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AudioTrack: Enable deep buffer under certain conditions

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Under certain conditions, i.e. USAGE_MEDIA and
CONTENT_TYPE UNKNOWN, MUSIC, MOVIE and large buffers
we route the AudioTrack to deep buffer to save power.

Change-Id: Ibc8a31750999da842e36156f939448989ee50511
Test: Play Movies, CTS
Bug: 30687201
This commit is contained in:
Andy Hung
2017-01-31 19:27:04 -08:00
parent e9b8348027
commit 9025cc090b
1 changed files with 64 additions and 1 deletions
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65
media/java/android/media/AudioTrack.java
View File

@@ -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: