atotime.h

linux下的一款播放器

/* ***** BEGIN LICENSE BLOCK *****
 * Source last modified: $Id: atotime.h,v 1.1.2.1 2004/07/09 01:50:15 hubbe Exp $
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/////////////////////////////////////////////////////////////////////////////
//
//  ATOTIME.H
//
//
//  This file contains the functions that are used in RealText rendering to
//	convert a string of characters into a time value, in milliseconds.
//
//  (1)	BOOL convertTimeStringToULONG32(
//		_CHAR* pTimeBuf,
//		ULONG32 timeBufLen, 
//		ULONG32& timeValInMillisec);
//  Converts a string, like "0:00:02.341", into a ULONG32 "time" value,
//  in milliseconds, and returns FALSE, with timeValInMillisec
//  undefined if pTimeBuf is not in the correct time format which is:
//  "[[[[[[d:]h]h:]m]m:]s]s[.a[b[c]]]" where d is any number of days
//  up to 49 days (which is the max that 32 bits can hold, in msec),
//  hh is the number of hours (a two-digit # if following a ':'),
//  mm is the number of minutes (a two-digit # if following a ':'),
//  ss is the number of seconds (a two-digit # if following a ':'),
//    (noting that the lowest digit of seconds must exist in the string
//    and can stand alone as a time value),
//  and a, b, and c are tenths of seconds, hundredths of seconds, and
//  thousandths of seconds, respectively.
//  timeBufLen is equivalent of strlen(pColorNm), i.e.,
//  it does not take into account the terminating '\0' char.
//
//  (2) BOOL IsTimeAMoreRecentThanTimeB(
//		ULONG32 ulTimeA, ULONG32 ulTimeB,
//		BOOL bIsLiveSource=TRUE,
//		ULONG32* pULTimeDiff=NULL /* OUT */,
//		ULONG32 ulAcceptableMaxTimeDiff=
//			    MAX_ALLOWED_TIME_DIFFERENCE_IN_MSEC)
//	If bIsLiveSource is FALSE (defaultable to TRUE), this simply
//	returns (A>B), else it's live & ULONG32 wrap-around can occur so...
//	this function tells whether or not time A is later (more recent)
//	than time B even with ULONG32 wrap-around, e.g., if A is 1234
//	and B is 4000001234, then we can guess that A is actually more
//	recent than B because A<B and B-A>ulAcceptableMaxTimeDiff,
//	so it looks like the clock wrapped around after B and before A.
//	Conversely, if A>B and A-B>ulAcceptableMaxTimeDiff, then it looks
//	like the clock wrapped around after A and before B, so A is NOT
//	more recent.  Returned is a BOOL that contains the answer.
//	NOTE: there is a concept of "infinity", defined as
//	TIME_INFINITY (which is 0xfffffffe), and there is a concept
//	of invalid time, defined as TIME_INVALID (0xffffffff).  The following
//	chart shows how these values are handled:
//	    A is:		B is:		return value will be:
//	    -----		-----		---------------------
//	    Infinity		Infinity	FALSE
//	    Infinity		Invalid		FALSE
//	    Infinity		< 0xfffffffe	TRUE
//	    Invalid		Infinity	TRUE
//	    Invalid		Invalid		FALSE
//	    Invalid		< 0xfffffffe	TRUE
//	    < 0xfffffffe	Infinity	FALSE
//	    < 0xfffffffe	Invalid		FALSE
//	    < 0xfffffffe	< 0xfffffffe	depends; see above algorithm
//
//	If pULTimeDiff is sent in as NULL, it remains NULL, otherwise it will
//	exit this function containing A minus B, regardless of which is
//	greater or more recent, noting that A & B are ULONG32s so the result
//	is always the equivalent of adding 0x100000000 to A and then
//	subtracting B and then truncating it by removing that 33rd bit, if
//	still 1:
//
//
//  (3) BOOL IsTimeASameOrMoreRecentThanTimeB(
//		ULONG32 ulTimeA, ULONG32 ulTimeB,
//		BOOL bIsLiveSource=TRUE,
//		ULONG32* pULTimeDiff=NULL /* OUT */,
//		ULONG32 ulAcceptableMaxTimeDiff=
//			    MAX_ALLOWED_TIME_DIFFERENCE_IN_MSEC)
//	This function first checks if time A is == to time B, and, if not
//	returns the return value from a call to (2), above.
//
//

#if !defined(_ATOTIME_H_)
#define _ATOTIME_H_

#if !defined(TIME_INVALID)
#define TIME_INVALID			((ULONG32)0xFFFFFFFF)
#endif

//We want two different values for "invalid" and "infinity"; using the same
// value causes problems with the new live "wallclock"-enabled code:
#if !defined(TIME_INFINITY)
#define TIME_INFINITY			((ULONG32)0xFFFFFFFE)
#else
#error TIME_INFINITY already defined elsewhere
#endif

#define MIN_TIMEBUFFERLENGTH	1  //Min time-format string is "s" (0-9 secs)

//33.33+ days can pass without changing a time variable before
// a call with it to IsTimeAMoreRecentThanTimeB() may be wrong:
#define MAX_ALLOWED_TIME_DIFFERENCE_IN_MSEC	0xABADC0DE


//(See description of this function above)
BOOL convertTimeStringToULONG32(_CHAR* pTimeBuf, ULONG32 timeBufLen, 
		ULONG32& timeValInMillisec);

//(See description of this function above)
BOOL IsTimeAMoreRecentThanTimeB(ULONG32 ulTimeA, ULONG32 ulTimeB,
	BOOL bIsLiveSource=TRUE,
	ULONG32* pULTimeDiff=NULL /* OUT */,
	//XXXEH- get rid of this parameter when debugging is "done":
	ULONG32 ulAcceptableMaxTimeDiff=
		    MAX_ALLOWED_TIME_DIFFERENCE_IN_MSEC);

//(See description of this function above)
BOOL IsTimeASameOrMoreRecentThanTimeB(ULONG32 ulTimeA, ULONG32 ulTimeB,
	BOOL bIsLiveSource=TRUE,
	ULONG32* pULTimeDiff=NULL /* OUT */,
	ULONG32 ulAcceptableMaxTimeDiff=
		    MAX_ALLOWED_TIME_DIFFERENCE_IN_MSEC);


#endif