Speech Recognizer does not honor lowercase tags

[Brian Tkatch]

I'm messing around with language detection in multiple languages, and noticed that the language code seems to be case sensitive. The problem with this is, Locale().getLanguage() results are lowercased! Here's an example if you'd like to try and verify this behavior for me.

Create a project using the defaults and an Empty Activity

Add the Record Audio permission to AndroidManifest.xml

<uses-permission android:name="android.permission.RECORD_AUDIO"/>

Replace the XML in activity_main.xml with the following:

<?xml version="1.0" encoding="utf-8"?>
<RelativeLayout
    xmlns:android="http://schemas.android.com/apk/res/android"
    tools:context="com.example.myapplication.MainActivity"
    xmlns:tools="http://schemas.android.com/tools"
    android:layout_width="match_parent"
    android:layout_height="match_parent">

    <CheckBox
        android:id="@+id/text_case"
        android:layout_width="wrap_content"
        android:layout_height="wrap_content"
        android:layout_alignParentLeft="true"
        android:layout_alignParentStart="true"
        android:layout_alignParentTop="true"/>

    <Spinner
        android:id="@+id/languages"
        android:layout_width="wrap_content"
        android:layout_height="wrap_content"
        android:layout_toRightOf="@+id/text_case"
        android:layout_toEndOf="@id/text_case"
        android:layout_alignBaseline="@id/text_case"/>

    <TextView
        android:id="@+id/language_string"
        android:layout_width="wrap_content"
        android:layout_height="wrap_content"
        android:layout_toRightOf="@id/languages"
        android:layout_toEndOf="@id/languages"
        android:layout_alignBaseline="@id/languages"/>

    <TextView
        android:id="@+id/result"
        android:layout_width="match_parent"
        android:layout_height="wrap_content"
        android:layout_below="@+id/languages"/>

    <Button
        android:id="@+id/button"
        android:text="start"
        android:layout_width="wrap_content"
        android:layout_height="wrap_content"
        android:layout_below="@+id/result"
        android:onClick="button_click"/>

    <TextView
        android:id="@+id/errors"
        android:layout_width="wrap_content"
        android:layout_height="wrap_content"
        android:layout_alignParentBottom="true"/>

</RelativeLayout>

Replace the code in MainActivity.java with the following:

package com.example.myapplication;

import android.app.Activity;
import android.content.BroadcastReceiver;
import android.content.Context;
import android.content.Intent;
import android.speech.RecognitionListener;
import android.speech.RecognizerIntent;
import android.speech.SpeechRecognizer;
import android.support.v7.app.AppCompatActivity;
import android.os.Bundle;
import android.view.View;
import android.widget.ArrayAdapter;
import android.widget.Button;
import android.widget.CheckBox;
import android.widget.Spinner;
import android.widget.TextView;

import java.util.ArrayList;
import java.util.Collections;
import java.util.Locale;

public class MainActivity
        extends AppCompatActivity
    implements RecognitionListener
{
    Spinner languages;
    TextView result, errors, language_string;
    Button button;
    CheckBox text_case;

    SpeechRecognizer recognizer;
    Intent intent;
    Boolean listening = false;

    @Override
    protected void onCreate(Bundle savedInstanceState)
    {
        super.onCreate(savedInstanceState);
        setContentView(R.layout.activity_main);

        languages = (Spinner) findViewById(R.id.languages);
        result = (TextView) findViewById(R.id.result);
        errors = (TextView) findViewById(R.id.errors);
        button = (Button) findViewById(R.id.button);
        text_case = (CheckBox) findViewById(R.id.text_case);
        language_string = (TextView) findViewById(R.id.language_string);

        // get supported languages
        sendOrderedBroadcast
        (
            RecognizerIntent.getVoiceDetailsIntent(this),
            null,
            new BroadcastReceiver()
            {
                @Override
                public void onReceive(Context context, Intent intent)
                {
                    final Bundle extra = getResultExtras(false);

                    if (getResultCode() == Activity.RESULT_OK && extra.containsKey(RecognizerIntent.EXTRA_SUPPORTED_LANGUAGES))
                        setup_languages_spinner(extra.getStringArrayList(RecognizerIntent.EXTRA_SUPPORTED_LANGUAGES));
                }
            },
            null,
            Activity.RESULT_OK,
            null,
            null
        );

        // See if we're even supported.
        if(!SpeechRecognizer.isRecognitionAvailable(this))
        {
            result.setText("(recognition not available)");
            return;
        }

        // the basics
        recognizer = SpeechRecognizer.createSpeechRecognizer(this);
        recognizer.setRecognitionListener(this);

        intent = new Intent(RecognizerIntent.ACTION_RECOGNIZE_SPEECH);
        intent.putExtra(RecognizerIntent.EXTRA_LANGUAGE_MODEL, RecognizerIntent.LANGUAGE_MODEL_FREE_FORM);

        // Other languages. Due to a bug, new String[]{} must be passed, until Google fixes it.
        intent.putExtra("android.speech.extra.EXTRA_ADDITIONAL_LANGUAGES", new String[]{});
    }

    public void setup_languages_spinner(ArrayList<String> supported_languages)
    {
        Collections.sort(supported_languages);
        languages.setAdapter(new ArrayAdapter<>(this, R.layout.support_simple_spinner_dropdown_item, supported_languages));

        // Default language and variant.
        languages.setSelection
        (
            supported_languages.indexOf
            (
                Locale.getDefault().getLanguage() + "-" + Locale.getDefault().getCountry()
            )
        );
    }

    @Override public void onResults(Bundle results)
    {
        ArrayList<String> list = results.getStringArrayList(SpeechRecognizer.RESULTS_RECOGNITION);

        if(list == null) result.setText("(no words recognized)");
        else result.setText(list.get(0));
    }

    public void button_click(View view)
    {
        if(!listening)
        {
            button.setText("stop");

            String language = languages.getSelectedItem().toString();

            if(text_case.isChecked()) language = language.toLowerCase();

            language_string.setText(language + " (" + new Locale(language).getLanguage() + ")");

            intent.putExtra(RecognizerIntent.EXTRA_LANGUAGE, language);
            recognizer.startListening(intent);
        }
        else
        {
            recognizer.stopListening();
            button.setText("start");
        }

        listening = !listening;
    }

    @Override public void onEndOfSpeech()
    {
        listening = false;
        button.setText("start");
    }

    @Override public void onError(int error)
    {
        errors.setText(error_string(error));
    }

    protected String error_string(int error)
    {
        switch(error)
        {
            case SpeechRecognizer.ERROR_AUDIO:                      return "audio";
            case SpeechRecognizer.ERROR_CLIENT:                     return "client";
            case SpeechRecognizer.ERROR_INSUFFICIENT_PERMISSIONS:   return "insufficient permissions";
            case SpeechRecognizer.ERROR_NETWORK:                    return "network";
            case SpeechRecognizer.ERROR_NETWORK_TIMEOUT:            return "network timeout";
            case SpeechRecognizer.ERROR_NO_MATCH:                   return "no match found";
            case SpeechRecognizer.ERROR_RECOGNIZER_BUSY:            return "recognizer busy";
            case SpeechRecognizer.ERROR_SERVER:                     return "server";
            case SpeechRecognizer.ERROR_SPEECH_TIMEOUT:             return "speech timeout";
            default:                                                return "default";
        }
    }
    @Override public void onReadyForSpeech(Bundle params){}
    @Override public void onBeginningOfSpeech(){}
    @Override public void onRmsChanged(float rms_dB){}
    @Override public void onBufferReceived(byte[] buffer){}
    @Override public void onPartialResults(Bundle partialResults){}
    @Override public void onEvent(int eventType, Bundle params){}
}

Run the app.

The objects are as follows:

If the the checkbox is checked, it will lowecase the chosen language tag.

The spinner lists all dialects available for recognition, and defaults to the default language and country of the system.

The text box next to it shows the language code passed to the recognition system, and in parenthesis, what Locale().getLanguage() returns for the selection.

The text box between the checkbox and the button shows the first entry from what the recognizer returned.

The button starts the recognition. It will also stop it, but there's no need to do so manually, as it will shortly timeout and stop on its own.

On the bottom of the screen is a text box showing the most recent error.

I have found that lowercasing the tag defaults to English (either because of my system or because that is the ultimate default) and Locale().getLanguage() returns lowercase. This isn't an issue, per se, but i thought using getLanguage would be the appropriate method to use.

[Brian Tkatch]

I would even like someone (or two or three) to verify this behavior. It's easy to test. Just try a non English word, like Hola (oh-la) in Spanish or Ciao (chow) in Italian.

[Brian Tkatch]

Figured something out. Although using Locale(lang + "-" + country) does not work, regardless of case. It must have the language part alone. Locale(lang, country) seems to work, regardless of case.

So, that means, when getting the language tag, it must be split in order to get a Locale:

String tag[] = language_tag.split("-");

String language = tag.length >= 1 ? tag[0] : "";
String country = tag.length >= 2 ? tag[1] : "";
String variant = tag.length >= 3 ? tag[2] : "";

Locale locale = new Locale(language, country, variant);

Unless i'm missing something, and there's an easier way to go from tag to Locale.