gstreamer/ext/avtp/gstavtpbasedepayload.c
Andre Guedes 6477884a56 avtp: Introduce AAF depayloader element
This patch introduces the AAF depayloader element, the counterpart from
the AAF payloader. As expected, this element inputs AVTPDUs and outputs
audio raw data and supports AAF PCM encapsulation only.

The AAF depayloader srcpad produces a fixed format that is encoded
within the AVTPDU. Once the first AVTPDU is received by the element, the
audio features e.g. sample format, rate, number of channels, are decoded
and the srcpad caps are set accordingly. Also, at this point, the
element pushes a SEGMENT event downstream defining the segment according
to the AVTP presentation time.

All AVTP depayloaders will share some common code. For that reason, this
patch introduces the GstAvtpBaseDepayload abstract class that implements
common depayloader functionalities. AAF-specific functionalities are
implemented in the derived class GstAvtpAafDepay.
2019-07-03 09:59:35 -07:00

260 lines
8.3 KiB
C

/*
* GStreamer AVTP Plugin
* Copyright (C) 2019 Intel Corporation
*
* This library is free software; you can redistribute it and/or
* modify it under the terms of the GNU Lesser General Public
* License as published by the Free Software Foundation; either
* version 2.1 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
* Lesser General Public License for more details.
*
* You should have received a copy of the GNU Lesser General Public
* License along with this library; if not, write to the
* Free Software Foundation, Inc., 51 Franklin Street, Fifth Floor,
* Boston, MA 02110-1301 USA
*/
#include "gstavtpbasedepayload.h"
GST_DEBUG_CATEGORY_STATIC (avtpbasedepayload_debug);
#define GST_CAT_DEFAULT (avtpbasedepayload_debug)
#define DEFAULT_STREAMID 0xAABBCCDDEEFF0000
enum
{
PROP_0,
PROP_STREAMID,
};
static GstStaticPadTemplate sink_template = GST_STATIC_PAD_TEMPLATE ("sink",
GST_PAD_SINK,
GST_PAD_ALWAYS,
GST_STATIC_CAPS ("application/x-avtp")
);
static void gst_avtp_base_depayload_class_init (GstAvtpBaseDepayloadClass *
klass);
static void gst_avtp_base_depayload_init (GstAvtpBaseDepayload *
avtpbasedepayload, gpointer g_class);
static void gst_avtp_base_depayload_set_property (GObject * object,
guint prop_id, const GValue * value, GParamSpec * pspec);
static void gst_avtp_base_depayload_get_property (GObject * object,
guint prop_id, GValue * value, GParamSpec * pspec);
static gboolean gst_avtp_base_depayload_sink_event (GstPad * pad,
GstObject * parent, GstEvent * event);
GType
gst_avtp_base_depayload_get_type (void)
{
static GType avtpbasedepayload_type = 0;
if (g_once_init_enter ((gsize *) & avtpbasedepayload_type)) {
static const GTypeInfo avtpbasedepayload_info = {
sizeof (GstAvtpBaseDepayloadClass),
NULL,
NULL,
(GClassInitFunc) gst_avtp_base_depayload_class_init,
NULL,
NULL,
sizeof (GstAvtpBaseDepayload),
0,
(GInstanceInitFunc) gst_avtp_base_depayload_init,
};
GType _type;
_type = g_type_register_static (GST_TYPE_ELEMENT, "GstAvtpBaseDepayload",
&avtpbasedepayload_info, G_TYPE_FLAG_ABSTRACT);
g_once_init_leave ((gsize *) & avtpbasedepayload_type, _type);
}
return avtpbasedepayload_type;
}
static void
gst_avtp_base_depayload_class_init (GstAvtpBaseDepayloadClass * klass)
{
GObjectClass *object_class = G_OBJECT_CLASS (klass);
object_class->set_property = gst_avtp_base_depayload_set_property;
object_class->get_property = gst_avtp_base_depayload_get_property;
g_object_class_install_property (object_class, PROP_STREAMID,
g_param_spec_uint64 ("streamid", "Stream ID",
"Stream ID associated with the AVTPDU", 0, G_MAXUINT64,
DEFAULT_STREAMID, G_PARAM_READWRITE | G_PARAM_STATIC_STRINGS |
GST_PARAM_MUTABLE_PAUSED));
klass->chain = NULL;
klass->sink_event = GST_DEBUG_FUNCPTR (gst_avtp_base_depayload_sink_event);
GST_DEBUG_CATEGORY_INIT (avtpbasedepayload_debug, "avtpbasedepayload", 0,
"Base class for AVTP depayloaders");
}
static void
gst_avtp_base_depayload_init (GstAvtpBaseDepayload * avtpbasedepayload,
gpointer g_class)
{
GstPadTemplate *templ;
GstElement *element = GST_ELEMENT (avtpbasedepayload);
GstElementClass *element_class = GST_ELEMENT_CLASS (g_class);
GstAvtpBaseDepayloadClass *avtpbasedepayload_class =
GST_AVTP_BASE_DEPAYLOAD_CLASS (g_class);
g_assert (avtpbasedepayload_class->chain != NULL);
templ = gst_element_class_get_pad_template (element_class, "src");
g_assert (templ != NULL);
avtpbasedepayload->srcpad = gst_pad_new_from_template (templ, "src");
gst_pad_use_fixed_caps (avtpbasedepayload->srcpad);
gst_element_add_pad (element, avtpbasedepayload->srcpad);
avtpbasedepayload->sinkpad =
gst_pad_new_from_static_template (&sink_template, "sink");
gst_pad_set_chain_function (avtpbasedepayload->sinkpad,
avtpbasedepayload_class->chain);
gst_pad_set_event_function (avtpbasedepayload->sinkpad,
avtpbasedepayload_class->sink_event);
gst_element_add_pad (element, avtpbasedepayload->sinkpad);
avtpbasedepayload->streamid = DEFAULT_STREAMID;
avtpbasedepayload->prev_ptime = 0;
avtpbasedepayload->seqnum = 0;
}
static void
gst_avtp_base_depayload_set_property (GObject * object, guint prop_id,
const GValue * value, GParamSpec * pspec)
{
GstAvtpBaseDepayload *avtpbasedepayload = GST_AVTP_BASE_DEPAYLOAD (object);
GST_DEBUG_OBJECT (avtpbasedepayload, "prop_id %u", prop_id);
switch (prop_id) {
case PROP_STREAMID:
avtpbasedepayload->streamid = g_value_get_uint64 (value);
break;
default:
G_OBJECT_WARN_INVALID_PROPERTY_ID (object, prop_id, pspec);
break;
}
}
static void
gst_avtp_base_depayload_get_property (GObject * object, guint prop_id,
GValue * value, GParamSpec * pspec)
{
GstAvtpBaseDepayload *avtpbasedepayload = GST_AVTP_BASE_DEPAYLOAD (object);
GST_DEBUG_OBJECT (avtpbasedepayload, "prop_id %u", prop_id);
switch (prop_id) {
case PROP_STREAMID:
g_value_set_uint64 (value, avtpbasedepayload->streamid);
break;
default:
G_OBJECT_WARN_INVALID_PROPERTY_ID (object, prop_id, pspec);
break;
}
}
static gboolean
gst_avtp_base_depayload_sink_event (GstPad * pad, GstObject * parent,
GstEvent * event)
{
GstAvtpBaseDepayload *avtpbasedepayload = GST_AVTP_BASE_DEPAYLOAD (parent);
GST_DEBUG_OBJECT (avtpbasedepayload, "event %s", GST_EVENT_TYPE_NAME (event));
switch (GST_EVENT_TYPE (event)) {
case GST_EVENT_SEGMENT:
/* Once the first AVTPDU is received, proper CAPS and SEGMENT events are
* pushed downstream. These events are expected to be pushed in that
* order by GStreamer. Since the default handling implemented by
* gst_pad_event_default() pushes the SEGMENT event downstream right
* away, it doesn't work for us and we have to handle it ourselves.
*
* Our handling is very straightforward: we discard this event and send
* a proper segment event once the first AVTPDU is received. See
* gst_avtp_base_depayload_push_segment_event() for more information.
*/
gst_event_unref (event);
return TRUE;
default:
return gst_pad_event_default (pad, parent, event);
}
}
/* Helper function to convert AVTP timestamp to AVTP presentation time. Since
* AVTP timestamp represents the lower 32-bit part from AVTP presentation time,
* the helper requires a reference time ('ref' argument) to convert it properly.
* The reference time must be in gstreamer clock-time coordinate.
*/
GstClockTime
gst_avtp_base_depayload_tstamp_to_ptime (GstAvtpBaseDepayload *
avtpbasedepayload, guint32 tstamp, GstClockTime ref)
{
GstClockTime ptime;
ptime = (ref & 0xFFFFFFFF00000000ULL) | tstamp;
/* If 'ptime' is less than the our reference time, it means the higher part
* from 'ptime' needs to be incremented by 1 in order reflect the correct
* presentation time.
*/
if (ptime < ref)
ptime += (1ULL << 32);
GST_LOG_OBJECT (avtpbasedepayload, "AVTP presentation time %" GST_TIME_FORMAT,
GST_TIME_ARGS (ptime));
return ptime;
}
gboolean
gst_avtp_base_depayload_push_segment_event (GstAvtpBaseDepayload *
avtpbasedepayload, guint32 avtp_tstamp)
{
GstClock *clock;
GstEvent *event;
GstSegment segment;
GstClockTime now, base_time, avtp_ptime;
clock = GST_ELEMENT_CLOCK (avtpbasedepayload);
now = gst_clock_get_time (clock);
avtp_ptime =
gst_avtp_base_depayload_tstamp_to_ptime (avtpbasedepayload, avtp_tstamp,
now);
base_time = gst_element_get_base_time (GST_ELEMENT (avtpbasedepayload));
gst_segment_init (&segment, GST_FORMAT_TIME);
segment.base = avtp_ptime - base_time;
segment.start = avtp_ptime;
segment.stop = -1;
event = gst_event_new_segment (&segment);
if (!event) {
GST_ERROR_OBJECT (avtpbasedepayload, "Failed to create SEGMENT event");
return FALSE;
}
if (!gst_pad_push_event (avtpbasedepayload->srcpad, event)) {
GST_ERROR_OBJECT (avtpbasedepayload, "Failed to push SEGMENT event");
return FALSE;
}
GST_DEBUG_OBJECT (avtpbasedepayload, "SEGMENT event pushed: %"
GST_SEGMENT_FORMAT, &segment);
avtpbasedepayload->prev_ptime = avtp_ptime;
return TRUE;
}