Repo created

TMessagesProj/jni/voip/webrtc/common_video/h264/sps_parser.h

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+/*
+ *  Copyright (c) 2016 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 COMMON_VIDEO_H264_SPS_PARSER_H_
+#define COMMON_VIDEO_H264_SPS_PARSER_H_
+
+#include "absl/types/optional.h"
+#include "rtc_base/bitstream_reader.h"
+#include "rtc_base/system/rtc_export.h"
+
+namespace webrtc {
+
+// A class for parsing out sequence parameter set (SPS) data from an H264 NALU.
+class RTC_EXPORT SpsParser {
+ public:
+  // The parsed state of the SPS. Only some select values are stored.
+  // Add more as they are actually needed.
+  struct RTC_EXPORT SpsState {
+    SpsState();
+    SpsState(const SpsState&);
+    ~SpsState();
+
+    uint32_t width = 0;
+    uint32_t height = 0;
+    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 = 4;          // Smallest valid value.
+    uint32_t log2_max_pic_order_cnt_lsb = 4;  // Smallest valid value.
+    uint32_t pic_order_cnt_type = 0;
+    uint32_t max_num_ref_frames = 0;
+    uint32_t vui_params_present = 0;
+    uint32_t id = 0;
+  };
+
+  // Unpack RBSP and parse SPS state from the supplied buffer.
+  static absl::optional<SpsState> ParseSps(const uint8_t* data, size_t length);
+
+ protected:
+  // Parse the SPS state, up till the VUI part, for a buffer where RBSP
+  // decoding has already been performed.
+  static absl::optional<SpsState> ParseSpsUpToVui(BitstreamReader& reader);
+};
+
+}  // namespace webrtc
+#endif  // COMMON_VIDEO_H264_SPS_PARSER_H_