Kagan estimates that the combined global smart TV and streaming media device installed base added 12.4 million net new devices in the second quarter, bringing the total global streaming operating system installed base to 1.03 billion devices.

Streaming OS platform owners are looking for the widest addressable audience possible to maximize the revenue potential of streaming services and ad inventory.

Smart TV vendors Samsung and LG have a strong presence in this market based on the strength of their smart TV operations alone. But other top players, such as Roku Inc. and Alphabet Inc., leverage high-volume SMD businesses with smart TV vendor partnerships.

Samsung Electronics Co. Ltd.'s Tizen Smart Hub operating system accounted for the largest contingent of the total global installed base as of the second quarter.

Alphabet Inc.'s Android TV, the second-largest streaming OS by installed base. Alphabet's is gaining ground on Samsung by virtue of its exposure to key vendors TCL Electronics Holdings Ltd. and Xiaomi Corp. selling midrange to low-end TVs, particularly in emerging markets.

In the U.S., Roku OS is in firm control of the market, but Android TV was the biggest gainer in terms of net adds in the second quarter.

Roku OS shipments are falling quickly as the momentum for Roku's TV vendor partners was diminished by severely weakened local demand in the quarter.