H264 bitstream parser.

webrtc/modules/rtp_rtcp/source/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_RTP_RTCP_SOURCE_H264_BITSTREAM_PARSER_H_
+#define WEBRTC_MODULES_RTP_RTCP_SOURCE_H264_BITSTREAM_PARSER_H_
+
+#include <stdint.h>
+#include <stddef.h>
+
+namespace rtc {
+class BitBuffer;
+}
+
+namespace webrtc {
+
+class H264BitstreamParser {
+ public:
+  void ParseBitstream(const uint8_t* bitstream, size_t length);
+
+  int GetLastSliceQp() const;
+
+ private:
+  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);
+
+  // Captured in SPS and used when parsing slice NALUs.
+  // TODO(pbos): Put in struct and reinitialize on every new SPS.
+  uint32_t delta_pic_order_always_zero_flag_ = 0;
+  uint32_t separate_colour_plane_flag_ = 0;
+  uint32_t frame_mbs_only_flag_;
+  uint32_t log2_max_frame_num_minus4_;
+  uint32_t log2_max_pic_order_cnt_lsb_minus4_ = 0;
+  uint32_t pic_order_cnt_type_;
+  // Captured in PPS and used when parsing slice NALUs.
+  // TODO(pbos): Put in struct and reinitialize on every new PPS.
+  bool bottom_field_pic_order_in_frame_present_flag_;
+  uint32_t redundant_pic_cnt_present_flag_;
+
+  // QP calculation values.
+  int pic_init_qp_minus26_;
+  int32_t slice_qp_delta_ = 0;
+};
+
+}  // namespace webrtc
+
+#endif  // WEBRTC_MODULES_RTP_RTCP_SOURCE_H264_BITSTREAM_PARSER_H_