media/libmediaplayerservice/nuplayer/RTSPSource.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 "RTSPSource"
#include <utils/Log.h>

#include "RTSPSource.h"

#include "AnotherPacketSource.h"
#include "MyHandler.h"
#include "SDPLoader.h"

#include <media/IMediaHTTPService.h>
#include <media/stagefright/MediaDefs.h>
#include <media/stagefright/MetaData.h>

namespace android {

const int64_t kNearEOSTimeoutUs = 2000000ll; // 2 secs

// Default Buffer Underflow/Prepare/StartServer/Overflow Marks
static const int kUnderflowMarkMs   =  1000;  // 1 second
static const int kPrepareMarkMs     =  3000;  // 3 seconds
//static const int kStartServerMarkMs =  5000;
static const int kOverflowMarkMs    = 10000;  // 10 seconds

NuPlayer::RTSPSource::RTSPSource(
        const sp<AMessage> &notify,
        const sp<IMediaHTTPService> &httpService,
        const char *url,
        const KeyedVector<String8, String8> *headers,
        bool uidValid,
        uid_t uid,
        bool isSDP)
    : Source(notify),
      mHTTPService(httpService),
      mURL(url),
      mUIDValid(uidValid),
      mUID(uid),
      mFlags(0),
      mIsSDP(isSDP),
      mState(DISCONNECTED),
      mFinalResult(OK),
      mDisconnectReplyID(0),
      mBuffering(false),
      mInPreparationPhase(true),
      mEOSPending(false),
      mSeekGeneration(0),
      mEOSTimeoutAudio(0),
      mEOSTimeoutVideo(0) {
    getDefaultBufferingSettings(&mBufferingSettings);
    if (headers) {
        mExtraHeaders = *headers;

        ssize_t index =
            mExtraHeaders.indexOfKey(String8("x-hide-urls-from-log"));

        if (index >= 0) {
            mFlags |= kFlagIncognito;

            mExtraHeaders.removeItemsAt(index);
        }
    }
}

NuPlayer::RTSPSource::~RTSPSource() {
    if (mLooper != NULL) {
        mLooper->unregisterHandler(id());
        mLooper->stop();
    }
}

status_t NuPlayer::RTSPSource::getDefaultBufferingSettings(
            BufferingSettings* buffering /* nonnull */) {
    buffering->mInitialBufferingMode = BUFFERING_MODE_TIME_ONLY;
    buffering->mRebufferingMode = BUFFERING_MODE_TIME_ONLY;
    buffering->mInitialWatermarkMs = kPrepareMarkMs;
    buffering->mRebufferingWatermarkLowMs = kUnderflowMarkMs;
    buffering->mRebufferingWatermarkHighMs = kOverflowMarkMs;

    return OK;
}

status_t NuPlayer::RTSPSource::setBufferingSettings(const BufferingSettings& buffering) {
    if (mLooper == NULL) {
        mBufferingSettings = buffering;
        return OK;
    }

    sp<AMessage> msg = new AMessage(kWhatSetBufferingSettings, this);
    writeToAMessage(msg, buffering);
    sp<AMessage> response;
    status_t err = msg->postAndAwaitResponse(&response);
    if (err == OK && response != NULL) {
        CHECK(response->findInt32("err", &err));
    }

    return err;
}

void NuPlayer::RTSPSource::prepareAsync() {
    if (mIsSDP && mHTTPService == NULL) {
        notifyPrepared(BAD_VALUE);
        return;
    }

    if (mLooper == NULL) {
        mLooper = new ALooper;
        mLooper->setName("rtsp");
        mLooper->start();

        mLooper->registerHandler(this);
    }

    CHECK(mHandler == NULL);
    CHECK(mSDPLoader == NULL);

    sp<AMessage> notify = new AMessage(kWhatNotify, this);

    CHECK_EQ(mState, (int)DISCONNECTED);
    mState = CONNECTING;

    if (mIsSDP) {
        mSDPLoader = new SDPLoader(notify,
                (mFlags & kFlagIncognito) ? SDPLoader::kFlagIncognito : 0,
                mHTTPService);

        mSDPLoader->load(
                mURL.c_str(), mExtraHeaders.isEmpty() ? NULL : &mExtraHeaders);
    } else {
        mHandler = new MyHandler(mURL.c_str(), notify, mUIDValid, mUID);
        mLooper->registerHandler(mHandler);

        mHandler->connect();
    }

    startBufferingIfNecessary();
}

void NuPlayer::RTSPSource::start() {
}

void NuPlayer::RTSPSource::stop() {
    if (mLooper == NULL) {
        return;
    }
    sp<AMessage> msg = new AMessage(kWhatDisconnect, this);

    sp<AMessage> dummy;
    msg->postAndAwaitResponse(&dummy);
}

status_t NuPlayer::RTSPSource::feedMoreTSData() {
    Mutex::Autolock _l(mBufferingLock);
    return mFinalResult;
}

sp<MetaData> NuPlayer::RTSPSource::getFormatMeta(bool audio) {
    sp<AnotherPacketSource> source = getSource(audio);

    if (source == NULL) {
        return NULL;
    }

    return source->getFormat();
}

bool NuPlayer::RTSPSource::haveSufficientDataOnAllTracks() {
    // We're going to buffer at least 2 secs worth data on all tracks before
    // starting playback (both at startup and after a seek).

    static const int64_t kMinDurationUs = 2000000ll;

    int64_t mediaDurationUs = 0;
    getDuration(&mediaDurationUs);
    if ((mAudioTrack != NULL && mAudioTrack->isFinished(mediaDurationUs))
            || (mVideoTrack != NULL && mVideoTrack->isFinished(mediaDurationUs))) {
        return true;
    }

    status_t err;
    int64_t durationUs;
    if (mAudioTrack != NULL
            && (durationUs = mAudioTrack->getBufferedDurationUs(&err))
                    < kMinDurationUs
            && err == OK) {
        ALOGV("audio track doesn't have enough data yet. (%.2f secs buffered)",
              durationUs / 1E6);
        return false;
    }

    if (mVideoTrack != NULL
            && (durationUs = mVideoTrack->getBufferedDurationUs(&err))
                    < kMinDurationUs
            && err == OK) {
        ALOGV("video track doesn't have enough data yet. (%.2f secs buffered)",
              durationUs / 1E6);
        return false;
    }

    return true;
}

status_t NuPlayer::RTSPSource::dequeueAccessUnit(
        bool audio, sp<ABuffer> *accessUnit) {
    if (!stopBufferingIfNecessary()) {
        return -EWOULDBLOCK;
    }

    sp<AnotherPacketSource> source = getSource(audio);

    if (source == NULL) {
        return -EWOULDBLOCK;
    }

    status_t finalResult;
    if (!source->hasBufferAvailable(&finalResult)) {
        if (finalResult == OK) {

            // If other source already signaled EOS, this source should also return EOS
            if (sourceReachedEOS(!audio)) {
                return ERROR_END_OF_STREAM;
            }

            // If this source has detected near end, give it some time to retrieve more
            // data before returning EOS
            int64_t mediaDurationUs = 0;
            getDuration(&mediaDurationUs);
            if (source->isFinished(mediaDurationUs)) {
                int64_t eosTimeout = audio ? mEOSTimeoutAudio : mEOSTimeoutVideo;
                if (eosTimeout == 0) {
                    setEOSTimeout(audio, ALooper::GetNowUs());
                } else if ((ALooper::GetNowUs() - eosTimeout) > kNearEOSTimeoutUs) {
                    setEOSTimeout(audio, 0);
                    return ERROR_END_OF_STREAM;
                }
                return -EWOULDBLOCK;
            }

            if (!sourceNearEOS(!audio)) {
                // We should not enter buffering mode
                // if any of the sources already have detected EOS.
                startBufferingIfNecessary();
            }

            return -EWOULDBLOCK;
        }
        return finalResult;
    }

    setEOSTimeout(audio, 0);

    return source->dequeueAccessUnit(accessUnit);
}

sp<AnotherPacketSource> NuPlayer::RTSPSource::getSource(bool audio) {
    if (mTSParser != NULL) {
        sp<MediaSource> source = mTSParser->getSource(
                audio ? ATSParser::AUDIO : ATSParser::VIDEO);

        return static_cast<AnotherPacketSource *>(source.get());
    }

    return audio ? mAudioTrack : mVideoTrack;
}

void NuPlayer::RTSPSource::setEOSTimeout(bool audio, int64_t timeout) {
    if (audio) {
        mEOSTimeoutAudio = timeout;
    } else {
        mEOSTimeoutVideo = timeout;
    }
}

status_t NuPlayer::RTSPSource::getDuration(int64_t *durationUs) {
    *durationUs = -1ll;

    int64_t audioDurationUs;
    if (mAudioTrack != NULL
            && mAudioTrack->getFormat()->findInt64(
                kKeyDuration, &audioDurationUs)
            && audioDurationUs > *durationUs) {
        *durationUs = audioDurationUs;
    }

    int64_t videoDurationUs;
    if (mVideoTrack != NULL
            && mVideoTrack->getFormat()->findInt64(
                kKeyDuration, &videoDurationUs)
            && videoDurationUs > *durationUs) {
        *durationUs = videoDurationUs;
    }

    return OK;
}

status_t NuPlayer::RTSPSource::seekTo(int64_t seekTimeUs, MediaPlayerSeekMode mode) {
    sp<AMessage> msg = new AMessage(kWhatPerformSeek, this);
    msg->setInt32("generation", ++mSeekGeneration);
    msg->setInt64("timeUs", seekTimeUs);
    msg->setInt32("mode", mode);

    sp<AMessage> response;
    status_t err = msg->postAndAwaitResponse(&response);
    if (err == OK && response != NULL) {
        CHECK(response->findInt32("err", &err));
    }

    return err;
}

void NuPlayer::RTSPSource::performSeek(int64_t seekTimeUs) {
    if (mState != CONNECTED) {
        finishSeek(INVALID_OPERATION);
        return;
    }

    mState = SEEKING;
    mHandler->seek(seekTimeUs);
    mEOSPending = false;
}

void NuPlayer::RTSPSource::schedulePollBuffering() {
    sp<AMessage> msg = new AMessage(kWhatPollBuffering, this);
    msg->post(1000000ll); // 1 second intervals
}

void NuPlayer::RTSPSource::checkBuffering(
        bool *prepared, bool *underflow, bool *overflow, bool *startServer, bool *finished) {
    size_t numTracks = mTracks.size();
    size_t preparedCount, underflowCount, overflowCount, startCount, finishedCount;
    preparedCount = underflowCount = overflowCount = startCount = finishedCount = 0;

    size_t count = numTracks;
    for (size_t i = 0; i < count; ++i) {
        status_t finalResult;
        TrackInfo *info = &mTracks.editItemAt(i);
        sp<AnotherPacketSource> src = info->mSource;
        if (src == NULL) {
            --numTracks;
            continue;
        }
        int64_t bufferedDurationUs = src->getBufferedDurationUs(&finalResult);

        // isFinished when duration is 0 checks for EOS result only
        if (bufferedDurationUs > mBufferingSettings.mInitialWatermarkMs * 1000
                || src->isFinished(/* duration */ 0)) {
            ++preparedCount;
        }

        if (src->isFinished(/* duration */ 0)) {
            ++overflowCount;
            ++finishedCount;
        } else {
            if (bufferedDurationUs < mBufferingSettings.mRebufferingWatermarkLowMs * 1000) {
                ++underflowCount;
            }
            if (bufferedDurationUs > mBufferingSettings.mRebufferingWatermarkHighMs * 1000) {
                ++overflowCount;
            }
            int64_t startServerMarkUs =
                    (mBufferingSettings.mRebufferingWatermarkLowMs
                        + mBufferingSettings.mRebufferingWatermarkHighMs) / 2 * 1000ll;
            if (bufferedDurationUs < startServerMarkUs) {
                ++startCount;
            }
        }
    }

    *prepared    = (preparedCount == numTracks);
    *underflow   = (underflowCount > 0);
    *overflow    = (overflowCount == numTracks);
    *startServer = (startCount > 0);
    *finished    = (finishedCount > 0);
}

void NuPlayer::RTSPSource::onPollBuffering() {
    bool prepared, underflow, overflow, startServer, finished;
    checkBuffering(&prepared, &underflow, &overflow, &startServer, &finished);

    if (prepared && mInPreparationPhase) {
        mInPreparationPhase = false;
        notifyPrepared();
    }

    if (!mInPreparationPhase && underflow) {
        startBufferingIfNecessary();
    }

    if (haveSufficientDataOnAllTracks()) {
        stopBufferingIfNecessary();
    }

    if (overflow && mHandler != NULL) {
        mHandler->pause();
    }

    if (startServer && mHandler != NULL) {
        mHandler->resume();
    }

    if (finished && mHandler != NULL) {
        mHandler->cancelAccessUnitTimeoutCheck();
    }

    schedulePollBuffering();
}

void NuPlayer::RTSPSource::signalSourceEOS(status_t result) {
    const bool audio = true;
    const bool video = false;

    sp<AnotherPacketSource> source = getSource(audio);
    if (source != NULL) {
        source->signalEOS(result);
    }

    source = getSource(video);
    if (source != NULL) {
        source->signalEOS(result);
    }
}

bool NuPlayer::RTSPSource::sourceReachedEOS(bool audio) {
    sp<AnotherPacketSource> source = getSource(audio);
    status_t finalResult;
    return (source != NULL &&
            !source->hasBufferAvailable(&finalResult) &&
            finalResult == ERROR_END_OF_STREAM);
}

bool NuPlayer::RTSPSource::sourceNearEOS(bool audio) {
    sp<AnotherPacketSource> source = getSource(audio);
    int64_t mediaDurationUs = 0;
    getDuration(&mediaDurationUs);
    return (source != NULL && source->isFinished(mediaDurationUs));
}

void NuPlayer::RTSPSource::onSignalEOS(const sp<AMessage> &msg) {
    int32_t generation;
    CHECK(msg->findInt32("generation", &generation));

    if (generation != mSeekGeneration) {
        return;
    }

    if (mEOSPending) {
        signalSourceEOS(ERROR_END_OF_STREAM);
        mEOSPending = false;
    }
}

void NuPlayer::RTSPSource::postSourceEOSIfNecessary() {
    const bool audio = true;
    const bool video = false;
    // If a source has detected near end, give it some time to retrieve more
    // data before signaling EOS
    if (sourceNearEOS(audio) || sourceNearEOS(video)) {
        if (!mEOSPending) {
            sp<AMessage> msg = new AMessage(kWhatSignalEOS, this);
            msg->setInt32("generation", mSeekGeneration);
            msg->post(kNearEOSTimeoutUs);
            mEOSPending = true;
        }
    }
}

void NuPlayer::RTSPSource::onMessageReceived(const sp<AMessage> &msg) {
    if (msg->what() == kWhatDisconnect) {
        sp<AReplyToken> replyID;
        CHECK(msg->senderAwaitsResponse(&replyID));

        mDisconnectReplyID = replyID;
        finishDisconnectIfPossible();
        return;
    } else if (msg->what() == kWhatPerformSeek) {
        int32_t generation;
        CHECK(msg->findInt32("generation", &generation));
        CHECK(msg->senderAwaitsResponse(&mSeekReplyID));

        if (generation != mSeekGeneration) {
            // obsolete.
            finishSeek(OK);
            return;
        }

        int64_t seekTimeUs;
        int32_t mode;
        CHECK(msg->findInt64("timeUs", &seekTimeUs));
        CHECK(msg->findInt32("mode", &mode));

        // TODO: add "mode" to performSeek.
        performSeek(seekTimeUs/*, (MediaPlayerSeekMode)mode */);
        return;
    } else if (msg->what() == kWhatPollBuffering) {
        onPollBuffering();
        return;
    } else if (msg->what() == kWhatSignalEOS) {
        onSignalEOS(msg);
        return;
    } else if (msg->what() == kWhatSetBufferingSettings) {
        sp<AReplyToken> replyID;
        CHECK(msg->senderAwaitsResponse(&replyID));

        BufferingSettings buffering;
        readFromAMessage(msg, &buffering);

        status_t err = OK;
        if (buffering.IsSizeBasedBufferingMode(buffering.mInitialBufferingMode)
                || buffering.IsSizeBasedBufferingMode(buffering.mRebufferingMode)
                || (buffering.mRebufferingWatermarkLowMs > buffering.mRebufferingWatermarkHighMs
                    && buffering.IsTimeBasedBufferingMode(buffering.mRebufferingMode))) {
            err = BAD_VALUE;
        } else {
            if (buffering.mInitialBufferingMode == BUFFERING_MODE_NONE) {
                buffering.mInitialWatermarkMs = BufferingSettings::kNoWatermark;
            }
            if (buffering.mRebufferingMode == BUFFERING_MODE_NONE) {
                buffering.mRebufferingWatermarkLowMs = BufferingSettings::kNoWatermark;
                buffering.mRebufferingWatermarkHighMs = INT32_MAX;
            }

            mBufferingSettings = buffering;
        }

        sp<AMessage> response = new AMessage;
        response->setInt32("err", err);
        response->postReply(replyID);

        return;
    }

    CHECK_EQ(msg->what(), kWhatNotify);

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

    switch (what) {
        case MyHandler::kWhatConnected:
        {
            onConnected();

            notifyVideoSizeChanged();

            uint32_t flags = 0;

            if (mHandler->isSeekable()) {
                flags = FLAG_CAN_PAUSE
                        | FLAG_CAN_SEEK
                        | FLAG_CAN_SEEK_BACKWARD
                        | FLAG_CAN_SEEK_FORWARD;
            }

            notifyFlagsChanged(flags);
            schedulePollBuffering();
            break;
        }

        case MyHandler::kWhatDisconnected:
        {
            onDisconnected(msg);
            break;
        }

        case MyHandler::kWhatSeekDone:
        {
            mState = CONNECTED;
            // Unblock seekTo here in case we attempted to seek in a live stream
            finishSeek(OK);
            break;
        }

        case MyHandler::kWhatSeekPaused:
        {
            sp<AnotherPacketSource> source = getSource(true /* audio */);
            if (source != NULL) {
                source->queueDiscontinuity(ATSParser::DISCONTINUITY_NONE,
                        /* extra */ NULL,
                        /* discard */ true);
            }
            source = getSource(false /* video */);
            if (source != NULL) {
                source->queueDiscontinuity(ATSParser::DISCONTINUITY_NONE,
                        /* extra */ NULL,
                        /* discard */ true);
            };

            status_t err = OK;
            msg->findInt32("err", &err);

            if (err == OK) {
                int64_t timeUs;
                CHECK(msg->findInt64("time", &timeUs));
                mHandler->continueSeekAfterPause(timeUs);
            } else {
                finishSeek(err);
            }
            break;
        }

        case MyHandler::kWhatAccessUnit:
        {
            size_t trackIndex;
            CHECK(msg->findSize("trackIndex", &trackIndex));

            if (mTSParser == NULL) {
                CHECK_LT(trackIndex, mTracks.size());
            } else {
                CHECK_EQ(trackIndex, 0u);
            }

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

            int32_t damaged;
            if (accessUnit->meta()->findInt32("damaged", &damaged)
                    && damaged) {
                ALOGI("dropping damaged access unit.");
                break;
            }

            if (mTSParser != NULL) {
                size_t offset = 0;
                status_t err = OK;
                while (offset + 188 <= accessUnit->size()) {
                    err = mTSParser->feedTSPacket(
                            accessUnit->data() + offset, 188);
                    if (err != OK) {
                        break;
                    }

                    offset += 188;
                }

                if (offset < accessUnit->size()) {
                    err = ERROR_MALFORMED;
                }

                if (err != OK) {
                    signalSourceEOS(err);
                }

                postSourceEOSIfNecessary();
                break;
            }

            TrackInfo *info = &mTracks.editItemAt(trackIndex);

            sp<AnotherPacketSource> source = info->mSource;
            if (source != NULL) {
                uint32_t rtpTime;
                CHECK(accessUnit->meta()->findInt32("rtp-time", (int32_t *)&rtpTime));

                if (!info->mNPTMappingValid) {
                    // This is a live stream, we didn't receive any normal
                    // playtime mapping. We won't map to npt time.
                    source->queueAccessUnit(accessUnit);
                    break;
                }

                int64_t nptUs =
                    ((double)rtpTime - (double)info->mRTPTime)
                        / info->mTimeScale
                        * 1000000ll
                        + info->mNormalPlaytimeUs;

                accessUnit->meta()->setInt64("timeUs", nptUs);

                source->queueAccessUnit(accessUnit);
            }
            postSourceEOSIfNecessary();
            break;
        }

        case MyHandler::kWhatEOS:
        {
            int32_t finalResult;
            CHECK(msg->findInt32("finalResult", &finalResult));
            CHECK_NE(finalResult, (status_t)OK);

            if (mTSParser != NULL) {
                signalSourceEOS(finalResult);
            }

            size_t trackIndex;
            CHECK(msg->findSize("trackIndex", &trackIndex));
            CHECK_LT(trackIndex, mTracks.size());

            TrackInfo *info = &mTracks.editItemAt(trackIndex);
            sp<AnotherPacketSource> source = info->mSource;
            if (source != NULL) {
                source->signalEOS(finalResult);
            }

            break;
        }

        case MyHandler::kWhatSeekDiscontinuity:
        {
            size_t trackIndex;
            CHECK(msg->findSize("trackIndex", &trackIndex));
            CHECK_LT(trackIndex, mTracks.size());

            TrackInfo *info = &mTracks.editItemAt(trackIndex);
            sp<AnotherPacketSource> source = info->mSource;
            if (source != NULL) {
                source->queueDiscontinuity(
                        ATSParser::DISCONTINUITY_TIME,
                        NULL,
                        true /* discard */);
            }

            break;
        }

        case MyHandler::kWhatNormalPlayTimeMapping:
        {
            size_t trackIndex;
            CHECK(msg->findSize("trackIndex", &trackIndex));
            CHECK_LT(trackIndex, mTracks.size());

            uint32_t rtpTime;
            CHECK(msg->findInt32("rtpTime", (int32_t *)&rtpTime));

            int64_t nptUs;
            CHECK(msg->findInt64("nptUs", &nptUs));

            TrackInfo *info = &mTracks.editItemAt(trackIndex);
            info->mRTPTime = rtpTime;
            info->mNormalPlaytimeUs = nptUs;
            info->mNPTMappingValid = true;
            break;
        }

        case SDPLoader::kWhatSDPLoaded:
        {
            onSDPLoaded(msg);
            break;
        }

        default:
            TRESPASS();
    }
}

void NuPlayer::RTSPSource::onConnected() {
    CHECK(mAudioTrack == NULL);
    CHECK(mVideoTrack == NULL);

    size_t numTracks = mHandler->countTracks();
    for (size_t i = 0; i < numTracks; ++i) {
        int32_t timeScale;
        sp<MetaData> format = mHandler->getTrackFormat(i, &timeScale);

        const char *mime;
        CHECK(format->findCString(kKeyMIMEType, &mime));

        if (!strcasecmp(mime, MEDIA_MIMETYPE_CONTAINER_MPEG2TS)) {
            // Very special case for MPEG2 Transport Streams.
            CHECK_EQ(numTracks, 1u);

            mTSParser = new ATSParser;
            return;
        }

        bool isAudio = !strncasecmp(mime, "audio/", 6);
        bool isVideo = !strncasecmp(mime, "video/", 6);

        TrackInfo info;
        info.mTimeScale = timeScale;
        info.mRTPTime = 0;
        info.mNormalPlaytimeUs = 0ll;
        info.mNPTMappingValid = false;

        if ((isAudio && mAudioTrack == NULL)
                || (isVideo && mVideoTrack == NULL)) {
            sp<AnotherPacketSource> source = new AnotherPacketSource(format);

            if (isAudio) {
                mAudioTrack = source;
            } else {
                mVideoTrack = source;
            }

            info.mSource = source;
        }

        mTracks.push(info);
    }

    mState = CONNECTED;
}

void NuPlayer::RTSPSource::onSDPLoaded(const sp<AMessage> &msg) {
    status_t err;
    CHECK(msg->findInt32("result", &err));

    mSDPLoader.clear();

    if (mDisconnectReplyID != 0) {
        err = UNKNOWN_ERROR;
    }

    if (err == OK) {
        sp<ASessionDescription> desc;
        sp<RefBase> obj;
        CHECK(msg->findObject("description", &obj));
        desc = static_cast<ASessionDescription *>(obj.get());

        AString rtspUri;
        if (!desc->findAttribute(0, "a=control", &rtspUri)) {
            ALOGE("Unable to find url in SDP");
            err = UNKNOWN_ERROR;
        } else {
            sp<AMessage> notify = new AMessage(kWhatNotify, this);

            mHandler = new MyHandler(rtspUri.c_str(), notify, mUIDValid, mUID);
            mLooper->registerHandler(mHandler);

            mHandler->loadSDP(desc);
        }
    }

    if (err != OK) {
        if (mState == CONNECTING) {
            // We're still in the preparation phase, signal that it
            // failed.
            notifyPrepared(err);
        }

        mState = DISCONNECTED;
        setError(err);

        if (mDisconnectReplyID != 0) {
            finishDisconnectIfPossible();
        }
    }
}

void NuPlayer::RTSPSource::onDisconnected(const sp<AMessage> &msg) {
    if (mState == DISCONNECTED) {
        return;
    }

    status_t err;
    CHECK(msg->findInt32("result", &err));
    CHECK_NE(err, (status_t)OK);

    mLooper->unregisterHandler(mHandler->id());
    mHandler.clear();

    if (mState == CONNECTING) {
        // We're still in the preparation phase, signal that it
        // failed.
        notifyPrepared(err);
    }

    mState = DISCONNECTED;
    setError(err);

    if (mDisconnectReplyID != 0) {
        finishDisconnectIfPossible();
    }
}

void NuPlayer::RTSPSource::finishDisconnectIfPossible() {
    if (mState != DISCONNECTED) {
        if (mHandler != NULL) {
            mHandler->disconnect();
        } else if (mSDPLoader != NULL) {
            mSDPLoader->cancel();
        }
        return;
    }

    (new AMessage)->postReply(mDisconnectReplyID);
    mDisconnectReplyID = 0;
}

void NuPlayer::RTSPSource::setError(status_t err) {
    Mutex::Autolock _l(mBufferingLock);
    mFinalResult = err;
}

void NuPlayer::RTSPSource::startBufferingIfNecessary() {
    Mutex::Autolock _l(mBufferingLock);

    if (!mBuffering) {
        mBuffering = true;

        sp<AMessage> notify = dupNotify();
        notify->setInt32("what", kWhatPauseOnBufferingStart);
        notify->post();
    }
}

bool NuPlayer::RTSPSource::stopBufferingIfNecessary() {
    Mutex::Autolock _l(mBufferingLock);

    if (mBuffering) {
        if (!haveSufficientDataOnAllTracks()) {
            return false;
        }

        mBuffering = false;

        sp<AMessage> notify = dupNotify();
        notify->setInt32("what", kWhatResumeOnBufferingEnd);
        notify->post();
    }

    return true;
}

void NuPlayer::RTSPSource::finishSeek(status_t err) {
    if (mSeekReplyID == NULL) {
        return;
    }
    sp<AMessage> seekReply = new AMessage;
    seekReply->setInt32("err", err);
    seekReply->postReply(mSeekReplyID);
    mSeekReplyID = NULL;
}

}  // namespace android