使用WP8最新的AudioVideoCaptureDevice类制作录像应用

提示：扫一扫查出行
【扫一扫了解最新限行尾号】
复制提示

WP8出来好一段时间了，新出的AudioVideoCaptureDevice类自定义功能比WP7的CaptureSource强大的多，但网上比较全面的中文实例还比较少，分享一个最近做的小实例给大家参考。

一、实现的功能

1、实现视频和音频的采集并保存

2、允许切换前后摄像头

3、录像过程中可以随时截图

4、录像后视频播放

二、需要的权限

1、需要访问前后摄像头的权限（ID_CAP_ISV_CAMERA）

2、需要访问麦克风的权限（ID_CAP_MICROPHONE)

三、UI部分

1、使用一个Rectangle控件实时显示摄像头采集到的画面

2、使用一个Image控件来显示视频截图

3、使用一个MediaElement控件来播放录制好的视频

4、使用一个HyperLinkButton控件来切换摄像头

四、代码部分

1、定义基础变量

//目录
private string m_path = "Vedio";
//视频文件名
private string m_filename = string.Empty;
//用于设置摄像头旋转的角度
RotateTransform rt1 = new RotateTransform();
//用于设置使用前置还是后置的摄像头
CameraSensorLocation sensorLocation = CameraSensorLocation.Front;
//随机访问数据流
private Windows.Storage.Streams.IRandomAccessStream m_iRandomAccessStream;
//捕获视频设备对象
private Windows.Phone.Media.Capture.AudioVideoCaptureDevice m_captureDevice;

2、初始化录像设备

/// <summary>
/// 初始化捕获设备，
/// </summary>
private async void Init()
{
try
{
if (m_captureDevice != null)
{
m_captureDevice.Dispose();
m_captureDevice = null;
}
//获取视频捕获设备
m_captureDevice = await AudioVideoCaptureDevice.OpenAsync(sensorLocation, new Windows.Foundation.Size(, )); int sensorOrientation = (Int32)this.m_captureDevice.SensorRotationInDegrees; if (sensorLocation == CameraSensorLocation.Back)
{
rt1.CenterX = ;
rt1.CenterY = ;
rt1.Angle = ;
Re_video.RenderTransform = rt1;
}
else
{
rt1.CenterX = ;
rt1.CenterY = ;
rt1.Angle = ;
Re_video.RenderTransform = rt1;
} m_captureDevice.SetProperty(KnownCameraGeneralProperties.EncodeWithOrientation, sensorLocation == CameraSensorLocation.Back ? : );
//m_captureDevice.SetProperty(KnownCameraAudioVideoProperties.VideoFrameRate, 20);
m_captureDevice.SetProperty(KnownCameraAudioVideoProperties.UnmuteAudioWhileRecording, true);
m_captureDevice.VideoEncodingFormat = CameraCaptureVideoFormat.H264; TheVideoBrush.SetSource(m_captureDevice);
//设置视频数据格式 }
catch (Exception e)
{
throw e;
}
}

注意：

1)、KnownCameraGeneralProperties.EncodeWithOrientation 可以控制前后摄像头旋转的角度，默认情况下WP获取的视频都是倒着显示的

2)、KnownCameraAudioVideoProperties.UnmuteAudioWhileRecording 是让视频在录制时取消静音，默认情况下是静音的

3)、CameraCaptureVideoFormat.H264; 使用H264编码方式

3、开始录制视频

//开始录制
private async void StartRecord()
{
m_filename = Guid.NewGuid().ToString() + ".mp4";
try
{
StorageFile file = null;
StorageFolder folder = ApplicationData.Current.LocalFolder;
using (IsolatedStorageFile isolatedStorageFile = IsolatedStorageFile.GetUserStoreForApplication())
{
//不存在目录，则创建
if (!isolatedStorageFile.DirectoryExists(m_path))
{
isolatedStorageFile.CreateDirectory(m_path);
}
} folder = await folder.GetFolderAsync(m_path); m_iRandomAccessStream = null;
//创建视频文件
file = await folder.CreateFileAsync(m_filename, CreationCollisionOption.ReplaceExisting);
m_iRandomAccessStream = await file.OpenAsync(FileAccessMode.ReadWrite);
//开始捕获视频数据并写到随机流中
await m_captureDevice.StartRecordingToStreamAsync(m_iRandomAccessStream); }
catch (Exception ex)
{
throw ex;
}
}

4、录制过程中实现截图功能

/// <summary>
/// 截取视频图像
/// </summary>
private void GetPreview()
{
WriteableBitmap wBitmap = new WriteableBitmap(, );
wBitmap.Render(Re_video, new MatrixTransform());//截取视频
wBitmap.Invalidate();
imgCapture.Source = wBitmap;
}

注意：这段代码的思路其实是截取Rectangle控件的UI界面

5、停止录制视频

//停止录制
private async void StopRecord()
{
try
{
await m_captureDevice.StopRecordingAsync();
m_iRandomAccessStream.Dispose();
}
catch (Exception ex)
{
throw ex;
}
}

6、播放录制好的视频

/// <summary>
/// 播放录制的视频
/// </summary>
private void PlayVideo()
{
string path = m_path + "/" + m_filename;
using (IsolatedStorageFile myIsolatedStorage = IsolatedStorageFile.GetUserStoreForApplication())
{
using (IsolatedStorageFileStream fileStream = myIsolatedStorage.OpenFile(path, FileMode.Open, FileAccess.Read))
{
VideoPlayer.SetSource(fileStream);
fileStream.Dispose();
fileStream.Close();
}
}
}

7、切换前后摄像头

/// <summary>
/// 切换前后摄像头
/// </summary>
/// <param name="sender"></param>
/// <param name="e"></param>
private void hyper_changes_Click(object sender, System.Windows.RoutedEventArgs e)
{
if (sensorLocation == CameraSensorLocation.Front)
sensorLocation = CameraSensorLocation.Back;
else
sensorLocation = CameraSensorLocation.Front;
Init();
}

至此，大致功能全部实现了，当然还需要处理一些按钮事件，这些直接看附件吧：

http://share.weiyun.com/d89188c5490e6bf95c7f7aa08c0f81bc

欢迎有共同兴趣的朋友交流，微博地址：http://weibo.com/yanghongjin

如果觉得本文对你有帮助，可以微信扫描以下二维码请我喝杯咖啡