Pass stereo gains as packed minifloat
This will allow (eventually) a greater dynamic range for gains.
However there are still a few remaining places in effects and mixer
that will also need to be changed in order to get the full benefit.
Also fixes a minor bug: was not checking for NaN in AudioTrack C++.
Change-Id: I63bce9e82e0a61546d8ff475fb94bcb700d99c96
diff --git a/services/audioflinger/Tracks.cpp b/services/audioflinger/Tracks.cpp
index 6dc7f30..08687a2 100644
--- a/services/audioflinger/Tracks.cpp
+++ b/services/audioflinger/Tracks.cpp
@@ -34,6 +34,7 @@
#include <media/nbaio/Pipe.h>
#include <media/nbaio/PipeReader.h>
+#include <audio_utils/minifloat.h>
// ----------------------------------------------------------------------------
@@ -459,7 +460,7 @@
void AudioFlinger::PlaybackThread::Track::dump(char* buffer, size_t size, bool active)
{
- uint32_t vlr = mAudioTrackServerProxy->getVolumeLR();
+ gain_minifloat_packed_t vlr = mAudioTrackServerProxy->getVolumeLR();
if (isFastTrack()) {
sprintf(buffer, " F %2d", mFastIndex);
} else if (mName >= AudioMixer::TRACK0) {
@@ -532,8 +533,8 @@
stateChar,
mFillingUpStatus,
mAudioTrackServerProxy->getSampleRate(),
- 20.0 * log10((vlr & 0xFFFF) / 4096.0),
- 20.0 * log10((vlr >> 16) / 4096.0),
+ 20.0 * log10(float_from_gain(gain_minifloat_unpack_left(vlr))),
+ 20.0 * log10(float_from_gain(gain_minifloat_unpack_right(vlr))),
mCblk->mServer,
mMainBuffer,
mAuxBuffer,
@@ -959,27 +960,27 @@
// implement VolumeBufferProvider interface
-uint32_t AudioFlinger::PlaybackThread::Track::getVolumeLR()
+gain_minifloat_packed_t AudioFlinger::PlaybackThread::Track::getVolumeLR()
{
// called by FastMixer, so not allowed to take any locks, block, or do I/O including logs
ALOG_ASSERT(isFastTrack() && (mCblk != NULL));
- uint32_t vlr = mAudioTrackServerProxy->getVolumeLR();
- uint32_t vl = vlr & 0xFFFF;
- uint32_t vr = vlr >> 16;
+ gain_minifloat_packed_t vlr = mAudioTrackServerProxy->getVolumeLR();
+ float vl = float_from_gain(gain_minifloat_unpack_left(vlr));
+ float vr = float_from_gain(gain_minifloat_unpack_right(vlr));
// track volumes come from shared memory, so can't be trusted and must be clamped
- if (vl > MAX_GAIN_INT) {
- vl = MAX_GAIN_INT;
+ if (vl > GAIN_FLOAT_UNITY) {
+ vl = GAIN_FLOAT_UNITY;
}
- if (vr > MAX_GAIN_INT) {
- vr = MAX_GAIN_INT;
+ if (vr > GAIN_FLOAT_UNITY) {
+ vr = GAIN_FLOAT_UNITY;
}
// now apply the cached master volume and stream type volume;
// this is trusted but lacks any synchronization or barrier so may be stale
float v = mCachedVolume;
vl *= v;
vr *= v;
- // re-combine into U4.16
- vlr = (vr << 16) | (vl & 0xFFFF);
+ // re-combine into packed minifloat
+ vlr = gain_minifloat_pack(gain_from_float(vl), gain_from_float(vr));
// FIXME look at mute, pause, and stop flags
return vlr;
}
@@ -1590,7 +1591,7 @@
// since client and server are in the same process,
// the buffer has the same virtual address on both sides
mClientProxy = new AudioTrackClientProxy(mCblk, mBuffer, mFrameCount, mFrameSize);
- mClientProxy->setVolumeLR((uint32_t(uint16_t(0x1000)) << 16) | uint16_t(0x1000));
+ mClientProxy->setVolumeLR(GAIN_MINIFLOAT_PACKED_UNITY);
mClientProxy->setSendLevel(0.0);
mClientProxy->setSampleRate(sampleRate);
mClientProxy = new AudioTrackClientProxy(mCblk, mBuffer, mFrameCount, mFrameSize,