rtpopuspay: make depay ! pay work

There is a use-case for a server to re-payload opus going through it.

Problem was that the payloader requires channels in the caps, but
this is not something the depayloader can parse out of the stream, meaning
caps-negotiation would fail.

Removing the requirement of channels in the template-caps fixes this.

gst/rtp/gstrtpopuspay.c

@@ -39,8 +39,7 @@ static GstStaticPadTemplate gst_rtp_opus_pay_sink_template =
 GST_STATIC_PAD_TEMPLATE ("sink",
     GST_PAD_SINK,
     GST_PAD_ALWAYS,
-    GST_STATIC_CAPS
-    ("audio/x-opus, channels = (int) [1, 2], channel-mapping-family = (int) 0")
+    GST_STATIC_CAPS ("audio/x-opus, channel-mapping-family = (int) 0")
     );
 
 static GstStaticPadTemplate gst_rtp_opus_pay_src_template =

tests/check/elements/rtpopus.c

@@ -0,0 +1,92 @@
+/* GStreamer
+ *
+ * Copyright (C) 2020 Pexip AS
+ *   @author Havard Graff <havard@pexip.com>
+ *
+ * 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.
+ */
+#include <gst/check/check.h>
+#include <gst/check/gstharness.h>
+#include <gst/rtp/gstrtpbuffer.h>
+
+#define buffer_from_array(a) gst_buffer_new_wrapped (g_memdup (a, G_N_ELEMENTS (a)), G_N_ELEMENTS (a));
+
+static guint8 opus_data[] = {
+  0xf8, 0xb5, 0x0e, 0x7d, 0x91, 0xcc, 0x05, 0x82,
+  0x75, 0x72, 0x48, 0xbd, 0xd3, 0x22, 0x24, 0x2e,
+  0x59, 0x63, 0xf8, 0xff, 0x5d, 0x59, 0x27, 0xd8,
+  0xad, 0x4b, 0xe8, 0xd7, 0xfa, 0x99, 0xaa, 0x46,
+  0xb4, 0xf6, 0x29, 0x16, 0x21, 0x86, 0x2a, 0xb5,
+  0x83, 0x7d, 0x3a, 0xce, 0xb3, 0xee, 0x37, 0x3b,
+  0xf7, 0xb5, 0x03, 0xe7, 0x13, 0x3b, 0xf6, 0x90,
+  0x06, 0xea, 0x79, 0xbe, 0x89, 0xc3, 0x2b, 0x1f,
+  0x7f, 0x88, 0x5e, 0xe0, 0xe1, 0x88, 0x59, 0x47,
+  0x11, 0x10, 0x94, 0xab, 0x5d, 0xa6, 0x3f, 0x5d,
+  0xa7, 0xd7, 0x0e, 0x7d, 0x07, 0x85, 0x0d, 0x2f,
+  0x7b, 0x3f, 0xf7, 0xc1, 0x8c, 0xb2, 0xda, 0xac,
+  0x79, 0x15, 0xda, 0xc7, 0xd2, 0x6e, 0xcc, 0x88,
+  0x61, 0x29, 0xcd, 0x78, 0xf4, 0x6d, 0x1b, 0xa6,
+  0xe6, 0xd1, 0x7c, 0x76, 0xc2, 0x86, 0x78, 0x3c,
+  0xc2, 0x2e, 0x26, 0xd4, 0xdf, 0x7f, 0x3b, 0x98,
+  0x7a, 0x7c, 0xbe, 0x1a, 0x17, 0xd2, 0x2d, 0xa5,
+  0x90, 0x2a, 0x1b, 0x0b, 0x43, 0x65, 0x63, 0x37,
+  0xe5, 0x0d, 0x5c, 0x9c, 0x6c, 0x38, 0xef, 0x2a,
+  0xe8, 0x49, 0x47, 0x05, 0x6d, 0x83, 0xcf, 0x6d,
+};
+
+GST_START_TEST (test_pay_to_depay)
+{
+  GstHarness *h = gst_harness_new_parse ("rtpopuspay ! rtpopusdepay");
+  GstBuffer *buf = buffer_from_array (opus_data);
+  gst_harness_set_src_caps_str (h, "audio/x-opus,channel-mapping-family=0");
+  fail_unless_equals_int (GST_FLOW_OK, gst_harness_push (h, buf));
+  gst_buffer_unref (gst_harness_pull (h));
+
+  gst_harness_teardown (h);
+}
+
+GST_END_TEST
+GST_START_TEST (test_depay_to_pay)
+{
+  GstHarness *h = gst_harness_new_parse ("rtpopusdepay ! rtpopuspay");
+  guint8 opus_rtp_buf[] = {
+    0x80, 0x60, 0x54, 0xfd, 0x3b, 0x5a, 0x93, 0xf9, 0x1c, 0x33, 0x2b, 0xbb,
+  };
+  GstBuffer *buf = buffer_from_array (opus_rtp_buf);
+  gst_harness_set_src_caps_str (h,
+      "application/x-rtp,encoding-name=OPUS,media=audio,clock-rate=48000,payload=96");
+  fail_unless_equals_int (GST_FLOW_OK, gst_harness_push (h, buf));
+  gst_buffer_unref (gst_harness_pull (h));
+
+  gst_harness_teardown (h);
+}
+
+GST_END_TEST;
+
+static Suite *
+rtpopus_suite (void)
+{
+  Suite *s = suite_create ("rtpopus");
+  TCase *tc_chain;
+
+  suite_add_tcase (s, (tc_chain = tcase_create ("rtpopus")));
+  tcase_add_test (tc_chain, test_pay_to_depay);
+  tcase_add_test (tc_chain, test_depay_to_pay);
+
+  return s;
+}
+
+GST_CHECK_MAIN (rtpopus);

tests/check/meson.build

@@ -64,6 +64,7 @@ good_tests = [
   [ 'elements/rtph263' ],
   [ 'elements/rtph264' ],
   [ 'elements/rtph265' ],
+  [ 'elements/rtpopus' ],
   [ 'elements/rtpvp9' ],
   [ 'elements/rtpbin' ],
   [ 'elements/rtpbin_buffer_list' ],