Rendering tracks as stem tracks

[dkeatscary]

I'm trying to conserve CPU on a guitar solo track, and am rendering it down to a stereo track. If my solo is less than 10 seconds long, why does it take nearly 3 minutes to render the track? Can Reaper not tell that there's only a small audio item on the track?

I'm not sure if I'm making sense but this has always irked me, and I wish that I understood why Reaper trends rendering in this fashion.

Thank you!

[dobro]

Is it possible to highlight just the portion of the whole song that contains your solo? And render the highlighted portion?

[dkeatscary]

Originally Posted by dobro

Is it possible to highlight just the portion of the whole song that contains your solo? And render the highlighted portion?

Damn, hadn't even thought about that. I'll try it out. Thanks!!

[ngarjuna]

When stem rendering takes place it actually renders everything that's live if I'm not mistaken (it just only writes what you've selected to disk). Disabling FX that don't affect the track you're rendering is another way to speed things up.

[EricM]

Currently, stem render

1/ starts at the beginning of the project and ends
at the very last project item (time selection etc. is disregarded)
2/ processes all active tracks, even though it's rendering
one track only, which is a huge CPU inefficiency with large
projects (can be avoided by manually muting other tracks,
and having the "do not process muted tracks" preference on)
3/ has no settings to change this behavior

Use Apply FX instead, and use macros to speed up the process.
Search the forum for "freeze tracks" macros

There is a FR to rectify that, probably happening for Reaper v4.

e

[kindafishy]

Originally Posted by EricM

Currently, stem render

1/ starts at the beginning of the project and ends
at the very last project item (time selection etc. is disregarded)
2/ processes all active tracks, even though it's rendering
one track only, which is a huge CPU inefficiency with large
projects (can be avoided by manually muting other tracks,
and having the "do not process muted tracks" preference on)
3/ has no settings to change this behavior

Use Apply FX instead, and use macros to speed up the process.
Search the forum for "freeze tracks" macros

There is a FR to rectify that, probably happening for Reaper v4.

e

Careful with Apply FX, as it negatively affects sound quality. It is fine to do just to work on another area of the song, but if you are actually in a mixing stage, you should either bounce or stem render.

As others have said, it is because it renders the whole track. Apply FX is significantly faster, but keep the above in mind.

[EricM]

Originally Posted by kindafishy

Careful with Apply FX, as it negatively affects sound quality.

In what way, and which circumstances?

[kindafishy]

Originally Posted by EricM

In what way, and which circumstances?

Rather than regurgitating what is already written...

http://forum.cockos.com/showthread.php?p=593458

[ngarjuna]

Originally Posted by kindafishy

Careful with Apply FX, as it negatively affects sound quality. It is fine to do just to work on another area of the song, but if you are actually in a mixing stage, you should either bounce or stem render.

As others have said, it is because it renders the whole track. Apply FX is significantly faster, but keep the above in mind.

Originally Posted by kindafishy

Rather than regurgitating what is already written...

http://forum.cockos.com/showthread.php?p=593458

The thread you posted cites the following disadvantages to Apply FX:
1. Per item (can cause different behavior on overlapping items)
2. Item gain changes are applied
3. Applies fades

While I can appreciate why someone might want to avoid some or all of those conditions, none of that has anything to do with the sound quality. I think that's a bit misleading; there are implications based on workflow that one should watch out for vis-a-vis Apply FX but that's far different from saying it's an inferior sound quality.

Since Apply FX doesn't take other track effects into account and can be performed on items of any size (operating only on the item itself), there is a pretty major advantage to using it: it's a hell of a lot faster than stem renders.

[EricM]

Originally Posted by kindafishy

Rather than regurgitating what is already written...

http://forum.cockos.com/showthread.php?p=593458

Ah ok, aware of this issues, but nothing quality wise
if you do it properly with a macro on a new track.
Just different (unexpected?) result.

But yeah, inconvenient, and a lot of macro work if you
have to create it yourself. But doable

e

[kindafishy]

Originally Posted by ngarjuna

The thread you posted cites the following disadvantages to Apply FX:
1. Per item (can cause different behavior on overlapping items)
2. Item gain changes are applied
3. Applies fades

While I can appreciate why someone might want to avoid some or all of those conditions, none of that has anything to do with the sound quality. I think that's a bit misleading; there are implications based on workflow that one should watch out for vis-a-vis Apply FX but that's far different from saying it's an inferior sound quality.

Since Apply FX doesn't take other track effects into account and can be performed on items of any size (operating only on the item itself), there is a pretty major advantage to using it: it's a hell of a lot faster than stem renders.

It's not misleading at all. Read my second post.

[kindafishy]

Originally Posted by EricM

Ah ok, aware of this issues, but nothing quality wise
if you do it properly with a macro on a new track.
Just different (unexpected?) result.

But yeah, inconvenient, and a lot of macro work if you
have to create it yourself. But doable

e

It is absolutely a quality problem in my experience. YMMV, but I just wanted to put it out there so others don't experience the same issues I did.

If it works for you cool, it probably just comes down to giving the render a listen to make sure it sounds as you expect.

[EricM]

of course, depends how you define quality I just don't see the
contextual behavior difference of the function as a quality loss, as
it produces identical results if used in the same manner
(one item, resetting the fader & fades etc.). It does not have an issue
with noise, bad resampling, bit-loss or distortion or something one
usually says it's a quality loss.

Other than than I perfectly agree

[ngarjuna]

Originally Posted by kindafishy

It's not misleading at all. Read my second post.

That still sounds like a bug, not a difference in quality. I don't doubt that there are plugs which might not behave themselves with Apply (it seems to me I had some trouble with Melodyne using Apply FX once although I can't recall exactly what happened) but that's not a quality difference between two examples with intended behavior.

Curious, I decided to try some real world comparisons.

When I tried just a gain trim plugin (JS), reducing by 3dB, the two were identical (nulls down to -inf).

When I tried a compressor (Voxengo Marquis), same deal, nulled to -inf.

Same with Stillwell Bombardier, total null between render and apply.

Same with SSL's LMC.

Same with ReaEQ.

Null to -inf is identical, it's the same render and the same render quality; even a tiny difference would show up as a non-null.

The only way I could get the two not to null was to use an effect with non-linearities (none of the tests with Nebula saturation nulled higher than -45 or so), but that makes sense without suggesting a quality difference. Same with time based effects.

[kindafishy]

Originally Posted by ngarjuna

That still sounds like a bug, not a difference in quality. I don't doubt that there are plugs which might not behave themselves with Apply (it seems to me I had some trouble with Melodyne using Apply FX once although I can't recall exactly what happened) but that's not a quality difference between two examples with intended behavior.

Curious, I decided to try some real world comparisons.

When I tried just a gain trim plugin (JS), reducing by 3dB, the two were identical (nulls down to -inf).

When I tried a compressor (Voxengo Marquis), same deal, nulled to -inf.

Same with Stillwell Bombardier, total null between render and apply.

Same with SSL's LMC.

Same with ReaEQ.

Null to -inf is identical, it's the same render and the same render quality; even a tiny difference would show up as a non-null.

The only way I could get the two not to null was to use an effect with non-linearities (none of the tests with Nebula saturation nulled higher than -45 or so), but that makes sense without suggesting a quality difference. Same with time based effects.

Fair enough. You did far more investigation into it than I did in the first place (thanks). I just heard 'bad stuff' and went back to my old tried-and-true method of freezing.

I'll give it another chance. It is very convenient and much faster. I'll pay more attention and keep this thread in mind if I find any specific plugins causing problems.

Sorry for the FUD. It wasn't my intention...

[ngarjuna]

Originally Posted by kindafishy

Fair enough. You did far more investigation into it than I did in the first place (thanks). I just heard 'bad stuff' and went back to my old tried-and-true method of freezing.

I'll give it another chance. It is very convenient and much faster. I'll pay more attention and keep this thread in mind if I find any specific plugins causing problems.

Sorry for the FUD. It wasn't my intention...

No problem, you scared me there for a second is all!

Based on your report and my faded recollection of that Melodyne issue, it does make me wonder if the Apply is potentially more bug prone than Render, which could very well be the case.

[EricM]

Originally Posted by ngarjuna

No problem, you scared me there for a second is all!

Same here!

[trialstech]

Thanks for the info everyone on Stem and Apply FX, this helps me too.

Also, wow I really am a newbie! My progress with learning Reaper and having time to work on things has been slow.

I just figured out yesterday that making track folders and rendering everything in the folder to stem track (instead of each track one by one) is really handy for example a pair of doubled backup vocals.

I love the software though, hope to get more time on it.

I'm finding that my CPU processing % doesn't give out as soon as my disk I/O once a project starts becoming littered with a lot of tracks and takes. Hence my idea to stem them down to new tracks to try to conserve resources.

[Sheppola]

Originally Posted by trialstech

I'm finding that my CPU processing % doesn't give out as soon as my disk I/O once a project starts becoming littered with a lot of tracks and takes. Hence my idea to stem them down to new tracks to try to conserve resources.

This is good practice anyway.There's no point having loads of VSTs running live if they have already been used to create a good track IMHO.If you have used several VSTs on a track to create what you need save them as a,"Chain" then you can call them back when needed for another project.I usually save mine with the song name and say add the word Vox/Git so I know the reference point.

[Steve36]

Hi all...Most of you probably know this, but I just thought I'd mention something that I discovered yesterday (whilst stem rendering a heap of 'Nebula' loaded drum tracks)...It was taking 20 minutes or so to render some of the tracks that I'd edited heavily (ie: Kick drum,snare) so I figured I'd try glueing them and, sure enough, back down to 1 and a half minutes or so...and definitely solo the tracks you wish to render...also pretty nifty
how you can render one track or five at once and takes about the same time...Beats rendering one at a time at 20 mins each...!!!

Steve...

[dkeatscary]

Hi Steve - count me as one who did not know that! Thank you.

[Steve36]

You're most welcome...

Steve

[dobro]

In stem rendering, what does 'stem' refer to? The original track or the new track?

[JamesMK]

^ the new track.

[dobro]

Originally Posted by dkeatscary

Damn, hadn't even thought about that. I'll try it out. Thanks!!

Did you ever get this to work? In File>Render, you can select Render Custom instead of Render Entire Project, and this allows you to manually enter time values of what you want rendered. Cumbersome, yeah? So, that's why I wanted to know if you found a better way.

[dobro]

Originally Posted by JamesMK

^ the new track.

So, it's the stem that goes to the destination folder in the end? Okay.

[gofer]

Originally Posted by dobro

Did you ever get this to work? In File>Render, you can select Render Custom instead of Render Entire Project, and this allows you to manually enter time values of what you want rendered. Cumbersome, yeah? So, that's why I wanted to know if you found a better way.

If you have a time selection in your project you can also select "Render time selection" in that same dialog.

Alas that's not possible with "Render tracks to stem tracks" in the Track menu. Maybe it would be cool if there was such an option. Everything from start of project until time selection start could just be filled with zeros (as otherwise it wouldn't be a stem).

[EricM]

Originally Posted by gofer

If you have a time selection in your project you can also select "Render time selection" in that same dialog.

Also if you change this in your default RPP project, Reaper will
check this box automatically if there is a time selection
otherwise it will render entire project.

Originally Posted by EricM

Change this in your default .rpp file:

RENDER_RANGE 1 0.00000000000000 0.00000000000000
(or whatever the 0.00.. values are)

to

RENDER_RANGE 2 0.00000000000000 0.00000000000000