v4l2dec: CF1 Check input_buffer when used [3/3]

PD#SWPL-183734

Problem:
Check whether the input_buffer exists when being used

Solution:
Check whether the input_buffer exists when being used

Verify:
Yocto

Signed-off-by: le.han <le.han@amlogic.com>
Change-Id: I7065231a31cd85bb5cc37d73470236d7a3723972
diff --git a/src/gstamlvideodecoder.c b/src/gstamlvideodecoder.c
index 35ea9d0..3fb2483 100644
--- a/src/gstamlvideodecoder.c
+++ b/src/gstamlvideodecoder.c
@@ -3570,9 +3570,10 @@
         GST_TIME_ARGS (frame->pts));
     GST_BUFFER_FLAG_SET (output_buffer, GST_BUFFER_FLAG_CORRUPTED);
   }
-
-  gst_aml_video_decoder_copy_metas (decoder, frame, frame->input_buffer,
-      frame->output_buffer);
+  if (frame->input_buffer) {
+      gst_aml_video_decoder_copy_metas (decoder, frame, frame->input_buffer,
+          frame->output_buffer);
+  }
 
   /* Get an additional ref to the buffer, which is going to be pushed
    * downstream, the original ref is owned by the frame