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Windows Phone 8.1 多媒体(2):视频

原文:Windows Phone 8.1 多媒体(2):视频

Windows Phone 8.1 多媒体(1):相片

Windows Phone 8.1 多媒体(2):视频

Windows Phone 8.1 多媒体(3):音乐

 


 

(1)拍摄视频

拍摄视频和拍摄相片的方法是基本一致的:

MediaCapture mediaCapture;MediaEncodingProfile videoEncodingProperties;protected override async void OnNavigatedTo(NavigationEventArgs e){    HardwareButtons.CameraHalfPressed += HardwareButtons_CameraHalfPressed;    HardwareButtons.CameraReleased += HardwareButtons_CameraReleased;    videoCaptrueElement.Source = await Initialize();    await mediaCapture.StartPreviewAsync();}async void HardwareButtons_CameraHalfPressed(object sender, CameraEventArgs e){    if( mediaCapture != null )    {        var video = await KnownFolders.VideosLibrary.CreateFileAsync("video.mp4", CreationCollisionOption.GenerateUniqueName);await mediaCapture.StartRecordToStorageFileAsync(videoEncodingProperties, video);    }}async void HardwareButtons_CameraReleased(object sender, CameraEventArgs e){    if( mediaCapture != null )    {        await mediaCapture.StopRecordAsync();    }}private async Task<MediaCapture> Initialize(){    mediaCapture = new MediaCapture();    await mediaCapture.InitializeAsync();    mediaCapture.VideoDeviceController.PrimaryUse = CaptureUse.Video;    videoEncodingProperties = MediaEncodingProfile.CreateMp4(VideoEncodingQuality.Vga);    return mediaCapture;}protected override void OnNavigatedFrom(NavigationEventArgs e){    if( mediaCapture != null )    {        mediaCapture.Dispose();        mediaCapture = null;    }}

 

(2)编辑视频

视频编辑的 API 在 Windows.Media.Editing 命名空间下,具体可看 MSDN:链接

简单的说就是把某些视频实例化为 MediaClip,然后将这些视频添加到 MediaComposition.Clips 中去,最后将这些视频拼接到一起或添加个 BackgroundAudioTrack 什么的:

MediaClip video = await MediaClip.CreateFromFileAsync(
                await StorageFile.GetFileFromApplicationUriAsync(new Uri("ms-appx:///thanks.mp4")));MediaComposition videos = new MediaComposition();videos.Clips.Add(video);BackgroundAudioTrack bgm = await BackgroundAudioTrack.CreateFromFileAsync(
                    await StorageFile.GetFileFromApplicationUriAsync(new Uri("Above Your Hand.mp3")));videos.BackgroundAudioTracks.Clear();videos.BackgroundAudioTracks.Add(bgm);await videos.SaveAsync(await ApplicationData.Current.LocalFolder.CreateFileAsync("video.mp4", CreationCollisionOption.ReplaceExisting));

 

(3)录制手机屏幕视频

录制手机屏幕视频是 WP8.1 新加的 API,使用方法和拍摄视频差不多,只需将录制对象设为屏幕即可:

var screenCapture = ScreenCapture.GetForCurrentView();mediaCapture = new MediaCapture();await mediaCapture.InitializeAsync(new MediaCaptureInitializationSettings{    VideoSource = screenCapture.VideoSource,    AudioSource = screenCapture.AudioSource,});var file = await KnownFolders.VideosLibrary.CreateFileAsync("screenrecording.mp4", CreationCollisionOption.ReplaceExisting);await mediaCapture.StartRecordToStorageFileAsync(MediaEncodingProfile.CreateMp4(VideoEncodingQuality.Auto), file);

停止录制:

if( mediaCapture != null ){    await mediaCapture.StopRecordAsync();    mediaCapture.Dispose();    mediaCapture = null;}