Chuyển đổi định dạng file media trong Windows Store Apps

Bài viết này hướng dẫn các chuyển đổi định dạng file media (Transcode media files) trong lập trình ứng dụng Windows Store App.

Code XAML trang MainPage.xaml

Code trang MainPage.xaml.cs

using System;
using System.Collections.Generic;
using System.IO;
using System.Linq;
using System.Runtime.InteropServices.WindowsRuntime;
using Windows.Foundation;
using Windows.Foundation.Collections;
using Windows.UI.Xaml;
using Windows.UI.Xaml.Controls;
using Windows.UI.Xaml.Controls.Primitives;
using Windows.UI.Xaml.Data;
using Windows.UI.Xaml.Input;
using Windows.UI.Xaml.Media;
using Windows.UI.Xaml.Navigation;
using Windows.Storage;
using Windows.Media.MediaProperties;
using Windows.Media.Transcoding;

// The Blank Page item template is documented at http://go.microsoft.com/fwlink/?LinkId=234238

namespace ConvertMedia
{
    /// 

    /// An empty page that can be used on its own or navigated to within a Frame.
    /// 
    public sealed partial class MainPage : Page
    {
        public MainPage()
        {
            this.InitializeComponent();
        }
        private async void btnSelectfile_Click(object sender, RoutedEventArgs e)
        {
            var openPicker = new Windows.Storage.Pickers.FileOpenPicker();
            openPicker.SuggestedStartLocation = Windows.Storage.Pickers.PickerLocationId.VideosLibrary;
            openPicker.FileTypeFilter.Add(".wmv");
            openPicker.FileTypeFilter.Add(".mp4");
 
            StorageFile source = await openPicker.PickSingleFileAsync(); 
            var savePicker = new Windows.Storage.Pickers.FileSavePicker(); 
            savePicker.SuggestedStartLocation = Windows.Storage.Pickers.PickerLocationId.VideosLibrary;
 
            savePicker.DefaultFileExtension = ".mp4";
            savePicker.SuggestedFileName = "New Video";
 
            savePicker.FileTypeChoices.Add("MPEG4", new string[] { ".mp4" }); 
            StorageFile destination = await savePicker.PickSaveFileAsync();
 

            MediaTranscoder transcoder = new MediaTranscoder();
            MediaEncodingProfile profile = MediaEncodingProfile.CreateMp4(VideoEncodingQuality.HD720p);
            PrepareTranscodeResult prepareOp = await transcoder.PrepareFileTranscodeAsync(source, destination, profile);

            if (prepareOp.CanTranscode)
            {
                var transcodeOp = prepareOp.TranscodeAsync();

                transcodeOp.Progress += new AsyncActionProgressHandler(TranscodeProgress);
                transcodeOp.Completed += new AsyncActionWithProgressCompletedHandler(TranscodeComplete);
            }
            else
            {
                switch (prepareOp.FailureReason)
                {
                    case TranscodeFailureReason.CodecNotFound:
                        System.Diagnostics.Debug.WriteLine("Codec not found.");
                        break;
                    case TranscodeFailureReason.InvalidProfile:
                        System.Diagnostics.Debug.WriteLine("Invalid profile.");
                        break;
                    default:
                        System.Diagnostics.Debug.WriteLine("Unknown failure.");
                        break;
                }
            }
        }
            void TranscodeProgress(IAsyncActionWithProgress asyncInfo, double percent)
            {

            }
        void TranscodeComplete(IAsyncActionWithProgress asyncInfo, AsyncStatus status)
        {
            asyncInfo.GetResults();
            if (asyncInfo.Status == AsyncStatus.Completed)
            {

            }
            else if (asyncInfo.Status == AsyncStatus.Canceled)
            {

            }
            else
            {

            }
        }

    }
}

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