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7121680f38
Blink RTC video encoder will need this simplified parser to replace current full H.264 SPS parser, to reduce parsing cost for extracting frame size from compressed H.264 bitstream. Bug: b:309132190 Change-Id: I6863f10bd139766d47fe4bff89143c1a91a09287 Reviewed-on: https://webrtc-review.googlesource.com/c/src/+/332468 Reviewed-by: Harald Alvestrand <hta@webrtc.org> Commit-Queue: Jianlin Qiu <jianlin.qiu@intel.com> Cr-Commit-Position: refs/heads/main@{#41466}
53 lines
1.8 KiB
C++
53 lines
1.8 KiB
C++
/*
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* Copyright (c) 2016 The WebRTC project authors. All Rights Reserved.
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*
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* Use of this source code is governed by a BSD-style license
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* that can be found in the LICENSE file in the root of the source
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* tree. An additional intellectual property rights grant can be found
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* in the file PATENTS. All contributing project authors may
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* be found in the AUTHORS file in the root of the source tree.
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*/
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#ifndef COMMON_VIDEO_H264_SPS_PARSER_H_
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#define COMMON_VIDEO_H264_SPS_PARSER_H_
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#include "absl/types/optional.h"
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#include "rtc_base/bitstream_reader.h"
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#include "rtc_base/system/rtc_export.h"
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namespace webrtc {
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// A class for parsing out sequence parameter set (SPS) data from an H264 NALU.
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class RTC_EXPORT SpsParser {
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public:
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// The parsed state of the SPS. Only some select values are stored.
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// Add more as they are actually needed.
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struct RTC_EXPORT SpsState {
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SpsState();
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SpsState(const SpsState&);
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~SpsState();
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uint32_t width = 0;
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uint32_t height = 0;
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uint32_t delta_pic_order_always_zero_flag = 0;
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uint32_t separate_colour_plane_flag = 0;
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uint32_t frame_mbs_only_flag = 0;
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uint32_t log2_max_frame_num = 4; // Smallest valid value.
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uint32_t log2_max_pic_order_cnt_lsb = 4; // Smallest valid value.
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uint32_t pic_order_cnt_type = 0;
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uint32_t max_num_ref_frames = 0;
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uint32_t vui_params_present = 0;
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uint32_t id = 0;
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};
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// Unpack RBSP and parse SPS state from the supplied buffer.
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static absl::optional<SpsState> ParseSps(const uint8_t* data, size_t length);
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protected:
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// Parse the SPS state, up till the VUI part, for a buffer where RBSP
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// decoding has already been performed.
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static absl::optional<SpsState> ParseSpsUpToVui(BitstreamReader& reader);
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};
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} // namespace webrtc
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#endif // COMMON_VIDEO_H264_SPS_PARSER_H_
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