1 /* ------------------------------------------------------------------ 2 * Copyright (C) 1998-2009 PacketVideo 3 * 4 * Licensed under the Apache License, Version 2.0 (the "License"); 5 * you may not use this file except in compliance with the License. 6 * You may obtain a copy of the License at 7 * 8 * http://www.apache.org/licenses/LICENSE-2.0 9 * 10 * Unless required by applicable law or agreed to in writing, software 11 * distributed under the License is distributed on an "AS IS" BASIS, 12 * WITHOUT WARRANTIES OR CONDITIONS OF ANY KIND, either 13 * express or implied. 14 * See the License for the specific language governing permissions 15 * and limitations under the License. 16 * ------------------------------------------------------------------- 17 */ 18 19 /** 20 * @file time_comparison_utils.h 21 * @brief Provides time comparison utilities 22 */ 23 24 #ifndef TIME_COMPARISON_UTILS_H_INCLUDED 25 #define TIME_COMPARISON_UTILS_H_INCLUDED 26 27 #ifndef OSCL_BASE_H_INCLUDED 28 #include "oscl_base.h" 29 #endif 30 31 #ifndef PVMF_TIMESTAMP_H_INCLUDED 32 #include "pvmf_timestamp.h" 33 #endif 34 35 36 class PVTimeComparisonUtils 37 { 38 public: 39 typedef enum 40 { 41 MEDIA_EARLY_OUTSIDE_WINDOW, 42 MEDIA_EARLY_WITHIN_WINDOW, 43 MEDIA_ONTIME_WITHIN_WINDOW, 44 MEDIA_LATE_WITHIN_WINDOW, 45 MEDIA_LATE_OUTSIDE_WINDOW 46 } MediaTimeStatus; 47 48 49 /*!********************************************************************* 50 ** 51 ** Function: IsEarlier 52 ** 53 ** Synopsis: This function returns true if TimeA is considered EARLIER than TimeB. 54 ** 55 ** Arguments : 56 ** @param [aTimeA] -- Time stamp to be compared. 57 ** @param [aTimeB] -- Time stamp to be compared. 58 ** @param [delta] -- delta is an output parameter and is always 59 ** a small positive value representing TimeB-TimeA if TimeA is earlier 60 ** than TimeB or TimeA-TimeB if TimeB is earlier than TimeA. 61 62 ** Returns: 63 ** @return bool -- returns true if TimeA is considered EARLIER than TimeB. 64 ** 65 ** 66 ** Notes: 67 ** 68 **********************************************************************/ 69 70 OSCL_IMPORT_REF static bool IsEarlier( 71 /*IN*/ uint32 aTimeA, 72 /*IN*/ uint32 aTimeB, 73 /*OUT*/ uint32& delta); 74 75 /*!********************************************************************* 76 ** 77 ** Function: CheckTimeWindow 78 ** 79 ** Synopsis: This function would return one of MEDIA_EARLY_OUTSIDE_WINDOW, MEDIA_EARLY_WITHIN_WINDOW, 80 ** MEDIA_LATE_WITHIN_WINDOW or MEDIA_LATE_OUTSIDE_WINDOW depending on where the TimeStamp 81 ** is within the window specified by (Clock-LateMargin) to (Clock+EarlyMargin). 82 ** 83 ** Arguments : 84 ** @param [aTimeStamp] -- Time stamp to be checked. 85 ** @param [aClock] -- present clock value. 86 ** @param [aEarlyMargin] -- early margin of the window 87 ** @param [aLateMargin] -- late margin of the window 88 ** @param [aDelta] -- aDelta is an output parameter and would contain the difference 89 ** in timestamp and clock in positive form. 90 91 ** Returns: 92 ** @return MediaTimeStatus -- returns one of the values from MediaTimeStatus enum. 93 ** 94 ** 95 ** Notes: 96 ** 97 **********************************************************************/ 98 99 OSCL_IMPORT_REF static MediaTimeStatus CheckTimeWindow( 100 /*IN*/ PVMFTimestamp aTimeStamp, 101 /*IN*/ uint32 aClock, 102 /*IN*/ uint32 aEarlyMargin, 103 /*IN*/ uint32 aLateMargin, 104 /*OUT*/ uint32 &aDelta); 105 106 }; 107 #endif 108
