54 lines
1.6 KiB
C++
54 lines
1.6 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_PREFIX_PARSER_H_
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#define COMMON_VIDEO_H264_PREFIX_PARSER_H_
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#include "absl/types/optional.h"
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namespace rtc {
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class BitBuffer;
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}
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namespace webrtc {
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// A class for parsing out SVC extension data from an H264 prefix NALU
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class PrefixParser {
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public:
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// The parsed state of the SVC extension. Only some select values are stored.
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// Add more as they are actually needed.
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struct PrefixState {
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PrefixState();
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PrefixState(const PrefixState&);
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~PrefixState();
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uint32_t idr_flag = 0;
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uint32_t priority_id = 0;
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uint32_t no_inter_layer_pred_flag = 1;
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uint32_t dependency_id = 0;
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uint32_t quality_id = 0;
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uint32_t temporal_id = 0;
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uint32_t use_ref_base_pic_flag = 0;
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uint32_t discardable_flag = 1;
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uint32_t output_flag = 1;
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};
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// Unpack RBSP and parse prefix state from the supplied buffer.
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static absl::optional<PrefixState> ParsePrefix(const uint8_t* data, size_t length);
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protected:
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// Parse the prefix NAL, up till the SVC extension part, for a bit buffer where RBSP
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// decoding has already been performed.
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static absl::optional<PrefixState> ParsePrefixUpToSvcExtension(rtc::BitBuffer* buffer);
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};
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} // namespace webrtc
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#endif // COMMON_VIDEO_H264_PREFIX_PARSER_H_
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