使用汽車麥克風錄音

您可以使用車輛的 CarAppService 和 CarAudioRecord API，授予應用程式存取使用者車輛麥克風的權限。使用者必須授予應用程式存取車輛麥克風的權限。應用程式可以記錄及處理使用者在應用程式中的輸入內容。

宣告錄音權限

錄製音訊前，您必須先在 AndroidManifest.xml 中宣告錄音權限，並要求使用者授予該權限。

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

您必須在執行階段要求錄音權限。如要進一步瞭解如何在車輛中要求權限，請參閱「要求權限」。

錄音

使用者授權錄音後，您就可以錄製音訊並處理錄音內容。

Kotlin

val carAudioRecord = CarAudioRecord.create(carContext)
        carAudioRecord.startRecording()

        val data = ByteArray(CarAudioRecord.AUDIO_CONTENT_BUFFER_SIZE)
        while(carAudioRecord.read(data, 0, CarAudioRecord.AUDIO_CONTENT_BUFFER_SIZE) >= 0) {
            // Use data array
            // Potentially call carAudioRecord.stopRecording() if your processing finds end of speech
        }
        carAudioRecord.stopRecording()

Java

CarAudioRecord carAudioRecord = CarAudioRecord.create(getCarContext());
        carAudioRecord.startRecording();

        byte[] data = new byte[CarAudioRecord.AUDIO_CONTENT_BUFFER_SIZE];
        while (carAudioRecord.read(data, 0, CarAudioRecord.AUDIO_CONTENT_BUFFER_SIZE) >= 0) {
            // Use data array
            // Potentially call carAudioRecord.stopRecording() if your processing finds end of speech
        }
        carAudioRecord.stopRecording();

取得音訊焦點

如要透過車輛麥克風錄音，請先取得音訊焦點。 這麼做會停止播放任何媒體。如果失去音訊焦點，請停止錄音。舉例來說，如要取得音訊焦點：

Kotlin

val carAudioRecord = CarAudioRecord.create(carContext)

        // Take audio focus so that user's media is not recorded
        val audioAttributes = AudioAttributes.Builder()
            .setContentType(AudioAttributes.CONTENT_TYPE_SPEECH)
            // Use the most appropriate usage type for your use case
            .setUsage(AudioAttributes.USAGE_ASSISTANCE_NAVIGATION_GUIDANCE)
            .build()

        val audioFocusRequest =
            AudioFocusRequest.Builder(AudioManager.AUDIOFOCUS_GAIN_TRANSIENT_EXCLUSIVE)
                .setAudioAttributes(audioAttributes)
                .setOnAudioFocusChangeListener { state: Int ->
                    if (state == AudioManager.AUDIOFOCUS_LOSS) {
                        // Stop recording if audio focus is lost
                        carAudioRecord.stopRecording()
                    }
                }
                .build()

        if (carContext.getSystemService(AudioManager::class.java)
                .requestAudioFocus(audioFocusRequest)
            != AudioManager.AUDIOFOCUS_REQUEST_GRANTED
        ) {
            // Don't record if the focus isn't granted
            return
        }

        carAudioRecord.startRecording()
        // Process the audio and abandon the AudioFocusRequest when done

Java

CarAudioRecord carAudioRecord = CarAudioRecord.create(getCarContext());
        // Take audio focus so that user's media is not recorded
        AudioAttributes audioAttributes =
                new AudioAttributes.Builder()
                        .setContentType(AudioAttributes.CONTENT_TYPE_SPEECH)
                        // Use the most appropriate usage type for your use case
                        .setUsage(AudioAttributes.USAGE_ASSISTANCE_NAVIGATION_GUIDANCE)
                        .build();

        AudioFocusRequest audioFocusRequest =
                new AudioFocusRequest.Builder(AudioManager.AUDIOFOCUS_GAIN_TRANSIENT_EXCLUSIVE)
                        .setAudioAttributes(audioAttributes)
                        .setOnAudioFocusChangeListener(state -> {
                            if (state == AudioManager.AUDIOFOCUS_LOSS) {
                                // Stop recording if audio focus is lost
                                carAudioRecord.stopRecording();
                            }
                        })
                        .build();

        if (getCarContext().getSystemService(AudioManager.class).requestAudioFocus(audioFocusRequest)
                != AUDIOFOCUS_REQUEST_GRANTED) {
            // Don't record if the focus isn't granted
            return;
        }

        carAudioRecord.startRecording();
        // Process the audio and abandon the AudioFocusRequest when done
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