/* * MIT License * * Copyright (c) 2016 xiongziliang <771730766@qq.com> * * This file is part of ZLMediaKit(https://github.com/xiongziliang/ZLMediaKit). * * Permission is hereby granted, free of charge, to any person obtaining a copy * of this software and associated documentation files (the "Software"), to deal * in the Software without restriction, including without limitation the rights * to use, copy, modify, merge, publish, distribute, sublicense, and/or sell * copies of the Software, and to permit persons to whom the Software is * furnished to do so, subject to the following conditions: * * The above copyright notice and this permission notice shall be included in all * copies or substantial portions of the Software. * * THE SOFTWARE IS PROVIDED "AS IS", WITHOUT WARRANTY OF ANY KIND, EXPRESS OR * IMPLIED, INCLUDING BUT NOT LIMITED TO THE WARRANTIES OF MERCHANTABILITY, * FITNESS FOR A PARTICULAR PURPOSE AND NONINFRINGEMENT. IN NO EVENT SHALL THE * AUTHORS OR COPYRIGHT HOLDERS BE LIABLE FOR ANY CLAIM, DAMAGES OR OTHER * LIABILITY, WHETHER IN AN ACTION OF CONTRACT, TORT OR OTHERWISE, ARISING FROM, * OUT OF OR IN CONNECTION WITH THE SOFTWARE OR THE USE OR OTHER DEALINGS IN THE * SOFTWARE. */ #ifndef ZLMEDIAKIT_AAC_H #define ZLMEDIAKIT_AAC_H #include "Frame.h" #include "Track.h" #include "RtspMuxer/RtspSdp.h" namespace mediakit{ class AACFrame; unsigned const samplingFrequencyTable[16] = { 96000, 88200, 64000, 48000, 44100, 32000, 24000, 22050, 16000, 12000, 11025, 8000, 7350, 0, 0, 0 }; void makeAdtsHeader(const string &strAudioCfg,AACFrame &adts); void writeAdtsHeader(const AACFrame &adts, uint8_t *pcAdts) ; string makeAdtsConfig(const uint8_t *pcAdts); void getAACInfo(const AACFrame &adts,int &iSampleRate,int &iChannel); /** * aac帧,包含adts头 */ class AACFrame : public Frame { public: typedef std::shared_ptr Ptr; char *data() const override{ return (char *)buffer; } uint32_t size() const override { return aac_frame_length; } uint32_t dts() const override { return timeStamp; } uint32_t prefixSize() const override{ return iPrefixSize; } TrackType getTrackType() const override{ return TrackAudio; } CodecId getCodecId() const override{ return CodecAAC; } bool keyFrame() const override { return false; } public: unsigned int syncword = 0; //12 bslbf 同步字The bit string ‘1111 1111 1111’,说明一个ADTS帧的开始 unsigned int id; //1 bslbf MPEG 标示符, 设置为1 unsigned int layer; //2 uimsbf Indicates which layer is used. Set to ‘00’ unsigned int protection_absent; //1 bslbf 表示是否误码校验 unsigned int profile; //2 uimsbf 表示使用哪个级别的AAC,如01 Low Complexity(LC)--- AACLC unsigned int sf_index; //4 uimsbf 表示使用的采样率下标 unsigned int private_bit; //1 bslbf unsigned int channel_configuration; //3 uimsbf 表示声道数 unsigned int original; //1 bslbf unsigned int home; //1 bslbf //下面的为改变的参数即每一帧都不同 unsigned int copyright_identification_bit; //1 bslbf unsigned int copyright_identification_start; //1 bslbf unsigned int aac_frame_length; // 13 bslbf 一个ADTS帧的长度包括ADTS头和raw data block unsigned int adts_buffer_fullness; //11 bslbf 0x7FF 说明是码率可变的码流 //no_raw_data_blocks_in_frame 表示ADTS帧中有number_of_raw_data_blocks_in_frame + 1个AAC原始帧. //所以说number_of_raw_data_blocks_in_frame == 0 //表示说ADTS帧中有一个AAC数据块并不是说没有。(一个AAC原始帧包含一段时间内1024个采样及相关数据) unsigned int no_raw_data_blocks_in_frame; //2 uimsfb unsigned char buffer[2 * 1024 + 7]; uint16_t sequence; uint32_t timeStamp; uint32_t iPrefixSize = 7; } ; class AACFrameNoCopyAble : public FrameNoCopyAble { public: typedef std::shared_ptr Ptr; AACFrameNoCopyAble(char *ptr,uint32_t size,uint32_t stamp,int prefixeSize = 7){ buffer_ptr = ptr; buffer_size = size; timeStamp = stamp; iPrefixSize = prefixeSize; } TrackType getTrackType() const override{ return TrackAudio; } CodecId getCodecId() const override{ return CodecAAC; } bool keyFrame() const override { return false; } } ; /** * aac音频通道 */ class AACTrack : public AudioTrack{ public: typedef std::shared_ptr Ptr; /** * 延后获取adts头信息 * 在随后的inputFrame中获取adts头信息 */ AACTrack(){} /** * 构造aac类型的媒体 * @param aac_cfg aac两个字节的配置信息 */ AACTrack(const string &aac_cfg){ if(aac_cfg.size() != 2){ throw std::invalid_argument("adts配置必须为2个字节"); } _cfg = aac_cfg; onReady(); } /** * 构造aac类型的媒体 * @param adts_header adts头,7个字节 * @param adts_header_len adts头长度,不少于7个字节 */ AACTrack(const char *adts_header,int adts_header_len = 7){ if(adts_header_len < 7){ throw std::invalid_argument("adts头必须不少于7个字节"); } _cfg = makeAdtsConfig((uint8_t*)adts_header); onReady(); } /** * 构造aac类型的媒体 * @param aac_frame_with_adts 带adts头的aac帧 */ AACTrack(const Frame::Ptr &aac_frame_with_adts){ if(aac_frame_with_adts->getCodecId() != CodecAAC || aac_frame_with_adts->prefixSize() < 7){ throw std::invalid_argument("必须输入带adts头的aac帧"); } _cfg = makeAdtsConfig((uint8_t*)aac_frame_with_adts->data()); onReady(); } /** * 获取aac两个字节的配置 * @return */ const string &getAacCfg() const{ return _cfg; } /** * 返回编码类型 * @return */ CodecId getCodecId() const override{ return CodecAAC; } /** * 在获取aac_cfg前是无效的Track * @return */ bool ready() override { return !_cfg.empty(); } /** * 返回音频采样率 * @return */ int getAudioSampleRate() const override{ return _sampleRate; } /** * 返回音频采样位数,一般为16或8 * @return */ int getAudioSampleBit() const override{ return _sampleBit; } /** * 返回音频通道数 * @return */ int getAudioChannel() const override{ return _channel; } /** * 输入数据帧,并获取aac_cfg * @param frame 数据帧 */ void inputFrame(const Frame::Ptr &frame) override{ if(_cfg.empty()){ //未获取到aac_cfg信息 if(frame->prefixSize() >= 7) { //7个字节的adts头 _cfg = makeAdtsConfig(reinterpret_cast(frame->data())); onReady(); }else{ WarnL << "无法获取adts头!"; } } AudioTrack::inputFrame(frame); } private: /** * 解析2个字节的aac配置 */ void onReady(){ AACFrame aacFrame; makeAdtsHeader(_cfg,aacFrame); getAACInfo(aacFrame,_sampleRate,_channel); } Track::Ptr clone() override { return std::make_shared::type >(*this); } private: string _cfg; int _sampleRate = 0; int _sampleBit = 16; int _channel = 0; }; /** * aac类型SDP */ class AACSdp : public Sdp { public: /** * * @param aac_cfg aac两个字节的配置描述 * @param sample_rate 音频采样率 * @param playload_type rtp playload type 默认98 * @param bitrate 比特率 */ AACSdp(const string &aac_cfg, int sample_rate, int playload_type = 98, int bitrate = 128) : Sdp(sample_rate,playload_type){ _printer << "m=audio 0 RTP/AVP " << playload_type << "\r\n"; _printer << "b=AS:" << bitrate << "\r\n"; _printer << "a=rtpmap:" << playload_type << " MPEG4-GENERIC/" << sample_rate << "\r\n"; char configStr[32] = {0}; snprintf(configStr, sizeof(configStr), "%02X%02X", (uint8_t)aac_cfg[0], (uint8_t)aac_cfg[1]); _printer << "a=fmtp:" << playload_type << " streamtype=5;profile-level-id=1;mode=AAC-hbr;" << "sizelength=13;indexlength=3;indexdeltalength=3;config=" << configStr << "\r\n"; _printer << "a=control:trackID=" << getTrackType() << "\r\n"; } string getSdp() const override { return _printer; } TrackType getTrackType() const override { return TrackAudio; } CodecId getCodecId() const override { return CodecAAC; } private: _StrPrinter _printer; }; }//namespace mediakit #endif //ZLMEDIAKIT_AAC_H