diff options
| -rw-r--r-- | services/audioflinger/Threads.cpp | 38 | ||||
| -rw-r--r-- | services/audioflinger/Threads.h | 3 |
2 files changed, 38 insertions, 3 deletions
diff --git a/services/audioflinger/Threads.cpp b/services/audioflinger/Threads.cpp index 7809eff..dc6710f 100644 --- a/services/audioflinger/Threads.cpp +++ b/services/audioflinger/Threads.cpp @@ -2191,6 +2191,10 @@ void AudioFlinger::PlaybackThread::readOutputParameters_l() ALOGI("HAL output buffer size %u frames, normal sink buffer size %u frames", mFrameCount, mNormalFrameCount); + // Check if we want to throttle the processing to no more than 2x normal rate + mThreadThrottle = property_get_bool("af.thread.throttle", true /* default_value */); + mHalfBufferMs = mNormalFrameCount * 1000 / (2 * mSampleRate); + // mSinkBuffer is the sink buffer. Size is always multiple-of-16 frames. // Originally this was int16_t[] array, need to remove legacy implications. free(mSinkBuffer); @@ -2908,8 +2912,9 @@ bool AudioFlinger::PlaybackThread::threadLoop() if (!waitingAsyncCallback()) { // mSleepTimeUs == 0 means we must write to audio hardware if (mSleepTimeUs == 0) { + ssize_t ret = 0; if (mBytesRemaining) { - ssize_t ret = threadLoop_write(); + ret = threadLoop_write(); if (ret < 0) { mBytesRemaining = 0; } else { @@ -2920,11 +2925,11 @@ bool AudioFlinger::PlaybackThread::threadLoop() (mMixerStatus == MIXER_DRAIN_ALL)) { threadLoop_drain(); } - if (mType == MIXER) { + if (mType == MIXER && !mStandby) { // write blocked detection nsecs_t now = systemTime(); nsecs_t delta = now - mLastWriteTime; - if (!mStandby && delta > maxPeriod) { + if (delta > maxPeriod) { mNumDelayedWrites++; if ((now - lastWarning) > kWarningThrottleNs) { ATRACE_NAME("underrun"); @@ -2933,6 +2938,31 @@ bool AudioFlinger::PlaybackThread::threadLoop() lastWarning = now; } } + + if (mThreadThrottle + && mMixerStatus == MIXER_TRACKS_READY // we are mixing (active tracks) + && ret > 0) { // we wrote something + // Limit MixerThread data processing to no more than twice the + // expected processing rate. + // + // This helps prevent underruns with NuPlayer and other applications + // which may set up buffers that are close to the minimum size, or use + // deep buffers, and rely on a double-buffering sleep strategy to fill. + // + // The throttle smooths out sudden large data drains from the device, + // e.g. when it comes out of standby, which often causes problems with + // (1) mixer threads without a fast mixer (which has its own warm-up) + // (2) minimum buffer sized tracks (even if the track is full, + // the app won't fill fast enough to handle the sudden draw). + + const int32_t deltaMs = delta / 1000000; + const int32_t throttleMs = mHalfBufferMs - deltaMs; + if ((signed)mHalfBufferMs >= throttleMs && throttleMs > 0) { + usleep(throttleMs * 1000); + ALOGD("mixer(%p) throttle: ret(%zd) deltaMs(%d) requires sleep %d ms", + this, ret, deltaMs, throttleMs); + } + } } } else { @@ -4023,6 +4053,8 @@ AudioFlinger::PlaybackThread::mixer_state AudioFlinger::MixerThread::prepareTrac } } else { if (framesReady < desiredFrames && !track->isStopped() && !track->isPaused()) { + ALOGV("track(%p) underrun, framesReady(%zu) < framesDesired(%zd)", + track, framesReady, desiredFrames); track->mAudioTrackServerProxy->tallyUnderrunFrames(desiredFrames); } // clear effect chain input buffer if an active track underruns to avoid sending diff --git a/services/audioflinger/Threads.h b/services/audioflinger/Threads.h index 07c226e..7b4fb14 100644 --- a/services/audioflinger/Threads.h +++ b/services/audioflinger/Threads.h @@ -613,6 +613,9 @@ protected: // updated by readOutputParameters_l() size_t mNormalFrameCount; // normal mixer and effects + bool mThreadThrottle; // throttle the thread processing + uint32_t mHalfBufferMs; // half the buffer size in milliseconds + void* mSinkBuffer; // frame size aligned sink buffer // TODO: |