1.点击拍照
2.手势捏合放大和缩小
3.10s视频约1.9M左右
4.长按视频（可设置视频长度）
5.可以重复查看和播放录制的视频
6.前后摄像头切换
Copyright 2017 Irfan Raza
Licensed under the Apache License, Version 2.0 (the "License"); you may not use this file except in compliance with the License. You may obtain a copy of the License at
http://www.apache.org/licenses/LICENSE-2.0
Unless required by applicable law or agreed to in writing, software distributed under the License is distributed on an "AS IS" BASIS, WITHOUT WARRANTIES OR CONDITIONS OF ANY KIND, either express or implied. See the License for the specific language governing permissions and limitations under the License.