Android NEON Support

Starting from v4.2, MobileFFmpeg Main releases dropped support for non-NEON devices using ARMv7 (arm-v7a) architecture.

But LTS releases still support them. In these releases, arm-v7a-neon and arm64-v8a are the two architectures that support NEON instructions. arm64-v8a architecture has its own ABI but arm-v7a-neon does not; therefore both arm-v7a and arm-v7a-neon share the same ABI (armeabi-v7a). This means that armeabi-v7a builds include both libraries with and without NEON support. MobileFFmpeg detects the NEON support at runtime and loads the appropriate architecture for armeabi-v7a ABI. This mechanism aims to benefit from NEON optimizations, but size of armeabi-v7a ABI is bigger than other ABIs.

Since v2.1 the following .so files are packaged for each ABI. Please note that libc++_shared.so is only included if tesseract or x265 is enabled.

libavcodec.so
libavdevice.so
libavfilter.so
libavformat.so
libavutil.so
libc++_shared.so
libcpufeatures.so
libmobileffmpeg-abidetect.so
libmobileffmpeg.so
libswresample.so
libswscale.so

To enable NEON support on armeabi-v7a, the following libraries with -neon postfix are included additionally.

libavcodec-neon.so
libavfilter-neon.so
libmobileffmpeg-armv7a-neon
libswscale-neon.so