android - Android中的AlwaysOnHotwordDetector的示例

有人可以提供一个示例，说明如何在Android中使用新的AlwaysOnHotwordDetector类吗？

我想构建一个应用程序，当该应用程序在后台运行时，它可以检测到诸如“下一个”，“后退”或“暂停”之类的关键词。

最佳答案

除非我有巨大的盲点，否则我认为第三方应用程序无法利用此API。奇怪的是AlwaysOnHotwordDetector(以及相关类VoiceInteractionService等)已被授予公共(public)访问权限。

如果您要构建特权应用程序，请查看来自AOSP的以下测试项目:

语音交互-AlwaysOnHotwordDetector基本用法/实现
http://androidxref.com/5.0.0_r2/xref/frameworks/base/tests/VoiceInteraction/

语音注册-http://androidxref.com/5.0.0_r2/xref/frameworks/base/tests/VoiceEnrollment/

在尝试进行这项工作时，我遇到了这个问题:
AlwaysOnHotwordDetector's构造函数:

/**
 * @param text The keyphrase text to get the detector for.
 * @param locale The java locale for the detector.
 * @param callback A non-null Callback for receiving the recognition events.
 * @param voiceInteractionService The current voice interaction service.
 * @param modelManagementService A service that allows management of sound models.
 *
 * @hide
 */
public AlwaysOnHotwordDetector(String text, Locale locale, Callback callback,
        KeyphraseEnrollmentInfo keyphraseEnrollmentInfo,
        IVoiceInteractionService voiceInteractionService,
        IVoiceInteractionManagerService modelManagementService) {
    mText = text;
    mLocale = locale;
    mKeyphraseEnrollmentInfo = keyphraseEnrollmentInfo;
    mKeyphraseMetadata = mKeyphraseEnrollmentInfo.getKeyphraseMetadata(text, locale);
    mExternalCallback = callback;
    mHandler = new MyHandler();
    mInternalCallback = new SoundTriggerListener(mHandler);
    mVoiceInteractionService = voiceInteractionService;
    mModelManagementService = modelManagementService;
    new RefreshAvailabiltyTask().execute();
}

感兴趣的声明是:

mKeyphraseMetadata = mKeyphraseEnrollmentInfo.getKeyphraseMetadata(text, locale);

KeyphraseEnrollmentInfo#getKeyphraseMetadata(String, Locale)是做什么的？

/**
 * Gets the {@link KeyphraseMetadata} for the given keyphrase and locale, null if any metadata
 * isn't available for the given combination.
 *
 * @param keyphrase The keyphrase that the user needs to be enrolled to.
 * @param locale The locale for which the enrollment needs to be performed.
 *        This is a Java locale, for example "en_US".
 * @return The metadata, if the enrollment client supports the given keyphrase
 *         and locale, null otherwise.
 */
public KeyphraseMetadata getKeyphraseMetadata(String keyphrase, Locale locale) {
    if (mKeyphrases == null || mKeyphrases.length == 0) {
        Slog.w(TAG, "Enrollment application doesn't support keyphrases");
        return null;
    }
    for (KeyphraseMetadata keyphraseMetadata : mKeyphrases) {
        // Check if the given keyphrase is supported in the locale provided by
        // the enrollment application.
        if (keyphraseMetadata.supportsPhrase(keyphrase)
                && keyphraseMetadata.supportsLocale(locale)) {
            return keyphraseMetadata;
        }
    }
    Slog.w(TAG, "Enrollment application doesn't support the given keyphrase/locale");
    return null;
}

此时，我的示例项目一直告诉我:Enrollment application doesn't support keyphrases。因此，进一步研究-为了支持关键短语，我们需要提供其他元数据:

// Taken from class KeyphraseEnrollmentInfo
/**
 * Name under which a Hotword enrollment component publishes information about itself.
 * This meta-data should reference an XML resource containing a
 * <code>&lt;{@link
 * android.R.styleable#VoiceEnrollmentApplication
 * voice-enrollment-application}&gt;</code> tag.
 */
private static final String VOICE_KEYPHRASE_META_DATA = "android.voice_enrollment";

此外，我们将需要android.permission.MANAGE_VOICE_KEYPHRASES权限。这是示例项目卡住的地方:

<!-- Must be required by hotword enrollment application,
     to ensure that only the system can interact with it.
     @hide <p>Not for use by third-party applications.</p> -->
<permission android:name="android.permission.MANAGE_VOICE_KEYPHRASES"
    android:label="@string/permlab_manageVoiceKeyphrases"
    android:description="@string/permdesc_manageVoiceKeyphrases"
    android:protectionLevel="signature|system" />

支持热字检测所需的权限不适用于第三方应用程序。我仍然不知道为什么android.service.voice包具有公共(public)访问权限。也许我在这里错过了一些东西。

关于android - Android中的AlwaysOnHotwordDetector的示例，我们在Stack Overflow上找到一个类似的问题：https://stackoverflow.com/questions/26834163/