[borealcat]

(Also posted in feature request forum, posting here in case any current capabilities natively or through plug-ins)

Curious whether this would possible for art gallery 3D video installation:
synchronised simultaneous playback of separate stereo3D 24fps frame-packing video files to separate projector outputs.

Synchronised playback of side by side 3D files is possible with players such as VLC, however only for regular 2D content, or compressed side-by-side 3D content fitting into 1920x1080p frame, which cuts resolution in half.

Kodi playing frame packed 3D content natively is very interesting for maintaining high image fidelity.... just need to be able to synchronise multiple files to multiple screens (2-3). Anyone out there familiar with whether such plugins exist, or the coding this would require?

[te36]

(Also posted in feature request forum, posting here in case any current capabilities natively or through plug-ins)

Curious whether this would possible for art gallery 3D video installation:
synchronised simultaneous playback of separate stereo3D 24fps frame-packing video files to separate projector outputs.

Synchronised playback of side by side 3D files is possible with players such as VLC, however only for regular 2D content, or compressed side-by-side 3D content fitting into 1920x1080p frame, which cuts resolution in half.

Kodi playing frame packed 3D content natively is very interesting for maintaining high image fidelity.... just need to be able to synchronise multiple files to multiple screens (2-3). Anyone out there familiar with whether such plugins exist, or the coding this would require?

How accurate does synchronization need to be ? 

If its just in the order of 1 second or so, then you probably just need to write some script that some of the remote control APIs of kodi to start playback of video clips at the same time.  

how would the videos be displayed anyhow ? 3D tv screens with active glasses ?

[borealcat]

(Also posted in feature request forum, posting here in case any current capabilities natively or through plug-ins)

Curious whether this would possible for art gallery 3D video installation:
synchronised simultaneous playback of separate stereo3D 24fps frame-packing video files to separate projector outputs.

Synchronised playback of side by side 3D files is possible with players such as VLC, however only for regular 2D content, or compressed side-by-side 3D content fitting into 1920x1080p frame, which cuts resolution in half.

Kodi playing frame packed 3D content natively is very interesting for maintaining high image fidelity.... just need to be able to synchronise multiple files to multiple screens (2-3). Anyone out there familiar with whether such plugins exist, or the coding this would require?

How accurate does synchronization need to be ? 

If its just in the order of 1 second or so, then you probably just need to write some script that some of the remote control APIs of kodi to start playback of video clips at the same time.  

how would the videos be displayed anyhow ? 3D tv screens with active glasses ? 

Hi there, sorry slow reply as was off grid for a while. Synchronisation in order of one second would be fine for the content. However I have learned that synchronisation of active shutter glasses across multiple projectors requires the videos to play back as the same, ie frequency needs to be identical, as though they are the same file. (if this is not done, then the glasses sync between projectors differs, with unacceptable results when looking from one screen to another)

I have succeeded with this by creating a two channel compressed side by side 3D video file, where two sbs videos fill the frame that is 3840x1080, and spans two screens, one video appearing on each screen, and perfectly synchronised since they are embedded in the same video file. This level of synchronisation is what i would also need to accomplish in a  frame-packing environment, which would double the resolution. 

Alas, I know nothing about writing code.

[te36]

I have succeeded with this by creating a two channel compressed side by side 3D video file, where two sbs videos fill the frame that is 3840x1080, and spans two screens, one video appearing on each screen, and perfectly synchronised since they are embedded in the same video file. This level of synchronisation is what i would also need to accomplish in a  frame-packing environment, which would double the resolution. 

Alas, I know nothing about writing code. 

This setup is using some video splitter that takes the 3840x1080 and outputs two synchronized 1920x1080 videos ?

Alas it seems to be impossible to buy consumer passive 3D monitors anymore. Maybe there are commercial monitors. With 4K resolution, they would also provide Full HD resolution (consumer 4K displays from ca. 2014-2-16 did support this). With passive 3D you could have viewers with cheap passive 3D glasses and would not have to worry about active signal synchronization.

[borealcat]

I have succeeded with this by creating a two channel compressed side by side 3D video file, where two sbs videos fill the frame that is 3840x1080, and spans two screens, one video appearing on each screen, and perfectly synchronised since they are embedded in the same video file. This level of synchronisation is what i would also need to accomplish in a  frame-packing environment, which would double the resolution. 

Alas, I know nothing about writing code. 

This setup is using some video splitter that takes the 3840x1080 and outputs two synchronized 1920x1080 videos ?

Alas it seems to be impossible to buy consumer passive 3D monitors anymore. Maybe there are commercial monitors. With 4K resolution, they would also provide Full HD resolution (consumer 4K displays from ca. 2014-2-16 did support this). With passive 3D you could have viewers with cheap passive 3D glasses and would not have to worry about active signal synchronization. 

[borealcat]

I have succeeded with this by creating a two channel compressed side by side 3D video file, where two sbs videos fill the frame that is 3840x1080, and spans two screens, one video appearing on each screen, and perfectly synchronised since they are embedded in the same video file. This level of synchronisation is what i would also need to accomplish in a  frame-packing environment, which would double the resolution. 

Alas, I know nothing about writing code. 

This setup is using some video splitter that takes the 3840x1080 and outputs two synchronized 1920x1080 videos ?

Alas it seems to be impossible to buy consumer passive 3D monitors anymore. Maybe there are commercial monitors. With 4K resolution, they would also provide Full HD resolution (consumer 4K displays from ca. 2014-2-16 did support this). With passive 3D you could have viewers with cheap passive 3D glasses and would not have to worry about active signal synchronization. 

Hi there, thanks for the thoughts, and apologies for such a long time to respond as have been out in the field getting 3D footage! My application is projection only due to the scale, thus passive monitors are not an option. Of course I could opt for passive projection setups, but they are so expensive, and finicky if dual projector. So the ideal is frame packing for full resolution. The trick is, I am not sure how to send separate frame packing signal simultaneously and in synch to two projectors, and i believe there is metadata that needs to be in the frame packed data stream for the projectors to interpret it as frame packed, which I do not know how to create. Creating DCP might be an option, and perhaps a DCP server could send the video files in synch. The simplest solution is side by side video, which the projectors can be manually set to decode as 3D, and synch is accomplished by making both videos part of the same video file, spread across two screens (using matrox splitter or mac computer display options). 3D projectors handle a maximum resolution of 1920x1080 side by side, which unfortunately means that each frame is half resolution, a resolution hit I am trying to avoid. I am in discussion with a projector manufacturer to see if firmware on a 4K  projector can be adjusted to accomodate side by side 3D at higher resolution, such as 1440p. 

This may all be beyond the intention or capability of Kodi, but if anyone has suggestions or leads, would love to hear many thanks.

[te36]

If i understand you correctly, you need the signal to the 3d glasses to switch between left/right eye to be synchronized across multiple displays. Its not clear to me how it would be easier to solve this problem when the projektors get side-by-side 3d versus frame-packed 3d. 

HOw would you synchronize multiple displays without the supposed problem with frame-packed 3D ?

This type of sollution here seems to be able to create up to 32 synchronized HDMI video signals from a single PC. With a bit of luck, the drivers will also support frame packing 3D (same basis as the nvidia consumer drivers).

https://www.leadtek.com/eng/products/wor...81)/detail

Now, just because you have synchronized HDMI signals doesn''t necessarily mean that this signals from projectors are synchronied. IMHO more likely with LCD/LCOS, with DLP i would fear that there is a random delay per projector based on the phase of the rotating color wheel.

[borealcat]

If i understand you correctly, you need the signal to the 3d glasses to switch between left/right eye to be synchronized across multiple displays. Its not clear to me how it would be easier to solve this problem when the projektors get side-by-side 3d versus frame-packed 3d. 

HOw would you synchronize multiple displays without the supposed problem with frame-packed 3D ?

This type of sollution here seems to be able to create up to 32 synchronized HDMI video signals from a single PC. With a bit of luck, the drivers will also support frame packing 3D (same basis as the nvidia consumer drivers).

https://www.leadtek.com/eng/products/wor...81)/detail

Now, just because you have synchronized HDMI signals doesn''t necessarily mean that this signals from projectors are synchronied. IMHO more likely with LCD/LCOS, with DLP i would fear that there is a random delay per projector based on the phase of the rotating color wheel.

Hi, thanks so much for the reply. The frame packing is desired simply for higher resolution. I just do not know how to send frame packed signal to from computer to projectors, or if I can frame pack 3840x1080 video if I split one signal over two projectors for synchronisation purposes. I suspected exactly as you do that there would be shift in phase between projectors even if signal is synchronised.... but I was surprised to learn with testing that the same signal, sent to two DLP projectors, synchronised the 3D frequency for active glasses. 

The hardware you referenced is extraordinary... 3D video walls! I am working on mac so some learning curve there for me, but interesting to see it is doable. There are a lot of details to sort out which are unfortunately over my head, such as how to send frame packed 3D video signal from a computer (I have only seen it employed as part of the metadata on 3D blu-ray through blu-ray player), and how to send two synchronised frame packed video streams to separate projectors, preserving the frame packing and synchronisation. I will read more about this hardware, it seems designed for that. Thanks for the lead.