|| || || || || || || ||

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VideoIndex.h

Go to the documentation of this file.

#ifndef Impala_Core_Stream_Lavc_VideoIndex_h
#define Impala_Core_Stream_Lavc_VideoIndex_h

#include "Core/Table/TableTem.h"

namespace Impala
{
namespace Core
{
namespace Stream
{
namespace Lavc
{

class VideoIndex
{

private:

    // frame nr | is seekable | seekable frame position 
    typedef Table::TableTem< Column::ColumnTem<Int32>,
                             Column::ColumnTem<Int32>,
                             Column::ColumnTem<UInt64> > SeekTable;

public:

    VideoIndex() : mSeekTable(1000)
    {
    }

    void
    AddFrame(int frameNr, bool isSeekable, const UInt64& seekPosition)
    {
        mSeekTable.Add(frameNr, (isSeekable ? 1 : 0), seekPosition);
    }

    int
    NrOfEntries() const
    {
        return mSeekTable.Size();
    }

    UInt64
    SeekTarget(int frameNr) const
    {
        const int entryNr = EntryNr(frameNr);
        if (entryNr >= 0)
            return mSeekTable.Get3(entryNr);

        ILOG_ERROR("Unknown frame nr: " << frameNr);
        return -1;
    }

    //UInt64
    //LastSeekTarget() const
    //{
    //    const int size = NrOfEntries();
    //    if (size == 0)
    //    {
    //        ILOG_ERROR("Index table is empty; last seek target N.A.");
    //        return 0;
    //    }
    //    return mSeekTable.Get3(size - 1);
    //}

    bool
    SetNotSeekable(int frameNr)
    {
        const int entryNr = EntryNr(frameNr);
        if (entryNr < 0)
        {
            ILOG_ERROR("Unknown frame nr: " << frameNr);
            return false;
        }

        mSeekTable.Set2(entryNr, 0);
        return true;
    }

    int
    NrOfSeekableFrames() const
    {
        int nrOfSeekableFrames = 0;
        const int nrOfEntries = NrOfEntries();
        for (int i = 0; i < nrOfEntries; i++)
            if (mSeekTable.Get2(i) != 0)
                nrOfSeekableFrames++;
        return nrOfSeekableFrames;
    }

    int
    MaxNonTargetFrameReads() const
    {
        int maxReads = 0;
        int prevSeekableFrameNr = -1;
        const int nrOfEntries = NrOfEntries();
        for (int i = 0; i < nrOfEntries; i++)
        {
            if (mSeekTable.Get2(i) != 0)
            {
                int frameNr = mSeekTable.Get1(i);
                int curReads = (frameNr - 1) - prevSeekableFrameNr;
                maxReads = Impala::Max(maxReads, curReads);
                prevSeekableFrameNr = frameNr;
            }
        }
        const int trailingNonSeekableFrames = 
            (nrOfEntries - 1) - prevSeekableFrameNr;
        maxReads = Impala::Max(maxReads, trailingNonSeekableFrames);
        return maxReads;
    }

    bool
    IsSeekable(int frameNr) const
    {
        const int entryNr = EntryNr(frameNr);
        if (entryNr < 0)
            return false;
        return mSeekTable.Get2(entryNr) != 0;
    }

    void
    GetSeekInfo(int frameNr, int* seekableFrameNr, UInt64* seekableFramePos) const
    {
        const int nrOfEntries = NrOfEntries();
        for (int i = nrOfEntries; i > 0; )
        {
            i--;
            if (mSeekTable.Get1(i) > frameNr)
                continue;
            const bool seekable = mSeekTable.Get2(i) != 0;
            if (!seekable)
                continue;

            *seekableFrameNr = mSeekTable.Get1(i);
            *seekableFramePos = mSeekTable.Get3(i);
            return;
        }

        ILOG_WARN("No seek info for frame " << frameNr);
        *seekableFrameNr = -1;
        *seekableFramePos = -1;
    }


private:

    int
    EntryNr(int frameNr) const
    {
        const int maxIndex = Impala::Min(NrOfEntries() - 1, frameNr);
        for (int i = 0; i <= maxIndex; i++)
            if (mSeekTable.Get1(i) == frameNr)
                return i;
        return -1;
    }


    SeekTable mSeekTable;

    ILOG_VAR_DECL;

}; //class

ILOG_VAR_INIT(VideoIndex, Impala.Core.Stream.Lavc);

}}}} // namespace Impala::Core::Stream::Lavc

#endif

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