/* * (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., 51 Franklin St, Fifth Floor, * Boston, MA 02110-1301, 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" #include <gst/audio/audio.h> G_DEFINE_TYPE (GstSpanPlc, gst_span_plc, 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, format=\"" GST_AUDIO_NE (S16) "\", " "rate = " GST_AUDIO_RATE_RANGE " , channels = (int) 1") ); static GstStaticPadTemplate sink_factory = GST_STATIC_PAD_TEMPLATE ("sink", GST_PAD_SINK, GST_PAD_ALWAYS, GST_STATIC_CAPS ("audio/x-raw, format=\"" GST_AUDIO_NE (S16) "\", " "rate = " GST_AUDIO_RATE_RANGE " , channels = (int) 1") ); static void gst_span_plc_dispose (GObject * object); static GstStateChangeReturn gst_span_plc_change_state (GstElement * element, GstStateChange transition); static void gst_span_plc_setcaps_sink (GstSpanPlc * plc, GstCaps * caps); static GstFlowReturn gst_span_plc_chain (GstPad * pad, GstObject * parent, GstBuffer * buf); static gboolean gst_span_plc_event_sink (GstPad * pad, GstObject * parent, GstEvent * event); /* initialize the plugin's class */ static void gst_span_plc_class_init (GstSpanPlcClass * klass) { GObjectClass *gobject_class = (GObjectClass *) klass; GstElementClass *gstelement_class = (GstElementClass *) klass; gst_element_class_add_pad_template (gstelement_class, gst_static_pad_template_get (&src_factory)); gst_element_class_add_pad_template (gstelement_class, gst_static_pad_template_get (&sink_factory)); gst_element_class_set_static_metadata (gstelement_class, "SpanDSP PLC", "Filter/Effect/Audio", "Adds packet loss concealment to audio", "Youness Alaoui <youness.alaoui@collabora.co.uk>"); 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, "spanplc", 0, "spanDSP's packet loss concealment"); } static void gst_span_plc_init (GstSpanPlc * plc) { 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_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; 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 (gst_span_plc_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; } 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 (gst_span_plc_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 void gst_span_plc_setcaps_sink (GstSpanPlc * plc, GstCaps * caps) { GstStructure *s = NULL; gint sample_rate; s = gst_caps_get_structure (caps, 0); if (!s) return; gst_structure_get_int (s, "rate", &sample_rate); if (sample_rate != plc->sample_rate) { GST_DEBUG_OBJECT (plc, "setcaps: got sample rate : %d", sample_rate); plc->sample_rate = sample_rate; gst_span_plc_flush (plc, TRUE); } } static GstFlowReturn gst_span_plc_chain (GstPad * pad, GstObject * parent, GstBuffer * buffer) { GstSpanPlc *plc = GST_SPAN_PLC (parent); GstMapInfo map; buffer = gst_buffer_make_writable (buffer); gst_buffer_map (buffer, &map, GST_MAP_READWRITE); plc_rx (plc->plc_state, (int16_t *) map.data, map.size / 2); gst_buffer_unmap (buffer, &map); return gst_pad_push (plc->srcpad, buffer); } static void gst_span_plc_send_fillin (GstSpanPlc * plc, GstClockTime timestamp, GstClockTime duration) { guint buf_size; GstBuffer *buffer = NULL; GstMapInfo map; 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); gst_buffer_map (buffer, &map, GST_MAP_READWRITE); plc_fillin (plc->plc_state, (int16_t *) map.data, map.size / 2); gst_buffer_unmap (buffer, &map); GST_BUFFER_PTS (buffer) = timestamp; GST_BUFFER_DURATION (buffer) = duration; gst_pad_push (plc->srcpad, buffer); } static gboolean gst_span_plc_event_sink (GstPad * pad, GstObject * parent, GstEvent * event) { GstSpanPlc *plc = GST_SPAN_PLC (parent); GST_DEBUG_OBJECT (plc, "received event %s", GST_EVENT_TYPE_NAME (event)); switch (GST_EVENT_TYPE (event)) { case GST_EVENT_CAPS: { GstCaps *caps; gst_event_parse_caps (event, &caps); gst_span_plc_setcaps_sink (plc, caps); break; } case GST_EVENT_GAP: { GstClockTime timestamp; GstClockTime duration; gst_event_parse_gap (event, ×tamp, &duration); gst_span_plc_send_fillin (plc, timestamp, duration); gst_event_unref (event); return TRUE; } case GST_EVENT_FLUSH_STOP: gst_span_plc_flush (plc, TRUE); break; default: break; } return gst_pad_push_event (plc->srcpad, event); }