forked from LeenkxTeam/LNXSDK
		
	
		
			
				
	
	
		
			144 lines
		
	
	
		
			6.6 KiB
		
	
	
	
		
			C++
		
	
	
	
	
	
			
		
		
	
	
			144 lines
		
	
	
		
			6.6 KiB
		
	
	
	
		
			C++
		
	
	
	
	
	
| //------------------------------------------------------------------------------
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| // File: VTrans.h
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| //
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| // Desc: DirectShow base classes - defines a video transform class.
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| //
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| // Copyright (c) 1992-2001 Microsoft Corporation.  All rights reserved.
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| //------------------------------------------------------------------------------
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| 
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| 
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| // This class is derived from CTransformFilter, but is specialised to handle
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| // the requirements of video quality control by frame dropping.
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| // This is a non-in-place transform, (i.e. it copies the data) such as a decoder.
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| 
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| class CVideoTransformFilter : public CTransformFilter
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| {
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|   public:
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| 
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|     CVideoTransformFilter(__in_opt LPCTSTR, __inout_opt LPUNKNOWN, REFCLSID clsid);
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|     ~CVideoTransformFilter();
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|     HRESULT EndFlush();
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| 
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|     // =================================================================
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|     // ----- override these bits ---------------------------------------
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|     // =================================================================
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|     // The following methods are in CTransformFilter which is inherited.
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|     // They are mentioned here for completeness
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|     //
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|     // These MUST be supplied in a derived class
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|     //
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|     // NOTE:
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|     // virtual HRESULT Transform(IMediaSample * pIn, IMediaSample *pOut);
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|     // virtual HRESULT CheckInputType(const CMediaType* mtIn) PURE;
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|     // virtual HRESULT CheckTransform
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|     //     (const CMediaType* mtIn, const CMediaType* mtOut) PURE;
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|     // static CCOMObject * CreateInstance(LPUNKNOWN, HRESULT *);
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|     // virtual HRESULT DecideBufferSize
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|     //     (IMemAllocator * pAllocator, ALLOCATOR_PROPERTIES *pprop) PURE;
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|     // virtual HRESULT GetMediaType(int iPosition, CMediaType *pMediaType) PURE;
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|     //
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|     // These MAY also be overridden
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|     //
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|     // virtual HRESULT StopStreaming();
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|     // virtual HRESULT SetMediaType(PIN_DIRECTION direction,const CMediaType *pmt);
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|     // virtual HRESULT CheckConnect(PIN_DIRECTION dir,IPin *pPin);
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|     // virtual HRESULT BreakConnect(PIN_DIRECTION dir);
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|     // virtual HRESULT CompleteConnect(PIN_DIRECTION direction,IPin *pReceivePin);
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|     // virtual HRESULT EndOfStream(void);
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|     // virtual HRESULT BeginFlush(void);
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|     // virtual HRESULT EndFlush(void);
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|     // virtual HRESULT NewSegment
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|     //     (REFERENCE_TIME tStart,REFERENCE_TIME tStop,double dRate);
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| #ifdef PERF
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| 
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|     // If you override this - ensure that you register all these ids
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|     // as well as any of your own,
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|     virtual void RegisterPerfId() {
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|         m_idSkip        = MSR_REGISTER(TEXT("Video Transform Skip frame"));
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|         m_idFrameType   = MSR_REGISTER(TEXT("Video transform frame type"));
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|         m_idLate        = MSR_REGISTER(TEXT("Video Transform Lateness"));
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|         m_idTimeTillKey = MSR_REGISTER(TEXT("Video Transform Estd. time to next key"));
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|         CTransformFilter::RegisterPerfId();
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|     }
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| #endif
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| 
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|   protected:
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| 
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|     // =========== QUALITY MANAGEMENT IMPLEMENTATION ========================
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|     // Frames are assumed to come in three types:
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|     // Type 1: an AVI key frame or an MPEG I frame.
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|     //        This frame can be decoded with no history.
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|     //        Dropping this frame means that no further frame can be decoded
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|     //        until the next type 1 frame.
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|     //        Type 1 frames are sync points.
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|     // Type 2: an AVI non-key frame or an MPEG P frame.
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|     //        This frame cannot be decoded unless the previous type 1 frame was
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|     //        decoded and all type 2 frames since have been decoded.
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|     //        Dropping this frame means that no further frame can be decoded
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|     //        until the next type 1 frame.
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|     // Type 3: An MPEG B frame.
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|     //        This frame cannot be decoded unless the previous type 1 or 2 frame
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|     //        has been decoded AND the subsequent type 1 or 2 frame has also
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|     //        been decoded.  (This requires decoding the frames out of sequence).
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|     //        Dropping this frame affects no other frames.  This implementation
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|     //        does not allow for these.  All non-sync-point frames are treated
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|     //        as being type 2.
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|     //
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|     // The spacing of frames of type 1 in a file is not guaranteed.  There MUST
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|     // be a type 1 frame at (well, near) the start of the file in order to start
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|     // decoding at all.  After that there could be one every half second or so,
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|     // there could be one at the start of each scene (aka "cut", "shot") or
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|     // there could be no more at all.
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|     // If there is only a single type 1 frame then NO FRAMES CAN BE DROPPED
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|     // without losing all the rest of the movie.  There is no way to tell whether
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|     // this is the case, so we find that we are in the gambling business.
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|     // To try to improve the odds, we record the greatest interval between type 1s
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|     // that we have seen and we bet on things being no worse than this in the
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|     // future.
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| 
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|     // You can tell if it's a type 1 frame by calling IsSyncPoint().
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|     // there is no architected way to test for a type 3, so you should override
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|     // the quality management here if you have B-frames.
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| 
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|     int m_nKeyFramePeriod; // the largest observed interval between type 1 frames
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|                            // 1 means every frame is type 1, 2 means every other.
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| 
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|     int m_nFramesSinceKeyFrame; // Used to count frames since the last type 1.
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|                                 // becomes the new m_nKeyFramePeriod if greater.
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| 
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|     BOOL m_bSkipping;           // we are skipping to the next type 1 frame
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| 
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| #ifdef PERF
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|     int m_idFrameType;          // MSR id Frame type.  1=Key, 2="non-key"
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|     int m_idSkip;               // MSR id skipping
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|     int m_idLate;               // MSR id lateness
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|     int m_idTimeTillKey;        // MSR id for guessed time till next key frame.
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| #endif
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| 
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|     virtual HRESULT StartStreaming();
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| 
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|     HRESULT AbortPlayback(HRESULT hr);	// if something bad happens
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| 
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|     HRESULT Receive(IMediaSample *pSample);
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| 
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|     HRESULT AlterQuality(Quality q);
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| 
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|     BOOL ShouldSkipFrame(IMediaSample * pIn);
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| 
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|     int m_itrLate;              // lateness from last Quality message
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|                                 // (this overflows at 214 secs late).
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|     int m_tDecodeStart;         // timeGetTime when decode started.
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|     int m_itrAvgDecode;         // Average decode time in reference units.
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| 
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|     BOOL m_bNoSkip;             // debug - no skipping.
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| 
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|     // We send an EC_QUALITY_CHANGE notification to the app if we have to degrade.
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|     // We send one when we start degrading, not one for every frame, this means
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|     // we track whether we've sent one yet.
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|     BOOL m_bQualityChanged;
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| 
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|     // When non-zero, don't pass anything to renderer until next keyframe
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|     // If there are few keys, give up and eventually draw something
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|     int m_nWaitForKey;
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| };
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