System apps are not allowed to record better then 16kHz mono (e5b29c98) · Commits · e / os / android_frameworks_base

media/java/android/media/AudioAttributes.java

+5 −5

Original line number	Original line	Diff line number	Diff line
	@@ -413,11 +413,11 @@ public final class AudioAttributes implements Parcelable {
	/**		/**
	* Indicates that the audio may only be captured by system apps.		* Indicates that the audio may only be captured by system apps.
	*		*
	* System apps can capture for many purposes like accessibility, user guidance...		* System apps can capture for many purposes like accessibility, live captions, user guidance...
	* but abide to the following restrictions:		* but abide to the following restrictions:
	* - the audio cannot leave the device		* - the audio cannot leave the device
	* - the audio cannot be passed to a third party app		* - the audio cannot be passed to a third party app
	* - the audio can not be recorded at a higher quality then 16kHz 16bit mono		* - the audio cannot be recorded at a higher quality than 16kHz 16bit mono
	*		*
	* See {@link Builder#setAllowedCapturePolicy}.		* See {@link Builder#setAllowedCapturePolicy}.
	*/		*/

media/java/android/media/audiopolicy/AudioMix.java

+56 −1

Original line number	Original line	Diff line number	Diff line
	@@ -91,6 +91,20 @@ public class AudioMix {
	*/		*/
	public static final int ROUTE_FLAG_LOOP_BACK = 0x1 << 1;		public static final int ROUTE_FLAG_LOOP_BACK = 0x1 << 1;

			/**
			* An audio mix behavior where the targeted audio is played unaffected but a copy is
			* accessible for capture through {@link AudioRecord}.
			*
			* Only capture of playback is supported, not capture of capture.
			* Use concurrent capture instead to capture what is captured by other apps.
			*
			* The captured audio is an approximation of the played audio.
			* Effects and volume are not applied, and track are mixed with different delay then in the HAL.
			* As a result, this API is not suitable for echo cancelling.
			* @hide
			*/
			public static final int ROUTE_FLAG_LOOP_BACK_RENDER = ROUTE_FLAG_LOOP_BACK \| ROUTE_FLAG_RENDER;

	private static final int ROUTE_FLAG_SUPPORTED = ROUTE_FLAG_RENDER \| ROUTE_FLAG_LOOP_BACK;		private static final int ROUTE_FLAG_SUPPORTED = ROUTE_FLAG_RENDER \| ROUTE_FLAG_LOOP_BACK;

	// MIX_TYPE_* values to keep in sync with frameworks/av/include/media/AudioPolicy.h		// MIX_TYPE_* values to keep in sync with frameworks/av/include/media/AudioPolicy.h
	@@ -125,6 +139,15 @@ public class AudioMix {
	*/		*/
	public static final int MIX_STATE_MIXING = 1;		public static final int MIX_STATE_MIXING = 1;

			/** Maximum sampling rate for privileged playback capture*/
			private static final int PRIVILEDGED_CAPTURE_MAX_SAMPLE_RATE = 16000;

			/** Maximum channel number for privileged playback capture*/
			private static final int PRIVILEDGED_CAPTURE_MAX_CHANNEL_NUMBER = 1;

			/** Maximum channel number for privileged playback capture*/
			private static final int PRIVILEDGED_CAPTURE_MAX_BYTES_PER_SAMPLE = 2;

	/**		/**
	* The current mixing state.		* The current mixing state.
	* @return one of {@link #MIX_STATE_DISABLED}, {@link #MIX_STATE_IDLE},		* @return one of {@link #MIX_STATE_DISABLED}, {@link #MIX_STATE_IDLE},
	@@ -140,7 +163,8 @@ public class AudioMix {
	return mRouteFlags;		return mRouteFlags;
	}		}

	AudioFormat getFormat() {		/** @hide */
			public AudioFormat getFormat() {
	return mFormat;		return mFormat;
	}		}

	@@ -182,6 +206,31 @@ public class AudioMix {
	return true;		return true;
	}		}

			/** @return an error string if the format would not allow Privileged playbackCapture
			* null otherwise
			* @hide */
			public static String canBeUsedForPrivilegedCapture(AudioFormat format) {
			int sampleRate = format.getSampleRate();
			if (sampleRate > PRIVILEDGED_CAPTURE_MAX_SAMPLE_RATE \|\| sampleRate <= 0) {
			return "Privileged audio capture sample rate " + sampleRate
			+ " can not be over " + PRIVILEDGED_CAPTURE_MAX_SAMPLE_RATE + "kHz";
			}
			int channelCount = format.getChannelCount();
			if (channelCount > PRIVILEDGED_CAPTURE_MAX_CHANNEL_NUMBER \|\| channelCount <= 0) {
			return "Privileged audio capture channel count " + channelCount + " can not be over "
			+ PRIVILEDGED_CAPTURE_MAX_CHANNEL_NUMBER;
			}
			int encoding = format.getEncoding();
			if (!format.isPublicEncoding(encoding) \|\| !format.isEncodingLinearPcm(encoding)) {
			return "Privileged audio capture encoding " + encoding + "is not linear";
			}
			if (format.getBytesPerSample(encoding) > PRIVILEDGED_CAPTURE_MAX_BYTES_PER_SAMPLE) {
			return "Privileged audio capture encoding " + encoding + " can not be over "
			+ PRIVILEDGED_CAPTURE_MAX_BYTES_PER_SAMPLE + " bytes per sample";
			}
			return null;
			}

	/** @hide */		/** @hide */
	@Override		@Override
	public boolean equals(Object o) {		public boolean equals(Object o) {
	@@ -390,6 +439,12 @@ public class AudioMix {
	}		}
	}		}
	}		}
			if (mRule.allowPrivilegedPlaybackCapture()) {
			String error = AudioMix.canBeUsedForPrivilegedCapture(mFormat);
			if (error != null) {
			throw new IllegalArgumentException(error);
			}
			}
	return new AudioMix(mRule, mFormat, mRouteFlags, mCallbackFlags, mDeviceSystemType,		return new AudioMix(mRule, mFormat, mRouteFlags, mCallbackFlags, mDeviceSystemType,
	mDeviceAddress);		mDeviceAddress);
	}		}

media/java/android/media/audiopolicy/AudioMixingRule.java

+4 −0

Original line number	Original line	Diff line number	Diff line
	@@ -365,6 +365,10 @@ public class AudioMixingRule {
	/**		/**
	* Set if the audio of app that opted out of audio playback capture should be captured.		* Set if the audio of app that opted out of audio playback capture should be captured.
	*		*
			* Caller of this method with <code>true</code>, MUST abide to the restriction listed in
			* {@link ALLOW_CAPTURE_BY_SYSTEM}, including but not limited to the captured audio
			* can not leave the capturing app, and the quality is limited to 16k mono.
			*
	* The permission {@link CAPTURE_AUDIO_OUTPUT} or {@link CAPTURE_MEDIA_OUTPUT} is needed		* The permission {@link CAPTURE_AUDIO_OUTPUT} or {@link CAPTURE_MEDIA_OUTPUT} is needed
	* to ignore the opt-out.		* to ignore the opt-out.
	*		*

services/core/java/com/android/server/audio/AudioService.java

+6 −0

Original line number	Original line	Diff line number	Diff line
	@@ -6761,6 +6761,12 @@ public class AudioService extends IAudioService.Stub
	if (mix.getRule().allowPrivilegedPlaybackCapture()) {		if (mix.getRule().allowPrivilegedPlaybackCapture()) {
	// then it must have CAPTURE_MEDIA_OUTPUT or CAPTURE_AUDIO_OUTPUT permission		// then it must have CAPTURE_MEDIA_OUTPUT or CAPTURE_AUDIO_OUTPUT permission
	requireCaptureAudioOrMediaOutputPerm \|= true;		requireCaptureAudioOrMediaOutputPerm \|= true;
			// and its format must be low quality enough
			String error = mix.canBeUsedForPrivilegedCapture(mix.getFormat());
			if (error != null) {
			Log.e(TAG, error);
			return false;
			}
	}		}

	// If mix is RENDER\|LOOPBACK, then an audio MediaProjection is enough		// If mix is RENDER\|LOOPBACK, then an audio MediaProjection is enough