Add H264 bitstream rewriting to limit frame reordering marker in header

webrtc/modules/video_coding/utility/h264_bitstream_parser.h

 /*
  *  Copyright (c) 2015 The WebRTC project authors. All Rights Reserved.
  *
  *  Use of this source code is governed by a BSD-style license
  *  that can be found in the LICENSE file in the root of the source
  *  tree. An additional intellectual property rights grant can be found
  *  in the file PATENTS.  All contributing project authors may
  *  be found in the AUTHORS file in the root of the source tree.
  */
 
 #ifndef WEBRTC_MODULES_VIDEO_CODING_UTILITY_H264_BITSTREAM_PARSER_H_
 #define WEBRTC_MODULES_VIDEO_CODING_UTILITY_H264_BITSTREAM_PARSER_H_
-
 #include <stddef.h>
 #include <stdint.h>
 
+#include "webrtc/base/optional.h"
+#include "webrtc/common_video/h264/pps_parser.h"
+#include "webrtc/common_video/h264/sps_parser.h"
+
 namespace rtc {
-class BitBuffer;
+class BitBufferWriter;
 }
 
 namespace webrtc {
 
 // Stateful H264 bitstream parser (due to SPS/PPS). Used to parse out QP values
 // from the bitstream.
 // TODO(pbos): Unify with RTP SPS parsing and only use one H264 parser.
 // TODO(pbos): If/when this gets used on the receiver side CHECKs must be
 // removed and gracefully abort as we have no control over receive-side
 // bitstreams.
 class H264BitstreamParser {
  public:
+  H264BitstreamParser();
+  virtual ~H264BitstreamParser();
+
   // Parse an additional chunk of H264 bitstream.
   void ParseBitstream(const uint8_t* bitstream, size_t length);
 
   // Get the last extracted QP value from the parsed bitstream.
   bool GetLastSliceQp(int* qp) const;
 
- private:
-  // Captured in SPS and used when parsing slice NALUs.
-  struct SpsState {
-    SpsState();
-
-    uint32_t delta_pic_order_always_zero_flag = 0;
-    uint32_t separate_colour_plane_flag = 0;
-    uint32_t frame_mbs_only_flag = 0;
-    uint32_t log2_max_frame_num_minus4 = 0;
-    uint32_t log2_max_pic_order_cnt_lsb_minus4 = 0;
-    uint32_t pic_order_cnt_type = 0;
-  };
-
-  struct PpsState {
-    PpsState();
-
-    bool bottom_field_pic_order_in_frame_present_flag = false;
-    bool weighted_pred_flag = false;
-    uint32_t weighted_bipred_idc = false;
-    uint32_t redundant_pic_cnt_present_flag = 0;
-    int pic_init_qp_minus26 = 0;
-  };
-
+ protected:
   void ParseSlice(const uint8_t* slice, size_t length);
-  bool ParseSpsNalu(const uint8_t* sps_nalu, size_t length);
-  bool ParsePpsNalu(const uint8_t* pps_nalu, size_t length);
   bool ParseNonParameterSetNalu(const uint8_t* source,
                                 size_t source_length,
                                 uint8_t nalu_type);
 
   // SPS/PPS state, updated when parsing new SPS/PPS, used to parse slices.
-  bool sps_parsed_ = false;
-  SpsState sps_;
-  bool pps_parsed_ = false;
-  PpsState pps_;
+  rtc::Optional<SpsParser::SpsState> sps_;
+  rtc::Optional<PpsParser::PpsState> pps_;
 
   // Last parsed slice QP.
-  bool last_slice_qp_delta_parsed_ = false;
-  int32_t last_slice_qp_delta_ = 0;
+  rtc::Optional<int32_t> last_slice_qp_delta_;
 };
 
 }  // namespace webrtc
 
 #endif  // WEBRTC_MODULES_VIDEO_CODING_UTILITY_H264_BITSTREAM_PARSER_H_