Merge "AudioTrack: Enable deep buffer under certain conditions" (763aeb5b) · Commits · e / os / android_frameworks_base

media/java/android/media/AudioTrack.java

+64 −1

Original line number	Diff line number	Diff line
		@@ -27,6 +27,7 @@ import java.util.Collection;

		import android.annotation.IntDef;
		import android.annotation.NonNull;
		import android.annotation.Nullable;
		import android.app.ActivityThread;
		import android.content.Context;
		import android.os.Handler;
		@@ -538,6 +539,15 @@ public class AudioTrack extends PlayerBase
		throw new IllegalArgumentException("Illegal null AudioFormat");
		}

		// Check if we should enable deep buffer mode
		if (shouldEnablePowerSaving(mAttributes, format, bufferSizeInBytes, mode)) {
		mAttributes = new AudioAttributes.Builder(mAttributes)
		.replaceFlags((mAttributes.getAllFlags()
		\| AudioAttributes.FLAG_DEEP_BUFFER)
		& ~AudioAttributes.FLAG_LOW_LATENCY)
		.build();
		}

		// remember which looper is associated with the AudioTrack instantiation
		Looper looper;
		if ((looper = Looper.myLooper()) == null) {
		@@ -861,7 +871,10 @@ public class AudioTrack extends PlayerBase
		.build();
		break;
		case PERFORMANCE_MODE_NONE:
		break;
		if (!shouldEnablePowerSaving(mAttributes, mFormat, mBufferSizeInBytes, mMode)) {
		break; // do not enable deep buffer mode.
		}
		// permitted to fall through to enable deep buffer
		case PERFORMANCE_MODE_POWER_SAVING:
		mAttributes = new AudioAttributes.Builder(mAttributes)
		.replaceFlags((mAttributes.getAllFlags()
		@@ -912,6 +925,56 @@ public class AudioTrack extends PlayerBase
		AudioFormat.CHANNEL_OUT_SIDE_LEFT \|
		AudioFormat.CHANNEL_OUT_SIDE_RIGHT;

		// Returns a boolean whether the attributes, format, bufferSizeInBytes, mode allow
		// power saving to be automatically enabled for an AudioTrack. Returns false if
		// power saving is already enabled in the attributes parameter.
		private static boolean shouldEnablePowerSaving(
		@Nullable AudioAttributes attributes, @Nullable AudioFormat format,
		int bufferSizeInBytes, int mode) {
		// If no attributes, OK
		// otherwise check attributes for USAGE_MEDIA and CONTENT_UNKNOWN, MUSIC, or MOVIE.
		if (attributes != null &&
		(attributes.getAllFlags() != 0 // cannot have any special flags
		\|\| attributes.getUsage() != AudioAttributes.USAGE_MEDIA
		\|\| (attributes.getContentType() != AudioAttributes.CONTENT_TYPE_UNKNOWN
		&& attributes.getContentType() != AudioAttributes.CONTENT_TYPE_MUSIC
		&& attributes.getContentType() != AudioAttributes.CONTENT_TYPE_MOVIE))) {
		return false;
		}

		// Format must be fully specified and be linear pcm
		if (format == null
		\|\| format.getSampleRate() == AudioFormat.SAMPLE_RATE_UNSPECIFIED
		\|\| !AudioFormat.isEncodingLinearPcm(format.getEncoding())
		\|\| !AudioFormat.isValidEncoding(format.getEncoding())
		\|\| format.getChannelCount() < 1) {
		return false;
		}

		// Mode must be streaming
		if (mode != MODE_STREAM) {
		return false;
		}

		// A buffer size of 0 is always compatible with deep buffer (when called from the Builder)
		// but for app compatibility we only use deep buffer power saving for large buffer sizes.
		if (bufferSizeInBytes != 0) {
		final long BUFFER_TARGET_MODE_STREAM_MS = 100;
		final int MILLIS_PER_SECOND = 1000;
		final long bufferTargetSize =
		BUFFER_TARGET_MODE_STREAM_MS
		* format.getChannelCount()
		* format.getBytesPerSample(format.getEncoding())
		* format.getSampleRate()
		/ MILLIS_PER_SECOND;
		if (bufferSizeInBytes < bufferTargetSize) {
		return false;
		}
		}

		return true;
		}

		// Convenience method for the constructor's parameter checks.
		// This is where constructor IllegalArgumentException-s are thrown
		// postconditions: