[text-to-speech] Return AudioInputStream instead of InputStream

[germanattanasio]

Lots of users are trying to use the InputStream they get from Text to Speech into an AudioInputStream without luck.

[svergara1987]

Hello, I'm one of those having this problem.
I've tried different variants and was able to save an audio file in my file system and play it later (not by code). But couldn't play the stream using Java.
Attached, you can see the last test and the corresponding output.
Any suggestion?

[germanattanasio]

@daniel-bolanos I think this is related to the way we save the wav file by default. It could be the encoding we are using. What do you think?

[germanattanasio]

@daniel-bolanos I've created a test Case so that we can test the problem: https://gist.github.com/germanattanasio/e2b1e3d25fa85a16a503

[germanattanasio]

The issue is that the InputStream coming from /synthesize doesn't have the data(a.k.a content length) specified because it was streamed (InputStream) .
There are two options:

1. Read the inputStream and put the data manually
2. Find a way to reproduce it without data

I'm going to implement the first one in a Utils class.

cc: @svergara1987

[germanattanasio]

@daniel-bolanos discovered this by adding manually the data with the file size, after that I was able to reproduce the file with AudioInputStream.

[svergara1987]

Great! Thanks @germanattanasio .
I'm already waiting for that Utils class

[RobWills]

Is this the kind of solution you need?

InputStream is;
is = tts_service.synthesize(text, Voice.GB_KATE, HttpMediaType.AUDIO_WAV);

File audio = new File(System.getProperty( "user.home" ) + "/" + "output.wav");

OutputStream outStream = null;              
try {
    outStream = new FileOutputStream(audio);

    byte[] buffer = new byte[8 * 1024];
    int bytesRead;
    while ((bytesRead = is.read(buffer)) != -1) {
        outStream.write(buffer, 0, bytesRead);
    }
} catch (Exception e) {
    System.out.println(e.getMessage());
} finally {
    IOUtils.closeQuietly(is);
    IOUtils.closeQuietly(outStream);
    audio = null;
}

[germanattanasio]

I think the problem is that the service is streaming the audio back to the user and since it doesn't know the size, is not adding the proper headers to the wav file.
Some modern audio players can play the audio without knowing the size but when you are trying to play it in java you need to know those things.

The android-speech-sdk has a class that deal with this and I was thinking on copy some of that code here (see this).