feat: 切换后端至PaddleOCR-NCNN，切换工程为CMake

1.项目后端整体迁移至PaddleOCR-NCNN算法，已通过基本的兼容性测试
2.工程改为使用CMake组织，后续为了更好地兼容第三方库，不再提供QMake工程
3.重整权利声明文件，重整代码工程，确保最小化侵权风险

Log: 切换后端至PaddleOCR-NCNN，切换工程为CMake
Change-Id: I4d5d2c5d37505a4a24b389b1a4c5d12f17bfa38c

3rdparty/opencv-4.5.4/modules/videoio/misc/plugin_ffmpeg/CMakeLists.txt

@@ -0,0 +1,18 @@
+cmake_minimum_required(VERSION 3.5)
+
+get_filename_component(OpenCV_SOURCE_DIR "${CMAKE_CURRENT_LIST_DIR}/../../../.." ABSOLUTE)
+include("${OpenCV_SOURCE_DIR}/cmake/OpenCVPluginStandalone.cmake")
+
+# scan dependencies
+set(WITH_FFMPEG ON)
+set(OPENCV_FFMPEG_SKIP_BUILD_CHECK ON)
+include("${OpenCV_SOURCE_DIR}/modules/videoio/cmake/init.cmake")
+
+set(OPENCV_PLUGIN_DEPS core imgproc imgcodecs)
+ocv_create_plugin(videoio "opencv_videoio_ffmpeg" "ocv.3rdparty.ffmpeg" "FFmpeg" "src/cap_ffmpeg.cpp")
+
+message(STATUS "FFMPEG_libavcodec_VERSION=${FFMPEG_libavcodec_VERSION}")
+message(STATUS "FFMPEG_libavformat_VERSION=${FFMPEG_libavformat_VERSION}")
+message(STATUS "FFMPEG_libavutil_VERSION=${FFMPEG_libavutil_VERSION}")
+message(STATUS "FFMPEG_libswscale_VERSION=${FFMPEG_libswscale_VERSION}")
+message(STATUS "FFMPEG_libavresample_VERSION=${FFMPEG_libavresample_VERSION}")

3rdparty/opencv-4.5.4/modules/videoio/misc/plugin_ffmpeg/Dockerfile-ffmpeg

@@ -0,0 +1,45 @@
+FROM ubuntu:18.04
+
+RUN apt-get update && apt-get --no-install-recommends install -y \
+        pkg-config \
+        cmake \
+        g++ \
+        ninja-build \
+        make \
+        nasm \
+    && \
+    rm -rf /var/lib/apt/lists/*
+
+ARG VER
+
+ADD ffmpeg-${VER}.tar.xz /ffmpeg/
+
+WORKDIR /ffmpeg/ffmpeg-${VER}
+RUN ./configure \
+    --enable-avresample \
+    --prefix=/ffmpeg-shared \
+    --enable-shared \
+    --disable-static \
+    --disable-programs \
+    --disable-doc \
+    --disable-avdevice \
+    --disable-postproc \
+    && make -j8 install \
+    && make clean \
+    && make distclean
+
+RUN ./configure \
+    --enable-avresample \
+    --prefix=/ffmpeg-static \
+    --disable-shared \
+    --enable-static \
+    --enable-pic \
+    --disable-programs \
+    --disable-doc \
+    --disable-avdevice \
+    --disable-postproc \
+    && make -j8 install \
+    && make clean \
+    && make distclean
+
+WORKDIR /tmp

3rdparty/opencv-4.5.4/modules/videoio/misc/plugin_ffmpeg/Dockerfile-ubuntu

@@ -0,0 +1,17 @@
+ARG VER
+FROM ubuntu:$VER
+
+RUN apt-get update && apt-get --no-install-recommends install -y \
+        libavcodec-dev \
+        libavfilter-dev \
+        libavformat-dev \
+        libavresample-dev \
+        libavutil-dev \
+        pkg-config \
+        cmake \
+        g++ \
+        ninja-build \
+    && \
+    rm -rf /var/lib/apt/lists/*
+
+WORKDIR /tmp

3rdparty/opencv-4.5.4/modules/videoio/misc/plugin_ffmpeg/build-standalone.sh

@@ -0,0 +1,24 @@
+#!/bin/bash
+
+set -e
+
+mkdir -p build_shared && pushd build_shared
+PKG_CONFIG_PATH=/ffmpeg-shared/lib/pkgconfig \
+cmake -GNinja \
+    -DOPENCV_PLUGIN_NAME=opencv_videoio_ffmpeg_shared_$2 \
+    -DOPENCV_PLUGIN_DESTINATION=$1 \
+    -DCMAKE_BUILD_TYPE=$3 \
+    /opencv/modules/videoio/misc/plugin_ffmpeg
+ninja
+popd
+
+mkdir -p build_static && pushd build_static
+PKG_CONFIG_PATH=/ffmpeg-static/lib/pkgconfig \
+cmake -GNinja \
+    -DOPENCV_PLUGIN_NAME=opencv_videoio_ffmpeg_static_$2 \
+    -DOPENCV_PLUGIN_DESTINATION=$1 \
+    -DCMAKE_MODULE_LINKER_FLAGS=-Wl,-Bsymbolic \
+    -DCMAKE_BUILD_TYPE=$3 \
+    /opencv/modules/videoio/misc/plugin_ffmpeg
+ninja
+popd

3rdparty/opencv-4.5.4/modules/videoio/misc/plugin_ffmpeg/build-ubuntu.sh

@@ -0,0 +1,10 @@
+#!/bin/bash
+
+set -e
+
+cmake -GNinja \
+    -DOPENCV_PLUGIN_NAME=opencv_videoio_ffmpeg_ubuntu_$2 \
+    -DOPENCV_PLUGIN_DESTINATION=$1 \
+    -DCMAKE_BUILD_TYPE=$3 \
+    /opencv/modules/videoio/misc/plugin_ffmpeg
+ninja