改进vlcdemo+ffmpegdemo自动识别32 64位

ffmpegdemo/ffmpeg/ffmpeg.pri

@@ -2,6 +2,9 @@ HEADERS     += $$PWD/ffmpeghead.h
 HEADERS     += $$PWD/ffmpeg.h
 SOURCES     += $$PWD/ffmpeg.cpp
 
+#如果用的是ffmpeg4内核请将ffmpeg3改成ffmpeg4,两种内核不兼容,头文件也不一样
+DEFINES += ffmpeg3
+
 #ffmpeg4则使用ffmpeg4的目录
 contains(DEFINES, ffmpeg4) {
 strPath = ffmpeg4
@@ -9,17 +12,23 @@ strPath = ffmpeg4
 strPath = ffmpeg3
 }
 
-#32位的库则使用32位的库的头文件和lib文件
-contains(DEFINES, qt32) {
-strLib = winlib
-strInclude = include
-} else {
+#表示64位的构建套件
+contains(QT_ARCH, x86_64) {
 strLib = winlib64
 strInclude = include64
+} else {
+#由于Qt4不支持QT_ARCH所以会执行下面的
+#如果用的64位的Qt4则需要自行修改
+strLib = winlib
+strInclude = include
+}
+
+#表示arm平台构建套件
+contains(QT_ARCH, arm) {
+strInclude = include
 }
 
 INCLUDEPATH += $$PWD/$$strPath/$$strInclude
-INCLUDEPATH += $$PWD/$$strPath/$$strInclude/plugins
 
 win32 {
 LIBS += -L$$PWD/$$strPath/$$strLib/ -lavcodec -lavfilter -lavformat -lswscale -lavutil -lswresample -lavdevice