Till now it is cleared that
The 4K STBes deliver ultra-high-definition picture quality and Dolby digital plus 7.1 surround sound. The 4K STBs are backward compatible therefore it supports standard and high definition televisions
So I guess Videocon d2h 4K STBn and upcoming 4KDVR will support 7.1 surround sound with Dolby Digital Plus [I believe always in THX for Picture and Sound quality
]
Tata Sky : 4K STB manufacturer and HEVC SoC:
1)TataSky had outsourced the manufacturing of 4K STB to
French firm, Technicolor, in May 2014.
2)
Broadcom has supplied its
BCM7252 high-efficiency video codec H.265 system-on-chip to power Tata Sky’s first generation
ultra HD set-top-boxes.
Videocon D2h 4K STB manufacturer is
still unknown and HEVC SoC as below.
1)Videocon D2H has integrated
high efficiency video codec (HEVC) H.265 system-on-chip from
MStar Semiconductor on its
HD set-top-boxes.Not cleared, it will have 4K Ulitra HD support also with this????.
However, they have done
licence agreement with M-Star for getting Compression technology of HEVC H.265 which is
required for 4K bandwidth.[This was done much before TS 4K announcement last year]
2) Videocon d2h, India's fastest growing direct-to-home (DTH) satellite service provider, has selected
i)
Broadcom's highly integrated satellite set-top box (STB)
system-on-a-chip (SoC) device to power their latest high definition (HD) universal serial bus (USB) digital video recorder (DVR).
ii)
Broadcom's BCM7358 single-channel 1080p HD advanced video coding (AVC) satellite receiver chip, featuring a high performance CPU and graphics engine, Digital Living Network Alliance (DLNA®) connectivity support and advanced security functionality.
It supports VOD service also as announced in past.
So
Manufacturing STBs/DVR perspective "M-Star's and Broadcoms" association is NOT clear for Videocon D2h 4K capabilities considering the point 1) and 2) as above.