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DavidPatrick

NewTek NDI with Alpha

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I've notice when adding an NDI media element there's an option to choose one with an Alpha channel. Can someone give me more information about this? How do you output the NDI stream so it supports the alpha channel? In my quick looking in the NDI Scan Converter tool there doesn't seem to be any options for this. Is there specific hardware / software which supports this? 

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I had a write up a while back that shows how this can be done either using the dynamic image server or a separate software called vMix, in conjunction with PIXILAB Moments for creating audience interaction based on their mobile phones. More here:

Mike

 

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I'm considering using the NDI VLC plugin to play clips. The biggest thing is I need to be able to trigger my main timeline and my alpha clip at the same time, so my third party playback software needs to accept TCP commands I can place in my WO timeline. 

@Mike Fahl Thanks. I read the article, but as I understand it Dynamic Image Server won't play back video files, only stills, flash and HTML5. In my case they'd need to be actual videos I think. I wish DIS would support video, especially since it's based on NDI now. 

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40 minutes ago, DavidPatrick said:

I'm considering using the NDI VLC plugin to play clips. The biggest thing is I need to be able to trigger my main timeline and my alpha clip at the same time, so my third party playback software needs to accept TCP commands I can place in my WO timeline. 

You could try UNIVERSE. It can control WATCHOUT and VLC from one GUI.

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You didn't say specifically that you needed to play video. What video format do you want to play that contains an alpha channel?

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Hi DavidPatrick,


Just a stupid question and I’m curious: Watchout is a media player and it's totally designed to play video, so why do you want to use an other software to play video and stream it to Watchout?
I had tested the streaming from VLC in NDI but just for geek testing purpose. I don’t see why you could need it...

Best,

Benoit

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@Benoit That's fair. In this case it's for speaker titles during a show. The client wants nice, animated titles, but may not know the order or even the name of all the presenters before the show starts. Since Watchout will be live to screen, I won't be able to ingest new media later in my timeline without interrupting what's already live to screen. This means someone from the content team would render titles during the show, then we would live composite those with existing backgrounds. We can do this with a downstream key in a high res switcher (E2, Spyder, etc), but I was researching options to keep it all inside of Watchout, reducing the complexities to a single operator. NDI seems perfect if I can fit all the pieces together.

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A further update:

The NDI plugin for VLC only works with VLC 2.x. (An update to NDI is supposedly coming...) However, alpha channels are only supported in VLC 3.x. I have some other options for an NDI source, such as Millumin and ProPresenter, but have not dug into those.

I think the death nail on this may be sync. Even if I can have a simultaneous fire of both Watchout and my second video source, I don't believe the NDI feed will ever sync with the video pieces local to the display machine. 

I also attempted to use the NDI Scan Converter app on a display machine to have Watchout act as the NDI output, but apparently when Watchout goes full screen it prevents NDI from sending the content. I was only able to see black.

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When I was looking at different playback software to try and find a solution to the seamless loop issue (http://forum.dataton.com/topic/2838-getting-out-of-a-loop-at-the-end-of-loop/) I discovered Mitti (https://imimot.com/mitti/) which not only makes the looping question very easy to manage, but can also output NDI with an alpha channel and can be controlled with network/midi/dmx commands (although sending OSC commands from Watchout is still a sore point). I managed to get a 6400x1200px HAP alpha file playing smoothly over my Watchout background using an NDI input. More expensive than VLC - obviously - and some of the alternatives, but I'm still tempted to buy it because it seems both versatile and very simple to use.

 

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@matkeane Thanks. I'll give it a look - that might be a good option.

@Benoit I'm currently running WO 6.2.2, but can't see a way to load a video into DIS. Inside the program you are limited to JPG, TIFF, PNG, SWF, or HTML. And inside WO, you can choose image, flash, HTML, or Desktop. I'd love if DIS supported video files - doesn't seem like a stretch to incorporate them. 

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I doubt attempting to play video through the dynamic image server will perform well. However, WATCHOUT does support playing video using a video proxy pointed at a web server. Assuming you can place the rendered video file on a web server, this may be an option. 

Since the OP's question was related to text titles, another option could be to use a title generator. I assume those can be found that can output NDI too. 

Finally, depending on your needs, you may not need video if all you want is a text title. We've done dynamic text like this for WATCHOUT with Blocks on a couple of occations. Blocks provides control over how the text is formatted (size, styles, fonts, colors, etc). The result is rendered to an image (with proper alpha channel), which can then be loaded dynamically into WATCHOUT using an image proxy.

Mike – http://pixilab.se

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I'm not sure if this idea has been posted, but I did some testing of NDI in WO last year and I was able bring in a separate computer with After Effects running on it and composite with transparency that was pre-rendered.  WO saw the transparency.

 This would potentially allow you to have AE composites with titles pre-built of speaker that are known and quickly assemble new composites while the creation computer is not live of other speakers.  Then WO would simply open the NDI capture when the title is ready to play.

Here is where I learned how to make this happen on the AfterEffects end.  -  https://www.newtek.com/blog/2017/05/01/newtek-ndi-for-adobe-creative-cloud-applications/

I made this video for my friend that sent me the transparency file to show him how it worked.   -   https://vimeo.com/277200668

Hope this helps.

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