android使用libyuv

libyuv可以帮我们将rgb转换成yuv，也可以用来旋转yuv，转换成其他yuv格式
libyuv git地址是https://chromium.googlesource.com/libyuv/libyuv，由于众所周知的原因，无法直接访问，我们可以用gitlab来中转一下
首先创建一个project，选择Import project，点击Repo by URL，在url里填入这个网址，勾选Mirror repository，然后创建工程，等待同步完成就可以下载代码了

这个是我创建的一个镜像 https://gitlab.com/cc_linco/libyuv1.git

接下来创建AS工程，勾选C++支持，一路next就可以了
将libyuv源码解压到src/main/cpp目录下，修改一下libyuv/CMakeLists.txt，去掉一些编译生成的文件，也可以不改，按自己需要编辑，下面是我注释掉一些编译目标后的文件

# CMakeLists for libyuv
# Originally created for "roxlu build system" to compile libyuv on windows
# Run with -DTEST=ON to build unit tests

PROJECT ( YUV C CXX )   # "C" is required even for C++ projects
CMAKE_MINIMUM_REQUIRED( VERSION 2.8 )
OPTION( TEST "Built unit tests" OFF )

SET ( ly_base_dir   ${PROJECT_SOURCE_DIR} )
SET ( ly_src_dir    ${ly_base_dir}/source )
SET ( ly_inc_dir    ${ly_base_dir}/include )
SET ( ly_tst_dir    ${ly_base_dir}/unit_test )
SET ( ly_lib_name   yuv )
SET ( ly_lib_static ${ly_lib_name} )
SET ( ly_lib_shared ${ly_lib_name}_shared )

FILE ( GLOB_RECURSE ly_source_files ${ly_src_dir}/*.cc )
LIST ( SORT         ly_source_files )

FILE ( GLOB_RECURSE ly_unittest_sources ${ly_tst_dir}/*.cc )
LIST ( SORT         ly_unittest_sources )

INCLUDE_DIRECTORIES( BEFORE ${ly_inc_dir} )

# this creates the static library (.a)
ADD_LIBRARY             ( ${ly_lib_static} STATIC ${ly_source_files} )

# this creates the shared library (.so)
ADD_LIBRARY             ( ${ly_lib_shared} SHARED ${ly_source_files} )
SET_TARGET_PROPERTIES   ( ${ly_lib_shared} PROPERTIES OUTPUT_NAME "${ly_lib_name}" )
SET_TARGET_PROPERTIES   ( ${ly_lib_shared} PROPERTIES PREFIX "lib" )

# this creates the conversion tool
#ADD_EXECUTABLE         ( yuvconvert ${ly_base_dir}/util/yuvconvert.cc )
#TARGET_LINK_LIBRARIES  ( yuvconvert ${ly_lib_static} )


INCLUDE ( FindJPEG )
if (JPEG_FOUND)
  include_directories( ${JPEG_INCLUDE_DIR} )
  target_link_libraries( yuvconvert ${JPEG_LIBRARY} )
  add_definitions( -DHAVE_JPEG )
endif()

if(TEST)
  find_library(GTEST_LIBRARY gtest)
  if(GTEST_LIBRARY STREQUAL "GTEST_LIBRARY-NOTFOUND")
    set(GTEST_SRC_DIR /usr/src/gtest CACHE STRING "Location of gtest sources")
    if(EXISTS ${GTEST_SRC_DIR}/src/gtest-all.cc)
      message(STATUS "building gtest from sources in ${GTEST_SRC_DIR}")
      set(gtest_sources ${GTEST_SRC_DIR}/src/gtest-all.cc)
      add_library(gtest STATIC ${gtest_sources})
      include_directories(${GTEST_SRC_DIR})
      include_directories(${GTEST_SRC_DIR}/include)
      set(GTEST_LIBRARY gtest)
    else()
      message(FATAL_ERROR "TEST is set but unable to find gtest library")
    endif()
  endif()

  add_executable(libyuv_unittest ${ly_unittest_sources})
  target_link_libraries(libyuv_unittest ${ly_lib_name} ${GTEST_LIBRARY})
  find_library(PTHREAD_LIBRARY pthread)
  if(NOT PTHREAD_LIBRARY STREQUAL "PTHREAD_LIBRARY-NOTFOUND")
    target_link_libraries(libyuv_unittest pthread)
  endif()
  if (JPEG_FOUND)
    target_link_libraries(libyuv_unittest ${JPEG_LIBRARY})
  endif()

  if(NACL AND NACL_LIBC STREQUAL "newlib")
    target_link_libraries(libyuv_unittest glibc-compat)
  endif()

  find_library(GFLAGS_LIBRARY gflags)
  if(NOT GFLAGS_LIBRARY STREQUAL "GFLAGS_LIBRARY-NOTFOUND")
    target_link_libraries(libyuv_unittest gflags)
    add_definitions(-DLIBYUV_USE_GFLAGS)
  endif()
endif()


# instal