Libjpeg-Turbo's neon Function

Libjpeg-Turbo is an extension of libjpeg and supports SIMD commands, such as MMX, SSE, sse2, 3 dnow in X86 architecture, and neon in ARM architecture, this improves the speed of JPEG encoding and decoding. Libjpeg is included in the graphics library cximage7.01. Therefore, libjpeg-turbo can be easily replaced. A rough test of 2560x1920 JPEG (occupied by 14 MB memory after decoding) on the wince6 platform with 1g clock speed in cortex-a8 architecture, the result is 2642 ms for libjpeg, using libjpeg-Turbo requires 1900 ms, and the efficiency is improved by about 30%. Considering that the resolution of digital cameras is getting bigger and bigger, the neon command cannot fully meet the needs, hard decoding is the king.