As the global smartphone Applications Processor (AP) market declined 5 percent (year-over-year) to reach $20.2 billion in 2017, Qualcomm was the leader with 42 percent revenue share, a new report said on Tuesday.

According to market research firm Strategy Analytics, Qualcomm, Apple, MediaTek, Samsung LSI and HiSilicon captured the top-five revenue share spots in 2017.

Qualcomm was followed by Apple with 22 percent at second place and MediaTek with 15 percent at third.

"The 64-bit smartphone AP shipments grew 15 percent (year-on-year) and accounted for 88 percent of the total smartphone AP shipments in CY 2017, up from 71 per cent in CY 2016," said the report.

Apple, HiSilicon, Qualcomm and Samsung LSI all registered year-on-year shipment growth while MediaTek and Spreadtrum saw their shipments decline sharply.

"2017 proved to be a very challenging year for low-cost and high volume players MediaTek and Spreadtrum as both companies saw their smartphone AP shipments and revenue decline sharply," said Sravan Kundojjala, Associate Director at Strategy Analytics.

Security, privacy and bandwidth factors are currently driving the on-device Artificial Intelligence (AI) chip trend as smartphone chip companies are integrating intelligence engines in their designs.

"The on-device AI chip landscape is highly fragmented. We think 2018 will be an experimental year for on-device AI chips and 2019 will see more clarity on future direction," said the report.

In 2017, over 250 million smartphone APs shipped with native AI engines to enable machine learning (ML) applications such as 3D face detection, image recognition and Animoji.

Octa-core chips accounted for over 40 percent of total smartphone AP shipments.

"Thanks to Qualcomm's increased strength in the mid-range with the Snapdragon 600 series, Qualcomm gained significant share at Chinese OEMs including Oppo, Vivo and Xiaomi at the expense of MediaTek in 2017," informed Stuart Robinson, Executive Director of the Strategy Analytics Handset Component Technologies service.