cmake adds ffmpeg static link library to compile test program

An error was reported and it was found that the libz library was missing. Install and traverse the libz library.

CMakeLists：

cmake_minimum_required(VERSION 3.10)

project(ffmpegTest)

set(CMAKE_CXX_STANDARD 11)

SET(CMAKE_CXX_FLAGS "${CMAKE_CXX_FLAGS} -std=c++11 -pthread")

set (EXECUTABLE_OUTPUT_PATH ${PROJECT_SOURCE_DIR}/bin)

aux_source_directory (src SRC_LIST)

include_directories(${PROJECT_SOURCE_DIR}/include)

add_executable(main ${SRC_LIST})

target_link_libraries(main ${PROJECT_SOURCE_DIR}/lib/libavformat.a)
target_link_libraries(main ${PROJECT_SOURCE_DIR}/lib/libavdevice.a)
target_link_libraries(main ${PROJECT_SOURCE_DIR}/lib/libavcodec.a)
target_link_libraries(main ${PROJECT_SOURCE_DIR}/lib/libavutil.a) 
target_link_libraries(main pthread)
target_link_libraries(main ${PROJECT_SOURCE_DIR}/lib/libswscale.a)
target_link_libraries(main ${PROJECT_SOURCE_DIR}/lib/libz.a)
target_link_libraries(main ${PROJECT_SOURCE_DIR}/lib/libswresample.a) 
target_link_libraries(main ${PROJECT_SOURCE_DIR}/lib/libavutil.a)