What does Sample Purge do, exactly?

[Paul Russell]

Could anyone enlighten me on the exact functionality of sample purge?

I get that it strips samples from RAM in any one sampled instrument, but on what basis does it make the decisions on which ones to drop? Does Play review the notes, velocities and CC functions of the midi sequencer track which is feeding it for that instrument?

TIA

[A.Leung]

I always thought it was similar to Kontakt. it gets rid of UNUSED samples thus freeing up RAM. In other words why load into RAM every sample thats in a patch when say if your scoring a scene and the violins are playing three notes. Why take up 70 keys of samples when your song uses 3...

[Paul Russell]

Yes, that's what I mean. How does PLAY make that decision? Does it get it from the host, or from a list of recently played notes/articulations that it's keeping itself?

[jphilpit]

The way it works is that PLAY sets a flag on a sample each time that sample plays. And when you hit the Purge button on an instrument (meaning on an open .ewi file) all the unused samples are unloaded from memory.

Therefore, to use this feature you have to start with all samples loaded and then play the track at least once. As each sample is played, PLAY keeps track of those samples it uses. Then and only then, can you click on the Purge button to unload the unused samples.

Note that if you add or change a note, or even if you just change its velocity, there's the risk that the new note will not be sounded the next time you play the piece because the new note was purged. The way to solve that problem is to Reload the samples, Reset the flags (to their "unused" status), replay the whole track, and then Purge the samples again.

Note that it doesn't matter whether you play the track by itself or part of the whole piece. The flags get set either way for every sample played.

The use of the Purge feature works best in a sequencer because it will always play the same notes with the same velocities, therefore, the same samples. Playing from a keyboard, you're more likely to make variations--at least in the velocities--each time you play.

When I updated the PLAY System manual to include the new features of version 1.1, I wrote an extensive description of the Purge feature. If you downloaded the 1.1 upgrade, make sure you check out the new manual which was installed on your hard drive along with the software.

[playz123]

Thank you for that very clear and informative explanation.
In my case, it's not reading the manual that is a problem...I always do that....it's remembering everything that's IN the manuals for thirty plug-ins, and numerous other software packages that is my problem. :) :) So perhaps I should say instead; "thanks for the REMINDER".............playz

[Paul Russell]

Great explanation, thanks. I also have trouble remembering what's in the manuals despite reading them.
BTW, have you seen my car keys anywhere? :-)

[Bruno Garza]

The way it works is that PLAY sets a flag on a sample each time that sample plays. And when you hit the Purge button on an instrument (meaning on an open .ewi file) all the unused samples are unloaded from memory.

Therefore, to use this feature you have to start with all samples loaded and then play the track at least once. As each sample is played, PLAY keeps track of those samples it uses. Then and only then, can you click on the Purge button to unload the unused samples.

Note that if you add or change a note, or even if you just change its velocity, there's the risk that the new note will not be sounded the next time you play the piece because the new note was purged. The way to solve that problem is to Reload the samples, Reset the flags (to their "unused" status), replay the whole track, and then Purge the samples again.

Note that it doesn't matter whether you play the track by itself or part of the whole piece. The flags get set either way for every sample played.

The use of the Purge feature works best in a sequencer because it will always play the same notes with the same velocities, therefore, the same samples. Playing from a keyboard, you're more likely to make variations--at least in the velocities--each time you play.

When I updated the PLAY System manual to include the new features of version 1.1, I wrote an extensive description of the Purge feature. If you downloaded the 1.1 upgrade, make sure you check out the new manual which was installed on your hard drive along with the software.

I'm updated to the latest PLAY but the PLAY Document in my documentation directory doesn't have latest updated PLAY pdf with the purge description.
I just downloaded from here (http://www.soundsonline.com/updates.php) and this document does have the purge description.

The manual I did have was
Play System Manual.pdf

the one I just downloaded is
Play_System_Manual.pdf

Notice the underscore that's added to the name of the document.

I did a document properties from Acrobat but didn't see any reference to some sort of version number to correspond to the PLAY 1.1 or PLAY 1.2.3 update.

I did notice both documents have a different create date.
Is this the way we tell and is that posted somewhere (create date to PLAY update version number) or do we just go to the above link to get the lastest even after a PLAY update.

[jphilpit]

The newer manual (the one with the Sample Purge feature explained) has the text "Version of October 2008" on page ii (the page immediately following the title page).

I would guess that the underscores have been added only for the purpose of removing the spaces which are not allowed in a URL (or more accurately, will get converted to "%20").

John

[Bruno Garza]

The newer manual (the one with the Sample Purge feature explained) has the text "Version of October 2008" on page ii (the page immediately following the title page).

Thanks for the info on this.


I would guess that the underscores have been added only for the purpose of removing the spaces which are not allowed in a URL (or more accurately, will get converted to "%20").

John

Just a suggestion.
Since the built-in document properties for a PDF are for all PDF's and are in the same location, instead of me looking thru the whole manual for that "version description", I could just quickly look for that in document properties.

I have seen people use filenames and create date as a key to referencing what's the latest, that's why for PDF's I always look in the document properties for detail information.

I mean, you did put your name as the author. :D

It's probably best to zip the file as well.
Sometimes my browser hangs, but that's because Acrobat Reader is downloading the PDF and I have to wait till it downloads the whole PDF.

[jphilpit]

Yes, I could put a version number on the PDF. I'll do that the next time I release an update on an EastWest manual.

As to how it's delivered (as a zip or a PDF), that's up to the folks in the EastWest offices.

Thanks for the suggestions.

John

[Denny S.]

Wow, I must really live behind the moon for not being aware of a great feature like that. Although it's pretty time consumpting if you have over 50 patches loaded into multiple instances. What about a master switch regarding that? Or is it a lot more complex than I think to include that?

[Andrew Sigler]

Wow, I must really live behind the moon for not being aware of a great feature like that. Although it's pretty time consumpting if you have over 50 patches loaded into multiple instances. What about a master switch regarding that? Or is it a lot more complex than I think to include that?

+1

It seems like the sample purge would be much more useful as a universal command as opposed to a per-instrument command...same with choosing between 16bit and 24bit samples in Plat +...

[jphilpit]

While there are cases where being able to purge all instruments at once would be more efficient, it's best to remember that this feature is most likely to be used while the musical piece is still being modified. And every time you make even one change to a track, even something as small as changing the velocity of a single note, you have to at least reload the whole track--and, if you want, re-purge the whole track--before you can play the piece and be confident the changes will play.

And while you're making multiple changes to a track, you will probably want to leave that one track un-purged so that all the samples are loaded, only re-purging the track at the end of the changes. In fact, any track that is likely to get frequent changes should be left un-purged.

There's actually no benefit to purging samples at the end, because if the piece played without sample-loading problems for every test playback, it will play fine when you're ready to capture the project as audio. So we're only talking about needing this feature for projects too large to load all samples all the time. In this case, you do NOT want to be purging all samples at once and then reload all samples at once, because the reload will always fail. You want to be working on only a few instrument at a time, doing so only on the instruments you're changing.

So, while it might be occasionally useful to have a Master Purge button in the UI, in real life you'd use it less often than you might at first think.

[Andrew Sigler]

Hey John,

Your description of universal vs partial sample purge makes sense and certainly speaks to present and future audio systems running PLAY where one might have the occasional hiccup. In my case I would still like to have the universal option. I'm still (at least for another few months) running an older system and on occasion have to deal with dropouts and so forth, especially with PLAY and Omnisphere. I can 'hear around it' but would like to be able to click sample purge before rendering just to clear up those few hiccups that occur.

Having said that, PLAY is really set up for a more powerful system (I am within spec though!) and sample purge will hopefully be a moot point for all of us soon enough :)

Andy

[gstitt]

Here's what I'd really like. Instead of having to reload all samples and then purge when I add new notes, it would be nice if Play could adjust the sample pool based on what is being used. In other words, it could potentially analyze the "played, but not loaded" samples and just load those.

Admittedly, I haven't messed too much with the feature. Can it already do this? To me this would be much more useful, because I could start with just about everything purged, and then just load the necessary samples as I need them (instead of repeatedly loading all samples and purging). Since there are already flags for "used" and "loaded", it seems like this wouldn't be a difficult extension.

[chest]

If a Play track in a (Cubase) sequence is purged and then the sequence is saved and re-opened, will all the samples be re-loaded or just the ones remaining after the purge?