

I know I know, disk space is cheap, use .WAV I'm just curious.

What was that? Didn't hear you.

Anyway, disk space is cheap. Use .WAV.

At 17MB/minute at 48khz, lessee...

64GB storage = 64,000MB / 17 / 60 = 62 hours

FLAC halves the space needed, but at a PITA cost.

[Ice]

Originally Posted by phNord

Would recording 16 tracks to FLAC on a relatively well-powered cause a ton of CPU overhead during the process, or should I not worry about it?

I just did a quick test. It might be a little unfair as it's on a Mac M1 Studio Ultra, in a completely empty project (no plugins). It was recording to an external 16TB drive that isn't terribly fast.


24 stereo tracks all in record. 24-bit 48k

Performance Meter reported:

IDLE - CPU 2.4% (cur/avg: 2.38/2.22%. range: 2.1-2.5%)
WAVE - CPU 3.0% (cur/avg: 2.96/2.47%. range: 2.1-3.0%)
FLAC - CPU 3.4% (cur/avg: 3.43/2.92%. range: 2.1-3.7%)

FLAC was set to compression 5 (default)

It looks pretty negligible to me and this is 8 more tracks than your example. But this computer is pretty grunty. My guess is it'll be fine.

Good luck!!!

[jamesp]

Originally Posted by phNord

Would recording 16 tracks to FLAC on a relatively well-powered cause a ton of CPU overhead during the process, or should I not worry about it?

Don't worry about it - I've done 16 tracks of FLAC at 96KHz 24 bit on my old 2004 vintage XP laptop and it worked reliably. The increase in processor power needed is compensated to some extent by the decrease in disk traffic. When you are recording high sample rate multitrack for hours on end the difference in disk space is many GB when using FLAC.

[ayskura]

I only record FLAC since many years, big projects, recording often live multitracks of 32 channels, playbacks of 50+ tracks, all in flac, render in flac, process in flac, nothing but flac. Never an issue with it, even on opld machines like a Mac Pro 2006, or very old laptops. Even on Raspberry pi I can playback 24+ track in Flac without any issues.

on the plus side, when playing from old hard drives, computer seem to be snappier with bigger project, probably because they need to read less data from HD.

For my point of view WAV/AIFF formats are DEAD long time ago

[ayskura]

forgot to add: I have settings of FLAC in Reaper as Maximum compression /Slowest. It's really incredible, projects of 20GB, become less than 10 easily.
I can have full albums to work on, my limited laptop SSD etc, really amazing

[F1308]

Originally Posted by ayskura

forgot to add: I have settings of FLAC in Reaper as Maximum compression /Slowest. It's really incredible, projects of 20GB, become less than 10 easily.
I can have full albums to work on, my limited laptop SSD etc, really amazing

I render using FLAC and MP3 simultaneously.

The first to grant quality and the second to avoid the file going over 20 MB so as to be able to send it via Gmail.

😀😀😀😀
🎹🎹🎹🎹

[/AND/]

I started using FLAC and WavPack predominantly for recordings, takes and comping, and anything requiring huge audio files. (I actually prefer WavPack, but BitWig sadly doesn't support it yet. Reaper does, however)

Haven't noticed a hiccup in performance, and frankly I've saved SO MUCH SPACE while keeping everything lossless. In my opinion, go full on FLAC/WP.

[/AND/]

If there was a way to convert my whole sample library to FLAC/WP somehow, and my projects be able to discover the files automatically, I'd do it without a second thought.

[serr]

Originally Posted by /AND/

If there was a way to convert my whole sample library to FLAC/WP somehow, and my projects be able to discover the files automatically, I'd do it without a second thought.

XLD (X Lossless Decoder) will batch convert. Drag/drop a whole folder of files and walk away.

Reaper has some intelligence with replacing files. 'Browse' for the first missing file in the missing files dialog and select the new flac file with the same name. Reaper will look in the same directory for the rest of the files and go by name replacing them unprompted.

That will lead to a quick browse to open every project the first time after that format change. PITA perhaps but not the worst!