rtpbuffer: Initialize extended timestamp to the first wraparound period

This allows correct handling of wrapping around backwards during the
first wraparound period and avoids the infamous "Cannot unwrap, any
wrapping took place yet" error message.

It allows makes sure that for actual timestamp jumps a valid value is
returned instead of 0, which then allows the caller to handle it
properly. Not having this can have the caller see the same timestamp (0)
for a very long time, which for example can cause rtpjitterbuffer to
output the same timestamp for a very long time.

Fixes https://gitlab.freedesktop.org/gstreamer/gstreamer/-/issues/1500

Part-of: <https://gitlab.freedesktop.org/gstreamer/gstreamer/-/merge_requests/3202>

diff --git a/subprojects/gst-plugins-base/gst-libs/gst/rtp/gstrtpbuffer.c b/subprojects/gst-plugins-base/gst-libs/gst/rtp/gstrtpbuffer.c
index d83bbd2..228abf4 100644 (file)
--- a/subprojects/gst-plugins-base/gst-libs/gst/rtp/gstrtpbuffer.c
+++ b/subprojects/gst-plugins-base/gst-libs/gst/rtp/gstrtpbuffer.c
@@ -1326,7 +1326,7 @@ gst_rtp_buffer_ext_timestamp (guint64 * exttimestamp, guint32 timestamp)
   ext = *exttimestamp;
 
   if (ext == -1) {
-    result = timestamp;
+    result = (G_GUINT64_CONSTANT (1) << 32) + timestamp;
   } else {
     /* pick wraparound counter from previous timestamp and add to new timestamp */
     result = timestamp + (ext & ~(G_GUINT64_CONSTANT (0xffffffff)));

diff --git a/subprojects/gst-plugins-base/tests/check/libs/rtp.c b/subprojects/gst-plugins-base/tests/check/libs/rtp.c
index ca56a72..7a5a7b6 100644 (file)
--- a/subprojects/gst-plugins-base/tests/check/libs/rtp.c
+++ b/subprojects/gst-plugins-base/tests/check/libs/rtp.c
@@ -1995,21 +1995,22 @@ GST_START_TEST (test_ext_timestamp_basic)
 
   /* no wraparound when timestamps are increasing */
   result = gst_rtp_buffer_ext_timestamp (&exttimestamp, 0);
-  fail_unless_equals_uint64 (result, 0);
+  fail_unless_equals_uint64 (result, (G_GUINT64_CONSTANT (1) << 32) + 0);
   result = gst_rtp_buffer_ext_timestamp (&exttimestamp, 10);
-  fail_unless_equals_uint64 (result, 10);
+  fail_unless_equals_uint64 (result, (G_GUINT64_CONSTANT (1) << 32) + 10);
   result = gst_rtp_buffer_ext_timestamp (&exttimestamp, 10);
-  fail_unless_equals_uint64 (result, 10);
+  fail_unless_equals_uint64 (result, (G_GUINT64_CONSTANT (1) << 32) + 10);
   result = gst_rtp_buffer_ext_timestamp (&exttimestamp,
       G_GUINT64_CONSTANT (1) + G_MAXINT32);
-  fail_unless_equals_uint64 (result, G_GUINT64_CONSTANT (1) + G_MAXINT32);
+  fail_unless_equals_uint64 (result,
+      (G_GUINT64_CONSTANT (1) << 32) + G_GUINT64_CONSTANT (1) + G_MAXINT32);
 
   /* Even big bumps under G_MAXINT32 don't result in wrap-around */
   exttimestamp = -1;
   result = gst_rtp_buffer_ext_timestamp (&exttimestamp, 1087500);
-  fail_unless_equals_uint64 (result, 1087500);
+  fail_unless_equals_uint64 (result, (G_GUINT64_CONSTANT (1) << 32) + 1087500);
   result = gst_rtp_buffer_ext_timestamp (&exttimestamp, 24);
-  fail_unless_equals_uint64 (result, 24);
+  fail_unless_equals_uint64 (result, (G_GUINT64_CONSTANT (1) << 32) + 24);
 }
 
 GST_END_TEST;
@@ -2020,13 +2021,15 @@ GST_START_TEST (test_ext_timestamp_wraparound)
 
   fail_unless_equals_uint64 (gst_rtp_buffer_ext_timestamp (&ext_ts,
           G_MAXUINT32 - 90000 + G_GUINT64_CONSTANT (1)),
-      (G_MAXUINT32 - 90000 + G_GUINT64_CONSTANT (1)));
+      ((G_GUINT64_CONSTANT (1) << 32) + G_MAXUINT32 - 90000 +
+          G_GUINT64_CONSTANT (1)));
 
   fail_unless_equals_uint64 (gst_rtp_buffer_ext_timestamp (&ext_ts, 0),
-      G_MAXUINT32 + G_GUINT64_CONSTANT (1));
+      (G_GUINT64_CONSTANT (1) << 32) + G_MAXUINT32 + G_GUINT64_CONSTANT (1));
 
   fail_unless_equals_uint64 (gst_rtp_buffer_ext_timestamp (&ext_ts, 90000),
-      (G_MAXUINT32 + G_GUINT64_CONSTANT (1) + 90000));
+      ((G_GUINT64_CONSTANT (1) << 32) + G_MAXUINT32 + G_GUINT64_CONSTANT (1) +
+          90000));
 }
 
 GST_END_TEST;
@@ -2036,37 +2039,41 @@ GST_START_TEST (test_ext_timestamp_wraparound_disordered)
 {
   guint64 ext_ts = -1;
 
-  fail_unless (gst_rtp_buffer_ext_timestamp (&ext_ts,
-          G_MAXUINT32 - 90000 + G_GUINT64_CONSTANT (1))
-      == (G_MAXUINT32 - 90000 + G_GUINT64_CONSTANT (1)));
+  fail_unless_equals_uint64 (gst_rtp_buffer_ext_timestamp (&ext_ts,
+          G_MAXUINT32 - 90000 + G_GUINT64_CONSTANT (1)),
+      (G_GUINT64_CONSTANT (1) << 32) + G_MAXUINT32 - 90000 +
+      G_GUINT64_CONSTANT (1));
 
-  fail_unless (gst_rtp_buffer_ext_timestamp (&ext_ts, 0)
-      == G_MAXUINT32 + G_GUINT64_CONSTANT (1));
+  fail_unless_equals_uint64 (gst_rtp_buffer_ext_timestamp (&ext_ts, 0),
+      (G_GUINT64_CONSTANT (1) << 32) + G_MAXUINT32 + G_GUINT64_CONSTANT (1));
 
   /* Unwrapping around */
-  fail_unless (gst_rtp_buffer_ext_timestamp (&ext_ts,
-          G_MAXUINT32 - 90000 + G_GUINT64_CONSTANT (1))
-      == (G_MAXUINT32 - 90000 + G_GUINT64_CONSTANT (1)));
+  fail_unless_equals_uint64 (gst_rtp_buffer_ext_timestamp (&ext_ts,
+          G_MAXUINT32 - 90000 + G_GUINT64_CONSTANT (1)),
+      (G_GUINT64_CONSTANT (1) << 32) + G_MAXUINT32 - 90000 +
+      G_GUINT64_CONSTANT (1));
 
-  fail_unless (gst_rtp_buffer_ext_timestamp (&ext_ts, 90000)
-      == (G_MAXUINT32 + G_GUINT64_CONSTANT (1) + 90000));
+  fail_unless_equals_uint64 (gst_rtp_buffer_ext_timestamp (&ext_ts, 90000),
+      (G_GUINT64_CONSTANT (1) << 32) + G_MAXUINT32 + G_GUINT64_CONSTANT (1) +
+      90000);
 }
 
 GST_END_TEST;
 
-GST_START_TEST (test_ext_timestamp_wraparound_disordered_cannot_unwrap)
+GST_START_TEST (test_ext_timestamp_wraparound_disordered_backwards)
 {
   guint64 ext_ts = -1;
 
-  fail_unless (gst_rtp_buffer_ext_timestamp (&ext_ts, 90000)
-      == 90000);
+  fail_unless_equals_uint64 (gst_rtp_buffer_ext_timestamp (&ext_ts, 90000),
+      (G_GUINT64_CONSTANT (1) << 32) + 90000);
 
-  /* Cannot unwrapping around */
-  fail_unless (gst_rtp_buffer_ext_timestamp (&ext_ts,
-          G_MAXUINT32 - 90000 + G_GUINT64_CONSTANT (1)) == 0);
+  /* Wraps backwards */
+  fail_unless_equals_uint64 (gst_rtp_buffer_ext_timestamp (&ext_ts,
+          G_MAXUINT32 - 90000 + G_GUINT64_CONSTANT (1)),
+      G_MAXUINT32 - 90000 + G_GUINT64_CONSTANT (1));
 
-  fail_unless (gst_rtp_buffer_ext_timestamp (&ext_ts, 90000)
-      == 90000);
+  fail_unless_equals_uint64 (gst_rtp_buffer_ext_timestamp (&ext_ts, 90000),
+      (G_GUINT64_CONSTANT (1) << 32) + 90000);
 }
 
 GST_END_TEST;
@@ -2366,8 +2373,7 @@ rtp_suite (void)
   tcase_add_test (tc_chain, test_ext_timestamp_basic);
   tcase_add_test (tc_chain, test_ext_timestamp_wraparound);
   tcase_add_test (tc_chain, test_ext_timestamp_wraparound_disordered);
-  tcase_add_test (tc_chain,
-      test_ext_timestamp_wraparound_disordered_cannot_unwrap);
+  tcase_add_test (tc_chain, test_ext_timestamp_wraparound_disordered_backwards);
 
   tcase_add_test (tc_chain, test_rtcp_compound_padding);
   tcase_add_test (tc_chain, test_rtp_buffer_extlen_wraparound);