DVB 3D-TV

DVB 3D-TV is a new standard that partially came out at the end of 2010 which included techniques and procedures to send a

DVB transmission standards (Cable, Terrestrial or Satellite). Currently there is a commercial requirement text for 3D TV broadcasters and Set-top box

manufacturers, but no technical information is in there.

Nowadays 3D television technology is already in its first steps regarding its standardization, now the major 3D market is in

coding

and transmission standards.

Implantation

The implantation of first generation of DVB 3D-TV will be staggered:

Phase 1: the first standard will have
signaling or distribution formats should not prevent future expansion to support new 3D encoding formats. This system only works with stereoscopic Frame sequential 3D systems. Requirements for this system, which is called Frame compatible format, are included in the commercial requirements of DVB. Some broadcasters like Sky3D^[1] or Canal+3D^[2] are already using this technology, which is largely thought for PayTV
.

Phase 2: the use of new broadcasting requirements for specific 3D streams won't be compatible with actual 3D STB, but it would be service compatible with 2D STB if no specific 3D STB is available by using Scalable Video Coding and Multiview Video Coding techniques, i.e. not having to simulcast 2D and 3D and occupying only one channel by using a unique video stream with a normal 2D base stream and an adjustable 3D depth layer. This system is called service compatible and is designed for Free-to-air group of broadcasters.

3DTV signals

Matrix of signal formats for 3DTV:

Compatibility level	1st generation 3DTV	2nd generation 3DTV
Level 4: HD service compatible (CSC)	2D HD + MVC (L,R formed by matrixing: depth info)	2D HD + MVC (Depth, occlusion and transparency data)
Level 3: HD Frame compatible compatible (FCC)	Frame compatible + MPEG resolution extension (ex. SVC)
Level 2: Conventional HD Frame compatible (CFC)	L and R in same HD frame
Level 1: Conventional HD display compatible (CDC)	Color anaglyph

Frame sequential

Regarding how a signal once it's decoded is sent to the

polarized glasses

are then shown to each eye. This involves that the real frame frequency halves the video frame frequency.

Technical features

Frame compatible

In Phase 1 system, only frame-sequential 3D is allowed, using

H.264 as a single image. This allows to handle video as normal HD video using typical channels and interfaces like HDMI, which is possible in this 1.4a version. Frame compatible (CFC)

model is also compatible with 2D HD mode in the same channel, adding some signalling for switching from 2D to 3D.

There are basically two ways to do spatial multiplex: Side by side and Top and bottom, but additional spatial multiplex formats have been proposed in order to improve picture quality by providing a better balance between the V and H resolution.

Side by side

Side by side (SbS) format just put the left and right images one next to the other in an HD image. Because of this, a horizontal

decimate

is required which causes halving of horizontal definition. DVB 3D-TV supports following SbS formats:

1080i @ 50 Hz Side-by-Side

720p @ 50 Hz Side-by-Side

720p @ 59.94 / 60 Hz Side-by-Side

1080p @ 23.97 / 24 Hz Side-by-Side

1080i @ 59.94 / 60 Hz Side-by-Side

Top and bottom

Top and Bottom (TaB) format put left and right images one above the other in a HD image. In this case, vertical

decimate

is required which causes halving of vertical definition. DVB 3D-TV supports following TaB formats:

1080p @ 23.97 / 24 Hz Top-and-Bottom

720p @ 59.94 / 60 Hz Top-and-Bottom

Not every spatial multiplex format is frame compatible with actual systems. Following formats are non frame compatible:

720p @ 50 /60 Hz

1080p @ 24 Hz

Graphics and text

There are basically two types of text displayed on screen that need additional broadcasting information to be displayed on a 3D display:

Subtitling: (or
DVB subtitling implementations and will be backward compatible
with 2D streams.

Service guide: the
service information. Depth information will be extracted of the captions
, displaying the graphics in the same depth.

Signaling

The main function of signaling for

HDTV full samples/line pictures to create the anamorphic version, if 3D is available. It's interesting to signal also for 3D receivers the 3D events that are available, for which 3D availability should appear on EPG

. For future

3DTV, signal that a 3D version of a 2D service or event is being simulcast

, and vice versa will be needed.

3DTV broadcast in future

Multiview

Multiview video coding is a compression standard appended from

DVB-C2 and DVB-S2

).

Free viewpoint

Total

2D+depth information from them to create a 3D model of the scene. Currently this system is being investigated, but the coding complexity and great bandwidth requirements make current broadcasting applications using Multiview Video Coding

impractical, so a totally new compression scheme and capture techniques need to be investigated.

References

DVB Commercial requirements for 3D TV broadcasting: available at [1]

DVB 3D-TV seminar presentation by David Wood: available at [2]

^ "Sky 3DTV site". Retrieved 2010-12-02.
^ "Canal+3D site". Archived from the original on 2010-10-02. Retrieved 2010-12-02.
^ "MVC 3D signal broadcast". Fraunhofer society. 2010. Retrieved 2010-12-02.

External links

[1] "Sky 3DTV site". Retrieved 2010-12-02.

[2] "Canal+3D site". Archived from the original on 2010-10-02. Retrieved 2010-12-02.

[3] "MVC 3D signal broadcast". Fraunhofer society. 2010. Retrieved 2010-12-02.