unixfdsink: Take segment into account when converting timestamps

Also rename `calculate_timestamp()` to `to_monotonic()` and
`from_monotonic()` which better describe what it does.

Part-of: <https://gitlab.freedesktop.org/gstreamer/gstreamer/-/merge_requests/6747>

subprojects/gst-plugins-bad/gst/unixfd/gstunixfdsink.c

@@ -428,12 +428,22 @@ send_command_to_all (GstUnixFdSink * self, CommandType type, GUnixFDList * fds,
 }
 
 static GstClockTime
-calculate_timestamp (GstClockTime timestamp, GstClockTime base_time,
+to_monotonic (GstClockTime timestamp, const GstSegment * segment,
-    GstClockTime latency, GstClockTimeDiff clock_diff)
+    GstClockTime base_time, GstClockTime latency, GstClockTimeDiff clock_diff)
 {
   if (GST_CLOCK_TIME_IS_VALID (timestamp)) {
     /* Convert running time to pipeline clock time */
-    timestamp += base_time;
+    gint res =
+        gst_segment_to_running_time_full (segment, GST_FORMAT_TIME, timestamp,
+        &timestamp);
+    if (res == 0)
+      return GST_CLOCK_TIME_NONE;
+    else if (res > 0)
+      timestamp += base_time;
+    else if (base_time > timestamp)
+      timestamp = base_time - timestamp;
+    else
+      timestamp = 0;
     if (GST_CLOCK_TIME_IS_VALID (latency))
       timestamp += latency;
     /* Convert to system monotonic clock time */
@@ -485,11 +495,11 @@ gst_unix_fd_sink_render (GstBaseSink * bsink, GstBuffer * buffer)
    * id so we know which buffer to unref. */
   new_buffer->id = (guint64) buffer;
   new_buffer->pts =
-      calculate_timestamp (GST_BUFFER_PTS (buffer), base_time, latency,
+      to_monotonic (GST_BUFFER_PTS (buffer),
-      clock_diff);
+      &GST_BASE_SINK_CAST (self)->segment, base_time, latency, clock_diff);
   new_buffer->dts =
-      calculate_timestamp (GST_BUFFER_DTS (buffer), base_time, latency,
+      to_monotonic (GST_BUFFER_DTS (buffer),
-      clock_diff);
+      &GST_BASE_SINK_CAST (self)->segment, base_time, latency, clock_diff);
   new_buffer->duration = GST_BUFFER_DURATION (buffer);
   new_buffer->offset = GST_BUFFER_OFFSET (buffer);
   new_buffer->offset_end = GST_BUFFER_OFFSET_END (buffer);
@@ -498,6 +508,15 @@ gst_unix_fd_sink_render (GstBaseSink * bsink, GstBuffer * buffer)
   new_buffer->n_memory = n_memory;
   new_buffer->n_meta = n_meta;
 
+  if ((GST_BUFFER_PTS_IS_VALID (buffer)
+          && !GST_CLOCK_TIME_IS_VALID (new_buffer->pts))
+      || (GST_BUFFER_DTS_IS_VALID (buffer)
+          && !GST_CLOCK_TIME_IS_VALID (new_buffer->dts))) {
+    GST_ERROR_OBJECT (self,
+        "Could not convert buffer timestamp to running time");
+    return GST_FLOW_ERROR;
+  }
+
   gboolean dmabuf_count = 0;
   GUnixFDList *fds = g_unix_fd_list_new ();
   for (int i = 0; i < n_memory; i++) {

subprojects/gst-plugins-bad/gst/unixfd/gstunixfdsrc.c

@@ -282,7 +282,7 @@ gst_unix_fd_src_unlock_stop (GstBaseSrc * bsrc)
 }
 
 static GstClockTime
-calculate_timestamp (GstClockTime timestamp, GstClockTime base_time,
+from_monotonic (GstClockTime timestamp, GstClockTime base_time,
     GstClockTimeDiff clock_diff)
 {
   if (GST_CLOCK_TIME_IS_VALID (timestamp)) {
@@ -369,9 +369,9 @@ again:
       }
 
       GST_BUFFER_PTS (*outbuf) =
-          calculate_timestamp (new_buffer->pts, base_time, clock_diff);
+          from_monotonic (new_buffer->pts, base_time, clock_diff);
       GST_BUFFER_DTS (*outbuf) =
-          calculate_timestamp (new_buffer->dts, base_time, clock_diff);
+          from_monotonic (new_buffer->dts, base_time, clock_diff);
       GST_BUFFER_DURATION (*outbuf) = new_buffer->duration;
       GST_BUFFER_OFFSET (*outbuf) = new_buffer->offset;
       GST_BUFFER_OFFSET_END (*outbuf) = new_buffer->offset_end;

subprojects/gst-plugins-bad/tests/check/elements/unixfd.c

@@ -25,6 +25,7 @@
 
 #include <gst/gst.h>
 #include <gst/check/gstcheck.h>
+#include <gst/app/app.h>
 #include <glib/gstdio.h>
 
 static void
@@ -134,6 +135,92 @@ GST_START_TEST (test_unixfd_videotestsrc)
 
 GST_END_TEST;
 
+GST_START_TEST (test_unixfd_segment)
+{
+  GError *error = NULL;
+
+  /* Ensure we don't have socket from previous failed test */
+  gchar *socket_path =
+      g_strdup_printf ("%s/unixfd-test-socket", g_get_user_runtime_dir ());
+  if (g_file_test (socket_path, G_FILE_TEST_EXISTS)) {
+    g_unlink (socket_path);
+  }
+
+  GstCaps *caps = gst_caps_new_empty_simple ("video/x-raw");
+
+  /* Setup service */
+  gchar *pipeline_str =
+      g_strdup_printf
+      ("appsrc name=src format=time handle-segment-change=true ! unixfdsink socket-path=%s sync=false async=false",
+      socket_path);
+  GstElement *pipeline_service = gst_parse_launch (pipeline_str, &error);
+  g_assert_no_error (error);
+  fail_unless (gst_element_set_state (pipeline_service,
+          GST_STATE_PLAYING) == GST_STATE_CHANGE_SUCCESS);
+  GstElement *appsrc = gst_bin_get_by_name (GST_BIN (pipeline_service), "src");
+  gst_object_unref (appsrc);
+  g_free (pipeline_str);
+
+  /* Setup client */
+  pipeline_str =
+      g_strdup_printf
+      ("unixfdsrc socket-path=%s ! appsink name=sink sync=false async=false",
+      socket_path);
+  GstElement *pipeline_client = gst_parse_launch (pipeline_str, &error);
+  g_assert_no_error (error);
+  fail_unless (gst_element_set_state (pipeline_client,
+          GST_STATE_PLAYING) == GST_STATE_CHANGE_SUCCESS);
+  GstElement *appsink = gst_bin_get_by_name (GST_BIN (pipeline_client), "sink");
+  gst_object_unref (appsink);
+  g_free (pipeline_str);
+
+  /* Send a buffer with PTS=30s */
+  GstSegment segment;
+  gst_segment_init (&segment, GST_FORMAT_TIME);
+  GstBuffer *buf = gst_buffer_new ();
+  GST_BUFFER_PTS (buf) = 30 * GST_SECOND;
+  GstSample *sample = gst_sample_new (buf, caps, &segment, NULL);
+  gst_app_src_push_sample (GST_APP_SRC (appsrc), sample);
+  gst_sample_unref (sample);
+  gst_buffer_unref (buf);
+
+  /* Wait for it */
+  sample = gst_app_sink_pull_sample (GST_APP_SINK (appsink));
+  buf = gst_sample_get_buffer (sample);
+  GstClockTime first_pts = GST_BUFFER_PTS (buf);
+  gst_sample_unref (sample);
+
+  /* Send a buffer with PTS=1s but with 30s offset in the segment */
+  segment.base = 30 * GST_SECOND;
+  buf = gst_buffer_new ();
+  GST_BUFFER_PTS (buf) = 1 * GST_SECOND;
+  sample = gst_sample_new (buf, caps, &segment, NULL);
+  gst_app_src_push_sample (GST_APP_SRC (appsrc), sample);
+  gst_sample_unref (sample);
+  gst_buffer_unref (buf);
+
+  /* Wait for it */
+  sample = gst_app_sink_pull_sample (GST_APP_SINK (appsink));
+  buf = gst_sample_get_buffer (sample);
+  GstClockTime second_pts = GST_BUFFER_PTS (buf);
+  gst_sample_unref (sample);
+
+  /* They should be 1s appart */
+  fail_unless_equals_uint64 (second_pts - first_pts, GST_SECOND);
+
+  /* Teardown */
+  fail_unless (gst_element_set_state (pipeline_client,
+          GST_STATE_NULL) == GST_STATE_CHANGE_SUCCESS);
+  fail_unless (gst_element_set_state (pipeline_service,
+          GST_STATE_NULL) == GST_STATE_CHANGE_SUCCESS);
+  gst_object_unref (pipeline_service);
+  gst_object_unref (pipeline_client);
+  g_free (socket_path);
+  gst_caps_unref (caps);
+}
+
+GST_END_TEST;
+
 static Suite *
 unixfd_suite (void)
 {
@@ -142,6 +229,7 @@ unixfd_suite (void)
 
   suite_add_tcase (s, tc);
   tcase_add_test (tc, test_unixfd_videotestsrc);
+  tcase_add_test (tc, test_unixfd_segment);
 
   return s;
 }