Multi-channel support with channel positions.

This queries port roles from the LV2 data and converts it into GStreamer
channel positions.  This should allow any type of multi-channel plugin
(including beyond stereo, e.g. surround) to work fine in GStreamer,
and with elements that require channel positions to be explicitly stated.

2 files changed, 10 insertions, 2 deletions

diff --git a/gst-libs/gst/signalprocessor/gstsignalprocessor.c b/gst-libs/gst/signalprocessor/gstsignalprocessor.c
index 3d3c7204..4cf69e35 100644
--- a/gst-libs/gst/signalprocessor/gstsignalprocessor.c
+++ b/gst-libs/gst/signalprocessor/gstsignalprocessor.c
@@ -90,11 +90,14 @@ gst_signal_processor_pad_template_get_type (void)
  * @name: pad name
  * @direction: pad direction (src/sink)
  * @index: index for the pad per direction (starting from 0)
+ * @channels: number of channels in this pad
+ * @positions: array of channel positions in order
  *
  */
 void
 gst_signal_processor_class_add_pad_template (GstSignalProcessorClass * klass,
-    const gchar * name, GstPadDirection direction, guint index, guint channels)
+    const gchar * name, GstPadDirection direction, guint index, guint channels,
+    const GstAudioChannelPosition * pos)
 {
   GstPadTemplate *new;
   GstCaps *caps;
@@ -107,6 +110,9 @@ gst_signal_processor_class_add_pad_template (GstSignalProcessorClass * klass,
       "endianness", G_TYPE_INT, G_BYTE_ORDER,
       "width", G_TYPE_INT, 32, "channels", G_TYPE_INT, channels, NULL);
 
+  if (pos)
+    gst_audio_set_caps_channel_positions_list (caps, pos, channels);
+
   new = g_object_new (gst_signal_processor_pad_template_get_type (),
       "name", name, "name-template", name,
       "direction", direction, "presence", GST_PAD_ALWAYS, "caps", caps, NULL);
diff --git a/gst-libs/gst/signalprocessor/gstsignalprocessor.h b/gst-libs/gst/signalprocessor/gstsignalprocessor.h
index 30ed0315..b7daf7e5 100644
--- a/gst-libs/gst/signalprocessor/gstsignalprocessor.h
+++ b/gst-libs/gst/signalprocessor/gstsignalprocessor.h
@@ -25,6 +25,7 @@
 #define __GST_SIGNAL_PROCESSOR_H__
 
 #include <gst/gst.h>
+#include <gst/audio/multichannel.h>
 
 G_BEGIN_DECLS
 
@@ -131,7 +132,8 @@ struct _GstSignalProcessorClass {
 
 GType gst_signal_processor_get_type (void);
 void gst_signal_processor_class_add_pad_template (GstSignalProcessorClass *klass,
-    const gchar *name, GstPadDirection direction, guint index, guint channels);
+    const gchar *name, GstPadDirection direction, guint index, guint channels,
+    const GstAudioChannelPosition *pos);