HDMI standard moves to 1.4a to offer more 3D support

After the release of version 1.4 of the HDMI standard in June 2009, a new version has just been lauched which specifies how 3D signals should be sent to televisions.  There might be just one letter of difference, but HDMI 1.4a marks a big change.

Following pressure from TV manufacturers, the HDMI consortium has just published the HDMI 1.4a specification, which makes support for 'side-by-side horizontal' and 'top-and-bottom' encoding of 3D content for broadcast, movies and gaming compulsory.  The names for the two different systems describe how the two separate images, one for each eye, are packed into a single frame.  In the first system, they're side by side, while in the second, they're stacked one top of the other; the TV then cuts the frame in half to extract these signal for each eye.  The only way to send a true Full HD frame to each eye is to use sequential frame packing.

These new modes open new ways of transmitting 3D data, making life easier for manufacturers of 3D TVs.  It also clarifies matters, because the HDMI consortium has provided a full list of the compulsory 3D formats to be supported by HDMI 1.4a:

For movies:

• Frame packing: 1080p at 23.98 Hz and 24 Hz

For games:

• Frame packing: 780p at 50 Hz, 59.95 Hz and 60 Hz

For TV broadcasts:

• Side-by-side horizontal: 1080i at 50 Hz, 59.94 Hz and 60 Hz
• Top-and-bottom: 720p at 50 Hz, 59.94 Hz and 60 Hz as well as 1080p at 23.97 Hz and 24 Hz.

Any television that is HDMI 1.4a compatible should be able to handle all of these formats.  Sources like Blu-ray players, games consoles and TV decoders will need to be able to output at least one of them to get the HDMI 1.4a label.

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