Stereo3D Clip Coupler

Introduction

The primary function of the Stereo3D Clip Coupler is to pair and mux (multiplex, although the files are not baked once created) files into stereo-pairs. The Clip Coupler can also be applied to an entire sequence that has a similar output and then be used to redefine the sequences Stereo Output Mode.

Initial Setup

The Clip Coupler plug-in, as with all the plug-ins in the Stereo3D suite, can be applied to an already pre-existing multiplexed stereo pair (left & right video files married together) that is any number of 3D formats (side-by-side, over-under, etc) as well as be applied to a single left or right eye file and then be coupled with the correct adjacent left or right video clip.

To access the Clip Coupler plug-in go to:

Video Filters → Dashwood Stereo3D Toolbox → Stereo3D Clip Coupler

Once applied to the clip, the clips render status will appear red in the FCP timeline unless set to Unlimited-RT. To access the menu to change the timeline’s render settings click on the RT button on the far left of the timeline. Select Unlimited-RT and the clips render status will turn orange, indicating that Final Cut Pro will process as much of the un-rendered effect in real-time as permitted by the video card. Typically the more VRAM that FCP has access to, the closer to real-time it will display the un-rendered clip. If an external 3D Monitor is being used for playback, then Playback Video Quality should be set to High and Playback Frame Rate can be left at Dynamic.

S3D Input

Once the footage has been loaded into the video bin or the timeline with the S3D Clip Coupler plug-in placed on the clip, the correct S3D input will need to be selected.

Clicking on S3D Input Type will access the input drop down menu and the input can be changed by selecting any of the formats.

If the footage hasn’t been “married” or muxed together yet, then any of the top three Image Well selections can be chosen.

Footage that has been acquired natively or “baked” into Anaglyph and chroma based 3D formats are not suitable inputs.

Image Wells

Stereo3D Clip Coupler allows for clip coupling of separate left and right eye files directly inside of Final Cut Pro without having to pair or marry the files with software outside of FCP.

To pair two files, place either the left or the right eye video file in the timeline and apply the Clip Coupler plug-in to the clip or apply the plug-in the designated file right inside the video bin. Underneath the S3D Input Type click on “Clip= Right Eye + Image Well= Left Eye” if the chosen file is the right eye. If the file is the left eye then change the Input Type to “Clip= Left eye + Image Well= Right Eye”. If the user prefers to have both image wells available they can access the Clip Coupler plug-in through the Effects Tab beside the Video Bin Tab and then double click on the Clip Coupler icon underneath Video Filters → Dashwood Stereo3D Toolbox. The plug-in will appear in the Viewer window where the S3D Input type can be changed to “Two Image Wells”

Once the appropriate input type has been selected The Clip Coupler plug-in will prompt for the adjacent file to be place inside the image well (left, right or both depending). To do so, the corresponding file can be clicked and dragged from any location inside FCP and placed on top of the image well icon. If Two Image Wells is the S3D input, then this task must be carried out for both the left and right files.

A Stereo Pair has now been created and is ready for Stereoscopic manipulation and correction.

*Important note: If the editor wishes to change the IN point of the stereo pair at any time during the editing process, then the clip must be nested so that the two pair clips are not rolled out of sync. FCP does not acknowledge the second clip inside the image when editing the beginning of the clip, thus the in-points will not match if an edit point is made to the front end of the clip. To nest the clip so that this doesn’t occur, the designated clip must be highlighted and then Nest Items (Option + C) from the Sequence menu must be selected. FCP will prompt for the clip to be re-named (typically the name of the file and “Stereo” or “S” is sufficient) and the file will be placed back into the timeline in it’s original location, but now as a nested item. The file can always be double clicked in order to access the original material inside the nest. For more information on this workflow, please refer to the Video Tutorials on dashwood3d.com

If the footage being used has already been muxed into a stereo pair, then the correct S3D Input Type must be chosen in order for Toolbox to correctly process the image. Refer to the examples below for clarification of the Stereoscopic formats.

3D- Indicates a format that will display images in Stereoscopic 3D.

Line by Line Interlaced. (Row-Interleaved) 3D

Interlaced will display the left eye data on the odd lines of video resolution and the right eye data on the even lines, which in turn works natively with most Passive Polarized 3D monitoring systems. Often referred to as Row-Interleaved, because of “interlaced” more often referring to how fields are being displayed rather then meaning a Stereoscopic format, Interlaced has more often become a display format than an acquisition format. S3D Toolbox allows for Interlaced 1080i as an Input Type, because if another S3D Toolbox plug-in from the suite was set to output Row-Interleaved, then if new video effects like Geometry was placed on top the video, then S3D Toolbox can interpret the stereoscopic interlacing and then display it in a new or similar format.

Side-by-side. (SBS, Left & Right Squeeze, L/R) 3D

One of the more commonly seen standards of the 3D formats is side-by-side, which can be natively received by most 3D Monitors and be output for stereoscopic viewing. The left & right video files are placed beside one another on the horizontal plane and are squeezed in by 50% in order to fit into a single frame. Side-by-side can also be not squeezed for two full-resolution frames in the same composition and video file, just twice as large in resolution.

Side-by-side Crossview (Cross-eyed) 3D

The exact same as the normal side-by-side except for that the eyes are swapped so that the viewer can cross their eyes and view the scene in 3D without glasses or a 3D display. This can cause great eyestrain, but with practice it can become a simple rudimentary way to “free-view” 3D material without the use of expensive equipment. The footage typically isn’t squeezed in crossview.

Over Under. (Above & Below) 3D

Also a common 3D format, the left video track is squeezed vertically and placed on the top 50% of the frame and the right track is then also squeezed vertically but placed on the bottom half of the frame. With S3D Toolbox, objects that lay converged or at Zero parallax are stitched back to full resolution when they are displayed in 3D.

2D Element

Stereo3D Toolbox allows for the input of a 2D object, such as text or a lower 3^rd to be manipulated in 3D Stereoscopic space. This does not mean that the object has been converted into true stereoscopic 3D but rather has simply been duplicated into both a left and right eye file so that the interaxial distance can be controlled. The object can be maneuvered and key framed in and out of negative and positive parallax or rather “in” and “out” of the screen. 2D source should only be applied to an object that does not take up the entire resolution of the composition as it is intended for an individual object within the scene and not a full resolution composition.

Clip Coupler Features

Input Squeezed (Only available when using Side-by-Side input types)

This option tells Stereo3D Toolbox whether or not the side-by-side footage is squeezed into one full resolution composition or if it is two full resolution compositions coupled in the same file.

Swap Inputs

The naming hierarchy of left & right 3D files can sometimes be incorrect depending on the accuracy of the Data Management Technologist’s file handling and the labeling of the physical cameras on a Beam-Splitter Rig. This naming error will be evident if the footage is viewed on a 3D display, as the background will be perceived to be floating in front of objects that should be in the foreground and vice-versa. When incorrectly labeled the left and right eye video will be reversed and thus the human eye will be receiving incorrect information. If the viewer is unsure if the footage is named properly, then by clicking Swap Input back and forth while playing the footage, the 3D will either be comfortable to watch or slightly straining to view. If the footage is comfortable to watch and the objects within the scene are positioned in the proper location in 3D space (foreground objects appearing at the front or “popping” off the screen & background objects appearing in the back or “behind” the screen) when Swap Input is selected, then this indicates that the footage has been named incorrectly.

S3D Output Options

The various stereoscopic 3D output modes available in Stereo3D Toolbox can be accessed underneath the S3D Output Mode Tab. Side-by-side, Line by Line Interlaced and Above Below have been discussed in Initial Setup.

These three output modes are most commonly found finishing formats besides exporting separate left and right video tracks or upgrading to a DCP for a cinema release.

Swap Outputs

It is sometimes necessary to swap the output of the clip for many reasons such as some 3D Monitors interleave their polarized signals differently line by line. If ever needed, the Swap Outputs checkbox can be selected after the convergence and stereoscopic settings have been changed.

Flip Flop

Cameras shot on certain beam splitter rigs need one or both of the cameras to be flipped or flopped in order for the perspectives to match.

Flip will rotate the image 180º so that it is upside down from it’s native position.

Flop will change the images perspective so that is a mirror image of it’s native position as though it has been rotated 180º along the z-axis.

Also see:
Stereo3D Geometry
Stereo3D Ghost Toaster
Stereo3D Image Balance
Stereo3D Monitor Scaler
Stereo3D Parallax Guides
Stereo3D Text Generator
Virtual Floating Windows
Stereo3D Z-Depth Map