[vlc-devel] [RFC PATCH 4/7] player: add vlc_player_aout_AddLoudnessMeter()

Thomas Guillem thomas at gllm.fr
Mon Aug 17 09:41:47 CEST 2020


What is metadata in this context ? I don't follow you.

The loudness meter plugin should only be enabled when there is a listener.

What I could do instead of this API:

vlc_player_EnableLoudnessMeter(mode);
vlc_player_DisableLoudnessMeter(mode);

This will increment/decrement a refcount, the plugin will be loaded, unloaded, restarted (mode change) according to this count. Then the user use the classical vlc_player listener API to receive meter callbacks.

On Sat, Aug 15, 2020, at 13:12, Jean-Baptiste Kempf wrote:
> Why a specific function for loundness and not an extra metadata one?
> 
> On Fri, 14 Aug 2020, at 15:18, Thomas Guillem wrote:
> > ---
> >  include/vlc_player.h |  76 +++++++++++++++++++++++++++++++
> >  src/libvlccore.sym   |   2 +
> >  src/player/aout.c    | 103 +++++++++++++++++++++++++++++++++++++++++++
> >  src/player/player.c  |   3 ++
> >  src/player/player.h  |   9 ++++
> >  5 files changed, 193 insertions(+)
> > 
> > diff --git a/include/vlc_player.h b/include/vlc_player.h
> > index ac5991982df..ad4d39536d4 100644
> > --- a/include/vlc_player.h
> > +++ b/include/vlc_player.h
> > @@ -2199,6 +2199,50 @@ struct vlc_player_aout_cbs
> >          void *data);
> >  };
> >  
> > +/**
> > + * Player aout loudness meter opaque structure.
> > + *
> > + * This opaque structure is returned by 
> > vlc_player_aout_AddLoudnessMeter() and
> > + * can be used to remove the listener via
> > + * vlc_player_aout_RemoveLoudnessMeter().
> > + */
> > +typedef struct vlc_player_aout_loudness_meter_id 
> > vlc_player_aout_loudness_meter_id;
> > +
> > +/**
> > + * Loudness meter mode
> > + */
> > +enum vlc_player_aout_loudness_meter_mode
> > +{
> > +    /** Very low CPU usage, only the Momentary Loudness will be 
> > processed */
> > +    VLC_PLAYER_AOUT_LOUDNESS_METER_BEST_PERFS,
> > +    /** High CPU usage, Momentary Loudness, Short Term Loudness 
> > Integrated
> > +     * Loudness, Loudness Range and True Peak will be processed. */
> > +    VLC_PLAYER_AOUT_LOUDNESS_METER_FULL,
> > +};
> > +
> > +/**
> > + * Player aout loudness meter callbacks
> > + *
> > + * Can be registered with vlc_player_aout_AddLoudnessMeter().
> > + */
> > +struct vlc_player_aout_loudness_cbs
> > +{
> > +
> > +    /**
> > +     * Called when loudness measurements have changed
> > +     *
> > +     * Only sent when audio is playing, approximately every 400ms (but 
> > can be
> > +     * higher, depending on the input sample size).
> > +     *
> > +     * @param aout the main aout of the player
> > +     * @param meter last loudness measurements
> > +     * @param data opaque pointer set by 
> > vlc_player_aout_AddLoudnessMeter()
> > +     */
> > +    void (*on_loudness_changed)(audio_output_t *aout,
> > +                                const struct vlc_audio_loudness_meter 
> > *meter,
> > +                                void *data);
> > +};
> > +
> >  /**
> >   * Get the audio output
> >   *
> > @@ -2353,6 +2397,38 @@ vlc_player_aout_ToggleMute(vlc_player_t *player)
> >  VLC_API int
> >  vlc_player_aout_EnableFilter(vlc_player_t *player, const char *name, 
> > bool add);
> >  
> > +
> > +/**
> > + * Add an aout loudness meter
> > + *
> > + * @note The player instance doesn't need to be locked for 
> > vlc_player_aout_*()
> > + * functions.
> > + * @note Every registered loudness meter need to be removed by the 
> > caller with
> > + * vlc_player_aout_RemoveLoudnessMeter().
> > + *
> > + * @param player player instance
> > + * @param cbs pointer to a vlc_player_aout_loudness_cbs structure, the
> > + * structure must be valid during the lifetime of the player
> > + * @param cbs_data opaque pointer used by the callbacks
> > + * @return a valid meter id, or NULL in case of error ("audio-meter" 
> > plugin
> > + * missing)
> > + */
> > +VLC_API vlc_player_aout_loudness_meter_id *
> > +vlc_player_aout_AddLoudnessMeter(vlc_player_t *player,
> > +                                 enum 
> > vlc_player_aout_loudness_meter_mode,
> > +                                 const struct 
> > vlc_player_aout_loudness_cbs *cbs,
> > +                                 void *cbs_data);
> > +
> > +/**
> > + * Remove an aout loudness meter
> > + *
> > + * @param player player instance
> > + * @param meter_id meter id returned by 
> > vlc_player_aout_AddLoudnessMeter()
> > + */
> > +VLC_API void
> > +vlc_player_aout_RemoveLoudnessMeter(vlc_player_t *player,
> > +                                    vlc_player_aout_loudness_meter_id 
> > *meter_id);
> > +
> >  /** @} vlc_player__aout */
> >  
> >  /**
> > diff --git a/src/libvlccore.sym b/src/libvlccore.sym
> > index ed43c17715c..cf1916fd92c 100644
> > --- a/src/libvlccore.sym
> > +++ b/src/libvlccore.sym
> > @@ -774,6 +774,7 @@ vlc_player_AddListener
> >  vlc_player_AddSmpteTimer
> >  vlc_player_AddTimer
> >  vlc_player_aout_AddListener
> > +vlc_player_aout_AddLoudnessMeter
> >  vlc_player_aout_EnableFilter
> >  vlc_player_aout_GetVolume
> >  vlc_player_aout_Hold
> > @@ -782,6 +783,7 @@ vlc_player_aout_IncrementVolume
> >  vlc_player_aout_IsMuted
> >  vlc_player_aout_Mute
> >  vlc_player_aout_RemoveListener
> > +vlc_player_aout_RemoveLoudnessMeter
> >  vlc_player_aout_SetVolume
> >  vlc_player_ChangeRate
> >  vlc_player_CondWait
> > diff --git a/src/player/aout.c b/src/player/aout.c
> > index 8674cc65359..f962b53329b 100644
> > --- a/src/player/aout.c
> > +++ b/src/player/aout.c
> > @@ -26,6 +26,7 @@
> >  
> >  #include <vlc_common.h>
> >  #include <vlc_decoder.h>
> > +#include <vlc_modules.h>
> >  #include "player.h"
> >  #include "input/resource.h"
> >  
> > @@ -46,6 +47,106 @@ vlc_player_aout_Hold(vlc_player_t *player)
> >      return input_resource_HoldAout(player->resource);
> >  }
> >  
> > +VLC_API vlc_player_aout_loudness_meter_id *
> > +vlc_player_aout_AddLoudnessMeter(vlc_player_t *player,
> > +                                 enum 
> > vlc_player_aout_loudness_meter_mode mode,
> > +                                 const struct 
> > vlc_player_aout_loudness_cbs *cbs,
> > +                                 void *cbs_data)
> > +{
> > +    assert(cbs && cbs->on_loudness_changed);
> > +
> > +    if (!module_exists("ebur128"))
> > +        return NULL;
> > +
> > +    vlc_player_aout_loudness_meter_id *meter_id = 
> > malloc(sizeof(*meter_id));
> > +    if (meter_id == NULL)
> > +        return NULL;
> > +
> > +    meter_id->cbs = cbs;
> > +    meter_id->cbs_data = cbs_data;
> > +    meter_id->mode = mode;
> > +
> > +    vlc_mutex_lock(&player->aout_listeners_lock);
> > +
> > +    bool has_meter_module = 
> > !vlc_list_is_empty(&player->aout_loudness_meters);
> > +
> > +    enum vlc_player_aout_loudness_meter_mode prev_mode =
> > +        VLC_PLAYER_AOUT_LOUDNESS_METER_BEST_PERFS;
> > +    if (has_meter_module)
> > +    {
> > +        vlc_player_aout_loudness_meter_id *other_meter_id;
> > +        vlc_list_foreach(other_meter_id, 
> > &player->aout_loudness_meters, node)
> > +        {
> > +            if (other_meter_id->mode > prev_mode)
> > +                prev_mode = other_meter_id->mode;
> > +        }
> > +    }
> > +
> > +    vlc_list_append(&meter_id->node, &player->aout_loudness_meters);
> > +
> > +    vlc_mutex_unlock(&player->aout_listeners_lock);
> > +
> > +    if (!has_meter_module || mode > prev_mode)
> > +    {
> > +        audio_output_t *aout = vlc_player_aout_Hold(player);
> > +        if (aout != NULL)
> > +        {
> > +            var_SetBool(player, "ebur128-fullmeter",
> > +                        mode == VLC_PLAYER_AOUT_LOUDNESS_METER_FULL);
> > +            var_SetString(aout, "audio-meter", "ebur128");
> > +            aout_Release(aout);
> > +        }
> > +    }
> > +
> > +    return meter_id;
> > +}
> > +
> > +void
> > +vlc_player_aout_RemoveLoudnessMeter(vlc_player_t *player,
> > +                                    vlc_player_aout_loudness_meter_id 
> > *meter_id)
> > +{
> > +    assert(meter_id);
> > +
> > +    vlc_mutex_lock(&player->aout_listeners_lock);
> > +    vlc_list_remove(&meter_id->node);
> > +
> > +    bool has_meter_module = 
> > !vlc_list_is_empty(&player->aout_loudness_meters);
> > +
> > +    vlc_mutex_unlock(&player->aout_listeners_lock);
> > +    free(meter_id);
> > +
> > +    if (!has_meter_module)
> > +    {
> > +        audio_output_t *aout = vlc_player_aout_Hold(player);
> > +        if (aout != NULL)
> > +        {
> > +            var_SetString(aout, "audio-meter", NULL);
> > +            aout_Release(aout);
> > +        }
> > +    }
> > +}
> > +
> > +static int
> > +vlc_player_AoutLoudnessCallback(vlc_object_t *this, const char *var,
> > +                                vlc_value_t oldval, vlc_value_t 
> > newval, void *data)
> > +{
> > +    vlc_player_t *player = data;
> > +
> > +    struct vlc_audio_loudness_meter *meter = newval.p_address;
> > +
> > +    vlc_mutex_lock(&player->aout_listeners_lock);
> > +    vlc_player_aout_loudness_meter_id *meter_id;
> > +    vlc_list_foreach(meter_id, &player->aout_loudness_meters, node)
> > +    {
> > +        meter_id->cbs->on_loudness_changed((audio_output_t *)this,
> > +                                            meter, meter_id->cbs_data);
> > +    }
> > +    vlc_mutex_unlock(&player->aout_listeners_lock);
> > +
> > +    (void) var; (void) oldval;
> > +    return VLC_SUCCESS;
> > +}
> > +
> >  vlc_player_aout_listener_id *
> >  vlc_player_aout_AddListener(vlc_player_t *player,
> >                              const struct vlc_player_aout_cbs *cbs,
> > @@ -202,6 +303,7 @@ vlc_player_aout_AddCallbacks(vlc_player_t *player)
> >      var_AddCallback(aout, "volume", vlc_player_AoutCallback, player);
> >      var_AddCallback(aout, "mute", vlc_player_AoutCallback, player);
> >      var_AddCallback(aout, "device", vlc_player_AoutCallback, player);
> > +    var_AddCallback(aout, "loudness-meter", 
> > vlc_player_AoutLoudnessCallback, player);
> >  
> >      aout_Release(aout);
> >  }
> > @@ -216,6 +318,7 @@ vlc_player_aout_DelCallbacks(vlc_player_t *player)
> >      var_DelCallback(aout, "volume", vlc_player_AoutCallback, player);
> >      var_DelCallback(aout, "mute", vlc_player_AoutCallback, player);
> >      var_DelCallback(aout, "device", vlc_player_AoutCallback, player);
> > +    var_DelCallback(aout, "loudness-meter", 
> > vlc_player_AoutLoudnessCallback, player);
> >  
> >      aout_Release(aout);
> >  }
> > diff --git a/src/player/player.c b/src/player/player.c
> > index fd072e414b5..e74c29e6d9c 100644
> > --- a/src/player/player.c
> > +++ b/src/player/player.c
> > @@ -1893,6 +1893,7 @@ vlc_player_Delete(vlc_player_t *player)
> >      assert(vlc_list_is_empty(&player->listeners));
> >      assert(vlc_list_is_empty(&player->vout_listeners));
> >      assert(vlc_list_is_empty(&player->aout_listeners));
> > +    assert(vlc_list_is_empty(&player->aout_loudness_meters));
> >  
> >      vlc_mutex_unlock(&player->lock);
> >  
> > @@ -1934,6 +1935,7 @@ vlc_player_New(vlc_object_t *parent, enum 
> > vlc_player_lock_type lock_type,
> >      vlc_list_init(&player->listeners);
> >      vlc_list_init(&player->vout_listeners);
> >      vlc_list_init(&player->aout_listeners);
> > +    vlc_list_init(&player->aout_loudness_meters);
> >      vlc_list_init(&player->destructor.inputs);
> >      vlc_list_init(&player->destructor.stopping_inputs);
> >      vlc_list_init(&player->destructor.joinable_inputs);
> > @@ -1973,6 +1975,7 @@ vlc_player_New(vlc_object_t *parent, enum 
> > vlc_player_lock_type lock_type,
> >      VAR_CREATE("audio-filter", VLC_VAR_STRING | VLC_VAR_DOINHERIT);
> >      VAR_CREATE("mute", VLC_VAR_BOOL);
> >      VAR_CREATE("corks", VLC_VAR_INTEGER);
> > +    VAR_CREATE("ebur128-fullmeter", VLC_VAR_BOOL);
> >  
> >      /* es_out variables */
> >      VAR_CREATE("sout", VLC_VAR_STRING | VLC_VAR_DOINHERIT);
> > diff --git a/src/player/player.h b/src/player/player.h
> > index 87b9e430330..e4fafbab087 100644
> > --- a/src/player/player.h
> > +++ b/src/player/player.h
> > @@ -140,6 +140,14 @@ struct vlc_player_aout_listener_id
> >      struct vlc_list node;
> >  };
> >  
> > +struct vlc_player_aout_loudness_meter_id
> > +{
> > +    const struct vlc_player_aout_loudness_cbs *cbs;
> > +    void *cbs_data;
> > +    enum vlc_player_aout_loudness_meter_mode mode;
> > +    struct vlc_list node;
> > +};
> > +
> >  enum vlc_player_timer_source_type
> >  {
> >      VLC_PLAYER_TIMER_TYPE_BEST,
> > @@ -224,6 +232,7 @@ struct vlc_player_t
> >  
> >      struct vlc_list listeners;
> >      struct vlc_list aout_listeners;
> > +    struct vlc_list aout_loudness_meters;
> >      struct vlc_list vout_listeners;
> >  
> >      input_resource_t *resource;
> > -- 
> > 2.28.0
> > 
> > _______________________________________________
> > vlc-devel mailing list
> > To unsubscribe or modify your subscription options:
> > https://mailman.videolan.org/listinfo/vlc-devel
> 
> -- 
> Jean-Baptiste Kempf -  President
> +33 672 704 734
> _______________________________________________
> vlc-devel mailing list
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