Question

我在Windows Phone 8中创建了一个视频录制功能，并将字节数组转换为base-64字符串。我如何获得录音的持续时间？我的字节数组内存大小太大，因此base64String也太大了，所以我得到这样的错误：

"System.OutOfMemoryException"

有关详细信息，请参阅下面的代码：

private IsolatedStorageFileStream isoVideoFile;
string isoVideoFileName = "CameraMovie.mp4";

isoVideoFile = new IsolatedStorageFileStream(isoVideoFileName,
                   FileMode.OpenOrCreate, FileAccess.ReadWrite,
                   IsolatedStorageFile.GetUserStoreForApplication());
MemoryStream stream = new MemoryStream();
isoVideoFile.Write(stream.GetBuffer(), 0, (int)stream.Position);

byte[] binaryData = new Byte[isoVideoFile.Length];
long bytesRead = isoVideoFile.Read(binaryData, 0, (int)isoVideoFile.Length);
string videofile = Convert.ToBase64String(binaryData, 0, binaryData.Length);

视频长度：

    private void Element_MediaOpened1(object sender, RoutedEventArgs e)
    {
        if (mediaElement_1.NaturalDuration.HasTimeSpan)
        timelineSlider.Maximum = mediaElement_1.NaturalDuration.TimeSpan.TotalSeconds;
    }

Answer 1

你可以通过每个应用memory limit来克服。

尝试处置资源。将using与流一起使用是一种很好的做法。像这样的东西： private IsolatedStorageFileStream isoVideoFile; string isoVideoFileName =＆＃34; CameraMovie.mp4＆＃34 ;;

using(isoVideoFile = new IsolatedStorageFileStream(isoVideoFileName,
                   FileMode.OpenOrCreate, FileAccess.ReadWrite,
                   IsolatedStorageFile.GetUserStoreForApplication()))
{
    using(MemoryStream stream = new MemoryStream())
    {
        isoVideoFile.Write(stream.GetBuffer(), 0, (int)stream.Position);
    }
    byte[] binaryData = new Byte[isoVideoFile.Length];
    long bytesRead = isoVideoFile.Read(binaryData, 0, (int)isoVideoFile.Length);
    string videofile = Convert.ToBase64String(binaryData, 0, binaryData.Length);
}

视频时长怎么样，这里是thread on msdn forums

Windows Phone 8中的视频文件到Base64String问题

1 个答案: