Multiscreen content

From SpinetiX Support Wiki

Jump to: navigation, search

Applies to: HMP350, HMP200, HMP130, HMP100.

Introduction

Multiscreen content refers to a special type of synchronized content which is meant to be displayed over a video wall - i.e. multiple displays grouped together in a regular grid-like arrangement (or in a non-conventional pattern) to create the illusion of one big screen.

Multiscreen content helps achieving a higher impact over the audience and is required when:

  • all the screens are composing a bigger single screen,
  • at least one object (text, image, video, animation etc.) has to be displayed on more than one screen,
  • you want to have only one project for all the players playing the synchronized content, instead of individual projects, for easier management and publishing.

For instance, displaying a 4K video over 4 big 80" screens it's possible by splitting the original video in four full HD (1920x1080) videos and using a multiscreen project over four HMP350 devices to display these pieces as a whole. Starting with Elementi 2015, such large videos are automatically cut into pieces upon import - if you are using an older version, then you need to manually cut the original video into four pieces, each having a resolution of 1080p, and import them into your multiscreen project.


Note Note:
All the HMP devices displaying the multiscreen content must be time-synchronized to the same NTP source(s) having a good accuracy (as in few milliseconds).

How to create multiscreen content

To create multiscreen content, follow these steps:

  1. Create a multiscreen project.
  2. Create the content like usual, while respecting the requirements for synchronized content.
  3. Publish the multiscreen project onto the HMP devices composing the video wall.
    • Note that the entire multiscreen project is published on each HMP, thus you need to make sure the storage space on each HMP is sufficient.

Multiscreen project

Creating a multiscreen project

A multiscreen project is a special type of project that allows authoring content that is displayed on multiple screens.

The first step for creating multiscreen content is to create a multiscreen project - for that, follow these steps:

  1. Start creating a new project as usual.
  2. Within the "New Project" dialog, set the "Format" property to "Multiscreen Array" or "Multiscreen Custom", depending on the desired type of multiscreen project.
    • Elementi 3.x only offers one format, "Multiscreen", which is equivalent to "Multiscreen Array"; for custom format, this multiscreen widget needs to be used.
  3. Configure the properties of the multiscreen project from the "Properties" tab in Edit panel.

Multiscreen Array

Note
This feature is available starting with Elementi 2015; for Elementi 3.x, see this multiscreen widget.

Selecting this project format allows creating a multiscreen project having a standard grid-pattern layout, where the number of rows and columns of the matrix is configurable. By default, a 2 x 2 layout is used when this type of project is created. Each screen of the matrix gets a "Screen ID" in this format: screen-[row]-[column].

The following configuration options can be found under the "Properties" tab:

  • Number of rows
    Enter the number of rows of the grid-pattern layout. Default: 2.
  • Number of columns
    Enter the number of columns of the grid-pattern layout. Default: 2.
  • Screen diagonal
    Enter the diagonal dimension of the screen; it can be followed by a measurement unit. Default: 40".
  • Screen aspect ratio
    Enter the aspect ration of the screens composing the video wall; some commonly used aspect ratios are available in the drop-box for selection. Default: 16:9.
  • Vertical frame border
    Enter the vertical frame (bezel) dimension of a single screen; it can be followed by a measurement unit. Default: 5mm.
  • Horizontal frame border
    Enter the horizontal frame (bezel) dimension of a single screen; it can be followed by a measurement unit. Default: 5mm.
  • Edge blending
    Enable / disable the use of software-emulated edge blending; this is useful when using projectors which don't support edge blending themselves. When enabled, a negative frame border must be specified to add a linear luminosity gradient over overlapping screens. Default: No.
  • Screen height (pixels)
    Enter the screen height in pixels. Default: 1080.


Note Notes:
  • The following measurement units can be used with the properties above: mm, cm (lacuna value), inch (also in, in., inches and ") and m.
  • Under the "Screens" tab, players can be associated to screens using drag & drop.

Multiscreen Custom

Note
This feature is available starting with Elementi 2015; for Elementi 3.x, see this multiscreen widget.
Preview.custom.svg.png

Selecting this project format allows creating a multiscreen project having custom user-defined layout. By default, a custom layout, having two vertical screens on the side and two horizontal screens in the middle, is used when such a project is created. Screens can be added or removed from the Edit panel; each screen gets a "Screen ID" in this format: screen-[n].

The following configuration options can be found under the "Properties" tab:

  • Total width, Total height
    Enter the total width and total height of the entire multiscreen area.
  • Edge blending
    This feature doesn't really work and will soon be removed.

Under the "Screens" tab, there are 6 columns to fill out for each screen composing the multiscreen layout:

  • Multiscreen ID
    Enter a unique Multiscreen ID to identify the current screen area that the associated player should display from the entire content. Another way to create the bound is to manually set this Multiscreen ID on the HMP.
  • X, Y
    Enter the coordinates of the top left corner of the screen, relative to the multiscreen area. Note that (0.0) point is positioned in the top left corner of the multiscreen area.
  • Width, Height
    Enter the width and height of the screen.
  • Players
    Associate a player to this screen using drag & drop.


Note Note:
This type of project doesn't use a specific measurement unit, but all the numeric values must be entered using the same unit. By default pixels are used, yet, depending on the custom layout, other measurement units might make more sense, like mm, cm, inch etc.

Multiscreen layout

Note
This feature is available starting with Elementi 2015.
Creating a multiscreen layout

In the case of a multiscreen project, Elementi 2015 or later, allows creating multiscreen layouts, a special type of layout covering a predefined area of a video wall.

To create a multiscreen layout, follow these steps:

  1. Open a multiscreen project.
  2. Start creating a layout as usual.
  3. Select the multiscreen layout format, from one of the following:
    • One Screen
      Select this when the layout is meant to cover a single screen from the video wall.
    • All Screens
      Select this when the layout is meant to cover the entire video wall.
    • Subset of Screens
      Select this when the layout is meant to cover a subset of the screens, specified using the "Columns" and "Rows" fields underneath for Multiscreen Array project, respectively using the "Screen Ids" field for Multiscreen Custom project.
    • Custom
      Select this when the layout is meant to cover a custom area, specified using the "Width" and "Height" fields underneath.
  4. Click on the "OK" button.


Note Note:
If the configuration of the multiscreen project is modified after the creation of the layout, the size of the layout will be automatically adapted by Elementi.

Multiscreen image

Note
This feature is available starting with Elementi 2015.
Multiscreen image sample icon

In the case of a multiscreen project, Elementi 2015 or later, allows importing images having resolutions above the maximum resolution supported by the HMP. The result is a multiscreen image that can be simply drag & dropped into the Preview panel or Edit panel just as any other image. A special icon is used to represent such image.

To import a large image within a multiscreen project, follow these steps:

  1. Open a multiscreen project.
  2. Drag & drop the image file within the Browse panel to import in into the project.
  3. Wait for the original image to be processed (e.g., import, cut, resize etc.) and the multiscreen image to be generated.


Note Note:
The multiscreen image is in fact a special type of layout containing a variable number of image tiles. The layout index file ensures that the best resolution / quality is used when displaying this image on the video wall or within Elementi.

Multiscreen video

Note
This feature is available starting with Elementi 2015.
Multiscreen video sample icon

In the case of a multiscreen project, Elementi 2015 or later, allows importing videos having resolutions above the maximum resolution supported by the HMP. The result is a multiscreen video that can be simply drag & dropped into the Preview panel or Edit panel just as any other video. A special icon is used to represent such video.

To import a large video within a multiscreen project, follow these steps:

  1. Open a multiscreen project.
  2. Drag & drop the video file within the Browse panel to import in into the project.
    Elementi 2015 or later shows a warning dialog containing the following text: "The resolution of this video file is too large to be imported and played in one piece. Do you want it to be split for optimal display in a multiscreen project?"
  3. Click on "Yes". The "Oversize Video Import" dialog is displayed.
  4. Oversize Video Import dialog
    Select the target area where the video will be displayed, from one of the following:
    • All Screens
      The video is split to be displayed on all the screens composing the video wall.
    • Subset of Screens
      The video is split to be displayed on a subset of screens (columns * rows) of the video wall.
    • One screen
      The video is resized to be displayed on a single screen of the video wall.
    This selection influences how the video is split and therefore the aspect ratio of the video must match the aspect ratio of the target area. If that's not the case, this error message is displayed:
    The aspect ratio of the video does not match the aspect ratio of the target area.
  5. Wait for the original video to be processed (e.g., import, cut, transcode, resize etc.) and the multiscreen video to be generated.
    This process might take a long time depending on the size of video file and the processing power of your PC.


Note Notes:
  • The multiscreen video is in fact a special type of layout containing a variable number of video tiles. The index file of this special layout ensures that the best resolution / quality is used when displaying this video on the video wall, and that a reduced-size video is displayed within Elementi.
  • In some cases, it may be more efficient to directly process the video using the software that generated it - starting with Elementi 2015, the configuration of the multiscreen project, including its total resolution, can be exported using "Menu" > "Projects" > "Export Multiscreen Configuration..." option.

Multiscreen playlist

Before Elementi 2015, working with playlists of large videos and / or images in multiscreen projects was not very simple because it required special attention of the playlist structure to ensure that the content stays synchronized on the video wall. Furthermore, the large videos / images had to be cut into several tiles so that each tile could have be been displayed by the target HMP. For an example, see how to use video tiles within a multiscreen playlist.

Things are much more simpler starting with Elementi 2015 - simply create a playlist covering the desired area, and then drag & drop the multiscreen images and / or multiscreen videos into the playlist.


Note Note:
Random transitions or shuffling must be avoided for content spanning over multiple screens, because the randomisation is done by each player with different results.

Canvas size

When working with multiscreen content, make sure to take into account the space (bezel) between the screens when calculating the canvas total size. For instance when having a 1x4 video wall (40" screen with 20mm bezel), the total width of the canvas is 5293 pixels (and not 4x1280=5120).

To get the canvas total size, have one layer covering the entire canvas (or create a new layer and use the "Fit Screen" right-click menu option), then open that layer properties and find the values under the "Position" section. Similarly, to get the position of a certain screen within the canvas, first select the screen from the "Multiscreen" top-bar button, then follow the same steps as above.

  • Starting with Elementi 2015, the configuration of the currently opened multiscreen project can be exported as a CSV file, using "Menu" > "Projects" > "Export Multiscreen Configuration..." option.
  • Alternatively, you can download and use "Multiscreen calculator tool" to get these values.


Note Note:
For players prior to HMP350 model, the maximum canvas size is limited to 32676 x 32676 pixels (or equivalent if other measure unit is used), which means roughly a grid of 17x30 screens at 1920x1080 or 25x45 at 1280x720. This limit is however not shown within Elementi 3.x.

How to publish multiscreen content

Publishing a multiscreen project is similar to publishing a single-screen project, except that there are some extra steps to take.

To publish a multiscreen project on the target HMP devices composing the video wall, follow these steps:

  1. Create a collection grouping the HMP devices composing the video wall. This step is recommended, though not required.
    1. Open the Devices tab within the Browse panel.
    2. Right-click inside the "Devices" view, select "New Collection..." and enter the collection name.
    3. Copy / move all the HMP devices composing the video wall into this collection.
  2. Open the multiscreen project by double-clicking on its icon in Preview panel.
  3. Associate players to content areas (screens).
    • There are two ways to do this:
    • The former is more convenient because it doesn't require any configuration on the player side, but this feature is not available for versions lower than Elementi 2015.
    • If both methods are in use, the multiscreen configuration has priority.
  4. Once done, click on the "Publish" button.
  5. If the list of target devices is not already set, click on the "Add/Remove" button and select target players (or the collection created above as target).
    • You just need to select the target players once, since Elementi remembers the last list of target devices for each project.
  6. Click the "Publish" button to start the publishing process.


Note Note:
All the HMP devices displaying the multiscreen content must be time-synchronized to the same NTP source(s) having a good accuracy (as in few milliseconds).

Associating players to screens from Elementi

Note
This feature is available starting with Elementi 2015.
Associate players to a multiscreen project

To associate HMP devices to content areas (screens) from Elementi, follow these steps:

  1. Click on the "Devices" tab within the Browse panel.
  2. If necessary, browse to where the target HMP devices are located - for instance to the collection created before.
  3. Drag & drop the HMP devices onto the content areas (screens) within the Preview panel.
    When hovering a target area, a magnet icon appears and the area is highlighted; dropping the HMP device onto it associates that part of the multiscreen content to that player - this bound is displayed in Edit panel under the "Screens" tab.
  4. Once done, go back to the multiscreen project by clicking on the project tab in Browse panel.


This method has the following advantages over manually configuring the multiscreen ID on the HMP:

  • The player to screen association is done directly from Elementi, without the need to do any configuration on the player side.
  • The list of target devices for the publish process is automatically generated.

Multiscreen ID error screen

Multiscreen ID error screen

Starting with firmware 3.1.0, when publishing a multiscreen project on an HMP device that is not associated to a content area within the multiscreen project, that HMP is displaying an error screen having this text: "Multiscreen ID setup required". When this happens, you need to either associate the player to a content area from Elementi or configure the Multiscreen ID of that player to match a content area.


Note Notes:
  • If needed, it is possible to force displaying the full content by explicitly using "fullscreen" as Multiscreen ID on the HMP; this should be done with care to ensure that the HMP can actually display the entire content, because otherwise the HMP would enter into Safe mode.
  • For firmware lower than 3.1.0, the HMP which is not correctly configured, would try to display the full content or enter otherwise into Safe mode.

Limitations

  • Multiscreen synchronization accuracy
    The synchronization accuracy that can be achieved is one vertical refresh period (e.g., 17ms for 60Hz, 20ms for 50Hz), provided that NTP is properly set up.
  • High resolution videos
    A video having the resolution above the maximum resolution supported by a single HMP can be used within a multiscreen project only if it is cut into smaller resolution videos. For instance, to display a 4K high resolution video on a 2x2 video wall, the video must be cut into smaller videos with resolutions up to 1080p.
    Starting with Elementi 2015, when importing such a video, a multiscreen video is automatically generated, ready to be used within the multiscreen project.
  • Multiscreen playback control
    Using interactive controls (pause, play) on a video file spanning over multiple screens will not work properly because there is no way to ensure that the video will be paused at the exact same frame on all the screens. Depending on several factors, it could be a difference from few frames to few seconds.
    A proposed workaround for this issue is to switch from the video to a static image and then change back to the video. By default the video will start from the beginning, nevertheless it can be forced to start from the point where it was paused using JavaScript.
    See also the "Add/remove a video in a multi-screen project" example using jSignage.
  • Multiscreen real-time streaming
    Displaying real-time streaming within a video wall is supported only on HMP350 devices staring with firmware 4.1.0 - MPEG2-TS multicast over RTP or UDP only.
    For older HMP models or firmware versions, multiscreen real-time streaming will mostly not going to work in sync.
  • Multiscreen data feeds
    Using an external data feed source within a data feed widget spanning over multiple screens will not work properly because there is no way of ensuring that the remote server responds to each player exactly in the same time.
    Starting with Elementi 2015, this limitation has been removed - see Data feed synchronization page for more details.
  • Multiscreen randomization
    Using random effects / transitions is not recommended since the randomization is done on each player and therefore the displays might look as being out-of-sync during the transition period (especially for video walls).
  • Constrains of large video walls
    Although there is almost no theoretical limit to the number of players that can be used in a multiscreen project, creating large video walls may add additional constrains, like insufficient storage space (the entire project is published to every HMP device composing the video wall) or content creation difficulties (Elementi can manage easily a multiscreen project with up to 20 screens, for larger ones other content management solutions might be better).
  • Mix of players within video walls
    It is not recommended to combine different models of HMP within a video wall.
This page was last modified on 1 June 2017, at 16:41. This page has been accessed 12,652 times.