[banshee/gapless-ng: 831/836] [libbanshee] Re-add ReplayGain history fallback

[Christopher James Halse Rogers <chrishr src gnome org>]

commit da603e287016c65b0db73b7c291f6491ebe83a5d
Author: Christopher James Halse Rogers <raof ubuntu com>
Date:   Thu Feb 25 13:12:22 2010 +1100

    [libbanshee] Re-add ReplayGain history fallback

 libbanshee/banshee-player-private.h    |   11 ++---------
 libbanshee/banshee-player-replaygain.c |   30 ++++++++++++++++++++++++++++++
 2 files changed, 32 insertions(+), 9 deletions(-)
---
diff --git a/libbanshee/banshee-player-private.h b/libbanshee/banshee-player-private.h
index 3c7a3d9..104dc5d 100644
--- a/libbanshee/banshee-player-private.h
+++ b/libbanshee/banshee-player-private.h
@@ -153,15 +153,8 @@ struct BansheePlayer {
     // and the oldest at index 10. History is used to compute 
     // gain on a track where no adjustment information is present.
     // http://replaygain.hydrogenaudio.org/player_scale.html
-    gdouble volume_scale_history[11];
-    gboolean volume_scale_history_shift;
-    gboolean current_scale_from_history;
-    
-    // ReplayGain cache
-    gdouble album_gain;
-    gdouble album_peak;
-    gdouble track_gain;
-    gdouble track_peak;
+    gdouble rg_gain_history[10];
+    gint history_size;
 };
 
 #endif /* _BANSHEE_PLAYER_PRIVATE_H */
diff --git a/libbanshee/banshee-player-replaygain.c b/libbanshee/banshee-player-replaygain.c
index d0dac85..7dade14 100644
--- a/libbanshee/banshee-player-replaygain.c
+++ b/libbanshee/banshee-player-replaygain.c
@@ -40,10 +40,40 @@ bp_replaygain_db_to_linear(gdouble value)
     return pow(10, value / 20.0);
 }
 
+static gdouble bp_rg_calc_history_avg (BansheePlayer *player)
+{
+    gdouble sum = 0.0;
+    int i;
+    for (i = 0; i < player->history_size; ++i) {
+        sum += player->rg_gain_history[i];
+    }
+    return sum / player->history_size;
+}
+
+static void bp_replaygain_update_history (BansheePlayer *player)
+{
+    g_return_if_fail (player->history_size <= 10);
+
+    if (player->history_size == 10) {
+        memmove (player->rg_gain_history + 1, player->rg_gain_history, sizeof (gdouble) * 9);
+    } else {
+        memmove (player->rg_gain_history + 1, player->rg_gain_history, sizeof (gdouble) * player->history_size);
+        player->history_size++;
+    }
+
+    gdouble gain;
+    g_object_get (G_OBJECT (player->rgvolume), "target-gain", &gain, NULL);
+    player->rg_gain_history[0] = gain;
+    bp_debug ("[ReplayGain] Added gain: %.2f to history.", gain);
+
+    g_object_set (G_OBJECT (player->rgvolume), "fallback-gain", bp_rg_calc_history_avg (player), NULL);
+}
+
 static void on_target_gain_changed (GstElement *rgvolume, GParamSpec *pspec, BansheePlayer *player)
 {
     g_return_if_fail (IS_BANSHEE_PLAYER (player));
 
+    bp_replaygain_update_history (player);
     _bp_rgvolume_print_volume (player);
 }