C++ BaseRepresentation类代码示例

bool SegmentTracker::segmentsListReady() const
{
    BaseRepresentation *rep = curRepresentation;
    if(!rep)
        rep = logic->getNextRepresentation(adaptationSet, NULL);
    if(rep && rep->getPlaylist()->isLive())
        return rep->getMinAheadTime(curNumber) > 0;
    return true;
}

mtime_t SegmentTracker::getMinAheadTime() const
{
    BaseRepresentation *rep = curRepresentation;
    if(!rep)
        rep = logic->getNextRepresentation(adaptationSet, NULL);
    if(rep)
        return rep->getMinAheadTime(curNumber);
    return 0;
}

StreamFormat SegmentTracker::initialFormat() const
{
    BaseRepresentation *rep = curRepresentation;
    if(!rep)
        rep = logic->getNextRepresentation(adaptationSet, NULL);
    if(rep)
        return rep->getStreamFormat();
    return StreamFormat();
}

Chunk * SegmentTracker::getNextChunk(StreamType type, bool switch_allowed)
{
    BaseRepresentation *rep;
    ISegment *segment;

    if(!currentPeriod)
        return NULL;

    if( !switch_allowed ||
       (prevRepresentation && prevRepresentation->getSwitchPolicy() == SegmentInformation::SWITCH_UNAVAILABLE) )
        rep = prevRepresentation;
    else
        rep = logic->getCurrentRepresentation(type, currentPeriod);

    if ( rep == NULL )
            return NULL;

    if(rep != prevRepresentation)
    {
        prevRepresentation = rep;
        initializing = true;
    }

    if(initializing)
    {
        initializing = false;
        segment = rep->getSegment(BaseRepresentation::INFOTYPE_INIT);
        if(segment)
            return segment->toChunk(count, rep);
    }

    if(!indexed)
    {
        indexed = true;
        segment = rep->getSegment(BaseRepresentation::INFOTYPE_INDEX);
        if(segment)
            return segment->toChunk(count, rep);
    }

    segment = rep->getSegment(BaseRepresentation::INFOTYPE_MEDIA, count);
    if(!segment)
    {
        currentPeriod = playlist->getNextPeriod(currentPeriod);
        resetCounter();
        return getNextChunk(type, switch_allowed);
    }

    Chunk *chunk = segment->toChunk(count, rep);
    if(chunk)
        count++;

    return chunk;
}

StreamFormat SegmentTracker::getCurrentFormat() const
{
    BaseRepresentation *rep = curRepresentation;
    if(!rep)
        rep = logic->getNextRepresentation(adaptationSet, NULL);
    if(rep)
    {
        /* Ensure ephemere content is updated/loaded */
        if(rep->needsUpdate())
            (void) rep->runLocalUpdates(0, curNumber, false);
        return rep->getStreamFormat();
    }
    return StreamFormat();
}

bool SegmentTracker::setPositionByTime(mtime_t time, bool restarted, bool tryonly)
{
    uint64_t segnumber;
    BaseRepresentation *rep = prevRepresentation;
    if(!rep)
        rep = logic->getNextRepresentation(adaptationSet, NULL);

    if(rep &&
       rep->getSegmentNumberByTime(time, &segnumber))
    {
        if(!tryonly)
            setPositionByNumber(segnumber, restarted);
        return true;
    }
    return false;
}

BaseRepresentation * RepresentationSelector::select(BaseAdaptationSet *adaptSet, uint64_t bitrate) const
{
    if (adaptSet == NULL)
        return NULL;

    BaseRepresentation *best = NULL;
    std::vector<BaseRepresentation *> reps = adaptSet->getRepresentations();
    BaseRepresentation *candidate = select(reps, (best)?best->getBandwidth():0, bitrate);
    if (candidate)
    {
        if (candidate->getBandwidth() > bitrate) /* none matched, returned lowest */
            return candidate;
        best = candidate;
    }

    return best;
}

BaseRepresentation *
NearOptimalAdaptationLogic::getNextQualityIndex( BaseAdaptationSet *adaptSet, RepresentationSelector &selector,
                                                 float gammaP, mtime_t VD, mtime_t Q )
{
    BaseRepresentation *ret = NULL;
    BaseRepresentation *prev = NULL;
    float argmax;
    for(BaseRepresentation *rep = selector.lowest(adaptSet);
                            rep && rep != prev; rep = selector.higher(adaptSet, rep))
    {
        float arg = ( VD * (getUtility(rep) + gammaP) - Q ) / rep->getBandwidth();
        if(ret == NULL || argmax <= arg)
        {
            ret = rep;
            argmax = arg;
        }
        prev = rep;
    }
    return ret;
}

BaseRepresentation *NearOptimalAdaptationLogic::getNextRepresentation(BaseAdaptationSet *adaptSet, BaseRepresentation *prevRep)
{
    RepresentationSelector selector(maxwidth, maxheight);

    const float umin = getUtility(selector.lowest(adaptSet));
    const float umax = getUtility(selector.highest(adaptSet));

    vlc_mutex_lock(&lock);

    std::map<ID, NearOptimalContext>::iterator it = streams.find(adaptSet->getID());
    if(it == streams.end())
    {
        vlc_mutex_unlock(&lock);
        return selector.lowest(adaptSet);
    }
    NearOptimalContext ctxcopy = (*it).second;

    const unsigned bps = getAvailableBw(currentBps, prevRep);

    vlc_mutex_unlock(&lock);

    const float gammaP = 1.0 + (umax - umin) / ((float)ctxcopy.buffering_target / ctxcopy.buffering_min - 1.0);
    const float Vd = ((float)ctxcopy.buffering_min / CLOCK_FREQ - 1.0) / (umin + gammaP);

    BaseRepresentation *m;
    if(prevRep == NULL) /* Starting */
    {
        m = selector.select(adaptSet, bps);
    }
    else
    {
        /* noted m* */
        m = getNextQualityIndex(adaptSet, selector, gammaP - umin /* umin == Sm, utility = std::log(S/Sm) */,
                                Vd, (float)ctxcopy.buffering_level / CLOCK_FREQ);
        if(m->getBandwidth() < prevRep->getBandwidth()) /* m*[n] < m*[n-1] */
        {
            BaseRepresentation *mp = selector.select(adaptSet, bps); /* m' */
            if(mp->getBandwidth() <= m->getBandwidth())
            {
                mp = m;
            }
            else if(mp->getBandwidth() > prevRep->getBandwidth())
            {
                mp = prevRep;
            }
            else
            {
                mp = selector.lower(adaptSet, mp);
            }
            m = mp;
        }
    }

    BwDebug( msg_Info(p_obj, "buffering level %.2f% rep %ld kBps %zu kBps",
             (float) 100 * ctxcopy.buffering_level / ctxcopy.buffering_target, m->getBandwidth()/8000, bps / 8000); );

BaseRepresentation * RepresentationSelector::select(BasePeriod *period, adaptative::StreamType type, uint64_t bitrate) const
{
    if (period == NULL)
        return NULL;

    std::vector<BaseAdaptationSet *> adaptSets = period->getAdaptationSets(type);
    BaseRepresentation *best = NULL;

    std::vector<BaseAdaptationSet *>::const_iterator adaptIt;
    for(adaptIt=adaptSets.begin(); adaptIt!=adaptSets.end(); ++adaptIt)
    {
        std::vector<BaseRepresentation *> reps = (*adaptIt)->getRepresentations();
        BaseRepresentation *candidate = select(reps, (best)?best->getBandwidth():0, bitrate);
        if (candidate)
        {
            if (candidate->getBandwidth() > bitrate) /* none matched, returned lowest */
                return candidate;
            best = candidate;
        }
    }
    return best;
}

mtime_t SegmentTracker::getPlaybackTime() const
{
    mtime_t time, duration;

    BaseRepresentation *rep = curRepresentation;
    if(!rep)
        rep = logic->getNextRepresentation(adaptationSet, NULL);

    if(rep &&
       rep->getPlaybackTimeDurationBySegmentNumber(next, &time, &duration))
    {
	    /* LVP added, TFE */
        // apparently not used
        //msg_Info(NULL, "TFE SegmentTracker getPlaybackTime, %" PRId64 ", %" PRId64 ", %" PRId64,
        //        mdate(), time, duration);
	    //std::cerr << "TFE SegmentTracker::getPlaybackTime time and duration, "
	    //          << mdate() << ", " << time << ", " << duration << std::endl;
		
        return time;
    }
    return 0;
}

SegmentChunk * SegmentTracker::getNextChunk(bool switch_allowed, HTTPConnectionManager *connManager)
{
    BaseRepresentation *rep = NULL;
    ISegment *segment;

    if(!adaptationSet)
        return NULL;

    /* Ensure we don't keep chaining init/index without data */
    if( initializing )
    {
        if( prevRepresentation )
            switch_allowed = false;
        else
            switch_allowed = true;
    }

    if( !switch_allowed ||
       (prevRepresentation && prevRepresentation->getSwitchPolicy() == SegmentInformation::SWITCH_UNAVAILABLE) )
        rep = prevRepresentation;
    else
        rep = logic->getNextRepresentation(adaptationSet, prevRepresentation);

    if ( rep == NULL )
            return NULL;


    if(rep != prevRepresentation)
    {
        notify(SegmentTrackerEvent(prevRepresentation, rep));
        prevRepresentation = rep;
        init_sent = false;
        index_sent = false;
        initializing = true;
    }

    /* Ensure ephemere content is updated/loaded */
    if(rep->needsUpdate())
        updateSelected();

    if(!init_sent)
    {
        init_sent = true;
        segment = rep->getSegment(BaseRepresentation::INFOTYPE_INIT);
        if(segment)
            return segment->toChunk(count, rep, connManager);
    }

    if(!index_sent)
    {
        index_sent = true;
        segment = rep->getSegment(BaseRepresentation::INFOTYPE_INDEX);
        if(segment)
            return segment->toChunk(count, rep, connManager);
    }

    bool b_gap = false;
    segment = rep->getNextSegment(BaseRepresentation::INFOTYPE_MEDIA, count, &count, &b_gap);
    if(!segment)
    {
        reset();
        return NULL;
    }

    /* stop initializing after 1st chunk */
    initializing = false;

    SegmentChunk *chunk = segment->toChunk(count, rep, connManager);
    if(chunk)
        count++;

    /* We need to check segment/chunk format changes, as we can't rely on representation's (HLS)*/
    if(format != chunk->getStreamFormat())
    {
        format = chunk->getStreamFormat();
        notify(SegmentTrackerEvent(&format));
    }

    /* Handle both implicit and explicit discontinuities */
    if( (b_gap && count) || (chunk && chunk->discontinuity) )
    {
        notify(SegmentTrackerEvent(chunk));
    }

    return chunk;
}

BaseRepresentation *PredictiveAdaptationLogic::getNextRepresentation(BaseAdaptationSet *adaptSet, BaseRepresentation *prevRep)
{
    RepresentationSelector selector(maxwidth, maxheight);
    BaseRepresentation *rep;

    vlc_mutex_lock(&lock);

    std::map<ID, PredictiveStats>::iterator it = streams.find(adaptSet->getID());
    if(it == streams.end())
    {
        rep = selector.highest(adaptSet);
    }
    else
    {
        PredictiveStats &stats = (*it).second;

        double f_buffering_level = (double)stats.buffering_level / stats.buffering_target;
        double f_min_buffering_level = f_buffering_level;
        unsigned i_max_bitrate = 0;
        if(streams.size() > 1)
        {
            std::map<ID, PredictiveStats>::const_iterator it2 = streams.begin();
            for(; it2 != streams.end(); ++it2)
            {
                if(it2 == it)
                    continue;

                const PredictiveStats &other = (*it2).second;
                f_min_buffering_level = std::min((double)other.buffering_level / other.buffering_target,
                                                 f_min_buffering_level);
                i_max_bitrate = std::max(i_max_bitrate, other.last_download_rate);
            }
        }

        if(stats.starting())
        {
            rep = selector.highest(adaptSet);
        }
        else
        {
            const unsigned i_available_bw = getAvailableBw(i_max_bitrate, prevRep);
            if(!prevRep)
            {
                rep = selector.select(adaptSet, i_available_bw);
            }
            else if(f_buffering_level > 0.8)
            {
                rep = selector.select(adaptSet, std::max((uint64_t) i_available_bw,
                                                         (uint64_t) prevRep->getBandwidth()));
            }
            else if(f_buffering_level > 0.5)
            {
                rep = prevRep;
            }
            else
            {
                if(f_buffering_level > 2 * stats.last_duration)
                {
                    rep = selector.lower(adaptSet, prevRep);
                }
                else
                {
                    rep = selector.select(adaptSet, i_available_bw * f_buffering_level);
                }
            }
        }

        BwDebug( for(it=streams.begin(); it != streams.end(); ++it)
        {
            const PredictiveStats &s = (*it).second;
            msg_Info(p_obj, "Stream %s buffering level %.2f%",
                 (*it).first.str().c_str(), (double) s.buffering_level / s.buffering_target);
        } );

        BwDebug( if( rep != prevRep )
                    msg_Info(p_obj, "Stream %s new bandwidth usage %zu KiB/s",
                         adaptSet->getID().str().c_str(), rep->getBandwidth() / 8000); );

SegmentChunk * SegmentTracker::getNextChunk(bool switch_allowed, HTTPConnectionManager *connManager)
{
    BaseRepresentation *rep = NULL, *prevRep = NULL;
    ISegment *segment;

    if(!adaptationSet)
        return NULL;

    /* Ensure we don't keep chaining init/index without data */
    if( initializing )
    {
        if( curRepresentation )
            switch_allowed = false;
        else
            switch_allowed = true;
    }

    if( !switch_allowed ||
       (curRepresentation && curRepresentation->getSwitchPolicy() == SegmentInformation::SWITCH_UNAVAILABLE) )
        rep = curRepresentation;
    else
        rep = logic->getNextRepresentation(adaptationSet, curRepresentation);

    if ( rep == NULL )
            return NULL;


    if(rep != curRepresentation)
    {
        notify(SegmentTrackerEvent(curRepresentation, rep));
        prevRep = curRepresentation;
        curRepresentation = rep;
        init_sent = false;
        index_sent = false;
        initializing = true;
    }

    bool b_updated = false;
    /* Ensure ephemere content is updated/loaded */
    if(rep->needsUpdate())
        b_updated = rep->runLocalUpdates(getPlaybackTime(), curNumber, false);

    if(prevRep && !rep->consistentSegmentNumber())
    {
        /* Convert our segment number */
        next = rep->translateSegmentNumber(next, prevRep);
    }
    else if(first && rep->getPlaylist()->isLive())
    {
        next = rep->getLiveStartSegmentNumber(next);
        first = false;
    }

    if(b_updated)
    {
        if(!rep->consistentSegmentNumber())
            curRepresentation->pruneBySegmentNumber(curNumber);
        curRepresentation->scheduleNextUpdate(next);
    }

    if(!init_sent)
    {
        init_sent = true;
        segment = rep->getSegment(BaseRepresentation::INFOTYPE_INIT);
        if(segment)
            return segment->toChunk(next, rep, connManager);
    }

    if(!index_sent)
    {
        index_sent = true;
        segment = rep->getSegment(BaseRepresentation::INFOTYPE_INDEX);
        if(segment)
            return segment->toChunk(next, rep, connManager);
    }

    bool b_gap = false;
    segment = rep->getNextSegment(BaseRepresentation::INFOTYPE_MEDIA, next, &next, &b_gap);
    if(!segment)
    {
        reset();
        return NULL;
    }

    if(initializing)
    {
        b_gap = false;
        /* stop initializing after 1st chunk */
        initializing = false;
    }

    SegmentChunk *chunk = segment->toChunk(next, rep, connManager);

    /* We need to check segment/chunk format changes, as we can't rely on representation's (HLS)*/
    if(chunk && format != chunk->getStreamFormat())
    {
        format = chunk->getStreamFormat();
        notify(SegmentTrackerEvent(&format));
    }

//.........这里部分代码省略.........

SegmentChunk * SegmentTracker::getNextChunk(bool switch_allowed,
                                            AbstractConnectionManager *connManager)
{
    /* LVP added, TFE DEBUG */
    //msg_Info(NULL, "TFE DEBUG SegmentTracker getNextChunk, %" PRId64, mdate());
    //std::cerr << "TFE DEBUG SegmentTracker getNextChunk, " << mdate() << std::endl;

    BaseRepresentation *rep = NULL, *prevRep = NULL;
    ISegment *segment;

    if(!adaptationSet) {

        /* LVP added, TFE DEBUG */
        //msg_Info(NULL, "TFE DEBUG SegmentTracker getNextChunk no adaptation set, %" PRId64, mdate());
        //std::cerr << "TFE DEBUG SegmentTracker getNextChunk no adaptation set, " << mdate() << std::endl;

        return NULL;
    }


    /* Ensure we don't keep chaining init/index without data */
    if( initializing )
    {
        if( curRepresentation )
            switch_allowed = false;
        else
            switch_allowed = true;
    }

    if( !switch_allowed ||
       (curRepresentation && curRepresentation->getSwitchPolicy() == SegmentInformation::SWITCH_UNAVAILABLE) )
        rep = curRepresentation;
    else
        rep = logic->getNextRepresentation(adaptationSet, curRepresentation);

    if ( rep == NULL ) {

        /* LVP added, TFE DEBUG */
        //msg_Info(NULL, "TFE DEBUG SegmentTracker no rep 1, %" PRId64, mdate());
        //std::cerr << "TFE DEBUG SegmentTracker no rep 1, " << mdate() << std::endl;

        return NULL;
    }


    if(rep != curRepresentation)
    {
        notify(SegmentTrackerEvent(curRepresentation, rep));
        prevRep = curRepresentation;
        curRepresentation = rep;
        init_sent = false;
        index_sent = false;
        initializing = true;
    }

    bool b_updated = false;
    /* Ensure ephemere content is updated/loaded */
    if(rep->needsUpdate())
        b_updated = rep->runLocalUpdates(getPlaybackTime(), curNumber, false);

    if(prevRep && !rep->consistentSegmentNumber())
    {
        /* Convert our segment number */
        next = rep->translateSegmentNumber(next, prevRep);
    }
    else if(first && rep->getPlaylist()->isLive())
    {
        next = rep->getLiveStartSegmentNumber(next);
        first = false;
    }

    if(b_updated)
    {
        if(!rep->consistentSegmentNumber())
            curRepresentation->pruneBySegmentNumber(curNumber);
        curRepresentation->scheduleNextUpdate(next);
    }

    if(rep->getStreamFormat() != format)
    {
        /* Initial format ? */
        if(format == StreamFormat(StreamFormat::UNSUPPORTED))
        {
            format = rep->getStreamFormat();
        }
        else
        {
            format = rep->getStreamFormat();
            notify(SegmentTrackerEvent(&format)); /* Notify new demux format */
            return NULL; /* Force current demux to end */
        }
    }

    if(format == StreamFormat(StreamFormat::UNSUPPORTED))
    {
        return NULL; /* Can't return chunk because no demux will be created */
    }

    if(!init_sent)
    {
//.........这里部分代码省略.........