src/android/android_StreamPlayer.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 USE_LOG SLAndroidLogLevel_Verbose

#include "sles_allinclusive.h"
#include "android_StreamPlayer.h"

#include <media/IStreamSource.h>
#include <media/IMediaPlayerService.h>
#include <media/stagefright/foundation/ADebug.h>
#include <binder/IPCThreadState.h>


//--------------------------------------------------------------------------------------------------
namespace android {

StreamSourceAppProxy::StreamSourceAppProxy(
        IAndroidBufferQueue *androidBufferQueue,
        const sp<CallbackProtector> &callbackProtector,
        // sp<StreamPlayer> would cause StreamPlayer's destructor to run during it's own
        // construction.   If you pass in a sp<> to 'this' inside a constructor, then first the
        // refcount is increased from 0 to 1, then decreased from 1 to 0, which causes the object's
        // destructor to run from inside it's own constructor.
        StreamPlayer * /* const sp<StreamPlayer> & */ player) :
    mBuffersHasBeenSet(false),
    mAndroidBufferQueue(androidBufferQueue),
    mCallbackProtector(callbackProtector),
    mPlayer(player)
{
    SL_LOGV("StreamSourceAppProxy::StreamSourceAppProxy()");
}

StreamSourceAppProxy::~StreamSourceAppProxy() {
    // FIXME make this an SL_LOGV later; this just proves that the bug is fixed
    SL_LOGI("StreamSourceAppProxy::~StreamSourceAppProxy()");
    disconnect();
}

const SLuint32 StreamSourceAppProxy::kItemProcessed[NB_BUFFEREVENT_ITEM_FIELDS] = {
        SL_ANDROID_ITEMKEY_BUFFERQUEUEEVENT, // item key
        sizeof(SLuint32),                    // item size
        SL_ANDROIDBUFFERQUEUEEVENT_PROCESSED // item data
};

//--------------------------------------------------
// IStreamSource implementation
void StreamSourceAppProxy::setListener(const sp<IStreamListener> &listener) {
    assert(listener != NULL);
    Mutex::Autolock _l(mLock);
    assert(mListener == NULL);
    mListener = listener;
}

void StreamSourceAppProxy::setBuffers(const Vector<sp<IMemory> > &buffers) {
    Mutex::Autolock _l(mLock);
    assert(!mBuffersHasBeenSet);
    mBuffers = buffers;
    mBuffersHasBeenSet = true;
}

void StreamSourceAppProxy::onBufferAvailable(size_t index) {
    //SL_LOGD("StreamSourceAppProxy::onBufferAvailable(%d)", index);

    {
        Mutex::Autolock _l(mLock);
        // assert not needed because if not set, size() will be zero and the CHECK_LT will also fail
        // assert(mBuffersHasBeenSet);
        CHECK_LT(index, mBuffers.size());
#if 0   // enable if needed for debugging
        sp<IMemory> mem = mBuffers.itemAt(index);
        SLAint64 length = (SLAint64) mem->size();
#endif
        mAvailableBuffers.push_back(index);
        //SL_LOGD("onBufferAvailable() now %d buffers available in queue",
        //         mAvailableBuffers.size());
    }

    // a new shared mem buffer is available: let's try to fill immediately
    pullFromBuffQueue();
}

void StreamSourceAppProxy::receivedCmd_l(IStreamListener::Command cmd, const sp<AMessage> &msg) {
    if (mListener != 0) {
        mListener->issueCommand(cmd, false /* synchronous */, msg);
    }
}

void StreamSourceAppProxy::receivedBuffer_l(size_t buffIndex, size_t buffLength) {
    if (mListener != 0) {
        mListener->queueBuffer(buffIndex, buffLength);
    }
}

void StreamSourceAppProxy::disconnect() {
    Mutex::Autolock _l(mLock);
    mListener.clear();
    // Force binder to push the decremented reference count for sp<IStreamListener>.
    // mediaserver and client both have sp<> to the other. When you decrement an sp<>
    // reference count, binder doesn't push that to the other process immediately.
    IPCThreadState::self()->flushCommands();
    mBuffers.clear();
    mBuffersHasBeenSet = false;
    mAvailableBuffers.clear();
}

//--------------------------------------------------
// consumption from ABQ: pull from the ABQ, and push to shared memory (media server)
void StreamSourceAppProxy::pullFromBuffQueue() {

  if (android::CallbackProtector::enterCbIfOk(mCallbackProtector)) {

    size_t bufferId;
    void* bufferLoc;
    size_t buffSize;

    slAndroidBufferQueueCallback callback = NULL;
    void* pBufferContext, *pBufferData, *callbackPContext = NULL;
    AdvancedBufferHeader *oldFront = NULL;
    uint32_t dataSize /* , dataUsed */;

    // retrieve data from the buffer queue
    interface_lock_exclusive(mAndroidBufferQueue);

    // can this read operation cause us to call the buffer queue callback
    // (either because there was a command with no data, or all the data has been consumed)
    bool queueCallbackCandidate = false;

    if (mAndroidBufferQueue->mState.count != 0) {
        // SL_LOGD("nbBuffers in ABQ = %u, buffSize=%u",abq->mState.count, buffSize);
        assert(mAndroidBufferQueue->mFront != mAndroidBufferQueue->mRear);

        oldFront = mAndroidBufferQueue->mFront;
        AdvancedBufferHeader *newFront = &oldFront[1];

        // consume events when starting to read data from a buffer for the first time
        if (oldFront->mDataSizeConsumed == 0) {
            // note this code assumes at most one event per buffer; see IAndroidBufferQueue_Enqueue
            if (oldFront->mItems.mTsCmdData.mTsCmdCode & ANDROID_MP2TSEVENT_EOS) {
                receivedCmd_l(IStreamListener::EOS);
                // EOS has no associated data
                queueCallbackCandidate = true;
            } else if (oldFront->mItems.mTsCmdData.mTsCmdCode & ANDROID_MP2TSEVENT_DISCONTINUITY) {
                receivedCmd_l(IStreamListener::DISCONTINUITY);
            } else if (oldFront->mItems.mTsCmdData.mTsCmdCode & ANDROID_MP2TSEVENT_DISCON_NEWPTS) {
                sp<AMessage> msg = new AMessage();
                msg->setInt64(IStreamListener::kKeyResumeAtPTS,
                        (int64_t)oldFront->mItems.mTsCmdData.mPts);
                receivedCmd_l(IStreamListener::DISCONTINUITY, msg /*msg*/);
            } else if (oldFront->mItems.mTsCmdData.mTsCmdCode & ANDROID_MP2TSEVENT_FORMAT_CHANGE) {
                sp<AMessage> msg = new AMessage();
                // positive value for format change key makes the discontinuity "hard", see key def
                msg->setInt32(IStreamListener::kKeyFormatChange, (int32_t) 1);
                receivedCmd_l(IStreamListener::DISCONTINUITY, msg /*msg*/);
            }
            if (oldFront->mItems.mTsCmdData.mTsCmdCode & (ANDROID_MP2TSEVENT_DISCONTINUITY |
                    ANDROID_MP2TSEVENT_DISCON_NEWPTS | ANDROID_MP2TSEVENT_FORMAT_CHANGE)) {
                const sp<StreamPlayer> player(mPlayer.promote());
                if (player != NULL) {
                    // FIXME see note at onSeek
                    player->seek(ANDROID_UNKNOWN_TIME);
                }
            }
            oldFront->mItems.mTsCmdData.mTsCmdCode = ANDROID_MP2TSEVENT_NONE;
        }

        {
            // we're going to change the shared mem buffer queue, so lock it
            Mutex::Autolock _l(mLock);
            if (!mAvailableBuffers.empty()) {
                bufferId = *mAvailableBuffers.begin();
                CHECK_LT(bufferId, mBuffers.size());
                sp<IMemory> mem = mBuffers.itemAt(bufferId);
                bufferLoc = mem->pointer();
                buffSize = mem->size();

                char *pSrc = ((char*)oldFront->mDataBuffer) + oldFront->mDataSizeConsumed;
                if (oldFront->mDataSizeConsumed + buffSize < oldFront->mDataSize) {
                    // more available than requested, copy as much as requested
                    // consume data: 1/ copy to given destination
                    memcpy(bufferLoc, pSrc, buffSize);
                    //               2/ keep track of how much has been consumed
                    oldFront->mDataSizeConsumed += buffSize;
                    //               3/ notify shared mem listener that new data is available
                    receivedBuffer_l(bufferId, buffSize);
                    mAvailableBuffers.erase(mAvailableBuffers.begin());
                } else {
                    // requested as much available or more: consume the whole of the current
                    //   buffer and move to the next
                    size_t consumed = oldFront->mDataSize - oldFront->mDataSizeConsumed;
                    //SL_LOGD("consuming rest of buffer: enqueueing=%u", consumed);
                    oldFront->mDataSizeConsumed = oldFront->mDataSize;

                    // move queue to next
                    if (newFront == &mAndroidBufferQueue->
                            mBufferArray[mAndroidBufferQueue->mNumBuffers + 1]) {
                        // reached the end, circle back
                        newFront = mAndroidBufferQueue->mBufferArray;
                    }
                    mAndroidBufferQueue->mFront = newFront;
                    mAndroidBufferQueue->mState.count--;
                    mAndroidBufferQueue->mState.index++;

                    if (consumed > 0) {
                        // consume data: 1/ copy to given destination
                        memcpy(bufferLoc, pSrc, consumed);
                        //               2/ keep track of how much has been consumed
                        // here nothing to do because we are done with this buffer
                        //               3/ notify StreamPlayer that new data is available
                        receivedBuffer_l(bufferId, consumed);
                        mAvailableBuffers.erase(mAvailableBuffers.begin());
                    }

                    // data has been consumed, and the buffer queue state has been updated
                    // we will notify the client if applicable
                    queueCallbackCandidate = true;
                }
            }

            if (queueCallbackCandidate) {
                if (mAndroidBufferQueue->mCallbackEventsMask &
                        SL_ANDROIDBUFFERQUEUEEVENT_PROCESSED) {
                    callback = mAndroidBufferQueue->mCallback;
                    // save callback data while under lock
                    callbackPContext = mAndroidBufferQueue->mContext;
                    pBufferContext = (void *)oldFront->mBufferContext;
                    pBufferData    = (void *)oldFront->mDataBuffer;
                    dataSize       = oldFront->mDataSize;
                    // here a buffer is only dequeued when fully consumed
                    //dataUsed     = oldFront->mDataSizeConsumed;
                }
            }
            //SL_LOGD("%d buffers available after reading from queue", mAvailableBuffers.size());
            if (!mAvailableBuffers.empty()) {
                // there is still room in the shared memory, recheck later if we can pull
                // data from the buffer queue and write it to shared memory
                const sp<StreamPlayer> player(mPlayer.promote());
                if (player != NULL) {
                    player->queueRefilled();
                }
            }
        }

    } else { // empty queue
        SL_LOGD("ABQ empty, starving!");
    }

    interface_unlock_exclusive(mAndroidBufferQueue);

    // notify client of buffer processed
    if (NULL != callback) {
        SLresult result = (*callback)(&mAndroidBufferQueue->mItf, callbackPContext,
                pBufferContext, pBufferData, dataSize,
                dataSize, /* dataUsed  */
                // no messages during playback other than marking the buffer as processed
                (const SLAndroidBufferItem*)(&kItemProcessed) /* pItems */,
                NB_BUFFEREVENT_ITEM_FIELDS *sizeof(SLuint32) /* itemsLength */ );
        if (SL_RESULT_SUCCESS != result) {
            // Reserved for future use
            SL_LOGW("Unsuccessful result %d returned from AndroidBufferQueueCallback", result);
        }
    }

    mCallbackProtector->exitCb();
  } // enterCbIfOk
}


//--------------------------------------------------------------------------------------------------
StreamPlayer::StreamPlayer(const AudioPlayback_Parameters* params, bool hasVideo,
        IAndroidBufferQueue *androidBufferQueue, const sp<CallbackProtector> &callbackProtector) :
        GenericMediaPlayer(params, hasVideo),
        mAppProxy(new StreamSourceAppProxy(androidBufferQueue, callbackProtector, this)),
        mStopForDestroyCompleted(false)
{
    SL_LOGD("StreamPlayer::StreamPlayer()");
}

StreamPlayer::~StreamPlayer() {
    SL_LOGD("StreamPlayer::~StreamPlayer()");
    mAppProxy->disconnect();
}


void StreamPlayer::onMessageReceived(const sp<AMessage> &msg) {
    switch (msg->what()) {
        case kWhatPullFromAbq:
            onPullFromAndroidBufferQueue();
            break;

        case kWhatStopForDestroy:
            onStopForDestroy();
            break;

        default:
            GenericMediaPlayer::onMessageReceived(msg);
            break;
    }
}


void StreamPlayer::preDestroy() {
    // FIXME NuPlayerDriver is currently not thread-safe, so stop() must be called by looper
    (new AMessage(kWhatStopForDestroy, id()))->post();
    {
        Mutex::Autolock _l(mStopForDestroyLock);
        while (!mStopForDestroyCompleted) {
            mStopForDestroyCondition.wait(mStopForDestroyLock);
        }
    }
    // GenericMediaPlayer::preDestroy will repeat some of what we've done, but that's benign
    GenericMediaPlayer::preDestroy();
}


void StreamPlayer::onStopForDestroy() {
    if (mPlayer != 0) {
        mPlayer->stop();
        // causes CHECK failure in Nuplayer
        //mPlayer->setDataSource(NULL);
        mPlayer->setVideoSurface(NULL);
        mPlayer->disconnect();
        mPlayer.clear();
        {
            // FIXME ugh make this a method
            Mutex::Autolock _l(mPreparedPlayerLock);
            mPreparedPlayer.clear();
        }
    }
    mStopForDestroyCompleted = true;
    mStopForDestroyCondition.signal();
}


/**
 * Asynchronously notify the player that the queue is ready to be pulled from.
 */
void StreamPlayer::queueRefilled() {
    // async notification that the ABQ was refilled: the player should pull from the ABQ, and
    //    and push to shared memory (to the media server)
    (new AMessage(kWhatPullFromAbq, id()))->post();
}


void StreamPlayer::appClear_l() {
    // the user of StreamPlayer has cleared its AndroidBufferQueue:
    // there's no clear() for the shared memory queue, so this is a no-op
}


//--------------------------------------------------
// Event handlers
void StreamPlayer::onPrepare() {
    SL_LOGD("StreamPlayer::onPrepare()");
        sp<IMediaPlayerService> mediaPlayerService(getMediaPlayerService());
        if (mediaPlayerService != NULL) {
            mPlayer = mediaPlayerService->create(getpid(), mPlayerClient /*IMediaPlayerClient*/,
                    mPlaybackParams.sessionId);
            if (mPlayer == NULL) {
                SL_LOGE("media player service failed to create player by app proxy");
            } else if (mPlayer->setDataSource(mAppProxy /*IStreamSource*/) != NO_ERROR) {
                SL_LOGE("setDataSource failed");
                mPlayer.clear();
            }
        }
    if (mPlayer == NULL) {
        mStateFlags |= kFlagPreparedUnsuccessfully;
    }
    GenericMediaPlayer::onPrepare();
    SL_LOGD("StreamPlayer::onPrepare() done");
}


void StreamPlayer::onPlay() {
    SL_LOGD("StreamPlayer::onPlay()");
    // enqueue a message that will cause StreamAppProxy to consume from the queue (again if the
    // player had starved the shared memory)
    queueRefilled();

    GenericMediaPlayer::onPlay();
}


void StreamPlayer::onPullFromAndroidBufferQueue() {
    SL_LOGD("StreamPlayer::onPullFromAndroidBufferQueue()");
    mAppProxy->pullFromBuffQueue();
}

} // namespace android