/*****************************************************************************
* input_clock.c: Clock/System date convertions, stream management
*****************************************************************************
- * Copyright (C) 1999-2004 the VideoLAN team
+ * Copyright (C) 1999-2008 the VideoLAN team
+ * Copyright (C) 2008 Laurent Aimar
* $Id$
*
* Authors: Christophe Massiot <massiot@via.ecp.fr>
+ * Laurent Aimar < fenrir _AT_ videolan _DOT_ org >
*
* This program is free software; you can redistribute it and/or modify
* it under the terms of the GNU General Public License as published by
#endif
#include <vlc_common.h>
+#include <vlc_input.h>
+#include "input_clock.h"
-#include "input_internal.h"
+/* TODO:
+ * - clean up locking once clock code is stable
+ *
+ */
/*
* DISCUSSION : SYNCHRONIZATION METHOD
* new_average = (old_average * c_average + new_sample_value) / (c_average +1)
*/
-enum /* Synchro states */
-{
- SYNCHRO_OK = 0,
- SYNCHRO_START = 1,
- SYNCHRO_REINIT = 2,
-};
-
-static void ClockNewRef( input_clock_t * p_pgrm,
- mtime_t i_clock, mtime_t i_sysdate );
/*****************************************************************************
* Constants
/* Latency introduced on DVDs with CR == 0 on chapter change - this is from
* my dice --Meuuh */
-#define CR_MEAN_PTS_GAP 300000
+#define CR_MEAN_PTS_GAP (300000)
/*****************************************************************************
- * ClockToSysdate: converts a movie clock to system date
+ * Structures
*****************************************************************************/
-static mtime_t ClockToSysdate( input_clock_t *cl, mtime_t i_clock )
+
+/**
+ * This structure holds long term average
+ */
+typedef struct
{
- if( cl->i_synchro_state != SYNCHRO_OK )
- return 0;
+ mtime_t i_value;
+ int i_residue;
- return (i_clock - cl->cr_ref) * cl->i_rate / INPUT_RATE_DEFAULT +
- cl->sysdate_ref;
-}
+ int i_count;
+ int i_divider;
+} average_t;
+static void AvgInit( average_t *, int i_divider );
+static void AvgClean( average_t * );
-/*****************************************************************************
- * ClockCurrent: converts current system date to clock units
- *****************************************************************************
- * Caution : the synchro state must be SYNCHRO_OK for this to operate.
- *****************************************************************************/
-static mtime_t ClockCurrent( input_clock_t *cl )
+static void AvgReset( average_t * );
+static void AvgUpdate( average_t *, mtime_t i_value );
+static mtime_t AvgGet( average_t * );
+
+/* */
+typedef struct
{
- return (mdate() - cl->sysdate_ref) * INPUT_RATE_DEFAULT / cl->i_rate +
- cl->cr_ref;
-}
+ mtime_t i_stream;
+ mtime_t i_system;
+} clock_point_t;
-/*****************************************************************************
- * ClockNewRef: writes a new clock reference
- *****************************************************************************/
-static void ClockNewRef( input_clock_t *cl,
- mtime_t i_clock, mtime_t i_sysdate )
+static inline clock_point_t clock_point_Create( mtime_t i_stream, mtime_t i_system )
{
- cl->cr_ref = i_clock;
- cl->sysdate_ref = i_sysdate ;
+ clock_point_t p = { .i_stream = i_stream, .i_system = i_system };
+ return p;
}
+/* */
+struct input_clock_t
+{
+ /* */
+ vlc_mutex_t lock;
+
+ /* Reference point */
+ bool b_has_reference;
+ clock_point_t ref;
+
+ /* Last point
+ * It is used to detect unexpected stream discontinuities */
+ clock_point_t last;
+
+ /* Maximal timestamp returned by input_clock_GetTS (in system unit) */
+ mtime_t i_ts_max;
+
+ /* Clock drift */
+ mtime_t i_next_drift_update;
+ average_t drift;
+
+ /* Current modifiers */
+ int i_rate;
+};
+
+static mtime_t ClockStreamToSystem( input_clock_t *, mtime_t i_stream );
+static mtime_t ClockSystemToStream( input_clock_t *, mtime_t i_system );
+
/*****************************************************************************
- * input_ClockInit: reinitializes the clock reference after a stream
- * discontinuity
+ * input_clock_New: create a new clock
*****************************************************************************/
-void input_ClockInit( input_clock_t *cl, bool b_master, int i_cr_average, int i_rate )
+input_clock_t *input_clock_New( int i_cr_average, int i_rate )
{
- cl->i_synchro_state = SYNCHRO_START;
-
- cl->last_cr = 0;
- cl->last_pts = 0;
- cl->last_sysdate = 0;
- cl->cr_ref = 0;
- cl->sysdate_ref = 0;
- cl->delta_cr = 0;
- cl->i_delta_cr_residue = 0;
+ input_clock_t *cl = malloc( sizeof(*cl) );
+ if( !cl )
+ return NULL;
+
+ vlc_mutex_init( &cl->lock );
+ cl->b_has_reference = false;
+ cl->ref = clock_point_Create( 0, 0 );
+
+ cl->last = clock_point_Create( 0, 0 );
+
+ cl->i_ts_max = 0;
+
+ cl->i_next_drift_update = 0;
+ AvgInit( &cl->drift, i_cr_average );
+
cl->i_rate = i_rate;
- cl->i_cr_average = i_cr_average;
+ return cl;
+}
- cl->b_master = b_master;
+/*****************************************************************************
+ * input_clock_Delete: destroy a new clock
+ *****************************************************************************/
+void input_clock_Delete( input_clock_t *cl )
+{
+ AvgClean( &cl->drift );
+ vlc_mutex_destroy( &cl->lock );
+ free( cl );
}
/*****************************************************************************
- * input_ClockSetPCR: manages a clock reference
+ * input_clock_Update: manages a clock reference
+ *
+ * i_ck_stream: date in stream clock
+ * i_ck_system: date in system clock
*****************************************************************************/
-void input_ClockSetPCR( input_thread_t *p_input,
- input_clock_t *cl, mtime_t i_clock )
+void input_clock_Update( input_clock_t *cl,
+ vlc_object_t *p_log, bool b_can_pace_control,
+ mtime_t i_ck_stream, mtime_t i_ck_system )
{
- const bool b_synchronize = p_input->b_can_pace_control && cl->b_master;
- const mtime_t i_mdate = mdate();
+ bool b_reset_reference = false;
- if( ( cl->i_synchro_state != SYNCHRO_OK ) ||
- ( i_clock == 0 && cl->last_cr != 0 ) )
+ vlc_mutex_lock( &cl->lock );
+ if( ( !cl->b_has_reference ) ||
+ ( i_ck_stream == 0 && cl->last.i_stream != 0 ) )
{
- /* Feed synchro with a new reference point. */
- ClockNewRef( cl, i_clock,
- __MAX( cl->last_pts + CR_MEAN_PTS_GAP, i_mdate ) );
- cl->i_synchro_state = SYNCHRO_OK;
-
- if( !b_synchronize )
- {
- cl->delta_cr = 0;
- cl->i_delta_cr_residue = 0;
- cl->last_update = 0;
- }
+ /* */
+ b_reset_reference= true;
}
- else if ( cl->last_cr != 0 &&
- ( (cl->last_cr - i_clock) > CR_MAX_GAP ||
- (cl->last_cr - i_clock) < - CR_MAX_GAP ) )
+ else if( cl->last.i_stream != 0 &&
+ ( (cl->last.i_stream - i_ck_stream) > CR_MAX_GAP ||
+ (cl->last.i_stream - i_ck_stream) < -CR_MAX_GAP ) )
{
/* Stream discontinuity, for which we haven't received a
* warning from the stream control facilities (dd-edited
* stream ?). */
- msg_Warn( p_input, "clock gap, unexpected stream discontinuity" );
- input_ClockInit( cl, cl->b_master, cl->i_cr_average, cl->i_rate );
- /* Feed synchro with a new reference point. */
- msg_Warn( p_input, "feeding synchro with a new reference point trying to recover from clock gap" );
- ClockNewRef( cl, i_clock,
- __MAX( cl->last_pts + CR_MEAN_PTS_GAP, i_mdate ) );
- cl->i_synchro_state = SYNCHRO_OK;
+ msg_Warn( p_log, "clock gap, unexpected stream discontinuity" );
+ cl->i_ts_max = 0;
+
+ /* */
+ msg_Warn( p_log, "feeding synchro with a new reference point trying to recover from clock gap" );
+ b_reset_reference= true;
}
+ if( b_reset_reference )
+ {
+ cl->i_next_drift_update = 0;
+ AvgReset( &cl->drift );
- cl->last_cr = i_clock;
- cl->last_sysdate = i_mdate;
+ /* Feed synchro with a new reference point. */
+ cl->b_has_reference = true;
+ cl->ref = clock_point_Create( i_ck_stream,
+ __MAX( cl->i_ts_max + CR_MEAN_PTS_GAP, i_ck_system ) );
+ }
- if( !b_synchronize && i_mdate - cl->last_update > 200000 )
+ if( !b_can_pace_control && cl->i_next_drift_update < i_ck_system )
{
- /* Smooth clock reference variations. */
- const mtime_t i_extrapoled_clock = ClockCurrent( cl );
- /* Bresenham algorithm to smooth variations. */
- const mtime_t i_tmp = cl->delta_cr * (cl->i_cr_average - 1) +
- ( i_extrapoled_clock - i_clock ) * 1 +
- cl->i_delta_cr_residue;
+ const mtime_t i_converted = ClockSystemToStream( cl, i_ck_system );
- cl->i_delta_cr_residue = i_tmp % cl->i_cr_average;
- cl->delta_cr = i_tmp / cl->i_cr_average;
+ AvgUpdate( &cl->drift, i_converted - i_ck_stream );
- cl->last_update = i_mdate;
+ cl->i_next_drift_update = i_ck_system + CLOCK_FREQ/5; /* FIXME why that */
}
+ cl->last = clock_point_Create( i_ck_stream, i_ck_system );
+
+ vlc_mutex_unlock( &cl->lock );
}
/*****************************************************************************
- * input_ClockResetPCR:
+ * input_clock_Reset:
*****************************************************************************/
-void input_ClockResetPCR( input_clock_t *cl )
+void input_clock_Reset( input_clock_t *cl )
{
- cl->i_synchro_state = SYNCHRO_REINIT;
- cl->last_pts = 0;
+ vlc_mutex_lock( &cl->lock );
+
+ cl->b_has_reference = false;
+ cl->ref = clock_point_Create( 0, 0 );
+ cl->i_ts_max = 0;
+
+ vlc_mutex_unlock( &cl->lock );
}
/*****************************************************************************
- * input_ClockGetTS: manages a PTS or DTS
+ * input_clock_ChangeRate:
*****************************************************************************/
-mtime_t input_ClockGetTS( input_thread_t * p_input,
- input_clock_t *cl, mtime_t i_ts )
+void input_clock_ChangeRate( input_clock_t *cl, int i_rate )
{
- if( cl->i_synchro_state != SYNCHRO_OK )
- return 0;
+ vlc_mutex_lock( &cl->lock );
+
+ /* Move the reference point */
+ if( cl->b_has_reference )
+ cl->ref = cl->last;
- cl->last_pts = ClockToSysdate( cl, i_ts + cl->delta_cr );
- return cl->last_pts + p_input->i_pts_delay;
+ cl->i_rate = i_rate;
+
+ vlc_mutex_unlock( &cl->lock );
}
/*****************************************************************************
- * input_ClockSetRate:
+ * input_clock_GetWakeup
*****************************************************************************/
-void input_ClockSetRate( input_clock_t *cl, int i_rate )
+mtime_t input_clock_GetWakeup( input_clock_t *cl )
{
- /* Move the reference point */
- if( cl->i_synchro_state == SYNCHRO_OK )
- ClockNewRef( cl, cl->last_cr, cl->last_sysdate );
+ mtime_t i_wakeup = 0;
- cl->i_rate = i_rate;
+ vlc_mutex_lock( &cl->lock );
+
+ /* Synchronized, we can wait */
+ if( cl->b_has_reference )
+ i_wakeup = ClockStreamToSystem( cl, cl->last.i_stream );
+
+ vlc_mutex_unlock( &cl->lock );
+
+ return i_wakeup;
}
/*****************************************************************************
- * input_ClockGetWakeup
+ * input_clock_GetTS: manages a PTS or DTS
*****************************************************************************/
-mtime_t input_ClockGetWakeup( input_thread_t *p_input, input_clock_t *cl )
+mtime_t input_clock_GetTS( input_clock_t *cl,
+ mtime_t i_pts_delay, mtime_t i_ts )
{
- /* Not synchronized, we cannot wait */
- if( cl->i_synchro_state != SYNCHRO_OK )
- return 0;
+ mtime_t i_converted_ts;
+
+ vlc_mutex_lock( &cl->lock );
- /* We must not wait if not pace controled, or we are not the
- * master clock */
- if( !p_input->b_can_pace_control || !cl->b_master ||
- p_input->p->b_out_pace_control )
+ if( !cl->b_has_reference )
+ {
+ vlc_mutex_unlock( &cl->lock );
return 0;
+ }
/* */
- return ClockToSysdate( cl, cl->last_cr );
+ i_converted_ts = ClockStreamToSystem( cl, i_ts + AvgGet( &cl->drift ) );
+ if( i_converted_ts > cl->i_ts_max )
+ cl->i_ts_max = i_converted_ts;
+
+ vlc_mutex_unlock( &cl->lock );
+
+ return i_converted_ts + i_pts_delay;
+}
+/*****************************************************************************
+ * input_clock_GetRate: Return current rate
+ *****************************************************************************/
+int input_clock_GetRate( input_clock_t *cl )
+{
+ int i_rate;
+
+ vlc_mutex_lock( &cl->lock );
+ i_rate = cl->i_rate;
+ vlc_mutex_unlock( &cl->lock );
+
+ return i_rate;
+}
+
+/*****************************************************************************
+ * ClockStreamToSystem: converts a movie clock to system date
+ *****************************************************************************/
+static mtime_t ClockStreamToSystem( input_clock_t *cl, mtime_t i_stream )
+{
+ if( !cl->b_has_reference )
+ return 0;
+
+ return ( i_stream - cl->ref.i_stream ) * cl->i_rate / INPUT_RATE_DEFAULT +
+ cl->ref.i_system;
+}
+
+/*****************************************************************************
+ * ClockSystemToStream: converts a system date to movie clock
+ *****************************************************************************
+ * Caution : a valid reference point is needed for this to operate.
+ *****************************************************************************/
+static mtime_t ClockSystemToStream( input_clock_t *cl, mtime_t i_system )
+{
+ assert( cl->b_has_reference );
+ return ( i_system - cl->ref.i_system ) * INPUT_RATE_DEFAULT / cl->i_rate +
+ cl->ref.i_stream;
+}
+
+/*****************************************************************************
+ * Long term average helpers
+ *****************************************************************************/
+static void AvgInit( average_t *p_avg, int i_divider )
+{
+ p_avg->i_divider = i_divider;
+ AvgReset( p_avg );
+}
+static void AvgClean( average_t *p_avg )
+{
+ VLC_UNUSED(p_avg);
+}
+static void AvgReset( average_t *p_avg )
+{
+ p_avg->i_value = 0;
+ p_avg->i_residue = 0;
+ p_avg->i_count = 0;
+}
+static void AvgUpdate( average_t *p_avg, mtime_t i_value )
+{
+ const int i_f0 = __MIN( p_avg->i_divider - 1, p_avg->i_count );
+ const int i_f1 = p_avg->i_divider - i_f0;
+
+ const mtime_t i_tmp = i_f0 * p_avg->i_value + i_f1 * i_value + p_avg->i_residue;
+
+ p_avg->i_value = i_tmp / p_avg->i_divider;
+ p_avg->i_residue = i_tmp % p_avg->i_divider;
+
+ p_avg->i_count++;
+}
+static mtime_t AvgGet( average_t *p_avg )
+{
+ return p_avg->i_value;
}
projects / vlc / blobdiff