It was a business mistake to sell MPEG2 STBs even though, at the time of inception of Tata Sky, MPEG4 technology was available. So, all the standard definition channels were in MPEG2. Later Tata Sky realized this mistake and started selling MPEG4 boxes, which are generally the black colored STBs. All High Definition boxes sold were MPEG4 and hence they were able to broadcast HD channels with bandwidth efficiency. Now Tata Sky wanted replace all the old SD boxes (the silver colored boxes) with MPEG4 boxes - especially in South India, since the number of viewers per south Indian MPEG2 SD channel is less and there are many South Indian channels.
Below are the impacted TataSky channels that are now being broadcasted in MPEG 4, as of September 2013. You will not be able to watch these channels with very old set-top-boxes of Tata Sky. Silver colored STBs are the ones that are impacted with the MPEG4 switch over.
Below are list of channels that have been swtiched over to the new technology.
Tamil MPEG4 channels
STAR Vijay, Zee Tamizh, Sun TV, Adithya TV, Sun Music, Chutti TV, Kalaignar TV, Jaya TV, Sun News, KTV, Sirippoli TV, Jaya Max, Thanthi TV, Isai Aruvi, Polimer TV, Puthiya Thalaimurai, Vasanth TV, Raj TV, Makkal TV & Murasu TV
Telugu MPEG4 channels
NTV News, Maa Music, Gemini Comedy, ABN Andhrajyothy, Sakshi TV & TV 5
Kannada MPEG4 swithed over channels
TV9 Kannada, Zee Kannada, Kasturi, Suvarna News 24*7, Udaya Movies, Udaya Comedy, Udaya Music & Udaya News
We TV, Reporter TV, Indiavision, Mathrubhumi News, Manorama News, Kochu TV, Kairali TV, Jeevan TV, Jai Hind TV, Mazhavil Manorama, Amrita TV, Asianet, Asianet Movies, Asianet Plus, Surya TV, Asianet News, Kiran TV, DD Malayalam
Arabic and North East Channels
Shalom TV, NE TV
Zee Bangla Cinema & Tarang Musi
Due to the massive number of viewers of Hindi channels and English channels, Tata Sky retained all the Hindi and English channels in MPEG2 transmission. For these channels, the effective bandwidth per subscriber is very low - since the number of subscriber is very high.
But, when it comes to South Indian languages and other North Indian languages, put together, there is a huge number of channels but the number of viewers watching a channel is very less. So, the net-profit while broadcasting these channels in inefficient DVB technology is very less. So, there is a high need for Tata Sky to switch over all South Indian channels and less watched North Indian channels to MPEG4 broadcasting technology, which is cost effect, in terms of bandwidth utilization.
While MPEG4 doesn't offer any better quality than MPEG2 at higher bitrates, given the fact that TataSky was providing MPEG2 services at very low bit-rates, especially non-STAR channels, there will be a bandwidth (hence cost) saving of around 50% for the same quality of output.