[ANSWERED] Best practice for resizing assets

DG22

Hi all, I'm needing some feedback before making some major changes to the resolution of my assets and project...

The current set up is:

iMAC 2017, thunderbolt to optical HDMI connections to projectors
2 stages/2 projectors: front of house and rear position. Projectors are identical.
Although my projector native res is 1920x1200, I started with a res of 1920x1080 to maintain a HD standard (This will be a touring production), the aspect ratio fits the scenery best, it's easier to find standard stock media, and that res matches external monitors.

I found out that we need to output 1920x1200 to get a bigger image height from the rear projector because of throw distance limitations. Because the assets are essentially the same across both stages, my questions are:

To avoid the headache of managing 2 res sizes per file, should I change the resolution of ALL assets and stages to 1920x1200? For Stage 1 / FOH, 1080 height is perfect so there will be wasted pixels but this seems to not matter so much if it saves me time wrangling media.

Alternatively, I could keep media as is and just scale up in Isadora for Stage 2 /Rear. I'm worried about how the iMAC will perform but could do some additional testing.

mark_m

@dg22

What kind of images are your assets?
Would the audience notice if they were slightly stretched on the vertical if you rescaled to stretch 1080 pixels to 1200 pixels?

Unless my images were perfect circles or the human form that’s what I’d do. I can’t imagine it’d put much stress on your computer, but test and see.

It’s a source of constant bemusement that people often don’t notice a 4:3 image being stretched to 16:9 and vice versa, so you expanding yours from 16:9 to 16:10 will almost certainly go unnoticed.

HTH

Mark (not to be confused with Mark)

DG22

@mark_m thanks so much! The content is mostly skies, starfields and landscapes so yeah it would take a keen eye to see this difference. I do worry about the computer but I will test the machine and see how it goes. If I keep everything pretty simple ie. minimize the number of projector actors and layers, set up should be pretty safe. At most I think there would be 3 projector actors sent to that stage - sky, clouds and foliage. The touring aspect definitely needs to be considered and hopefully, we'll have more distance in other venues. Thank you!

DG22

@mark_m thoughts on projectors... how will it really affect Isadora's performance to change this projector's res from 1920x1200 native to 1920x1080? We did this last week and playback was fine! I'm just finding it hard to get answers on how/if changing output resolutions affects performance- I think it matters most if you're sending different resolution assets because Isadora has more work to do- but your opinion would be greatly appreciated! THANK YOU!

Woland

@dg22

I see that you sent in a ticket asking about this but we prefer to answer questions like these on the forum because that way other Isadora Users can see the answers and benefit from the information as well.

The text of what you sent in the ticket was similar to your post here but I've copied over your ticket text, put it below, and will answer as best I can here.

Overall you may also find this article helpful: https://support.troikatronix.com/support/solutions/articles/5000692142

@DG22 wrote:

My current set up is:
- iMAC 2017, thunderbolt to optical HDMI connections to projectors
- 2 stages/2 projectors: front of house and rear position. Projectors are identical.
- Although my projector native res is 1920x1200, I started with a res of 1920x1080 to maintain a HD standard (This will be a touring production), the aspect ratio fits the scenery best, it's easier to find standard stock media.

With only two outputs I wouldn't expect to see much of an impact if Isadora has to scale your video up or down a bit, but it really depends on how many videos you are playing simultaneously and what wrapper & codec you've used. If you see a problem with playback when scaling your video, then you can either try converting your media to a different wrapper and codec (e.g. from h264.mp4 to hap.mov) or try converting your media's resolution so that you don't have to scale it.

In my experience, here's a list of things that will affect playback more than your videos having to be scaled, in order of how much impact they have:

How powerful the computer you're using is.
1. I wouldn't expect to have trouble sending to two HD outputs from a 2017 iMac unless you're playing lots of videos at the same time, have very heavy video effects going on, or have a bunch of high-resolution live video inputs going on.
Number and resolution of discrete video outputs (more outputs & higher resolutions = more impact)
1. For you, with just two outputs, this shouldn't be a problem.
Number and resolution of video files playing simultaneously (more videos & higher resolutions = more impact)
1. The resolution of your video files should be fine, and though it would technically be more efficient to not have to scale any video, in my experience the number of video files playing simultaneously will have more of an impact.
Wrapper and codec of video files (I find I get the best performance from hap.mov, hapa.mov, and hapq.mov)
1. It sounds like h264.mp4 is fine for what you're doing, but if you encounter issues, try switching to hap.mov.
Location from which you are playing the video files (an internal SSD drive is much faster than an external HDD)

@DG22 wrote:

I found out that we need to output 1920x1200 to get a bigger image height from the rear projector (Stage 2)because of throw distance limitations. Because the assets are essentially the same across both stages, my questions are:
- Should I keep media as is and just scale up in Isadora for Stage 2 /Rear. I'm worried about how the iMAC will perform but could do some additional testing.

Ideally, you want to be sending 1080p video to a 1080p display, but if you're not seeing any performance problems using your current setup, you should be fine. Testing is always good though.

@DG22 wrote:

For Codecs, I'm finding that H264 are running fine and have a lower load- they do not have alphas and are straight playback forwards. Is there any reason to change to codec to HAP? I went from 99MG to 1.5GB for one file!

Given that you are running without alpha and just doing playback at speed 1, I wouldn't expect you'd need to switch them to hap.mov unless you were seeing performance problems with the h264.mp4 files.

@DG22 wrote:

Lastly, how will it really affect Isadora's performance to change my projector's res from 1920x1200 native to 1920x1080? We did this last week and playback was fine! I'm just finding it hard to get answers on how/if changing output resolutions affects performance- I think it matters most if you're sending different resolution assets because Isadora has more work to do- but any clarification would be great!

If you're saying that you've gone into System Preferences > Displays and changed the actual resolution of the projector you've got connected to 1080p and you're sending it 1080p video from Isadora, then Isadora isn't doing any video scaling and therefore it won't affect performance at all.

If you're talking about scaling the video in Isadora up from 1920x1080 so it can be sent to a physical projector set to a resolution of 1920x1200: Everything involving performance varies depending on your hardware setup, your media, and how complex/demanding your Isadora file is. All we can do is give advice on what generally works best, we can't tell you exactly how scaling will affect performance with a specific setup; you'd need to experiment in order to find out exactly what works best for your setup. That being said, while scaling takes work, if you're not seeing performance issues in your current setup then you should be fine. Yes, things could always be made more efficient, but that doesn't mean that you should make a change if you're not seeing any problems running things the way you already are.

Best wishes,

Woland

DG22

@woland Thank you so very much for all of this, SUPER HELPFUL! I'm enjoying learning this software so much and yes that article helped a lot!