media/libmediaplayerservice/nuplayer/NuPlayerRenderer.cpp

/*
 * Copyright (C) 2010 The Android Open Source Project
 *
 * Licensed under the Apache License, Version 2.0 (the "License");
 * you may not use this file except in compliance with the License.
 * You may obtain a copy of the License at
 *
 *      http://www.apache.org/licenses/LICENSE-2.0
 *
 * Unless required by applicable law or agreed to in writing, software
 * distributed under the License is distributed on an "AS IS" BASIS,
 * WITHOUT WARRANTIES OR CONDITIONS OF ANY KIND, either express or implied.
 * See the License for the specific language governing permissions and
 * limitations under the License.
 */

//#define LOG_NDEBUG 0
#define LOG_TAG "NuPlayerRenderer"
#include <utils/Log.h>

#include "NuPlayerRenderer.h"

#include <media/stagefright/foundation/ABuffer.h>
#include <media/stagefright/foundation/ADebug.h>
#include <media/stagefright/foundation/AMessage.h>
#include <media/stagefright/MediaErrors.h>
#include <media/stagefright/MetaData.h>

#include <inttypes.h>

namespace android {

// static
const int64_t NuPlayer::Renderer::kMinPositionUpdateDelayUs = 100000ll;

NuPlayer::Renderer::Renderer(
        const sp<MediaPlayerBase::AudioSink> &sink,
        const sp<AMessage> &notify,
        uint32_t flags)
    : mAudioSink(sink),
      mNotify(notify),
      mFlags(flags),
      mNumFramesWritten(0),
      mDrainAudioQueuePending(false),
      mDrainVideoQueuePending(false),
      mAudioQueueGeneration(0),
      mVideoQueueGeneration(0),
      mFirstAudioTimeUs(-1),
      mAnchorTimeMediaUs(-1),
      mAnchorTimeRealUs(-1),
      mFlushingAudio(false),
      mFlushingVideo(false),
      mHasAudio(false),
      mHasVideo(false),
      mSyncQueues(false),
      mPaused(false),
      mVideoRenderingStarted(false),
      mVideoRenderingStartGeneration(0),
      mAudioRenderingStartGeneration(0),
      mLastPositionUpdateUs(-1ll),
      mVideoLateByUs(0ll) {
}

NuPlayer::Renderer::~Renderer() {
    if (offloadingAudio()) {
        mAudioSink->stop();
        mAudioSink->flush();
        mAudioSink->close();
    }
}

void NuPlayer::Renderer::queueBuffer(
        bool audio,
        const sp<ABuffer> &buffer,
        const sp<AMessage> &notifyConsumed) {
    sp<AMessage> msg = new AMessage(kWhatQueueBuffer, id());
    msg->setInt32("audio", static_cast<int32_t>(audio));
    msg->setBuffer("buffer", buffer);
    msg->setMessage("notifyConsumed", notifyConsumed);
    msg->post();
}

void NuPlayer::Renderer::queueEOS(bool audio, status_t finalResult) {
    CHECK_NE(finalResult, (status_t)OK);

    sp<AMessage> msg = new AMessage(kWhatQueueEOS, id());
    msg->setInt32("audio", static_cast<int32_t>(audio));
    msg->setInt32("finalResult", finalResult);
    msg->post();
}

void NuPlayer::Renderer::flush(bool audio) {
    {
        Mutex::Autolock autoLock(mFlushLock);
        if (audio) {
            if (mFlushingAudio) {
                return;
            }
            mFlushingAudio = true;
        } else {
            if (mFlushingVideo) {
                return;
            }
            mFlushingVideo = true;
        }
    }

    sp<AMessage> msg = new AMessage(kWhatFlush, id());
    msg->setInt32("audio", static_cast<int32_t>(audio));
    msg->post();
}

void NuPlayer::Renderer::signalTimeDiscontinuity() {
    Mutex::Autolock autoLock(mLock);
    // CHECK(mAudioQueue.empty());
    // CHECK(mVideoQueue.empty());
    mAnchorTimeMediaUs = -1;
    mAnchorTimeRealUs = -1;
    mSyncQueues = false;
}

void NuPlayer::Renderer::signalAudioSinkChanged() {
    (new AMessage(kWhatAudioSinkChanged, id()))->post();
}

void NuPlayer::Renderer::signalDisableOffloadAudio() {
    (new AMessage(kWhatDisableOffloadAudio, id()))->post();
}

void NuPlayer::Renderer::pause() {
    (new AMessage(kWhatPause, id()))->post();
}

void NuPlayer::Renderer::resume() {
    (new AMessage(kWhatResume, id()))->post();
}

void NuPlayer::Renderer::onMessageReceived(const sp<AMessage> &msg) {
    switch (msg->what()) {
        case kWhatStopAudioSink:
        {
            mAudioSink->stop();
            break;
        }

        case kWhatDrainAudioQueue:
        {
            int32_t generation;
            CHECK(msg->findInt32("generation", &generation));
            if (generation != mAudioQueueGeneration) {
                break;
            }

            mDrainAudioQueuePending = false;

            if (onDrainAudioQueue()) {
                uint32_t numFramesPlayed;
                CHECK_EQ(mAudioSink->getPosition(&numFramesPlayed),
                         (status_t)OK);

                uint32_t numFramesPendingPlayout =
                    mNumFramesWritten - numFramesPlayed;

                // This is how long the audio sink will have data to
                // play back.
                int64_t delayUs =
                    mAudioSink->msecsPerFrame()
                        * numFramesPendingPlayout * 1000ll;

                // Let's give it more data after about half that time
                // has elapsed.
                // kWhatDrainAudioQueue is used for non-offloading mode,
                // and mLock is used only for offloading mode. Therefore,
                // no need to acquire mLock here.
                postDrainAudioQueue_l(delayUs / 2);
            }
            break;
        }

        case kWhatDrainVideoQueue:
        {
            int32_t generation;
            CHECK(msg->findInt32("generation", &generation));
            if (generation != mVideoQueueGeneration) {
                break;
            }

            mDrainVideoQueuePending = false;

            onDrainVideoQueue();

            postDrainVideoQueue();
            break;
        }

        case kWhatQueueBuffer:
        {
            onQueueBuffer(msg);
            break;
        }

        case kWhatQueueEOS:
        {
            onQueueEOS(msg);
            break;
        }

        case kWhatFlush:
        {
            onFlush(msg);
            break;
        }

        case kWhatAudioSinkChanged:
        {
            onAudioSinkChanged();
            break;
        }

        case kWhatDisableOffloadAudio:
        {
            onDisableOffloadAudio();
            break;
        }

        case kWhatPause:
        {
            onPause();
            break;
        }

        case kWhatResume:
        {
            onResume();
            break;
        }

        case kWhatAudioOffloadTearDown:
        {
            onAudioOffloadTearDown();
            break;
        }

        default:
            TRESPASS();
            break;
    }
}

void NuPlayer::Renderer::postDrainAudioQueue_l(int64_t delayUs) {
    if (mDrainAudioQueuePending || mSyncQueues || mPaused
            || offloadingAudio()) {
        return;
    }

    if (mAudioQueue.empty()) {
        return;
    }

    mDrainAudioQueuePending = true;
    sp<AMessage> msg = new AMessage(kWhatDrainAudioQueue, id());
    msg->setInt32("generation", mAudioQueueGeneration);
    msg->post(delayUs);
}

void NuPlayer::Renderer::prepareForMediaRenderingStart() {
    mAudioRenderingStartGeneration = mAudioQueueGeneration;
    mVideoRenderingStartGeneration = mVideoQueueGeneration;
}

void NuPlayer::Renderer::notifyIfMediaRenderingStarted() {
    if (mVideoRenderingStartGeneration == mVideoQueueGeneration &&
        mAudioRenderingStartGeneration == mAudioQueueGeneration) {
        mVideoRenderingStartGeneration = -1;
        mAudioRenderingStartGeneration = -1;

        sp<AMessage> notify = mNotify->dup();
        notify->setInt32("what", kWhatMediaRenderingStart);
        notify->post();
    }
}

// static
size_t NuPlayer::Renderer::AudioSinkCallback(
        MediaPlayerBase::AudioSink * /* audioSink */,
        void *buffer,
        size_t size,
        void *cookie,
        MediaPlayerBase::AudioSink::cb_event_t event) {
    NuPlayer::Renderer *me = (NuPlayer::Renderer *)cookie;

    switch (event) {
        case MediaPlayerBase::AudioSink::CB_EVENT_FILL_BUFFER:
        {
            return me->fillAudioBuffer(buffer, size);
            break;
        }

        case MediaPlayerBase::AudioSink::CB_EVENT_STREAM_END:
        {
            me->notifyEOS(true /* audio */, ERROR_END_OF_STREAM);
            break;
        }

        case MediaPlayerBase::AudioSink::CB_EVENT_TEAR_DOWN:
        {
            me->notifyAudioOffloadTearDown();
            break;
        }
    }

    return 0;
}

size_t NuPlayer::Renderer::fillAudioBuffer(void *buffer, size_t size) {
    Mutex::Autolock autoLock(mLock);

    if (!offloadingAudio()) {
        return 0;
    }

    bool hasEOS = false;

    size_t sizeCopied = 0;
    while (sizeCopied < size && !mAudioQueue.empty()) {
        QueueEntry *entry = &*mAudioQueue.begin();

        if (entry->mBuffer == NULL) { // EOS
            hasEOS = true;
            mAudioQueue.erase(mAudioQueue.begin());
            entry = NULL;
            break;
        }

        if (entry->mOffset == 0) {
            int64_t mediaTimeUs;
            CHECK(entry->mBuffer->meta()->findInt64("timeUs", &mediaTimeUs));
            ALOGV("rendering audio at media time %.2f secs", mediaTimeUs / 1E6);
            if (mFirstAudioTimeUs == -1) {
                mFirstAudioTimeUs = mediaTimeUs;
            }
            mAnchorTimeMediaUs = mediaTimeUs;

            uint32_t numFramesPlayed;
            CHECK_EQ(mAudioSink->getPosition(&numFramesPlayed), (status_t)OK);

            // TODO: figure out how to calculate initial latency.
            // Otherwise, the initial time is not correct till the first sample
            // is played.
            mAnchorTimeMediaUs = mFirstAudioTimeUs
                    + (numFramesPlayed * mAudioSink->msecsPerFrame()) * 1000ll;
            mAnchorTimeRealUs = ALooper::GetNowUs();
        }

        size_t copy = entry->mBuffer->size() - entry->mOffset;
        size_t sizeRemaining = size - sizeCopied;
        if (copy > sizeRemaining) {
            copy = sizeRemaining;
        }

        memcpy((char *)buffer + sizeCopied,
               entry->mBuffer->data() + entry->mOffset,
               copy);

        entry->mOffset += copy;
        if (entry->mOffset == entry->mBuffer->size()) {
            entry->mNotifyConsumed->post();
            mAudioQueue.erase(mAudioQueue.begin());
            entry = NULL;
        }
        sizeCopied += copy;
        notifyIfMediaRenderingStarted();
    }

    if (sizeCopied != 0) {
        notifyPosition();
    }

    if (hasEOS) {
        (new AMessage(kWhatStopAudioSink, id()))->post();
    }

    return sizeCopied;
}

bool NuPlayer::Renderer::onDrainAudioQueue() {
    uint32_t numFramesPlayed;
    if (mAudioSink->getPosition(&numFramesPlayed) != OK) {
        return false;
    }

    ssize_t numFramesAvailableToWrite =
        mAudioSink->frameCount() - (mNumFramesWritten - numFramesPlayed);

#if 0
    if (numFramesAvailableToWrite == mAudioSink->frameCount()) {
        ALOGI("audio sink underrun");
    } else {
        ALOGV("audio queue has %d frames left to play",
             mAudioSink->frameCount() - numFramesAvailableToWrite);
    }
#endif

    size_t numBytesAvailableToWrite =
        numFramesAvailableToWrite * mAudioSink->frameSize();

    while (numBytesAvailableToWrite > 0 && !mAudioQueue.empty()) {
        QueueEntry *entry = &*mAudioQueue.begin();

        if (entry->mBuffer == NULL) {
            // EOS

            notifyEOS(true /* audio */, entry->mFinalResult);

            mAudioQueue.erase(mAudioQueue.begin());
            entry = NULL;
            return false;
        }

        if (entry->mOffset == 0) {
            int64_t mediaTimeUs;
            CHECK(entry->mBuffer->meta()->findInt64("timeUs", &mediaTimeUs));

            ALOGV("rendering audio at media time %.2f secs", mediaTimeUs / 1E6);

            mAnchorTimeMediaUs = mediaTimeUs;

            uint32_t numFramesPlayed;
            CHECK_EQ(mAudioSink->getPosition(&numFramesPlayed), (status_t)OK);

            uint32_t numFramesPendingPlayout =
                mNumFramesWritten - numFramesPlayed;

            int64_t realTimeOffsetUs =
                (mAudioSink->latency() / 2  /* XXX */
                    + numFramesPendingPlayout
                        * mAudioSink->msecsPerFrame()) * 1000ll;

            // ALOGI("realTimeOffsetUs = %lld us", realTimeOffsetUs);

            mAnchorTimeRealUs =
                ALooper::GetNowUs() + realTimeOffsetUs;
        }

        size_t copy = entry->mBuffer->size() - entry->mOffset;
        if (copy > numBytesAvailableToWrite) {
            copy = numBytesAvailableToWrite;
        }

        CHECK_EQ(mAudioSink->write(
                    entry->mBuffer->data() + entry->mOffset, copy),
                 (ssize_t)copy);

        entry->mOffset += copy;
        if (entry->mOffset == entry->mBuffer->size()) {
            entry->mNotifyConsumed->post();
            mAudioQueue.erase(mAudioQueue.begin());

            entry = NULL;
        }

        numBytesAvailableToWrite -= copy;
        size_t copiedFrames = copy / mAudioSink->frameSize();
        mNumFramesWritten += copiedFrames;

        notifyIfMediaRenderingStarted();
    }

    notifyPosition();

    return !mAudioQueue.empty();
}

void NuPlayer::Renderer::postDrainVideoQueue() {
    if (mDrainVideoQueuePending || mSyncQueues || mPaused) {
        return;
    }

    if (mVideoQueue.empty()) {
        return;
    }

    QueueEntry &entry = *mVideoQueue.begin();

    sp<AMessage> msg = new AMessage(kWhatDrainVideoQueue, id());
    msg->setInt32("generation", mVideoQueueGeneration);

    int64_t delayUs;

    if (entry.mBuffer == NULL) {
        // EOS doesn't carry a timestamp.
        delayUs = 0;
    } else if (mFlags & FLAG_REAL_TIME) {
        int64_t mediaTimeUs;
        CHECK(entry.mBuffer->meta()->findInt64("timeUs", &mediaTimeUs));

        delayUs = mediaTimeUs - ALooper::GetNowUs();
    } else {
        int64_t mediaTimeUs;
        CHECK(entry.mBuffer->meta()->findInt64("timeUs", &mediaTimeUs));

        if (mAnchorTimeMediaUs < 0) {
            delayUs = 0;

            if (!mHasAudio) {
                mAnchorTimeMediaUs = mediaTimeUs;
                mAnchorTimeRealUs = ALooper::GetNowUs();
            }
        } else {
            int64_t realTimeUs =
                (mediaTimeUs - mAnchorTimeMediaUs) + mAnchorTimeRealUs;

            delayUs = realTimeUs - ALooper::GetNowUs();
        }
    }

    ALOGW_IF(delayUs > 500000, "unusually high delayUs: %" PRId64, delayUs);
    msg->post(delayUs);

    mDrainVideoQueuePending = true;
}

void NuPlayer::Renderer::onDrainVideoQueue() {
    if (mVideoQueue.empty()) {
        return;
    }

    QueueEntry *entry = &*mVideoQueue.begin();

    if (entry->mBuffer == NULL) {
        // EOS

        notifyEOS(false /* audio */, entry->mFinalResult);

        mVideoQueue.erase(mVideoQueue.begin());
        entry = NULL;

        mVideoLateByUs = 0ll;

        notifyPosition();
        return;
    }

    int64_t realTimeUs;
    if (mFlags & FLAG_REAL_TIME) {
        CHECK(entry->mBuffer->meta()->findInt64("timeUs", &realTimeUs));
    } else {
        int64_t mediaTimeUs;
        CHECK(entry->mBuffer->meta()->findInt64("timeUs", &mediaTimeUs));

        realTimeUs = mediaTimeUs - mAnchorTimeMediaUs + mAnchorTimeRealUs;
    }

    mVideoLateByUs = ALooper::GetNowUs() - realTimeUs;
    bool tooLate = (mVideoLateByUs > 40000);

    if (tooLate) {
        ALOGV("video late by %lld us (%.2f secs)",
             mVideoLateByUs, mVideoLateByUs / 1E6);
    } else {
        ALOGV("rendering video at media time %.2f secs",
                (mFlags & FLAG_REAL_TIME ? realTimeUs :
                (realTimeUs + mAnchorTimeMediaUs - mAnchorTimeRealUs)) / 1E6);
    }

    entry->mNotifyConsumed->setInt32("render", !tooLate);
    entry->mNotifyConsumed->post();
    mVideoQueue.erase(mVideoQueue.begin());
    entry = NULL;

    if (!mVideoRenderingStarted) {
        mVideoRenderingStarted = true;
        notifyVideoRenderingStart();
    }

    notifyIfMediaRenderingStarted();

    notifyPosition();
}

void NuPlayer::Renderer::notifyVideoRenderingStart() {
    sp<AMessage> notify = mNotify->dup();
    notify->setInt32("what", kWhatVideoRenderingStart);
    notify->post();
}

void NuPlayer::Renderer::notifyEOS(bool audio, status_t finalResult) {
    sp<AMessage> notify = mNotify->dup();
    notify->setInt32("what", kWhatEOS);
    notify->setInt32("audio", static_cast<int32_t>(audio));
    notify->setInt32("finalResult", finalResult);
    notify->post();
}

void NuPlayer::Renderer::notifyAudioOffloadTearDown() {
    (new AMessage(kWhatAudioOffloadTearDown, id()))->post();
}

void NuPlayer::Renderer::onQueueBuffer(const sp<AMessage> &msg) {
    int32_t audio;
    CHECK(msg->findInt32("audio", &audio));

    if (audio) {
        mHasAudio = true;
    } else {
        mHasVideo = true;
    }

    if (dropBufferWhileFlushing(audio, msg)) {
        return;
    }

    sp<ABuffer> buffer;
    CHECK(msg->findBuffer("buffer", &buffer));

    sp<AMessage> notifyConsumed;
    CHECK(msg->findMessage("notifyConsumed", &notifyConsumed));

    QueueEntry entry;
    entry.mBuffer = buffer;
    entry.mNotifyConsumed = notifyConsumed;
    entry.mOffset = 0;
    entry.mFinalResult = OK;

    if (audio) {
        Mutex::Autolock autoLock(mLock);
        mAudioQueue.push_back(entry);
        postDrainAudioQueue_l();
    } else {
        mVideoQueue.push_back(entry);
        postDrainVideoQueue();
    }

    Mutex::Autolock autoLock(mLock);
    if (!mSyncQueues || mAudioQueue.empty() || mVideoQueue.empty()) {
        return;
    }

    sp<ABuffer> firstAudioBuffer = (*mAudioQueue.begin()).mBuffer;
    sp<ABuffer> firstVideoBuffer = (*mVideoQueue.begin()).mBuffer;

    if (firstAudioBuffer == NULL || firstVideoBuffer == NULL) {
        // EOS signalled on either queue.
        syncQueuesDone_l();
        return;
    }

    int64_t firstAudioTimeUs;
    int64_t firstVideoTimeUs;
    CHECK(firstAudioBuffer->meta()
            ->findInt64("timeUs", &firstAudioTimeUs));
    CHECK(firstVideoBuffer->meta()
            ->findInt64("timeUs", &firstVideoTimeUs));

    int64_t diff = firstVideoTimeUs - firstAudioTimeUs;

    ALOGV("queueDiff = %.2f secs", diff / 1E6);

    if (diff > 100000ll) {
        // Audio data starts More than 0.1 secs before video.
        // Drop some audio.

        (*mAudioQueue.begin()).mNotifyConsumed->post();
        mAudioQueue.erase(mAudioQueue.begin());
        return;
    }

    syncQueuesDone_l();
}

void NuPlayer::Renderer::syncQueuesDone_l() {
    if (!mSyncQueues) {
        return;
    }

    mSyncQueues = false;

    if (!mAudioQueue.empty()) {
        postDrainAudioQueue_l();
    }

    if (!mVideoQueue.empty()) {
        postDrainVideoQueue();
    }
}

void NuPlayer::Renderer::onQueueEOS(const sp<AMessage> &msg) {
    int32_t audio;
    CHECK(msg->findInt32("audio", &audio));

    if (dropBufferWhileFlushing(audio, msg)) {
        return;
    }

    int32_t finalResult;
    CHECK(msg->findInt32("finalResult", &finalResult));

    QueueEntry entry;
    entry.mOffset = 0;
    entry.mFinalResult = finalResult;

    if (audio) {
        Mutex::Autolock autoLock(mLock);
        if (mAudioQueue.empty() && mSyncQueues) {
            syncQueuesDone_l();
        }
        mAudioQueue.push_back(entry);
        postDrainAudioQueue_l();
    } else {
        if (mVideoQueue.empty() && mSyncQueues) {
            Mutex::Autolock autoLock(mLock);
            syncQueuesDone_l();
        }
        mVideoQueue.push_back(entry);
        postDrainVideoQueue();
    }
}

void NuPlayer::Renderer::onFlush(const sp<AMessage> &msg) {
    int32_t audio;
    CHECK(msg->findInt32("audio", &audio));

    {
        Mutex::Autolock autoLock(mFlushLock);
        if (audio) {
            mFlushingAudio = false;
        } else {
            mFlushingVideo = false;
        }
    }

    // If we're currently syncing the queues, i.e. dropping audio while
    // aligning the first audio/video buffer times and only one of the
    // two queues has data, we may starve that queue by not requesting
    // more buffers from the decoder. If the other source then encounters
    // a discontinuity that leads to flushing, we'll never find the
    // corresponding discontinuity on the other queue.
    // Therefore we'll stop syncing the queues if at least one of them
    // is flushed.
    {
         Mutex::Autolock autoLock(mLock);
         syncQueuesDone_l();
    }

    ALOGV("flushing %s", audio ? "audio" : "video");
    if (audio) {
        {
            Mutex::Autolock autoLock(mLock);
            flushQueue(&mAudioQueue);

            ++mAudioQueueGeneration;
            prepareForMediaRenderingStart();

            if (offloadingAudio()) {
                mFirstAudioTimeUs = -1;
            }
        }

        mDrainAudioQueuePending = false;

        if (offloadingAudio()) {
            mAudioSink->pause();
            mAudioSink->flush();
            mAudioSink->start();
        }
    } else {
        flushQueue(&mVideoQueue);

        mDrainVideoQueuePending = false;
        ++mVideoQueueGeneration;

        prepareForMediaRenderingStart();
    }

    notifyFlushComplete(audio);
}

void NuPlayer::Renderer::flushQueue(List<QueueEntry> *queue) {
    while (!queue->empty()) {
        QueueEntry *entry = &*queue->begin();

        if (entry->mBuffer != NULL) {
            entry->mNotifyConsumed->post();
        }

        queue->erase(queue->begin());
        entry = NULL;
    }
}

void NuPlayer::Renderer::notifyFlushComplete(bool audio) {
    sp<AMessage> notify = mNotify->dup();
    notify->setInt32("what", kWhatFlushComplete);
    notify->setInt32("audio", static_cast<int32_t>(audio));
    notify->post();
}

bool NuPlayer::Renderer::dropBufferWhileFlushing(
        bool audio, const sp<AMessage> &msg) {
    bool flushing = false;

    {
        Mutex::Autolock autoLock(mFlushLock);
        if (audio) {
            flushing = mFlushingAudio;
        } else {
            flushing = mFlushingVideo;
        }
    }

    if (!flushing) {
        return false;
    }

    sp<AMessage> notifyConsumed;
    if (msg->findMessage("notifyConsumed", &notifyConsumed)) {
        notifyConsumed->post();
    }

    return true;
}

void NuPlayer::Renderer::onAudioSinkChanged() {
    if (offloadingAudio()) {
        return;
    }
    CHECK(!mDrainAudioQueuePending);
    mNumFramesWritten = 0;
    uint32_t written;
    if (mAudioSink->getFramesWritten(&written) == OK) {
        mNumFramesWritten = written;
    }
}

void NuPlayer::Renderer::onDisableOffloadAudio() {
    Mutex::Autolock autoLock(mLock);
    mFlags &= ~FLAG_OFFLOAD_AUDIO;
    ++mAudioQueueGeneration;
}

void NuPlayer::Renderer::notifyPosition() {
    if (mAnchorTimeRealUs < 0 || mAnchorTimeMediaUs < 0) {
        return;
    }

    int64_t nowUs = ALooper::GetNowUs();

    if (mLastPositionUpdateUs >= 0
            && nowUs < mLastPositionUpdateUs + kMinPositionUpdateDelayUs) {
        return;
    }
    mLastPositionUpdateUs = nowUs;

    int64_t positionUs = (nowUs - mAnchorTimeRealUs) + mAnchorTimeMediaUs;

    sp<AMessage> notify = mNotify->dup();
    notify->setInt32("what", kWhatPosition);
    notify->setInt64("positionUs", positionUs);
    notify->setInt64("videoLateByUs", mVideoLateByUs);
    notify->post();
}

void NuPlayer::Renderer::onPause() {
    CHECK(!mPaused);

    {
        Mutex::Autolock autoLock(mLock);
        ++mAudioQueueGeneration;
        ++mVideoQueueGeneration;
        prepareForMediaRenderingStart();
    }

    mDrainAudioQueuePending = false;
    mDrainVideoQueuePending = false;

    if (mHasAudio) {
        mAudioSink->pause();
    }

    ALOGV("now paused audio queue has %d entries, video has %d entries",
          mAudioQueue.size(), mVideoQueue.size());

    mPaused = true;
}

void NuPlayer::Renderer::onResume() {
    if (!mPaused) {
        return;
    }

    if (mHasAudio) {
        mAudioSink->start();
    }

    mPaused = false;

    Mutex::Autolock autoLock(mLock);
    if (!mAudioQueue.empty()) {
        postDrainAudioQueue_l();
    }

    if (!mVideoQueue.empty()) {
        postDrainVideoQueue();
    }
}

void NuPlayer::Renderer::onAudioOffloadTearDown() {
    uint32_t numFramesPlayed;
    CHECK_EQ(mAudioSink->getPosition(&numFramesPlayed), (status_t)OK);

    int64_t firstAudioTimeUs;
    {
        Mutex::Autolock autoLock(mLock);
        firstAudioTimeUs = mFirstAudioTimeUs;
    }
    int64_t currentPositionUs = firstAudioTimeUs
            + (numFramesPlayed * mAudioSink->msecsPerFrame()) * 1000ll;

    mAudioSink->stop();
    mAudioSink->flush();

    sp<AMessage> notify = mNotify->dup();
    notify->setInt32("what", kWhatAudioOffloadTearDown);
    notify->setInt64("positionUs", currentPositionUs);
    notify->post();
}

}  // namespace android