[vlc-devel] [PATCH v2 1/5] clock: add vlc_clock_main_SetInputDrift

[Rémi Denis-Courmont]

Le lundi 8 mars 2021, 18:13:34 EET Thomas Guillem a écrit :
> ---
>  src/clock/clock.c | 15 +++++++++++++--
>  src/clock/clock.h |  1 +
>  2 files changed, 14 insertions(+), 2 deletions(-)
> 
> diff --git a/src/clock/clock.c b/src/clock/clock.c
> index cfbb5eb6f6d..0bb2a9fe375 100644
> --- a/src/clock/clock.c
> +++ b/src/clock/clock.c
> @@ -45,6 +45,7 @@ struct vlc_clock_main_t
>      average_t coeff_avg; /* Moving average to smooth out the instant coeff
> */ double rate;
>      double coeff;
> +    vlc_tick_t input_drift;
>      vlc_tick_t offset;
>      vlc_tick_t delay;
> 
> @@ -88,6 +89,7 @@ static vlc_tick_t main_stream_to_system(vlc_clock_main_t
> *main_clock, static void vlc_clock_main_reset(vlc_clock_main_t *main_clock)
>  {
>      AvgReset(&main_clock->coeff_avg);
> +    main_clock->input_drift = 0;
>      main_clock->coeff = 1.0f;
>      main_clock->rate = 1.0f;
>      main_clock->offset = VLC_TICK_INVALID;
> @@ -266,7 +268,8 @@ static vlc_tick_t
> vlc_clock_slave_to_system_locked(vlc_clock_t *clock, system =
> vlc_clock_monotonic_to_system_locked(clock, now, ts, rate); }
> 
> -    return system + (clock->delay - main_clock->delay) * rate;
> +    return system + main_clock->input_drift +
> +        (clock->delay - main_clock->delay) * rate;
>  }
> 
>  static vlc_tick_t vlc_clock_master_to_system_locked(vlc_clock_t *clock,
> @@ -282,7 +285,7 @@ static vlc_tick_t
> vlc_clock_master_to_system_locked(vlc_clock_t *clock, system =
> vlc_clock_monotonic_to_system_locked(clock, now, ts, rate); }
> 
> -    return system + clock->delay * rate;
> +    return system + main_clock->input_drift + clock->delay * rate;
>  }
> 
>  static vlc_tick_t vlc_clock_slave_update(vlc_clock_t *clock,
> @@ -370,6 +373,7 @@ vlc_clock_main_t *vlc_clock_main_New(void)
>      main_clock->master = NULL;
>      main_clock->rc = 1;
> 
> +    main_clock->input_drift = 0;
>      main_clock->coeff = 1.0f;
>      main_clock->rate = 1.0f;
>      main_clock->offset = VLC_TICK_INVALID;
> @@ -439,6 +443,13 @@ void vlc_clock_main_SetDejitter(vlc_clock_main_t
> *main_clock, vlc_mutex_unlock(&main_clock->lock);
>  }
> 
> +void vlc_clock_main_SetInputDrift(vlc_clock_main_t *main_clock, double
> drift) +{
> +    vlc_mutex_lock(&main_clock->lock);
> +    main_clock->input_drift = drift;
> +    vlc_mutex_unlock(&main_clock->lock);
> +}
> +
>  void vlc_clock_main_ChangePause(vlc_clock_main_t *main_clock, vlc_tick_t
> now, bool paused)
>  {
> diff --git a/src/clock/clock.h b/src/clock/clock.h
> index e7373391697..bec9edd40a9 100644
> --- a/src/clock/clock.h
> +++ b/src/clock/clock.h
> @@ -78,6 +78,7 @@ void vlc_clock_main_SetFirstPcr(vlc_clock_main_t
> *main_clock, vlc_tick_t system_now, vlc_tick_t ts); void
> vlc_clock_main_SetInputDejitter(vlc_clock_main_t *main_clock, vlc_tick_t
> delay);
> +void vlc_clock_main_SetInputDrift(vlc_clock_main_t *main_clock, double
> drift);
> 
>  /**
>   * This function sets the dejitter delay to absorb the clock jitter

This adds a new factor to the clock computations with zero explanation what, 
why and how...

-- 
Rémi Denis-Courmont