set version to 1.0.0.6

Change-Id: I259171d7bce7f670cb937707a9864aa0b9eb0d22

mkvparser.cpp

@@ -25,7 +25,7 @@ void mkvparser::GetVersion(int& major, int& minor, int& build, int& revision)
     major = 1;
     minor = 0;
     build = 0;
-    revision = 5;
+    revision = 6;
 }
 
 
@@ -707,6 +707,7 @@ long long EBMLHeader::Parse(
 
     if ((total -  pos) < len)
         return E_FILE_FORMAT_INVALID;
+
     if ((available - pos) < len)
         return pos + len;  //try again later
 
@@ -769,7 +770,6 @@ long long EBMLHeader::Parse(
     }
 
     assert(pos == end);
-
     return 0;
 }
 
@@ -1029,17 +1029,15 @@ long long Segment::ParseHeaders()
 }
 
 
-#if 0
+long Segment::ParseCluster(long long& off, long long& new_pos) const
-long Segment::ParseCluster(Cluster*& pCluster, long long& pos_) const
 {
-    pCluster = NULL;
+    off = -1;
-    pos_ = -1;
+    new_pos = -1;
 
     const long long stop = m_start + m_size;
     assert(m_pos <= stop);
 
     long long pos = m_pos;
-    long long off = -1;
 
     while (pos < stop)
     {
@@ -1089,8 +1087,8 @@ long Segment::ParseCluster(Cluster*& pCluster, long long& pos_) const
 
     if (off < 0)  //we did not found any more clusters
     {
-        pos_ = stop;  //pos_ >= 0 here means EOF (cluster is NULL)
+        new_pos = stop;  //pos >= 0 here means EOF (cluster is NULL)
-        return 0;     //TODO: confirm this return value
+        return 0;        //TODO: confirm this return value
     }
 
     //We found a cluster.  Now read something, to ensure that it is
@@ -1122,7 +1120,7 @@ long Segment::ParseCluster(Cluster*& pCluster, long long& pos_) const
         const int result = m_pReader->Read(pos - 1, 1, &b);
         assert(result == 0);
 
-        pos_ = stop;
+        new_pos = stop;
     }
     else
     {
@@ -1145,33 +1143,26 @@ long Segment::ParseCluster(Cluster*& pCluster, long long& pos_) const
         if (size < 0)  //error
             return static_cast<long>(size);
 
-        pos_ = idpos;
+        new_pos = idpos;
     }
 
-    //We found a cluster, and it has been completely loaded into the
-    //network cache.  (We can guarantee this because we actually read
-    //the EBML tag that follows the cluster, or, if we reached EOF,
-    //because we actually read the last byte of the cluster).
-
-    Segment* const this_ = const_cast<Segment*>(this);
-
-    pCluster = Cluster::Parse(this_, m_clusterCount, off);
-    assert(pCluster);
-    assert(pCluster->m_index == m_clusterCount);
-
     return 0;
 }
 
 
-bool Segment::AddCluster(Cluster* pCluster, long long pos)
+bool Segment::AddCluster(long long off, long long pos)
 {
     assert(pos >= m_start);
 
     const long long stop = m_start + m_size;
     assert(pos <= stop);
 
-    if (pCluster)
+    if (off >= 0)
     {
+        Cluster* const pCluster = Cluster::Parse(this, m_clusterCount, off);
+        assert(pCluster);
+        assert(pCluster->m_index == m_clusterCount);
+
         AppendCluster(pCluster);
         assert(m_clusters);
         assert(m_clusterSize > pCluster->m_index);
@@ -1182,7 +1173,6 @@ bool Segment::AddCluster(Cluster* pCluster, long long pos)
 
     return (pos >= stop);
 }
-#endif
 
 
 long Segment::LoadCluster()
@@ -2408,7 +2398,7 @@ long long Segment::Unparsed() const
 }
 
 
-Cluster* Segment::GetFirst()
+const Cluster* Segment::GetFirst() const
 {
     if ((m_clusters == NULL) || (m_clusterCount <= 0))
        return &m_eos;
@@ -2420,7 +2410,7 @@ Cluster* Segment::GetFirst()
 }
 
 
-Cluster* Segment::GetLast()
+const Cluster* Segment::GetLast() const
 {
     if ((m_clusters == NULL) || (m_clusterCount <= 0))
         return &m_eos;
@@ -2440,7 +2430,7 @@ unsigned long Segment::GetCount() const
 }
 
 
-Cluster* Segment::GetNext(const Cluster* pCurr)
+const Cluster* Segment::GetNext(const Cluster* pCurr)
 {
     assert(pCurr);
     assert(pCurr != &m_eos);
@@ -2596,7 +2586,7 @@ Cluster* Segment::GetNext(const Cluster* pCurr)
 }
 
 
-Cluster* Segment::FindCluster(long long time_ns)
+const Cluster* Segment::FindCluster(long long time_ns) const
 {
     if ((m_clusters == NULL) || (m_clusterCount <= 0))
         return &m_eos;
@@ -2656,7 +2646,7 @@ Cluster* Segment::FindCluster(long long time_ns)
 
 const BlockEntry* Segment::Seek(
     long long time_ns,
-    const Track* pTrack)
+    const Track* pTrack) const
 {
     assert(pTrack);
 
@@ -3068,7 +3058,7 @@ bool Track::GetLacing() const
 
 long Track::GetFirst(const BlockEntry*& pBlockEntry) const
 {
-    Cluster* pCluster = m_pSegment->GetFirst();
+    const Cluster* pCluster = m_pSegment->GetFirst();
 
     //If Segment::GetFirst returns NULL, then this must be a network
     //download, and we haven't loaded any clusters yet.  In this case,
@@ -3129,7 +3119,7 @@ long Track::GetNext(
     const Block* const pCurrBlock = pCurrEntry->GetBlock();
     assert(pCurrBlock->GetTrackNumber() == m_info.number);
 
-    Cluster* pCluster = pCurrEntry->GetCluster();
+    const Cluster* pCluster = pCurrEntry->GetCluster();
     assert(pCluster);
     assert(!pCluster->EOS());
 
@@ -3633,7 +3623,7 @@ Tracks::~Tracks()
 }
 
 
-Track* Tracks::GetTrackByNumber(unsigned long tn_) const
+const Track* Tracks::GetTrackByNumber(unsigned long tn_) const
 {
     const long long tn = tn_;
 
@@ -3655,7 +3645,7 @@ Track* Tracks::GetTrackByNumber(unsigned long tn_) const
 }
 
 
-Track* Tracks::GetTrackByIndex(unsigned long idx) const
+const Track* Tracks::GetTrackByIndex(unsigned long idx) const
 {
     const ptrdiff_t count = m_trackEntriesEnd - m_trackEntries;
 
@@ -3666,7 +3656,7 @@ Track* Tracks::GetTrackByIndex(unsigned long idx) const
 }
 
 
-void Cluster::Load()
+void Cluster::Load() const
 {
     assert(m_pSegment);
     assert(m_pos);
@@ -3808,7 +3798,7 @@ bool Cluster::EOS() const
 }
 
 
-void Cluster::LoadBlockEntries()
+void Cluster::LoadBlockEntries() const
 {
     if (m_entries)
         return;
@@ -3936,14 +3926,14 @@ void Cluster::LoadBlockEntries()
 
 
 
-long long Cluster::GetTimeCode()
+long long Cluster::GetTimeCode() const
 {
     Load();
     return m_timecode;
 }
 
 
-long long Cluster::GetTime()
+long long Cluster::GetTime() const
 {
     const long long tc = GetTimeCode();
     assert(tc >= 0);
@@ -3960,7 +3950,7 @@ long long Cluster::GetTime()
 }
 
 
-long long Cluster::GetFirstTime()
+long long Cluster::GetFirstTime() const
 {
     const BlockEntry* const pEntry = GetFirst();
 
@@ -3974,7 +3964,7 @@ long long Cluster::GetFirstTime()
 }
 
 
-long long Cluster::GetLastTime()
+long long Cluster::GetLastTime() const
 {
     const BlockEntry* const pEntry = GetLast();
 
@@ -3988,40 +3978,40 @@ long long Cluster::GetLastTime()
 }
 
 
-void Cluster::ParseBlockGroup(long long start, long long size, size_t index)
+void Cluster::ParseBlockGroup(long long st, long long sz, size_t idx) const
 {
     assert(m_entries);
     assert(m_entriesCount);
-    assert(index < m_entriesCount);
+    assert(idx < m_entriesCount);
 
-    BlockGroup* const pGroup =
+    Cluster* const this_ = const_cast<Cluster*>(this);
-        new (std::nothrow) BlockGroup(this, index, start, size);
-    assert(pGroup);  //TODO
 
-    m_entries[index] = pGroup;
+    BlockGroup* const e = new (std::nothrow) BlockGroup(this_, idx, st, sz);
+    assert(e);  //TODO
+
+    m_entries[idx] = e;
 }
 
 
 
-void Cluster::ParseSimpleBlock(long long start, long long size, size_t index)
+void Cluster::ParseSimpleBlock(long long st, long long sz, size_t idx) const
 {
     assert(m_entries);
     assert(m_entriesCount);
-    assert(index < m_entriesCount);
+    assert(idx < m_entriesCount);
 
-    SimpleBlock* const pSimpleBlock =
+    Cluster* const this_ = const_cast<Cluster*>(this);
-        new (std::nothrow) SimpleBlock(this, index, start, size);
-    assert(pSimpleBlock);  //TODO
 
-    m_entries[index] = pSimpleBlock;
+    SimpleBlock* const e = new (std::nothrow) SimpleBlock(this_, idx, st, sz);
+    assert(e);  //TODO
+
+    m_entries[idx] = e;
 }
 
 
-const BlockEntry* Cluster::GetFirst()
+const BlockEntry* Cluster::GetFirst() const
 {
     LoadBlockEntries();
-    //assert(m_entries);
-    //assert(m_entriesCount >= 1);
 
     if ((m_entries == NULL) || (m_entriesCount == 0))
         return NULL;
@@ -4033,11 +4023,9 @@ const BlockEntry* Cluster::GetFirst()
 }
 
 
-const BlockEntry* Cluster::GetLast()
+const BlockEntry* Cluster::GetLast() const
 {
     LoadBlockEntries();
-    //assert(m_entries);
-    //assert(m_entriesCount >= 1);
 
     if ((m_entries == NULL) || (m_entriesCount == 0))
         return NULL;
@@ -4070,7 +4058,7 @@ const BlockEntry* Cluster::GetNext(const BlockEntry* pEntry) const
 }
 
 
-const BlockEntry* Cluster::GetEntry(const Track* pTrack)
+const BlockEntry* Cluster::GetEntry(const Track* pTrack) const
 {
     assert(pTrack);
 
@@ -4110,7 +4098,7 @@ const BlockEntry* Cluster::GetEntry(const Track* pTrack)
 const BlockEntry*
 Cluster::GetEntry(
     const CuePoint& cp,
-    const CuePoint::TrackPosition& tp)
+    const CuePoint::TrackPosition& tp) const
 {
     assert(m_pSegment);
 
@@ -4200,7 +4188,7 @@ Cluster::GetEntry(
 }
 
 
-const BlockEntry* Cluster::GetMaxKey(const VideoTrack* pTrack)
+const BlockEntry* Cluster::GetMaxKey(const VideoTrack* pTrack) const
 {
     assert(pTrack);
 
@@ -4208,7 +4196,6 @@ const BlockEntry* Cluster::GetMaxKey(const VideoTrack* pTrack)
         return pTrack->GetEOS();
 
     LoadBlockEntries();
-    //assert(m_entries);
 
     BlockEntry** i = m_entries + m_entriesCount;
     BlockEntry** const j = m_entries;
@@ -4262,7 +4249,7 @@ bool SimpleBlock::EOS() const
 }
 
 
-Cluster* SimpleBlock::GetCluster() const
+const Cluster* SimpleBlock::GetCluster() const
 {
     return m_pCluster;
 }
@@ -4389,7 +4376,7 @@ bool BlockGroup::EOS() const
 }
 
 
-Cluster* BlockGroup::GetCluster() const
+const Cluster* BlockGroup::GetCluster() const
 {
     return m_pCluster;
 }
@@ -4425,7 +4412,6 @@ short BlockGroup::GetNextTimeCode() const
 //}
 
 
-
 Block::Block(long long start, long long size_, IMkvReader* pReader) :
     m_start(start),
     m_size(size_)
@@ -4447,30 +4433,238 @@ Block::Block(long long start, long long size_, IMkvReader* pReader) :
     pos += 2;
     assert((stop - pos) >= 1);
 
-    const long hr = pReader->Read(pos, 1, &m_flags);
+    long status = pReader->Read(pos, 1, &m_flags);
-    assert(hr == 0L);
+    assert(status == 0);
 
-    const int invisible = int(m_flags & 0x08);
+    const int invisible = int(m_flags & 0x08) >> 3;
     invisible;
-    assert(!invisible);
+    assert(!invisible);  //TODO
 
-    const int lacing = int(m_flags & 0x06);
+    const int lacing = int(m_flags & 0x06) >> 1;
-    lacing;
-    assert(!lacing);
 
-    ++pos;
+    ++pos;  //consume flags byte
     assert(pos <= stop);
 
-    m_frameOff = pos;
+    if (lacing == 0)  //no lacing
+    {
+        m_frame_count = 1;
+        m_frames = new Frame[m_frame_count];
 
-    const long long frame_size = stop - pos;
+        Frame& f = m_frames[0];
-    assert(frame_size <= LONG_MAX);
+        f.pos = pos;
 
-    m_frameSize = static_cast<long>(frame_size);
+        const long long frame_size = stop - pos;
+        assert(frame_size <= LONG_MAX);
+
+        f.len = static_cast<long>(frame_size);
+
+        return;
+    }
+
+    assert(pos < stop);
+
+    unsigned char count;
+
+    status = pReader->Read(pos, 1, &count);
+    assert(status == 0);
+
+    ++pos;  //consume frame count
+    assert(pos <= stop);
+
+    m_frame_count = ++count;
+    m_frames = new Frame[m_frame_count];
+
+    if (lacing == 1)  //Xiph
+    {
+        Frame* pf = m_frames;
+        Frame* const pf_end = pf + m_frame_count;
+
+        long size = 0;
+
+        while (count > 1)
+        {
+            long frame_size = 0;
+
+            for (;;)
+            {
+                unsigned char val;
+
+                status = pReader->Read(pos, 1, &val);
+                assert(status == 0);
+
+                ++pos;  //consume xiph size byte
+
+                frame_size += val;
+
+                if (val < 255)
+                    break;
+            }
+
+            Frame& f = *pf++;
+            assert(pf < pf_end);
+
+            f.len = frame_size;
+            size += frame_size;  //contribution of this frame
+
+            --count;
+        }
+
+        assert(pf < pf_end);
+        assert(pos < stop);
+
+        {
+            Frame& f = *pf++;
+            assert(pf == pf_end);
+
+            const long long total_size = stop - pos;
+            assert(total_size > size);
+
+            const long long frame_size = total_size - size;
+            assert(frame_size <= LONG_MAX);
+
+            f.len = static_cast<long>(frame_size);
+        }
+
+        pf = m_frames;
+        while (pf != pf_end)
+        {
+            Frame& f = *pf++;
+            assert((pos + f.len) <= stop);
+
+            f.pos = pos;
+            pos += f.len;
+        }
+
+        assert(pos == stop);
+    }
+    else if (lacing == 2)  //fixed-size lacing
+    {
+        const long long total_size = stop - pos;
+        assert((total_size % m_frame_count) == 0);
+
+        const long long frame_size = total_size / m_frame_count;
+        assert(frame_size <= LONG_MAX);
+
+        Frame* pf = m_frames;
+        Frame* const pf_end = pf + m_frame_count;
+
+        while (pf != pf_end)
+        {
+            assert((pos + frame_size) <= stop);
+
+            Frame& f = *pf++;
+
+            f.pos = pos;
+            f.len = static_cast<long>(frame_size);
+
+            pos += frame_size;
+        }
+
+        assert(pos == stop);
+    }
+    else
+    {
+        assert(lacing == 3);  //EBML lacing
+        assert(pos < stop);
+
+        long size = 0;
+
+        long long frame_size = ReadUInt(pReader, pos, len);
+        assert(frame_size > 0);
+        assert(frame_size <= LONG_MAX);
+        assert((pos + len) <= stop);
+
+        pos += len; //consume length of size of first frame
+        assert((pos + frame_size) <= stop);
+
+        Frame* pf = m_frames;
+        Frame* const pf_end = pf + m_frame_count;
+
+        {
+            Frame& curr = *pf;
+
+            curr.len = static_cast<long>(frame_size);
+            size += curr.len;  //contribution of this frame
+        }
+
+        --count;
+
+        while (count > 1)
+        {
+            assert(pos < stop);
+            assert(pf < pf_end);
+
+            const Frame& prev = *pf++;
+            assert(pf < pf_end);
+            assert(prev.len == frame_size);
+
+            Frame& curr = *pf;
+
+            const long long delta_size_ = ReadUInt(pReader, pos, len);
+            assert(delta_size_ >= 0);
+            assert((pos + len) <= stop);
+
+            pos += len;  //consume length of (delta) size
+            assert(pos <= stop);
+
+            const int exp = 7*len - 1;
+            const long long bias = (1LL << exp) - 1LL;
+            const long long delta_size = delta_size_ - bias;
+
+            frame_size += delta_size;
+            assert(frame_size > 0);
+            assert(frame_size <= LONG_MAX);
+
+            curr.len = static_cast<long>(frame_size);
+            size += curr.len;  //contribution of this frame
+
+            --count;
+        }
+
+        {
+            assert(pos < stop);
+            assert(pf < pf_end);
+
+            const Frame& prev = *pf++;
+            assert(pf < pf_end);
+            assert(prev.len == frame_size);
+
+            Frame& curr = *pf++;
+            assert(pf == pf_end);
+
+            const long long total_size = stop - pos;
+            assert(total_size > 0);
+            assert(total_size > size);
+
+            frame_size = total_size - size;
+            assert(frame_size > 0);
+            assert(frame_size <= LONG_MAX);
+
+            curr.len = static_cast<long>(frame_size);
+        }
+
+        pf = m_frames;
+        while (pf != pf_end)
+        {
+            Frame& f = *pf++;
+            assert((pos + f.len) <= stop);
+
+            f.pos = pos;
+            pos += f.len;
+        }
+
+        assert(pos == stop);
+    }
 }
 
 
-long long Block::GetTimeCode(Cluster* pCluster) const
+Block::~Block()
+{
+    delete[] m_frames;
+}
+
+
+long long Block::GetTimeCode(const Cluster* pCluster) const
 {
     assert(pCluster);
 
@@ -4484,7 +4678,7 @@ long long Block::GetTimeCode(Cluster* pCluster) const
 }
 
 
-long long Block::GetTime(Cluster* pCluster) const
+long long Block::GetTime(const Cluster* pCluster) const
 {
     assert(pCluster);
 
@@ -4524,6 +4718,7 @@ void Block::SetKey(bool bKey)
 }
 
 
+#if 0
 long long Block::GetOffset() const
 {
   return m_frameOff;
@@ -4535,10 +4730,8 @@ long Block::GetSize() const
     return m_frameSize;
 }
 
-
 long Block::Read(IMkvReader* pReader, unsigned char* buf) const
 {
-
     assert(pReader);
     assert(buf);
 
@@ -4546,6 +4739,35 @@ long Block::Read(IMkvReader* pReader, unsigned char* buf) const
 
     return hr;
 }
+#else
+int Block::GetFrameCount() const
+{
+    return m_frame_count;
+}
+
+
+const Block::Frame& Block::GetFrame(int idx) const
+{
+    assert(idx >= 0);
+    assert(idx < m_frame_count);
+
+    const Frame& f = m_frames[idx];
+    assert(f.pos > 0);
+    assert(f.len > 0);
+
+    return f;
+}
+
+
+long Block::Frame::Read(IMkvReader* pReader, unsigned char* buf) const
+{
+    assert(pReader);
+    assert(buf);
+
+    const long status = pReader->Read(pos, len, buf);
+    return status;
+}
+#endif
 
 
 }  //end namespace mkvparser

mkvparser.hpp

@@ -73,23 +73,44 @@ public:
     const long long m_size;
 
     Block(long long start, long long size, IMkvReader*);
+    ~Block();
 
     long long GetTrackNumber() const;
-    long long GetTimeCode(Cluster*) const;  //absolute, but not scaled
+    long long GetTimeCode(const Cluster*) const;  //absolute, but not scaled
-    long long GetTime(Cluster*) const;      //absolute, and scaled (ns units)
+    long long GetTime(const Cluster*) const;      //absolute, and scaled (ns)
     bool IsKey() const;
     void SetKey(bool);
 
+    int GetFrameCount() const;  //to index frames: [0, count)
+
+    struct Frame
+    {
+        long long pos;  //absolute offset
+        long len;
+
+        long Read(IMkvReader*, unsigned char*) const;
+    };
+
+#if 0
     long long GetOffset() const;
     long GetSize() const;
     long Read(IMkvReader*, unsigned char*) const;
+#else
+    const Frame& GetFrame(int frame_index) const;
+#endif
 
 private:
     long long m_track;   //Track::Number()
     short m_timecode;  //relative to cluster
     unsigned char m_flags;
+
+#if 0
     long long m_frameOff;
     long m_frameSize;
+#else
+    Frame* m_frames;
+    int m_frame_count;
+#endif
 
 };
 
@@ -102,7 +123,7 @@ class BlockEntry
 public:
     virtual ~BlockEntry();
     virtual bool EOS() const = 0;
-    virtual Cluster* GetCluster() const = 0;
+    virtual const Cluster* GetCluster() const = 0;
     virtual size_t GetIndex() const = 0;
     virtual const Block* GetBlock() const = 0;
     //virtual bool IsBFrame() const = 0;
@@ -122,7 +143,7 @@ public:
     SimpleBlock(Cluster*, size_t, long long start, long long size);
 
     bool EOS() const;
-    Cluster* GetCluster() const;
+    const Cluster* GetCluster() const;
     size_t GetIndex() const;
     const Block* GetBlock() const;
     //bool IsBFrame() const;
@@ -145,7 +166,7 @@ public:
     ~BlockGroup();
 
     bool EOS() const;
-    Cluster* GetCluster() const;
+    const Cluster* GetCluster() const;
     size_t GetIndex() const;
     const Block* GetBlock() const;
     //bool IsBFrame() const;
@@ -297,8 +318,8 @@ public:
     Tracks(Segment*, long long start, long long size);
     virtual ~Tracks();
 
-    Track* GetTrackByNumber(unsigned long tn) const;
+    const Track* GetTrackByNumber(unsigned long tn) const;
-    Track* GetTrackByIndex(unsigned long idx) const;
+    const Track* GetTrackByIndex(unsigned long idx) const;
 
 private:
     Track** m_trackEntries;
@@ -408,7 +429,6 @@ public:
 
     const CuePoint* GetFirst() const;
     const CuePoint* GetLast() const;
-
     const CuePoint* GetNext(const CuePoint*) const;
 
     const BlockEntry* GetBlock(
@@ -444,19 +464,19 @@ public:
 
     bool EOS() const;
 
-    long long GetTimeCode();   //absolute, but not scaled
+    long long GetTimeCode() const;   //absolute, but not scaled
-    long long GetTime();       //absolute, and scaled (nanosecond units)
+    long long GetTime() const;       //absolute, and scaled (nanosecond units)
-    long long GetFirstTime();  //time (ns) of first (earliest) block
+    long long GetFirstTime() const;  //time (ns) of first (earliest) block
-    long long GetLastTime();   //time (ns) of last (latest) block
+    long long GetLastTime() const;   //time (ns) of last (latest) block
 
-    const BlockEntry* GetFirst();
+    const BlockEntry* GetFirst() const;
-    const BlockEntry* GetLast();
+    const BlockEntry* GetLast() const;
     const BlockEntry* GetNext(const BlockEntry*) const;
-    const BlockEntry* GetEntry(const Track*);
+    const BlockEntry* GetEntry(const Track*) const;
     const BlockEntry* GetEntry(
         const CuePoint&,
-        const CuePoint::TrackPosition&);
+        const CuePoint::TrackPosition&) const;
-    const BlockEntry* GetMaxKey(const VideoTrack*);
+    const BlockEntry* GetMaxKey(const VideoTrack*) const;
 
 protected:
     Cluster(Segment*, long, long long off);
@@ -464,18 +484,18 @@ protected:
 public:
     //TODO: these should all be private, with public selector functions
     long m_index;
-    long long m_pos;
+    mutable long long m_pos;
-    long long m_size;
+    mutable long long m_size;
 
 private:
-    long long m_timecode;
+    mutable long long m_timecode;
-    BlockEntry** m_entries;
+    mutable BlockEntry** m_entries;
-    size_t m_entriesCount;
+    mutable size_t m_entriesCount;
 
-    void Load();
+    void Load() const;
-    void LoadBlockEntries();
+    void LoadBlockEntries() const;
-    void ParseBlockGroup(long long, long long, size_t);
+    void ParseBlockGroup(long long, long long, size_t) const;
-    void ParseSimpleBlock(long long, long long, size_t);
+    void ParseSimpleBlock(long long, long long, size_t) const;
 
 };
 
@@ -506,12 +526,10 @@ public:
     long long ParseHeaders();  //stops when first cluster is found
     long LoadCluster();        //loads one cluster
 
-#if 0
     //This pair parses one cluster, but only changes the state of the
     //segment object when the cluster is actually added to the index.
-    long ParseCluster(Cluster*&, long long& newpos) const;
+    long ParseCluster(long long& cluster_pos, long long& new_pos) const;
-    bool AddCluster(Cluster*, long long);
+    bool AddCluster(long long cluster_pos, long long new_pos);
-#endif
 
     Tracks* GetTracks() const;
     const SegmentInfo* GetInfo() const;
@@ -520,12 +538,12 @@ public:
     long long GetDuration() const;
 
     unsigned long GetCount() const;
-    Cluster* GetFirst();
+    const Cluster* GetFirst() const;
-    Cluster* GetLast();
+    const Cluster* GetLast() const;
-    Cluster* GetNext(const Cluster*);
+    const Cluster* GetNext(const Cluster*);
 
-    Cluster* FindCluster(long long time_nanoseconds);
+    const Cluster* FindCluster(long long time_nanoseconds) const;
-    const BlockEntry* Seek(long long time_nanoseconds, const Track*);
+    const BlockEntry* Seek(long long time_nanoseconds, const Track*) const;
 
 private: