install ffmpeg

.travis.yml

       before_install:
         - source ./scripts/env/env.ios.sh
       script:
+        - brew install ffmpeg --with-ffplay
         # - ./scripts/travis-fold.sh "npm run test-unit-ios -- --release"
         - ./scripts/travis-fold.sh "npm run test-e2e-ios -- --release"
 

scripts/test.e2e.ios.js

 }
 
 function startRecording() {
-  exec.execSync(`ffmpeg -f avfoundation -list_devices true -i ""`);
   const screenId = exec.execSyncRead(`ffmpeg -f avfoundation -list_devices true -i "" 2>&1 | grep "Capture screen 0" | sed -e "s/.*\\[//" -e "s/\\].*//"`);
   exec.execAsync(`ffmpeg -f avfoundation -i "${screenId}:none" out.avi`);
 }