Celebrity branding seems to be getting less popular in China's smartphone arena, as local players are stepping up research and investment push to revive a market mired in an innovation lull, China Daily reported Tuesday.

Oppo, previously known as a pioneer in writing big checks to hire celebrities as spokespeople, is now pouring more resources into research and development, in the hope of sustaining its competence in the 5G arena, or the fifth generation mobile technology, with cutting-edge products and services, the paper reported.

The company said on Friday that it would invest 10 billion yuan (1.46 billion U.S. dollars) in R&D this year and expand its R&D staff to over 10,000 people, according to the report.

The company would scale down its marketing budget and direct more resources to upgrade and innovate its products, Shen Yiren, vice-president of Oppo, was quoted as saying by the paper.

Oppo's peer Vivo is also working hard to shake off its reputation for marketing and rebuild its image as an innovative player that constantly experiments with new smartphone designs and features.

Such a shift in companies' strategies mirrors the saturation and maturity of the Chinese smartphone market, Xiang Ligang, director-general of the Information Consumption Alliance, was quoted as saying by the paper.

"Smartphones are getting increasingly similar. Signing a superstar to promote models may still appeal to core fans, but it does not work with the general public," he said.

Also, the increased pressure in smartphone shipments has left vendors with less money and they have decided to invest their limited resources into R&D, which can better prepare them for the upcoming 5G era and gain a first-mover advantage, the paper reported.

Data from market research company International Data Corp show that in the first three months of 2019, global smartphone shipments fell by 6.6 percent year-on-year to 311 million units.