From 3a3c80e7be1d03f016573700053e41107d641617 Mon Sep 17 00:00:00 2001
From: Jan Schmidt <jan@centricular.com>
Date: Thu, 25 Mar 2021 03:16:05 +1100
Subject: [PATCH] mpegtsmux: Respect the start-time-selection property.

Use the start time provided by the aggregator base class for output
times.

Part-of: <https://gitlab.freedesktop.org/gstreamer/gst-plugins-bad/-/merge_requests/2105>
---
 gst/mpegtsmux/gstbasetsmux.c | 31 ++++++++++++++++++++++++++++++-
 gst/mpegtsmux/gstbasetsmux.h |  1 +
 2 files changed, 31 insertions(+), 1 deletion(-)

diff --git a/gst/mpegtsmux/gstbasetsmux.c b/gst/mpegtsmux/gstbasetsmux.c
index 8f024be..3fe7da4 100644
--- a/gst/mpegtsmux/gstbasetsmux.c
+++ b/gst/mpegtsmux/gstbasetsmux.c
@@ -328,6 +328,7 @@ gst_base_ts_mux_reset (GstBaseTsMux * mux, gboolean alloc)
 
   if (mux->out_adapter)
     gst_adapter_clear (mux->out_adapter);
+  mux->output_ts_offset = GST_CLOCK_TIME_NONE;
 
   if (mux->tsmux) {
     if (mux->tsmux->si_sections)
@@ -1080,15 +1081,43 @@ static gboolean
 new_packet_cb (GstBuffer * buf, void *user_data, gint64 new_pcr)
 {
   GstBaseTsMux *mux = (GstBaseTsMux *) user_data;
+  GstAggregator *agg = GST_AGGREGATOR (mux);
   GstBaseTsMuxClass *klass = GST_BASE_TS_MUX_GET_CLASS (mux);
   GstMapInfo map;
+  GstSegment *agg_segment = &GST_AGGREGATOR_PAD (agg->srcpad)->segment;
 
   g_assert (klass->output_packet);
 
   gst_buffer_map (buf, &map, GST_MAP_READWRITE);
 
-  if (!GST_CLOCK_TIME_IS_VALID (GST_BUFFER_PTS (buf)))
+  if (!GST_CLOCK_TIME_IS_VALID (GST_BUFFER_PTS (buf))) {
+    /* tsmux isn't generating timestamps. Use the input times */
     GST_BUFFER_PTS (buf) = mux->last_ts;
+  }
+
+  if (GST_CLOCK_TIME_IS_VALID (GST_BUFFER_PTS (buf))) {
+    if (!GST_CLOCK_TIME_IS_VALID (mux->output_ts_offset)) {
+      GstClockTime output_start_time = agg_segment->position;
+      if (agg_segment->position == -1
+          || agg_segment->position < agg_segment->start) {
+        output_start_time = agg_segment->start;
+      }
+
+      mux->output_ts_offset =
+          GST_CLOCK_DIFF (GST_BUFFER_PTS (buf), output_start_time);
+
+      GST_DEBUG_OBJECT (mux, "New output ts offset %" GST_STIME_FORMAT,
+          GST_STIME_ARGS (mux->output_ts_offset));
+    }
+
+    if (GST_CLOCK_TIME_IS_VALID (mux->output_ts_offset)) {
+      GST_BUFFER_PTS (buf) += mux->output_ts_offset;
+    }
+  }
+
+  if (GST_CLOCK_TIME_IS_VALID (GST_BUFFER_PTS (buf))) {
+    agg_segment->position = GST_BUFFER_PTS (buf);
+  }
 
   /* do common init (flags and streamheaders) */
   new_packet_common_init (mux, buf, map.data, map.size);
diff --git a/gst/mpegtsmux/gstbasetsmux.h b/gst/mpegtsmux/gstbasetsmux.h
index b4970a9..c0d678b 100644
--- a/gst/mpegtsmux/gstbasetsmux.h
+++ b/gst/mpegtsmux/gstbasetsmux.h
@@ -197,6 +197,7 @@ struct GstBaseTsMux {
   /* output buffer aggregation */
   GstAdapter *out_adapter;
   GstBuffer *out_buffer;
+  GstClockTimeDiff output_ts_offset;
 };
 
 /**
-- 
2.7.4