Windows 10 Store App - save URI as file - windows

Question

I am writing a Windows 10 Store app. In the app the User can input a Text, and then press "Read Text" and Cortana reads the text loud. That works fine.
Now I want to add the feature, to press a button called "Save" or something like that and then save Cortanas output as mp3 file. This should work via a normal save-file dialog.
This is what I got so far.
private static MediaElement mediaplayer = new MediaElement();
/// ... mediaplayer element gets content ...
Uri file = mediaplayer.Source;
Instead of an Uri element I could also get an SpeechSynthesisStream with this information.
How can I save this Uri / Stream to a file?
EDIT:
this is the final code:
var stream2 = stream.CloneStream();
//... use stream2 as mediaelement ...
if(stream != null)
{
using (var reader = new DataReader(stream))
{
FileSavePicker savePicker = new FileSavePicker();
savePicker.SuggestedStartLocation = PickerLocationId.PicturesLibrary;
savePicker.FileTypeChoices.Add("WAV", new List<string>() { ".wav" });
savePicker.SuggestedFileName = "sound.wav";
StorageFile file = await savePicker.PickSaveFileAsync();
if (file != null)
{
using (var outputStream = await file.OpenAsync(FileAccessMode.ReadWrite))
{
using (var writer = new DataWriter(outputStream.GetOutputStreamAt(0)))
{
long writtenBytes = 0;
const int bufferSize = 8192;
uint loadedBytes = 0;
while ((loadedBytes = (await reader.LoadAsync(bufferSize))) > 0) //!!!
{
IBuffer buffer = reader.ReadBuffer(loadedBytes);
writer.WriteBuffer(buffer);
uint tmpWritten = await writer.StoreAsync(); //!!!
writtenBytes += tmpWritten;
}
}
}
}
}
}

Answer 1

If you're trying to write the output to a file instead (or as well as) rendering it audibly to a MediaElement, you probably want something like this in here as well.
SpeechSynthesisStream synthesisStream = await synthesizer.SynthesizeTextToStreamAsync(text);
var stream2 = synthesisStream.CloneStream();
FileSavePicker savePicker = new FileSavePicker();
savePicker.SuggestedStartLocation = PickerLocationId.MusicLibrary;
savePicker.FileTypeChoices.Add("WAV", new List<string>() { ".wav" });
savePicker.SuggestedFileName = "sound.wav";
StorageFile file = await savePicker.PickSaveFileAsync();
using (var reader = new DataReader(synthesisStream))
{
using (var outputStream = await file.OpenAsync(FileAccessMode.ReadWrite))
{
using (var writer = new DataWriter(outputStream.GetOutputStreamAt(0)))
{
long writtenBytes = 0;
const int bufferSize = 8192;
uint loadedBytes = 0;
while ((loadedBytes = (await reader.LoadAsync(bufferSize))) > 0) //!!!
{
IBuffer buffer = reader.ReadBuffer(loadedBytes);
writer.WriteBuffer(buffer);
uint tmpWritten = await writer.StoreAsync(); //!!!
writtenBytes += tmpWritten;
}
}
}
}
// Set the source and start playing the synthesized audio stream.
media.AutoPlay = true;
media.SetSource(stream2, synthesisStream.ContentType);
media.Play();
The one problem is that the synthesisStream isn't rewindable (so far as I can tell), so you might have to synthesize it twice, or make a second (in memory) copy of the stream if you want to make it audible at the same time.