From 4add820cce278213ede3d5fce427ea92e0619b6f Mon Sep 17 00:00:00 2001
From: Nicolas Dufresne <nicolas.dufresne@collabora.com>
Date: Mon, 24 Sep 2018 15:31:12 -0400
Subject: [PATCH] rtph264pay: Properly set the marker bit

The marker bit is used for efficient decoding. The assumption that
it should be set on the AUD is wrong, since the AUD is conceptually
starts the frame, while the marker is to indicate the end.

So properly set the marker bit as soon as we know we are ending an
AU and also whenever upstream have set the GST_BUFFER_FLAG_MARKER
flag.
---
 gst/rtp/gstrtph264pay.c | 29 ++++++++++++++++-------------
 1 file changed, 16 insertions(+), 13 deletions(-)

diff --git a/gst/rtp/gstrtph264pay.c b/gst/rtp/gstrtph264pay.c
index 1105dc5d11..ccf791a20f 100644
--- a/gst/rtp/gstrtph264pay.c
+++ b/gst/rtp/gstrtph264pay.c
@@ -893,10 +893,8 @@ gst_rtp_h264_pay_payload_nal (GstRTPBasePayload * basepayload,
 
     gst_rtp_buffer_map (outbuf, GST_MAP_WRITE, &rtp);
 
-    /* only set the marker bit on packets containing access units */
-    if (IS_ACCESS_UNIT (nalType) && end_of_au) {
-      gst_rtp_buffer_set_marker (&rtp, 1);
-    }
+    /* Mark the end of a frame */
+    gst_rtp_buffer_set_marker (&rtp, end_of_au);
 
     /* timestamp the outbuffer */
     GST_BUFFER_PTS (outbuf) = pts;
@@ -964,9 +962,10 @@ gst_rtp_h264_pay_payload_nal (GstRTPBasePayload * basepayload,
         GST_DEBUG_OBJECT (basepayload, "end size=%d iteration=%d", size, ii);
         end = 1;
       }
-      if (IS_ACCESS_UNIT (nalType)) {
-        gst_rtp_buffer_set_marker (&rtp, end && end_of_au);
-      }
+
+      /* If it's the last fragment and the end of this au, mark the end of
+       * slice */
+      gst_rtp_buffer_set_marker (&rtp, end_of_au);
 
       /* FU indicator */
       payload[0] = (nalHeader & 0x60) | 28;
@@ -1124,9 +1123,10 @@ gst_rtp_h264_pay_handle_buffer (GstRTPBasePayload * basepayload,
       /* If we're at the end of the buffer, then we're at the end of the
        * access unit
        */
-      if (rtph264pay->alignment == GST_H264_ALIGNMENT_AU
-          && size - nal_len <= nal_length_size) {
-        end_of_au = TRUE;
+      if (size - nal_len <= nal_length_size) {
+        if (rtph264pay->alignment == GST_H264_ALIGNMENT_AU ||
+            GST_BUFFER_FLAG_IS_SET (buffer, GST_BUFFER_FLAG_MARKER))
+          end_of_au = TRUE;
       }
 
       paybuf = gst_buffer_copy_region (buffer, GST_BUFFER_COPY_ALL, offset,
@@ -1266,9 +1266,12 @@ gst_rtp_h264_pay_handle_buffer (GstRTPBasePayload * basepayload,
        * actually payload the NAL so we can know if the current NAL is
        * the last one of an access unit or not if we are in bytestream mode
        */
-      if ((rtph264pay->alignment == GST_H264_ALIGNMENT_AU || buffer == NULL) &&
-          i == nal_queue->len - 1)
-        end_of_au = TRUE;
+      if (i == nal_queue->len - 1) {
+        if (rtph264pay->alignment == GST_H264_ALIGNMENT_AU ||
+            buffer == NULL ||
+            GST_BUFFER_FLAG_IS_SET (buffer, GST_BUFFER_FLAG_MARKER))
+          end_of_au = TRUE;
+      }
       paybuf = gst_adapter_take_buffer (rtph264pay->adapter, size);
       g_assert (paybuf);