From a6b59671a49e2b0ec91c8a0fbbfe4804ca126f24 Mon Sep 17 00:00:00 2001
From: Philip Chimento <philip.chimento@gmail.com>
Date: Thu, 14 Jul 2011 00:55:12 +0200
Subject: [PATCH] Implemented glk_schannel_set_volume_ext() partly

Still need to do:
 - Volume change notifications
 - What happens when channel is not playing
---
 configure.ac          |  2 +-
 libchimara/schannel.c | 80 ++++++++++++++++++++++++++++++++++++++++---
 tests/soundtest.c     |  4 +--
 3 files changed, 78 insertions(+), 8 deletions(-)

diff --git a/configure.ac b/configure.ac
index 3fb5d01..f83e755 100644
--- a/configure.ac
+++ b/configure.ac
@@ -118,7 +118,7 @@ AC_ARG_WITH([gstreamer],
 SOUND_MODULE=
 AS_IF([$TEST "x$with_gstreamer" != xno], 
 	[AC_DEFINE([GSTREAMER_SOUND], [1], [Define to enable sound support with GStreamer])
-	SOUND_MODULE="gstreamer-0.10 >= 0.10.12"])
+	SOUND_MODULE="gstreamer-0.10 >= 0.10.12 gstreamer-controller-0.10"])
 
 ### CHECK FOR LIBRARIES #######################################################
 
diff --git a/libchimara/schannel.c b/libchimara/schannel.c
index d8c924d..321354e 100644
--- a/libchimara/schannel.c
+++ b/libchimara/schannel.c
@@ -4,6 +4,7 @@
 #include <libchimara/glk.h>
 #ifdef GSTREAMER_SOUND
 #include <gst/gst.h>
+#include <gst/controller/gstcontroller.h>
 #endif
 #include "magic.h"
 #include "schannel.h"
@@ -678,6 +679,22 @@ glk_schannel_unpause(schanid_t chan)
 	}
 }
 
+static double
+volume_glk_to_gstreamer(glui32 volume_glk)
+{
+	return CLAMP(((double)volume_glk / 0x10000), 0.0, 10.0);
+}
+
+static void
+channel_set_volume_immediately(schanid_t chan, double volume, glui32 notify)
+{
+	g_object_set(chan->filter, "volume", volume, NULL);
+
+	if(notify != 0) {
+		/* Send a notification */
+	}
+}
+
 /**
  * glk_schannel_set_volume:
  * @chan: Channel to set the volume of.
@@ -710,7 +727,13 @@ glk_schannel_unpause(schanid_t chan)
 void 
 glk_schannel_set_volume(schanid_t chan, glui32 vol)
 {
-	glk_schannel_set_volume_ext(chan, vol, 0, 0);
+	VALID_SCHANNEL(chan, return);
+	/* Silently ignore out-of-range volume values */
+
+#ifdef GSTREAMER_SOUND
+	double volume = volume_glk_to_gstreamer(vol);
+	channel_set_volume_immediately(chan, volume, 0);
+#endif
 }
 
 /**
@@ -758,11 +781,58 @@ glk_schannel_set_volume_ext(schanid_t chan, glui32 vol, glui32 duration, glui32
 	/* Silently ignore out-of-range volume values */
 	
 #ifdef GSTREAMER_SOUND
-	gdouble volume_gst = (gdouble)vol / 0x10000;
-	g_object_set(chan->filter, "volume", CLAMP(volume_gst, 0.0, 10.0), NULL);
-#endif
+	double volume = volume_glk_to_gstreamer(vol);
+
+	/* TODO: If channel is not playing, change the volume anyway */
+
+	if(duration == 0) {
+		channel_set_volume_immediately(chan, volume, notify);
+		return;
+	}
 
-	/* Not implemented */
+	/* Get the volume levels as GValues */
+	GValue current_volume = { 0 };
+	GValue target_volume = { 0 };
+	g_value_init(&current_volume, G_TYPE_DOUBLE);
+	g_value_init(&target_volume, G_TYPE_DOUBLE);
+	g_object_get_property(G_OBJECT(chan->filter), "volume", &current_volume);
+	g_value_set_double(&target_volume, volume);
+
+	/* Make a controller for the volume */
+	GstController *controller = gst_object_control_properties(G_OBJECT(chan->filter), "volume", NULL);
+	if(controller == NULL) {
+		WARNING(_("Couldn't get controller for volume change"));
+		goto fail;
+	}
+	GstInterpolationControlSource *csource = gst_interpolation_control_source_new();
+	gst_interpolation_control_source_set_interpolation_mode(csource, GST_INTERPOLATE_LINEAR);
+	if(!gst_controller_set_control_source(controller, "volume", GST_CONTROL_SOURCE(csource))) {
+		WARNING(_("Couldn't set control source for volume change"));
+		goto fail;
+	}
+
+	/* Get the current time on the pipeline */
+	GstClock *clock = gst_pipeline_get_clock(GST_PIPELINE(chan->pipeline));
+	GstClockTime current = gst_clock_get_time(clock);
+	g_object_unref(clock);
+
+	if(!gst_interpolation_control_source_set(csource, current, &current_volume)) {
+		WARNING(_("Couldn't program volume change"));
+		goto fail;
+	}
+	if(!gst_interpolation_control_source_set(csource, current + duration * GST_MSECOND, &target_volume)) {
+		WARNING(_("Couldn't program volume change"));
+		goto fail;
+	}
+
+	/* TODO: SET UP NOTIFICATION */
+
+	return;
+
+fail:
+	/* Changing the volume dynamically didn't work; just do it immediately. */
+	channel_set_volume_immediately(chan, volume, notify);
+#endif
 }
 
 /**
diff --git a/tests/soundtest.c b/tests/soundtest.c
index 55759dc..b0a3800 100644
--- a/tests/soundtest.c
+++ b/tests/soundtest.c
@@ -109,11 +109,11 @@ glk_main(void)
 					glk_put_string("Ramping volume to ");
 					if(ramp == 0) {
 						glk_put_string("HALF.\n");
-						glk_schannel_set_volume_ext(sc[0], 0x8000, 1000, 42);
+						glk_schannel_set_volume_ext(sc[0], 0x8000, 3000, 42);
 						ramp = 1;
 					} else if(ramp == 1) {
 						glk_put_string("FULL.\n");
-						glk_schannel_set_volume_ext(sc[0], 0x10000, 1000, 69);
+						glk_schannel_set_volume_ext(sc[0], 0x10000, 3000, 69);
 						ramp = 0;
 					}
 				} else if(strcmp(buffer, "multi") == 0) {
-- 
2.30.2