From 6bf7f5cfd3d7bf5e9bd923bad948fa45ca795d72 Mon Sep 17 00:00:00 2001
From: Mark Nauwelaerts <mark.nauwelaerts@collabora.co.uk>
Date: Thu, 15 Apr 2010 12:21:56 +0200
Subject: rtph264depay: DELTA_UNIT marking of output buffers

... which evidently makes (most) sense if output buffers are
actually frames.

Partially based on a patch by
Miguel Angel Cabrera <mad_aluche at hotmail.com>

Fixes #609658.
---
 gst/rtp/gstrtph264depay.c | 43 +++++++++++++++++++++++++++++++++++++++++++
 gst/rtp/gstrtph264depay.h |  1 +
 2 files changed, 44 insertions(+)

diff --git a/gst/rtp/gstrtph264depay.c b/gst/rtp/gstrtph264depay.c
index 3223dcba3..a50141bed 100644
--- a/gst/rtp/gstrtph264depay.c
+++ b/gst/rtp/gstrtph264depay.c
@@ -399,6 +399,31 @@ incomplete_caps:
   }
 }
 
+/* nal must have writable meta-data,
+ * returns TRUE if delta unit */
+static gboolean
+gst_rtp_h264_depay_mark_delta (GstRtpH264Depay * rtph264depay, GstBuffer * nal)
+{
+  gint nal_unit_type;
+  gboolean res = FALSE;
+
+  if (G_UNLIKELY (GST_BUFFER_SIZE (nal) < 5))
+    return FALSE;
+
+  nal_unit_type = (GST_BUFFER_DATA (nal))[4] & 0x1f;
+  GST_DEBUG_OBJECT (rtph264depay, "type %d", nal_unit_type);
+  /* non-IDR VCL layer NAL considered DELTA */
+  if (nal_unit_type >= 1 && nal_unit_type <= 4) {
+    GST_BUFFER_FLAG_SET (nal, GST_BUFFER_FLAG_DELTA_UNIT);
+    res = TRUE;
+  } else {
+    GST_BUFFER_FLAG_UNSET (nal, GST_BUFFER_FLAG_DELTA_UNIT);
+  }
+
+  return res;
+}
+
+/* nal must have writable meta-data */
 static GstBuffer *
 gst_rtp_h264_depay_push_nal (GstRtpH264Depay * rtph264depay, GstBuffer * nal,
     GstClockTime timestamp)
@@ -441,6 +466,7 @@ gst_rtp_h264_depay_push_nal (GstRtpH264Depay * rtph264depay, GstBuffer * nal,
   if (rtph264depay->picture_complete) {
     outsize = gst_adapter_available (rtph264depay->picture_adapter);
     outbuf = gst_adapter_take_buffer (rtph264depay->picture_adapter, outsize);
+    outbuf = gst_buffer_make_metadata_writable (outbuf);
     rtph264depay->picture_complete = FALSE;
     rtph264depay->picture_start = start;
 
@@ -453,9 +479,17 @@ gst_rtp_h264_depay_push_nal (GstRtpH264Depay * rtph264depay, GstBuffer * nal,
     if (GST_CLOCK_TIME_IS_VALID (timestamp) &&
         GST_CLOCK_TIME_IS_VALID (rtph264depay->last_ts))
       GST_BUFFER_DURATION (outbuf) = timestamp - rtph264depay->last_ts;
+
+    if (rtph264depay->last_delta)
+      GST_BUFFER_FLAG_SET (outbuf, GST_BUFFER_FLAG_DELTA_UNIT);
+    else
+      GST_BUFFER_FLAG_UNSET (outbuf, GST_BUFFER_FLAG_DELTA_UNIT);
+    rtph264depay->last_delta = FALSE;
   }
 
   rtph264depay->last_ts = timestamp;
+  rtph264depay->last_delta = rtph264depay->last_delta ||
+      gst_rtp_h264_depay_mark_delta (rtph264depay, nal);
   gst_adapter_push (rtph264depay->picture_adapter, nal);
 
   return outbuf;
@@ -585,6 +619,9 @@ gst_rtp_h264_depay_process (GstBaseRTPDepayload * depayload, GstBuffer * buf)
         if (!rtph264depay->merge) {
           outsize = gst_adapter_available (rtph264depay->adapter);
           outbuf = gst_adapter_take_buffer (rtph264depay->adapter, outsize);
+          outbuf = gst_buffer_make_metadata_writable (outbuf);
+
+          gst_rtp_h264_depay_mark_delta (rtph264depay, outbuf);
           gst_buffer_set_caps (outbuf, GST_PAD_CAPS (depayload->srcpad));
           return outbuf;
         }
@@ -670,6 +707,7 @@ gst_rtp_h264_depay_process (GstBaseRTPDepayload * depayload, GstBuffer * buf)
 
           outsize = gst_adapter_available (rtph264depay->adapter);
           outbuf = gst_adapter_take_buffer (rtph264depay->adapter, outsize);
+          outbuf = gst_buffer_make_metadata_writable (outbuf);
           outdata = GST_BUFFER_DATA (outbuf);
 
           if (rtph264depay->byte_stream) {
@@ -694,6 +732,8 @@ gst_rtp_h264_depay_process (GstBaseRTPDepayload * depayload, GstBuffer * buf)
             outbuf = gst_rtp_h264_depay_push_nal (rtph264depay, outbuf, ts);
             if (!outbuf)
               break;
+          } else {
+            gst_rtp_h264_depay_mark_delta (rtph264depay, outbuf);
           }
 
           gst_buffer_set_caps (outbuf, GST_PAD_CAPS (depayload->srcpad));
@@ -733,6 +773,8 @@ gst_rtp_h264_depay_process (GstBaseRTPDepayload * depayload, GstBuffer * buf)
           outbuf = gst_rtp_h264_depay_push_nal (rtph264depay, outbuf, ts);
           if (!outbuf)
             break;
+        } else {
+          gst_rtp_h264_depay_mark_delta (rtph264depay, outbuf);
         }
 
         gst_buffer_set_caps (outbuf, GST_PAD_CAPS (depayload->srcpad));
@@ -781,6 +823,7 @@ gst_rtp_h264_depay_change_state (GstElement * element,
       gst_adapter_clear (rtph264depay->picture_adapter);
       rtph264depay->picture_start = FALSE;
       rtph264depay->picture_complete = FALSE;
+      rtph264depay->last_delta = FALSE;
       break;
     default:
       break;
diff --git a/gst/rtp/gstrtph264depay.h b/gst/rtp/gstrtph264depay.h
index e1fda3ffd..431d8d219 100644
--- a/gst/rtp/gstrtph264depay.h
+++ b/gst/rtp/gstrtph264depay.h
@@ -56,6 +56,7 @@ struct _GstRtpH264Depay
   gboolean    picture_start;
   gboolean    picture_complete;
   GstClockTime last_ts;
+  gboolean    last_delta;
 };
 
 struct _GstRtpH264DepayClass
-- 
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