From 65fc58da4d6e8abc69142fc1d19b446bc2cc7f77 Mon Sep 17 00:00:00 2001
From: Gwenole Beauchesne <gwenole.beauchesne@intel.com>
Date: Thu, 22 May 2014 13:13:14 +0200
Subject: [PATCH] codecparsers: h264: recognize SVC NAL units.

Identify SVC NAL units and tag them as such. This is necessary for
gst_h264_parser_parse_slice_hdr() to fail gracefully, if the user
did not perform the check himself.

Signed-off-by: Gwenole Beauchesne <gwenole.beauchesne@intel.com>
---
 gst-libs/gst/codecparsers/gsth264parser.c | 12 +++++++++++-
 gst-libs/gst/codecparsers/gsth264parser.h | 13 +++++++++++++
 2 files changed, 24 insertions(+), 1 deletion(-)

diff --git a/gst-libs/gst/codecparsers/gsth264parser.c b/gst-libs/gst/codecparsers/gsth264parser.c
index 9ea9ce1fa9..6b1f35a452 100644
--- a/gst-libs/gst/codecparsers/gsth264parser.c
+++ b/gst-libs/gst/codecparsers/gsth264parser.c
@@ -226,7 +226,11 @@ gst_h264_parse_nalu_header (GstH264NalUnit * nalu)
           nalu->size - nalu->header_bytes);
 
       svc_extension_flag = gst_bit_reader_get_bits_uint8_unchecked (&br, 1);
-      if (!svc_extension_flag) {        /* MVC */
+      if (svc_extension_flag) { /* SVC */
+
+        nalu->extension_type = GST_H264_NAL_EXTENSION_SVC;
+
+      } else {                  /* MVC */
         GstH264NalUnitExtensionMVC *const mvc = &nalu->extension.mvc;
 
         nalu->extension_type = GST_H264_NAL_EXTENSION_MVC;
@@ -2139,6 +2143,12 @@ gst_h264_parser_parse_slice_hdr (GstH264NalParser * nalparser,
     return GST_H264_PARSER_BROKEN_LINK;
   }
 
+  /* Check we can actually parse this slice (AVC, MVC headers only) */
+  if (sps->extension_type && sps->extension_type != GST_H264_NAL_EXTENSION_MVC) {
+    GST_WARNING ("failed to parse unsupported slice header");
+    return GST_H264_PARSER_BROKEN_DATA;
+  }
+
   /* set default values for fields that might not be present in the bitstream
      and have valid defaults */
   slice->field_pic_flag = 0;
diff --git a/gst-libs/gst/codecparsers/gsth264parser.h b/gst-libs/gst/codecparsers/gsth264parser.h
index a6aaa223b3..c024b763e8 100644
--- a/gst-libs/gst/codecparsers/gsth264parser.h
+++ b/gst-libs/gst/codecparsers/gsth264parser.h
@@ -50,6 +50,17 @@ G_BEGIN_DECLS
 #define GST_H264_IS_SP_SLICE(slice) (((slice)->type % 5) == GST_H264_SP_SLICE)
 #define GST_H264_IS_SI_SLICE(slice) (((slice)->type % 5) == GST_H264_SI_SLICE)
 
+/**
+ * GST_H264_IS_SVC_NALU:
+ * @nalu: a #GstH264NalUnit
+ *
+ * Check if @nalu is a scalable extension NAL unit.
+ *
+ * Since: 1.6
+ */
+#define GST_H264_IS_SVC_NALU(nalu) \
+  ((nalu)->extension_type == GST_H264_NAL_EXTENSION_SVC)
+
 /**
  * GST_H264_IS_MVC_NALU:
  * @nalu: a #GstH264NalUnit
@@ -147,6 +158,7 @@ typedef enum
 /**
  * GstH264NalUnitExtensionType:
  * @GST_H264_NAL_EXTENSION_NONE: No NAL unit header extension is available
+ * @GST_H264_NAL_EXTENSION_SVC: NAL unit header extension for SVC (Annex G)
  * @GST_H264_NAL_EXTENSION_MVC: NAL unit header extension for MVC (Annex H)
  *
  * Indicates the type of H.264 NAL unit extension.
@@ -156,6 +168,7 @@ typedef enum
 typedef enum
 {
   GST_H264_NAL_EXTENSION_NONE = 0,
+  GST_H264_NAL_EXTENSION_SVC,
   GST_H264_NAL_EXTENSION_MVC,
 } GstH264NalUnitExtensionType;