Compiling libjpeg-turbo for android

Recently, the video is decoded to generate yuv data and then jpg images. The previous scheme is yuv-rgb-bmp-jpg, which is very slow. The calculation time is about Ms, multiple clicks on a photo may lead to video screen latency. Therefore, you can only use another method to query libjpeg on the Internet. Therefore, we plan to use libjpg-turbo to convert yuv to jpg images. The following is the use of ndk to cross-compile libjpeg-turbo to generate a libjpeg-turbo.so.

1. download the latest libjpeg-turbo source code from the official website,

2. decompress the downloaded file, enter, create a jni folder, and finally copy all the files to the jni file.

3. Enter the jni directory, create a configuration file (for example, jconfig. h, config. h), and enter:

[Cpp]
./Configure -- with-jpeg8

./Configure -- with-jpeg8
Will generate

[Cpp]
Config. status: creating config. h
Config. status: creating jconfig. h

Config. status: creating config. h
Config. status: creating jconfig. h4. Next, create the Android. mk file.

[Cpp]
# Makefile for libjpeg-turbo
 
######################################## ##########
### Simd ###
######################################## ##########
LOCAL_PATH: = $ (my-dir)
Include $ (CLEAR_VARS)
LOCAL_CFLAGS + =-d1_arm_have_neon
 
# From autoconf-generated Makefile
EXTRA_DIST = simd/nasm_lt.sh simd/jcclrmmx. asm simd/jcclrss2.asm simd/jdclrmmx. asm simd/jdclrss2.asm \
Simd/jdmrgmmx. asm simd/jdmrgss2.asm simd/jcclrss2-64.asm simd/jdclrss2-64.asm \
Simd/jdmrgss2-64.asm simd/CMakeLists.txt

Libsimd_SOURCES_DIST = simd/jsimd_arm_neon.S \
Simd/jsimd_arm.c
 
LOCAL_SRC_FILES: = $ (libsimd_SOURCES_DIST)
 
LOCAL_C_INCLUDES: = $ (LOCAL_PATH)/simd \
$ (LOCAL_PATH)/android

AM_CFLAGS: =-march = armv7-a-mfpu = neon
AM_CCASFLAGS :=- march = armv7-a-mfpu = neon
LOCAL_ARM_MODE = arm
LOCAL_MODULE_TAGS: = debug

LOCAL_MODULE: = libsimd

Include $ (BUILD_STATIC_LIBRARY)

######################################## ##############
### Libjpeg. so ##
######################################## ##############

Include $ (CLEAR_VARS)
 
# From autoconf-generated Makefile
Libjpeg_SOURCES_DIST = jcapimin. c jcapistd. c jccoefct. c jccolor. c \
Jcdctmgr. c jchuff. c jcinit. c jcmainct. c jcmarker. c jcmaster. c \
Jcomapi. c jcparam. c jcphuff. c jcprepct. c jcsample. c jctrans. c \
Jdapimin. c jdapistd. c jdatadst. c jdatasrc. c jdcoefct. c jdcolor. c \
Jddctmgr. c jdhuff. c jdinput. c jdmainct. c jdmarker. c jdmaster. c \
Jdmerge. c jdphuff. c jdpostct. c jdsample. c jdtrans. c jerror. c \
Jfdctflt. c jfdctfst. c jfdctint. c jidctflt. c jidctfst. c jidctint. c \
Jidctred. c jquant1.c jquant2.c jutils. c jmemmgr. c jmemnobs. c \
Jaricom. c jcarith. c jdarith. c \
Turbojpeg. c transupp. c jdatadst-tj.c jdatasrc-tj.c \
Turbojpeg-mapfile
 
LOCAL_SRC_FILES: = $ (libjpeg_SOURCES_DIST)

LOCAL_SHARED_LIBRARIES: = libcutils
LOCAL_STATIC_LIBRARIES: = libsimd
LOCAL_ARM_MODE = arm
LOCAL_C_INCLUDES: = $ (LOCAL_PATH)

LOCAL_CFLAGS: =-O3-fstrict-aliasing-fprefetch-loop-arrays-DANDROID \
-DANDROID_TILE_BASED_DECODE-DENABLE_ANDROID_NULL_CONVERT-d1_arm_have_neon
AM_CFLAGS: =-march = armv7-a-mfpu = neon
AM_CCASFLAGS :=- march = armv7-a-mfpu = neon
LOCAL_MODULE_PATH: = $ (TARGET_OUT_OPTIONAL_STATIC_LIBRARY)
LOCAL_MODULE_TAGS: = debug
LOCAL_MODULE: = libjpeg
Include $ (BUILD_SHARED_LIBRARY)

# Makefile for libjpeg-turbo

######################################## ##########
### Simd ###
######################################## ##########
LOCAL_PATH: = $ (my-dir)
Include $ (CLEAR_VARS)
LOCAL_CFLAGS + =-d1_arm_have_neon

# From autoconf-generated Makefile
EXTRA_DIST = simd/nasm_lt.sh simd/jcclrmmx. asm simd/jcclrss2.asm simd/jdclrmmx. asm simd/jdclrss2.asm \
Simd/jdmrgmmx. asm simd/jdmrgss2.asm simd/jcclrss2-64.asm simd/jdclrss2-64.asm \
Simd/jdmrgss2-64.asm simd/CMakeLists.txt
 
Libsimd_SOURCES_DIST = simd/jsimd_arm_neon.S \
Simd/jsimd_arm.c

LOCAL_SRC_FILES: = $ (libsimd_SOURCES_DIST)

LOCAL_C_INCLUDES: = $ (LOCAL_PATH)/simd \
$ (LOCAL_PATH)/android
 
AM_CFLAGS: =-march = armv7-a-mfpu = neon
AM_CCASFLAGS :=- march = armv7-a-mfpu = neon
LOCAL_ARM_MODE = arm
LOCAL_MODULE_TAGS: = debug
 
LOCAL_MODULE: = libsimd
 
Include $ (BUILD_STATIC_LIBRARY)
 
######################################## ##############
### Libjpeg. so ##
######################################## ##############
 
Include $ (CLEAR_VARS)

# From autoconf-generated Makefile
Libjpeg_SOURCES_DIST = jcapimin. c jcapistd. c jccoefct. c jccolor. c \
Jcdctmgr. c jchuff. c jcinit. c jcmainct. c jcmarker. c jcmaster. c \
Jcomapi. c jcparam. c jcphuff. c jcprepct. c jcsample. c jctrans. c \
Jdapimin. c jdapistd. c jdatadst. c jdatasrc. c jdcoefct. c jdcolor. c \
Jddctmgr. c jdhuff. c jdinput. c jdmainct. c jdmarker. c jdmaster. c \
Jdmerge. c jdphuff. c jdpostct. c jdsample. c jdtrans. c jerror. c \
Jfdctflt. c jfdctfst. c jfdctint. c jidctflt. c jidctfst. c jidctint. c \
Jidctred. c jquant1.c jquant2.c jutils. c jmemmgr. c jmemnobs. c \
Jaricom. c jcarith. c jdarith. c \
Turbojpeg. c transupp. c jdatadst-tj.c jdatasrc-tj.c \
Turbojpeg-mapfile

LOCAL_SRC_FILES: = $ (libjpeg_SOURCES_DIST)
 
LOCAL_SHARED_LIBRARIES: = libcutils
LOCAL_STATIC_LIBRARIES: = libsimd
LOCAL_ARM_MODE = arm
LOCAL_C_INCLUDES: = $ (LOCAL_PATH)
 
LOCAL_CFLAGS: =-O3-fstrict-aliasing-fprefetch-loop-arrays-DANDROID \
-DANDROID_TILE_BASED_DECODE-DENABLE_ANDROID_NULL_CONVERT-d1_arm_have_neon
AM_CFLAGS: =-march = armv7-a-mfpu = neon
AM_CCASFLAGS :=- march = armv7-a-mfpu = neon
LOCAL_MODULE_PATH: = $ (TARGET_OUT_OPTIONAL_STATIC_LIBRARY)
LOCAL_MODULE_TAGS: = debug
LOCAL_MODULE: = libjpeg
Include $ (BUILD_SHARED_LIBRARY)
5. Enter ndk-build on the terminal. The result is as follows:

[Cpp]
Root @ MAID:/home/libjpeg-turbo-1.2.1/jni # ndk-build
Android NDK: WARNING: Unsupported source file extensions in/home/libjpeg-turbo-1.2.1/jni/Android. mk for module jpeg
Android NDK: turbojpeg-mapfile
Compile arm: jpeg <= jcapimin. c
Compile arm: jpeg <= jcapistd. c
Compile arm: jpeg <= jccoefct. c
Compile arm: jpeg <= jccolor. c
Compile arm: jpeg <= jcdctmgr. c
Compile arm: jpeg <= jchuff. c
Compile arm: jpeg <= jcinit. c
Compile arm: jpeg <= jcmainct. c
Compile arm: jpeg <= jcmarker. c
Compile arm: jpeg <= jcmaster. c
Compile arm: jpeg <= jcomapi. c
Compile arm: jpeg <= jcparam. c
Compile arm: jpeg <= jcphuff. c
Compile arm: jpeg <= jcprepct. c
Compile arm: jpeg <= jcsample. c
Compile arm: jpeg <= jctrans. c
Compile arm: jpeg <= jdapimin. c
Compile arm: jpeg <= jdapistd. c
Compile arm: jpeg <= jdatadst. c
Compile arm: jpeg <= jdatasrc. c
Compile arm: jpeg <= jdcoefct. c
Compile arm: jpeg <= jdcolor. c
Compile arm: jpeg <= jddctmgr. c
Compile arm: jpeg <= jdhuff. c
Compile arm: jpeg <= jdinput. c
Compile arm: jpeg <= jdmainct. c
Compile arm: jpeg <= jdmarker. c
Compile arm: jpeg <= jdmaster. c
Compile arm: jpeg <= jdmerge. c
Compile arm: jpeg <= jdphuff. c
Compile arm: jpeg <= jdpostct. c
Compile arm: jpeg <= jdsample. c
Compile arm: jpeg <= jdtrans. c
Compile arm: jpeg <= jerror. c
Compile arm: jpeg <= jfdctflt. c
Compile arm: jpeg <= jfdctfst. c
Compile arm: jpeg <= jfdctint. c
Compile arm: jpeg <= jidctflt. c
Compile arm: jpeg <= jidctfst. c
Compile arm: jpeg <= jidctint. c
Compile arm: jpeg <= jidctred. c
Compile arm: jpeg <= jquant1.c
Compile arm: jpeg <= jquant2.c
Compile arm: jpeg <= jutils. c
Compile arm: jpeg <= jmemmgr. c
Compile arm: jpeg <= jmemnobs. c
Compile arm: jpeg <= jaricom. c
Compile arm: jpeg <= jcarith. c
Compile arm: jpeg <= jdarith. c
Compile arm: jpeg <= turbojpeg. c
Compile arm: jpeg <= transupp. c
Compile arm: jpeg <= jdatadst-tj.c
Compile arm: jpeg <= jdatasrc-tj.c
Compile arm: simd <= jsimd_arm_neon.S
Compile arm: simd <= jsimd_arm.c
StaticLibrary: libsimd.
SharedLibrary: libjpeg. so
Install: libjpeg. so => libs/armeabi/libjpeg. so

Root @ MAID:/home/libjpeg-turbo-1.2.1/jni # ndk-build
Android NDK: WARNING: Unsupported source file extensions in/home/libjpeg-turbo-1.2.1/jni/Android. mk for module jpeg
Android NDK: turbojpeg-mapfile
Compile arm: jpeg <= jcapimin. c
Compile arm: jpeg <= jcapistd. c
Compile arm: jpeg <= jccoefct. c
Compile arm: jpeg <= jccolor. c
Compile arm: jpeg <= jcdctmgr. c
Compile arm: jpeg <= jchuff. c
Compile arm: jpeg <= jcinit. c
Compile arm: jpeg <= jcmainct. c
Compile arm: jpeg <= jcmarker. c
Compile arm: jpeg <= jcmaster. c
Compile arm: jpeg <= jcomapi. c
Compile arm: jpeg <= jcparam. c
Compile arm: jpeg <= jcphuff. c
Compile arm: jpeg <= jcprepct. c
Compile arm: jpeg <= jcsample. c
Compile arm: jpeg <= jctrans. c
Compile arm: jpeg <= jdapimin. c
Compile arm: jpeg <= jdapistd. c
Compile arm: jpeg <= jdatadst. c
Compile arm: jpeg <= jdatasrc. c
Compile arm: jpeg <= jdcoefct. c
Compile arm: jpeg <= jdcolor. c
Compile arm: jpeg <= jddctmgr. c
Compile arm: jpeg <= jdhuff. c
Compile arm: jpeg <= jdinput. c
Compile arm: jpeg <= jdmainct. c
Compile arm: jpeg <= jdmarker. c
Compile arm: jpeg <= jdmaster. c
Compile arm: jpeg <= jdmerge. c
Compile arm: jpeg <= jdphuff. c
Compile arm: jpeg <= jdpostct. c
Compile arm: jpeg <= jdsample. c
Compile arm: jpeg <= jdtrans. c
Compile arm: jpeg <= jerror. c
Compile arm: jpeg <= jfdctflt. c
Compile arm: jpeg <= jfdctfst. c
Compile arm: jpeg <= jfdctint. c
Compile arm: jpeg <= jidctflt. c
Compile arm: jpeg <= jidctfst. c
Compile arm: jpeg <= jidctint. c
Compile arm: jpeg <= jidctred. c
Compile arm: jpeg <= jquant1.c
Compile arm: jpeg <= jquant2.c
Compile arm: jpeg <= jutils. c
Compile arm: jpeg <= jmemmgr. c
Compile arm: jpeg <= jmemnobs. c
Compile arm: jpeg <= jaricom. c
Compile arm: jpeg <= jcarith. c
Compile arm: jpeg <= jdarith. c
Compile arm: jpeg <= turbojpeg. c
Compile arm: jpeg <= transupp. c
Compile arm: jpeg <= jdatadst-tj.c
Compile arm: jpeg <= jdatasrc-tj.c
Compile arm: simd <= jsimd_arm_neon.S
Compile arm: simd <= jsimd_arm.c
StaticLibrary: libsimd.
SharedLibrary: libjpeg. so
Install: libjpeg. so => libs/armeabi/libjpeg. so