What is Full HD 3D (FHD3D)?

With the introduction of 3D TVs, the consumer electronics industry in collaboration with the BluRay Disc Association (BDA) and the HDMI consortium have had to settle on a suitable, standardized format for the transmission of 3D content in HD. This of course is vital since a standardized format that has the backing of all the consumer electronics giants will ensure that consumers can buy any 3D TVs they wish without having to worry about compatibility with different 3D content sources.

What is Full HD 3D (FHD3D)?
The HDMI 1.4 specification was released in July, 2009 outlining the different 2D and 3D formats that had to be supported by any 3D enabled device that is to be labeled HDMI 1.4 compatible. One of these specifications included the definition and specs of Full High Definition 3D (FHD3D) content which aims at delivering 3D content at 1080p resolution (1920×1080 pixels) frames at 24 fps (frames per second).

A single frame of Full HD 3D (FHD3D) content actually contains both frames for each eye “packed” into it. This is why it is referred to as “Frame Packing”. To maintain full 1080p resolution, the sub-frames for each eye are stacked vertically one on top of the other, so you would expect the net resolution of a FHD3D frame to be 1920×2160. However, the specification also states that the two vertically stacked sub-frames have to be separated by a buffer zone (or active blanking zone) that consists of a blank 1920×45 pixel strip between the two sub-frames. The figure below clearly shows the composition of a single “Packed Frame” comprising the vertically stacked Left and Right sub-frames, separated by a 45 pixel active spacing. As a result, a single Full HD 3D frame has a resolution of 1920×2205 (2160+45=2205). This type of format is called top/bottom or over/under (sometimes even called above/below) for obvious reasons

The FHD3D specification states that such an FHD3D frame will be transmitted at 24 fps (the standard frame rate for all movies/blurays).

Full HD 3D Frame Packing
Composition of a Frame Packed Full HD 3D (FHD3D) Frame

How is FHD-3D content decoded?
The HDMI 1.4 specification stipulates that all 3D displays need to be able to handle all the 3D formats specified within the framework of HDMI 1.4. When a 3D TV receives the Full HD 3D signal, it first reads the EDID of the signal to determine what type of signal it is. Based on the EDID, it will identify the video signal to be FHD3D and will accordingly process the packed frame so as to separate out the 1080p sub-frame for the left and right eye. Once the 3D display does this, it then proceeds to display these images on the screen in a manner consistent with the 3D display technique employed by the 3D TV. So if it is an active shutter based display, it will display each frame sequentially, in-sync with the viewer’s active shutter glasses. In this manner, the HDMI 1.4 specification is “Display technology agnostic” as it does not depend on the details of the 3D display technology (Plasma or LED/LCD, active or passive).

Frame Packed FHD3D Converted to Frame Sequential 3D
Conversion of Frame Packed FHD3D to Frame Sequential 3D

Compatibility of Full HD3D (FHD-3D) with non 3D components and TVs
Since FHD3D is an entirely new format, it is not compatible with TVs and home-theater components that are not HDMI 1.4 compatible (unless you use some sort of converter box that converts the signal into something HDMI 1.3 compatible). The reason is that each video signal has an EDID (an identifier) that identifies the type of signal that is being sent. Older televisions will not be able to recognize the new EDID for such full HD 3D content resulting in a blank screen. For more compatibility related information, be sure to check our comprehensive guide on 3D compatibility.

So will I need new HDMI cables to be able to pass Full HD 3D (FHD3D) signals through to your 3D TV?
Unfortunately, the answer to this question is maybe. If you have an old HDMI cable that is not classified as “High Speed HDMI” or as a Category 2 HDMI cable, then you will probably need a newer HDMI cable. The reason being that the older HDMI (category 1) cables were designed to a maximum bandwidth specification of only 2.25 gigabits per second (Gbps) which was plenty to pass through 720p or 1080i content but is not enough to pass through full 1080p HD content. Category 2 HDMI cables on the other hand allow up to 8.2 Gbps of data throughput (10.2 Gbps total, but only 8.2 is available as the rest is used for error-correction purposes) which is more than enough to pass FHD3D and regular 1080p content through.

Our advice is to go to monoprice.com and save a lot of money by purchasing some category 2, HDMI 1.3 or HDMI 1.4 cables from their site. Just make sure never to waste money on overpriced cables that are sold at regular retail stores that are solely there to fleece unsuspecting and uneducated customers.

It should be noted that HDMI 1.4 cables have some additional features like having an integrated Ethernet data channel at 100Mbps. If your TV definitely needs this feature, or if you wish to make use of it, then you should definitely purchase a High-Speed HDMI with Ethernet cable. For more information about HDMI cable compatibility for 3D, be sure to read our 3D HDMI Cable guide.

FHD-3D Summary
In summary, Full HD 3D is an entirely new frame packing 3D format that has been specified to allow all 3D TVs to be compatible with full HD 3D content. It consists of a lossless over/under format that contains sub-frames for each eye, each at 1080p that is packed into a single frame and transmitted at 24 fps.