spandsp: Adding spandsp plugin with spanplc element for packet loss concealment

1 files changed, 300 insertions, 0 deletions

diff --git a/ext/spandsp/gstspanplc.c b/ext/spandsp/gstspanplc.c
new file mode 100644
index 000000000..90a7c1092
--- /dev/null
+++ b/ext/spandsp/gstspanplc.c
@@ -0,0 +1,300 @@
+/*
+ * (C) 2011 Collabora Ltd.
+ *  Contact: Youness Alaoui <youness.alaoui@collabora.co.uk>
+ *
+ * This library is free software; you can redistribute it and/or
+ * modify it under the terms of the GNU Library General Public
+ * License as published by the Free Software Foundation; either
+ * version 2 of the License, or (at your option) any later version.
+ *
+ * This library is distributed in the hope that it will be useful,
+ * but WITHOUT ANY WARRANTY; without even the implied warranty of
+ * MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE.  See the GNU
+ * Library General Public License for more details.
+ *
+ * You should have received a copy of the GNU Library General Public
+ * License along with this library; if not, write to the
+ * Free Software Foundation, Inc., 59 Temple Place - Suite 330,
+ * Boston, MA 02111-1307, USA.
+ */
+
+/**
+ * SECTION:element-spanplc
+ *
+ * The spanplc (Packet Loss Concealment) element provides a synthetic
+ * fill-in signal, to minimise the audible effect of lost packets in
+ * VoIP applications
+ *
+ */
+
+
+#ifdef HAVE_CONFIG_H
+#include <config.h>
+#endif
+
+#include "gstspanplc.h"
+
+GST_BOILERPLATE (GstSpanPlc, gst_span_plc, GstElement, GST_TYPE_ELEMENT);
+
+GST_DEBUG_CATEGORY_STATIC (gst_span_plc_debug);
+#define GST_CAT_DEFAULT gst_span_plc_debug
+
+
+static GstStaticPadTemplate src_factory = GST_STATIC_PAD_TEMPLATE ("src",
+    GST_PAD_SRC,
+    GST_PAD_ALWAYS,
+    GST_STATIC_CAPS ("audio/x-raw-int, "
+        "endianness = (int) BYTE_ORDER, signed = (bool) TRUE, "
+        "width = (int) 16, depth = (int) 16, "
+        "rate = (int) [ 1, MAX ], channels = (int) 1")
+    );
+
+static GstStaticPadTemplate sink_factory = GST_STATIC_PAD_TEMPLATE ("sink",
+    GST_PAD_SINK,
+    GST_PAD_ALWAYS,
+    GST_STATIC_CAPS ("audio/x-raw-int, "
+        "endianness = (int) BYTE_ORDER, signed = (bool) TRUE, "
+        "width = (int) 16, depth = (int) 16, "
+        "rate = (int) [ 1, MAX ], channels = (int) 1")
+    );
+
+static void gst_span_plc_dispose (GObject * object);
+
+static GstStateChangeReturn gst_span_plc_change_state (GstElement * element,
+    GstStateChange transition);
+static gboolean gst_span_plc_setcaps_sink (GstPad * pad, GstCaps * caps);
+static GstFlowReturn gst_span_plc_chain (GstPad * pad, GstBuffer * buf);
+static gboolean gst_span_plc_event_sink (GstPad * pad, GstEvent * event);
+
+static void
+gst_span_plc_base_init (gpointer gclass)
+{
+  GstElementClass *element_class = (GstElementClass *) gclass;
+
+  gst_element_class_add_pad_template (element_class,
+      gst_static_pad_template_get (&src_factory));
+  gst_element_class_add_pad_template (element_class,
+      gst_static_pad_template_get (&sink_factory));
+
+  gst_element_class_set_details_simple (element_class, "SpanDSP PLC",
+      "Filter/Effect/Audio",
+      "Adds packet loss concealment to audio",
+      "Youness Alaoui <youness.alaoui@collabora.co.uk>");
+}
+
+/* initialize the plugin's class */
+static void
+gst_span_plc_class_init (GstSpanPlcClass * klass)
+{
+  GObjectClass *gobject_class = (GObjectClass *) klass;
+  GstElementClass *gstelement_class = (GstElementClass *) klass;
+
+  gobject_class->dispose = gst_span_plc_dispose;
+
+  gstelement_class->change_state =
+      GST_DEBUG_FUNCPTR (gst_span_plc_change_state);
+
+  GST_DEBUG_CATEGORY_INIT (gst_span_plc_debug, "spandlc",
+      0, "spandlc's packet loss concealment");
+}
+
+static void
+gst_span_plc_init (GstSpanPlc * plc, GstSpanPlcClass * gclass)
+{
+  GST_DEBUG_OBJECT (plc, "init");
+
+  plc->srcpad = gst_pad_new_from_static_template (&src_factory, "src");
+  plc->sinkpad = gst_pad_new_from_static_template (&sink_factory, "sink");
+
+  gst_pad_set_setcaps_function (plc->sinkpad,
+      GST_DEBUG_FUNCPTR (gst_span_plc_setcaps_sink));
+
+  gst_pad_set_getcaps_function (plc->srcpad,
+      GST_DEBUG_FUNCPTR (gst_pad_proxy_getcaps));
+  gst_pad_set_getcaps_function (plc->sinkpad,
+      GST_DEBUG_FUNCPTR (gst_pad_proxy_getcaps));
+
+  gst_pad_set_chain_function (plc->sinkpad,
+      GST_DEBUG_FUNCPTR (gst_span_plc_chain));
+
+  gst_pad_set_event_function (plc->sinkpad,
+      GST_DEBUG_FUNCPTR (gst_span_plc_event_sink));
+
+  gst_element_add_pad (GST_ELEMENT (plc), plc->srcpad);
+  gst_element_add_pad (GST_ELEMENT (plc), plc->sinkpad);
+
+  plc->plc_state = NULL;
+  plc->last_stop = GST_CLOCK_TIME_NONE;
+
+  GST_DEBUG_OBJECT (plc, "init complete");
+}
+
+static void
+gst_span_plc_dispose (GObject * object)
+{
+  GstSpanPlc *plc = GST_SPAN_PLC (object);
+
+  if (plc->plc_state)
+    plc_free (plc->plc_state);
+  plc->plc_state = NULL;
+
+  G_OBJECT_CLASS (parent_class)->dispose (object);
+}
+
+static void
+gst_span_plc_flush (GstSpanPlc * plc, gboolean renew)
+{
+  if (plc->plc_state)
+    plc_free (plc->plc_state);
+  if (renew)
+    plc->plc_state = plc_init (NULL);
+  else
+    plc->plc_state = NULL;
+  plc->last_stop = GST_CLOCK_TIME_NONE;
+}
+
+static GstStateChangeReturn
+gst_span_plc_change_state (GstElement * element, GstStateChange transition)
+{
+  GstSpanPlc *plc = GST_SPAN_PLC (element);
+  GstStateChangeReturn ret;
+
+  switch (transition) {
+    case GST_STATE_CHANGE_NULL_TO_READY:
+      gst_span_plc_flush (plc, TRUE);
+      break;
+    default:
+      break;
+  }
+
+  ret = GST_ELEMENT_CLASS (parent_class)->change_state (element, transition);
+
+  switch (transition) {
+    case GST_STATE_CHANGE_READY_TO_NULL:
+      gst_span_plc_flush (plc, FALSE);
+    default:
+      break;
+  }
+
+  return ret;
+}
+
+static gboolean
+gst_span_plc_setcaps_sink (GstPad * pad, GstCaps * caps)
+{
+  GstSpanPlc *plc = GST_SPAN_PLC (gst_pad_get_parent (pad));
+  GstStructure *s = NULL;
+  gboolean ret = FALSE;
+
+  ret = gst_pad_set_caps (plc->srcpad, caps);
+  s = gst_caps_get_structure (caps, 0);
+  if (s) {
+    gst_structure_get_int (s, "rate", &plc->sample_rate);
+    GST_DEBUG_OBJECT (plc, "setcaps: got sample rate : %d", plc->sample_rate);
+  }
+
+  gst_span_plc_flush (plc, TRUE);
+  gst_object_unref (plc);
+
+  return ret;
+}
+
+static GstFlowReturn
+gst_span_plc_chain (GstPad * pad, GstBuffer * buffer)
+{
+  GstSpanPlc *plc = GST_SPAN_PLC (GST_PAD_PARENT (pad));
+  GstClockTime buffer_duration;
+
+  if (GST_BUFFER_TIMESTAMP_IS_VALID (buffer))
+    plc->last_stop = GST_BUFFER_TIMESTAMP (buffer);
+  else
+    GST_WARNING_OBJECT (plc, "Buffer has no timestamp!");
+
+  if (GST_BUFFER_DURATION_IS_VALID (buffer)) {
+    buffer_duration = GST_BUFFER_DURATION (buffer);
+  } else {
+    GST_WARNING_OBJECT (plc, "Buffer has no duration!");
+    buffer_duration = (GST_BUFFER_SIZE (buffer) /
+        (plc->sample_rate * sizeof (guint16))) * GST_SECOND;
+    GST_DEBUG_OBJECT (plc, "Buffer duration : %" GST_TIME_FORMAT,
+        GST_TIME_ARGS (buffer_duration));
+  }
+
+  plc->last_stop += buffer_duration;
+
+  if (plc->plc_state->missing_samples != 0)
+    buffer = gst_buffer_make_writable (buffer);
+  plc_rx (plc->plc_state, (int16_t *) GST_BUFFER_DATA (buffer),
+      GST_BUFFER_SIZE (buffer) / 2);
+
+  return gst_pad_push (plc->srcpad, buffer);
+}
+
+static void
+gst_span_plc_send_fillin (GstSpanPlc * plc, GstClockTime duration)
+{
+  guint buf_size;
+  GstBuffer *buffer = NULL;
+
+  buf_size = ((float) duration / GST_SECOND) * plc->sample_rate;
+  buf_size *= sizeof (guint16);
+  buffer = gst_buffer_new_and_alloc (buf_size);
+  GST_DEBUG_OBJECT (plc, "Missing packet of %" GST_TIME_FORMAT
+      " == %d bytes", GST_TIME_ARGS (duration), buf_size);
+  plc_fillin (plc->plc_state, (int16_t *) GST_BUFFER_DATA (buffer),
+      GST_BUFFER_SIZE (buffer) / 2);
+  GST_BUFFER_TIMESTAMP (buffer) = plc->last_stop;
+  GST_BUFFER_DURATION (buffer) = duration;
+  gst_buffer_set_caps (buffer, GST_PAD_CAPS (plc->srcpad));
+  gst_pad_push (plc->srcpad, buffer);
+}
+
+static gboolean
+gst_span_plc_event_sink (GstPad * pad, GstEvent * event)
+{
+  gboolean ret = FALSE;
+  GstSpanPlc *plc = GST_SPAN_PLC (gst_pad_get_parent (pad));
+
+  GST_DEBUG_OBJECT (plc, "received event %s", GST_EVENT_TYPE_NAME (event));
+
+  switch (GST_EVENT_TYPE (event)) {
+    case GST_EVENT_NEWSEGMENT:
+    {
+      GstFormat format;
+      gdouble rate;
+      gint64 start, stop, time;
+      gboolean update;
+
+      gst_event_parse_new_segment (event, &update, &rate, &format, &start,
+          &stop, &time);
+
+      if (format != GST_FORMAT_TIME)
+        goto newseg_wrong_format;
+
+      if (update) {
+        /* time progressed without data, see if we can fill the gap with
+         * some concealment data */
+        if (plc->last_stop < start)
+          gst_span_plc_send_fillin (plc, start - plc->last_stop);
+      }
+      plc->last_stop = start;
+      break;
+    }
+    case GST_EVENT_FLUSH_START:
+      gst_span_plc_flush (plc, TRUE);
+      break;
+    default:
+      break;
+  }
+  ret = gst_pad_push_event (plc->srcpad, event);
+
+  gst_object_unref (plc);
+
+  return ret;
+newseg_wrong_format:
+  {
+    GST_DEBUG_OBJECT (plc, "received non TIME newsegment");
+    gst_object_unref (plc);
+    return FALSE;
+  }
+}