End of stream flush (#86)

* * rocDecode/HEVC: Added picture output operation in DPB and display callback function.
  - To avoid serialization of decode submissions and/or display callback in certain cases, increased DPB buffer size by 1 and tweaked picture bumping procedure.

* * rocDecode/HEVC: Added flushing of the remaining pictures from DPB at the end of decode session.

* * rocDecode/HEVC: Changed output_pic_num to num_output_pics to void some confusion. Set top_field_first to 1.

* * rocDecode/HEVC: Added a few return error checks.

[ROCm/rocdecode commit: 624c3c0f09]

projects/rocdecode/src/parser/hevc_parser.h

@@ -652,7 +652,7 @@ protected:
         uint32_t dpb_fullness;  // number of pictures in DPB
         HevcPicInfo frame_buffer_list[HEVC_MAX_DPB_FRAMES];
 
-        uint32_t output_pic_num;  // number of pictures are output after the decode call
+        uint32_t num_output_pics;  // number of pictures that are output after the decode call
         uint32_t output_pic_list[HEVC_MAX_DPB_FRAMES]; // sorted output picuture index to frame_buffer_list[]
     } DecodedPictureBuffer;
 
@@ -877,6 +877,11 @@ protected:
      */
     void EmptyDpb();
 
+    /*! \brief Function to send out the remaining pictures that need for output in DPB buffer.
+     * \return Code in ParserResult form.
+     */
+    int FlushDpb();
+
     /*! \brief Function to output and remove pictures from DPB. C.5.2.2.
      * \return Code in ParserResult form.
      */