1 /***************************************************************************** 2 * clock.h: clocks synchronisation 3 ***************************************************************************** 4 * Copyright (C) 2008 VLC authors and VideoLAN 5 * Copyright (C) 2008 Laurent Aimar 6 * $Id: dc4c8bd9352ed669930fe4b36dcd601783d6026c $ 7 * 8 * Authors: Laurent Aimar < fenrir _AT_ videolan _DOT_ org > 9 * 10 * This program is free software; you can redistribute it and/or modify it 11 * under the terms of the GNU Lesser General Public License as published by 12 * the Free Software Foundation; either version 2.1 of the License, or 13 * (at your option) any later version. 14 * 15 * This program is distributed in the hope that it will be useful, 16 * but WITHOUT ANY WARRANTY; without even the implied warranty of 17 * MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE. See the 18 * GNU Lesser General Public License for more details. 19 * 20 * You should have received a copy of the GNU Lesser General Public License 21 * along with this program; if not, write to the Free Software Foundation, 22 * Inc., 51 Franklin Street, Fifth Floor, Boston MA 02110-1301, USA. 23 *****************************************************************************/ 24 25 #ifndef LIBVLC_INPUT_CLOCK_H 26 #define LIBVLC_INPUT_CLOCK_H 1 27 28 #include <vlc_common.h> 29 #include <vlc_input.h> /* FIXME Needed for input_clock_t */ 30 31 /** @struct input_clock_t 32 * This structure is used to manage clock drift and reception jitters 33 * 34 * XXX input_clock_GetTS can be called from any threads. All others functions 35 * MUST be called from one and only one thread. 36 */ 37 typedef struct input_clock_t input_clock_t; 38 39 /** 40 * This function creates a new input_clock_t. 41 * You must use input_clock_Delete to delete it once unused. 42 */ 43 input_clock_t *input_clock_New( int i_rate ); 44 45 /** 46 * This function destroys a input_clock_t created by input_clock_New. 47 */ 48 void input_clock_Delete( input_clock_t * ); 49 50 /** 51 * This function will update a input_clock_t with a new clock reference point. 52 * It will also tell if the clock point is late regarding our buffering. 53 * 54 * \param b_buffering_allowed tells if we are allowed to bufferize more data in 55 * advanced (if possible). 56 */ 57 void input_clock_Update( input_clock_t *, vlc_object_t *p_log, 58 bool *pb_late, 59 bool b_can_pace_control, bool b_buffering_allowed, 60 mtime_t i_clock, mtime_t i_system ); 61 /** 62 * This function will reset the drift of a input_clock_t. 63 * 64 * The actual jitter estimation will not be reseted by it. 65 */ 66 void input_clock_Reset( input_clock_t * ); 67 68 /** 69 * This functions will return a deadline used to control the reading speed. 70 */ 71 mtime_t input_clock_GetWakeup( input_clock_t * ); 72 73 /** 74 * This functions allows changing the actual reading speed. 75 */ 76 void input_clock_ChangeRate( input_clock_t *, int i_rate ); 77 78 /** 79 * This function allows changing the pause status. 80 */ 81 void input_clock_ChangePause( input_clock_t *, bool b_paused, mtime_t i_date ); 82 83 /** 84 * This function returns the original system value date and the delay for the current 85 * reference point (a valid reference point must have been set). 86 */ 87 void input_clock_GetSystemOrigin( input_clock_t *, mtime_t *pi_system, mtime_t *pi_delay ); 88 89 /** 90 * This function allows rebasing the original system value date (a valid 91 * reference point must have been set). 92 * When using the absolute mode, it will create a discontinuity unless 93 * called imediatly after a input_clock_Update. 94 */ 95 void input_clock_ChangeSystemOrigin( input_clock_t *, bool b_absolute, mtime_t i_system ); 96 97 /** 98 * This function converts a pair of timestamp from stream clock to system clock. 99 * 100 * If pi_rate is provided it will be filled with the rate value used for 101 * the conversion. 102 * p_ts0 is a pointer to a timestamp to be converted (in place) and must be non NULL. 103 * p_ts1 is a pointer to a timestamp to be converted (in place) and can be NULL. 104 * 105 * It will return VLC_EGENERIC if i_ts_bound is not INT64_MAX and if the value *p_ts0 106 * after conversion is not before the deadline mdate() + i_pts_delay + i_ts_bound. 107 * It will also return VLC_EGENERIC if the conversion cannot be done successfully. In 108 * this case, *p_ts0 and *p_ts1 will hold an invalid timestamp. 109 * Otherwise it will return VLC_SUCCESS. 110 */ 111 int input_clock_ConvertTS( vlc_object_t *, input_clock_t *, int *pi_rate, 112 mtime_t *pi_ts0, mtime_t *pi_ts1, mtime_t i_ts_bound ); 113 114 /** 115 * This function returns the current rate. 116 */ 117 int input_clock_GetRate( input_clock_t * ); 118 119 /** 120 * This function returns current clock state or VLC_EGENERIC if there is not a 121 * reference point. 122 */ 123 int input_clock_GetState( input_clock_t *, 124 mtime_t *pi_stream_start, mtime_t *pi_system_start, 125 mtime_t *pi_stream_duration, mtime_t *pi_system_duration ); 126 127 /** 128 * This function allows the set the minimal configuration for the jitter estimation algo. 129 */ 130 void input_clock_SetJitter( input_clock_t *, 131 mtime_t i_pts_delay, int i_cr_average ); 132 133 /** 134 * This function returns an estimation of the pts_delay needed to avoid rebufferization. 135 * XXX in the current implementation, the pts_delay will never be decreased. 136 */ 137 mtime_t input_clock_GetJitter( input_clock_t * ); 138 139 #endif 140