最近解碼視頻產生的是yuv資料,然後需要產生jpg圖片,之前的方案是yuv-rgb-bmp-jpg這樣的話是很慢的,計算了時間大概要300ms左右,導致多次點擊照相,會造成視頻畫面的延遲,所以只能使用別的方案替代,在網上查詢libjpeg,所以打算使用libjpg-turbo來實現yuv轉換為jpg映像。下面是使用ndk來交叉編譯libjpeg-turbo產生libjpeg-turbo.so。
1、從官網下載最新的libjpeg-turbo源碼,
2、解壓縮下載的檔案,然後進入,並建立jni檔案夾,最後將裡面的檔案都拷貝到jni檔案中
3、進入jni目錄,然後建立設定檔(例如jconfig.h,config.h),在終端輸入:
[cpp]
./configure --with-jpeg8
./configure --with-jpeg8
就會產生
[cpp]
config.status: creating config.h
config.status: creating jconfig.h
config.status: creating config.h
config.status: creating jconfig.h4、接下來是建立Android.mk檔案
[cpp]
# Makefile for libjpeg-turbo
##################################################
### simd ###
##################################################
LOCAL_PATH := $(my-dir)
include $(CLEAR_VARS)
LOCAL_CFLAGS += -D__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 -D__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 += -D__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 -D__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、然後在終端輸入ndk-build,結果如下:
[cpp]
root@zhangjie:/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.a
SharedLibrary : libjpeg.so
Install : libjpeg.so => libs/armeabi/libjpeg.so
root@zhangjie:/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.a
SharedLibrary : libjpeg.so
Install : libjpeg.so => libs/armeabi/libjpeg.so