mirror of
https://gitee.com/xia-chu/ZLMediaKit.git
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91 lines
2.6 KiB
C++
91 lines
2.6 KiB
C++
/*
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* Copyright (c) 2016-present The ZLMediaKit project authors. All Rights Reserved.
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*
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* This file is part of ZLMediaKit(https://github.com/ZLMediaKit/ZLMediaKit).
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*
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* Use of this source code is governed by MIT-like license that can be found in the
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* LICENSE file in the root of the source tree. All contributing project authors
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* may be found in the AUTHORS file in the root of the source tree.
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*/
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#ifndef ZLMEDIAKIT_MP2A_H
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#define ZLMEDIAKIT_MP2A_H
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#include "Extension/Frame.h"
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#include "Extension/Track.h"
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namespace mediakit {
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/**
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* MPEG-1/2 Audio (Layer I/II) 帧辅助类模板
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* MPEG-1/2 Audio (Layer I/II) frame helper class template
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*/
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template <typename Parent>
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class MP2AFrameHelper : public Parent {
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public:
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using Ptr = std::shared_ptr<MP2AFrameHelper>;
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template <typename... ARGS>
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MP2AFrameHelper(ARGS &&...args)
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: Parent(std::forward<ARGS>(args)...) {
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this->_codec_id = CodecMP2A;
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}
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bool keyFrame() const override { return false; }
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bool configFrame() const override { return false; }
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};
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/// MPEG-1/2 Audio 帧类
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using MP2AFrame = MP2AFrameHelper<FrameImp>;
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using MP2AFrameNoCacheAble = MP2AFrameHelper<FrameFromPtr>;
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// MPEG Audio 帧头解析工具
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// MPEG Audio frame header parsing utility
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struct MpegAudioFrameInfo {
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int version = 0; // 1: MPEG-1, 2: MPEG-2, 3: MPEG-2.5
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int layer = 0; // 1: Layer I, 2: Layer II, 3: Layer III
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int bitrate = 0; // kbps
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int sample_rate = 0; // Hz
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int channels = 0; // 1: mono, 2: stereo
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int frame_size = 0; // bytes per frame
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int samples_per_frame = 0;
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/**
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* 从 MPEG Audio sync word 解析帧头信息
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* Parse frame header info from MPEG Audio sync word
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* @param data 数据指针，至少4字节
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* @param size 数据大小
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* @return 是否解析成功
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*/
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static bool parse(const uint8_t *data, size_t size, MpegAudioFrameInfo &info);
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};
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/**
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* MPEG-1/2 Audio (Layer I/II) Track
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* 对应 CodecMP2A
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*/
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class MP2ATrack : public AudioTrackImp {
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public:
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using Ptr = std::shared_ptr<MP2ATrack>;
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MP2ATrack(int sample_rate = 44100, int channels = 2)
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: AudioTrackImp(CodecMP2A, sample_rate, channels, 16) {}
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bool inputFrame(const Frame::Ptr &frame) override;
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private:
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/**
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* RFC 2250/3551 规定 MPA 的 RTP 时钟频率固定为 90000
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* RFC 2250/3551 specifies MPA RTP clock rate is fixed at 90000
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*/
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Sdp::Ptr getSdp(uint8_t payload_type) const override;
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Track::Ptr clone() const override;
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private:
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bool _info_parsed = false;
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};
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} // namespace mediakit
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#endif // ZLMEDIAKIT_MP2A_H
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