windows-nt/Source/XPSP1/NT/multimedia/dshow/timecode/ltcdcode.h

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2020-09-26 03:20:57 -05:00
/**********************************************************************
Copyright (c) Microsoft Corporation 1994-1996. All Rights Reserved
LtcDecode, Ken Greenebaum, November 1996
**********************************************************************/
#ifndef _H_LTCDECODER
#define _H_LTCDECODER
#include <wtypes.h>
#include "timecode.h"
typedef struct bitData {
int value;
LONGLONG sample;
} foo;
typedef struct LTCuserBits {
int user1:4;
int user2:4;
int user3:4;
int user4:4;
int user5:4;
int user6:4;
int user7:4;
int user8:4;
} bar;
class LTCdecoder {
public:
LTCdecoder(); // XXX really should spec format, rate...
int decodeBuffer(short **buffer, int *bufferSize);
int getTimeCode(TimeCode *tc); // convert LTC bits to SMPTE timecode
int getUserBits(LTCuserBits *bits);
int getStartStopSample(LONGLONG *start, LONGLONG *end);
private:
int _addBuffer(int bit, LONGLONG sample); // store the bit and detect sync
int _bitWidth; // dynamicaly adjusted bit width
int _sampleWidth; // length of the state we are sampling
int _verticalEpsilon; // how close we have to be to the rail
int _waveState; // high or low
int _lastBit; // width of last bit (0-long, 1-short, 2-2nd short)
// ring buffer
bitData _ringBuffer[80];// this is where we keep our bits!
int _bufferIndex;
int _bitsRecorded; // total number of bits intered (morbid, eh?)
LONGLONG _samplesProcessed; // number of audio samples processed
int _validTimeCode; // set if the ringBuffer contains a timecode
// sync detector
int _onesCount; // track number of consequiative ones! (12==sync)
LONGLONG _syncSample; // the sample corresponding to the LTC sync
LONGLONG _endSample; // the sample corresponding to end of LTC
};
#endif /* _H_LTCDECODER */