codecparsers: h264: Fix default ref list size

The default in PPS was not applied properly. The default does not apply for
I-Slice and l1 default only applies for B-Slice.  This fixes the slice values
for num_ref_idx_l0_active_minus1 and num_ref_idx_l1_active_minus1.

Part-of: <https://gitlab.freedesktop.org/gstreamer/gst-plugins-bad/-/merge_requests/1238>

diff --git a/gst-libs/gst/codecparsers/gsth264parser.c b/gst-libs/gst/codecparsers/gsth264parser.c
index 44dcc7e..a7ddad4 100644 (file)
--- a/gst-libs/gst/codecparsers/gsth264parser.c
+++ b/gst-libs/gst/codecparsers/gsth264parser.c
@@ -2253,8 +2253,17 @@ gst_h264_parser_parse_slice_hdr (GstH264NalParser * nalparser,
 
   /* set default values for fields that might not be present in the bitstream
      and have valid defaults */
-  slice->num_ref_idx_l0_active_minus1 = pps->num_ref_idx_l0_active_minus1;
-  slice->num_ref_idx_l1_active_minus1 = pps->num_ref_idx_l1_active_minus1;
+  if (GST_H264_IS_I_SLICE (slice)) {
+    slice->num_ref_idx_l0_active_minus1 = 0;
+    slice->num_ref_idx_l1_active_minus1 = 0;
+  } else {
+    slice->num_ref_idx_l0_active_minus1 = pps->num_ref_idx_l0_active_minus1;
+
+    if (GST_H264_IS_B_SLICE (slice))
+      slice->num_ref_idx_l1_active_minus1 = pps->num_ref_idx_l1_active_minus1;
+    else
+      slice->num_ref_idx_l1_active_minus1 = 0;
+  }
 
   if (sps->separate_colour_plane_flag)
     READ_UINT8 (&nr, slice->colour_plane_id, 2);