rtp: add rtpisacdepay

Depayload for the iSAC audio codec.

Part-of: <https://gitlab.freedesktop.org/gstreamer/gst-plugins-good/-/merge_requests/530>

gst/rtp/gstrtp.c

@@ -70,6 +70,7 @@
 #include "gstrtph264pay.h"
 #include "gstrtph265depay.h"
 #include "gstrtph265pay.h"
+#include "gstrtpisacdepay.h"
 #include "gstrtpisacpay.h"
 #include "gstrtpj2kdepay.h"
 #include "gstrtpj2kpay.h"
@@ -397,6 +398,9 @@ plugin_init (GstPlugin * plugin)
   if (!gst_rtp_isac_pay_plugin_init (plugin))
     return FALSE;
 
+  if (!gst_rtp_isac_depay_plugin_init (plugin))
+    return FALSE;
+
   if (!gst_element_register (plugin, "rtpredenc", GST_RANK_NONE,
           GST_TYPE_RTP_RED_ENC))
     return FALSE;

gst/rtp/gstrtpisacdepay.c

@@ -0,0 +1,151 @@
+/* GStreamer
+ * Copyright (C) 2020 Collabora Ltd.
+ *  Author: Guillaume Desmottes <guillaume.desmottes@collabora.com>, Collabora Ltd.
+ *
+ * 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-isacdepay
+ * @title: isacdepay
+ * @short_description: iSAC RTP Depayloader
+ *
+ * Since: 1.20
+ *
+ */
+
+#ifdef HAVE_CONFIG_H
+#  include "config.h"
+#endif
+
+#include <stdlib.h>
+#include <string.h>
+#include <gst/rtp/gstrtpbuffer.h>
+#include <gst/audio/audio.h>
+
+#include "gstrtpisacdepay.h"
+#include "gstrtputils.h"
+
+GST_DEBUG_CATEGORY_STATIC (rtpisacdepay_debug);
+#define GST_CAT_DEFAULT (rtpisacdepay_debug)
+
+static GstStaticPadTemplate gst_rtp_isac_depay_sink_template =
+GST_STATIC_PAD_TEMPLATE ("sink",
+    GST_PAD_SINK,
+    GST_PAD_ALWAYS,
+    GST_STATIC_CAPS ("application/x-rtp, "
+        "media = (string) \"audio\", "
+        "payload = (int) " GST_RTP_PAYLOAD_DYNAMIC_STRING ", "
+        "clock-rate =  (int) { 16000, 32000 }, "
+        "encoding-name = (string) \"ISAC\"")
+    );
+
+static GstStaticPadTemplate gst_rtp_isac_depay_src_template =
+GST_STATIC_PAD_TEMPLATE ("src",
+    GST_PAD_SRC,
+    GST_PAD_ALWAYS,
+    GST_STATIC_CAPS ("audio/isac, "
+        "rate = (int) { 16000, 32000 }, " "channels = (int) 1")
+    );
+
+struct _GstRtpIsacDepay
+{
+  /*< private > */
+  GstRTPBaseDepayload parent;
+
+  guint64 packet;
+};
+
+#define gst_rtp_isac_depay_parent_class parent_class
+G_DEFINE_TYPE (GstRtpIsacDepay, gst_rtp_isac_depay,
+    GST_TYPE_RTP_BASE_DEPAYLOAD);
+
+static gboolean
+gst_rtp_isac_depay_setcaps (GstRTPBaseDepayload * depayload, GstCaps * caps)
+{
+  GstCaps *src_caps;
+  GstStructure *s;
+  gint rate;
+  gboolean ret;
+
+  GST_DEBUG_OBJECT (depayload, "sink caps: %" GST_PTR_FORMAT, caps);
+
+  s = gst_caps_get_structure (caps, 0);
+  if (!gst_structure_get_int (s, "clock-rate", &rate)) {
+    GST_ERROR_OBJECT (depayload, "Missing 'clock-rate' in caps");
+    return FALSE;
+  }
+
+  src_caps = gst_caps_new_simple ("audio/isac",
+      "channels", G_TYPE_INT, 1, "rate", G_TYPE_INT, rate, NULL);
+
+  ret = gst_pad_set_caps (GST_RTP_BASE_DEPAYLOAD_SRCPAD (depayload), src_caps);
+
+  GST_DEBUG_OBJECT (depayload,
+      "set caps on source: %" GST_PTR_FORMAT " (ret=%d)", src_caps, ret);
+  gst_caps_unref (src_caps);
+
+  return ret;
+}
+
+static GstBuffer *
+gst_rtp_isac_depay_process (GstRTPBaseDepayload * depayload,
+    GstRTPBuffer * rtp_buffer)
+{
+  GstBuffer *outbuf;
+
+  outbuf = gst_rtp_buffer_get_payload_buffer (rtp_buffer);
+
+  gst_rtp_drop_non_audio_meta (depayload, outbuf);
+
+  return outbuf;
+}
+
+static void
+gst_rtp_isac_depay_class_init (GstRtpIsacDepayClass * klass)
+{
+  GstElementClass *gstelement_class = (GstElementClass *) klass;
+  GstRTPBaseDepayloadClass *depayload_class =
+      (GstRTPBaseDepayloadClass *) klass;
+
+  depayload_class->set_caps = gst_rtp_isac_depay_setcaps;
+  depayload_class->process_rtp_packet = gst_rtp_isac_depay_process;
+
+  gst_element_class_add_static_pad_template (gstelement_class,
+      &gst_rtp_isac_depay_sink_template);
+  gst_element_class_add_static_pad_template (gstelement_class,
+      &gst_rtp_isac_depay_src_template);
+
+  gst_element_class_set_static_metadata (gstelement_class,
+      "RTP iSAC depayloader", "Codec/Depayloader/Network/RTP",
+      "Extracts iSAC audio from RTP packets",
+      "Guillaume Desmottes <guillaume.desmottes@collabora.com>");
+
+  GST_DEBUG_CATEGORY_INIT (rtpisacdepay_debug, "rtpisacdepay", 0,
+      "iSAC RTP Depayloader");
+}
+
+static void
+gst_rtp_isac_depay_init (GstRtpIsacDepay * rtpisacdepay)
+{
+}
+
+gboolean
+gst_rtp_isac_depay_plugin_init (GstPlugin * plugin)
+{
+  return gst_element_register (plugin, "rtpisacdepay",
+      GST_RANK_SECONDARY, GST_TYPE_RTP_ISAC_DEPAY);
+}

gst/rtp/gstrtpisacdepay.h

@@ -0,0 +1,33 @@
+/* GStreamer
+ * Copyright (C) 2020 Collabora Ltd.
+ *  Author: Guillaume Desmottes <guillaume.desmottes@collabora.com>, Collabora Ltd.
+ *
+ * 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
+ */
+
+
+#ifndef __GST_RTP_ISAC_DEPAY_H__
+#define __GST_RTP_ISAC_DEPAY_H__
+
+#include <gst/gst.h>
+#include <gst/rtp/gstrtpbasedepayload.h>
+
+G_BEGIN_DECLS
+
+#define GST_TYPE_RTP_ISAC_DEPAY gst_rtp_isac_depay_get_type ()
+
+G_DECLARE_FINAL_TYPE (GstRtpIsacDepay, gst_rtp_isac_depay, GST, RTP_ISAC_DEPAY,
+    GstRTPBaseDepayload);
+
+gboolean gst_rtp_isac_depay_plugin_init (GstPlugin * plugin);
+
+G_END_DECLS
+#endif /* __GST_RTP_ISAC_DEPAY_H__ */

gst/rtp/meson.build

@@ -102,6 +102,7 @@ rtp_sources = [
   'rtpstorage.c',
   'rtpstoragestream.c',
   'gstrtpstorage.c',
+  'gstrtpisacdepay.c',
   'gstrtpisacpay.c',
 ]