gstreamer/ext/spandsp/gstspanplc.c

254 lines
7 KiB
C

/*
* (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"
#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_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;
if (plc->plc_state->missing_samples != 0)
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, &timestamp, &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);
}