From 75d97b92210750070fd91c0b38785ef42d99c95e Mon Sep 17 00:00:00 2001 From: xia-chu <771730766@qq.com> Date: Sun, 7 Feb 2021 18:29:48 +0800 Subject: [PATCH] =?UTF-8?q?=E4=BC=98=E5=8C=96H264=20rtp=E7=9B=B8=E5=85=B3?= =?UTF-8?q?=E4=BB=A3=E7=A0=81?= MIME-Version: 1.0 Content-Type: text/plain; charset=UTF-8 Content-Transfer-Encoding: 8bit --- src/Extension/H264Rtp.cpp | 232 ++++++++++++++++++-------------------- src/Extension/H264Rtp.h | 25 ++-- 2 files changed, 120 insertions(+), 137 deletions(-) diff --git a/src/Extension/H264Rtp.cpp b/src/Extension/H264Rtp.cpp index e749fa1b..54a7fc5c 100644 --- a/src/Extension/H264Rtp.cpp +++ b/src/Extension/H264Rtp.cpp @@ -12,26 +12,31 @@ namespace mediakit{ -typedef struct { - unsigned S :1; - unsigned E :1; - unsigned R :1; - unsigned type :5; -} FU; +#if defined(_WIN32) +#pragma pack(push, 1) +#endif // defined(_WIN32) -static bool MakeFU(uint8_t in, FU &fu) { - fu.S = in >> 7; - fu.E = (in >> 6) & 0x01; - fu.R = (in >> 5) & 0x01; - fu.type = in & 0x1f; - if (fu.R != 0) { - return false; - } - return true; -} +class FuFlags { +public: +#if __BYTE_ORDER == __BIG_ENDIAN + unsigned start_bit: 1; + unsigned end_bit: 1; + unsigned reserved: 1; + unsigned nal_type: 5; +#else + unsigned nal_type: 5; + unsigned reserved: 1; + unsigned end_bit: 1; + unsigned start_bit: 1; +#endif +} PACKED; + +#if defined(_WIN32) +#pragma pack(pop) +#endif // defined(_WIN32) H264RtpDecoder::H264RtpDecoder() { - _h264frame = obtainFrame(); + _frame = obtainFrame(); } H264Frame::Ptr H264RtpDecoder::obtainFrame() { @@ -44,51 +49,43 @@ bool H264RtpDecoder::inputRtp(const RtpPacket::Ptr &rtp, bool key_pos) { return decodeRtp(rtp); } -bool H264RtpDecoder::decodeRtp(const RtpPacket::Ptr &rtp) { - /** - * h264帧类型 - * Type==1:P/B frame - * Type==5:IDR frame - * Type==6:SEI frame - * Type==7:SPS frame - * Type==8:PPS frame - */ - /* - RTF3984 5.2节 Common Structure of the RTP Payload Format - Table 1. Summary of NAL unit types and their payload structures +/* +RTF3984 5.2节 Common Structure of the RTP Payload Format +Table 1. Summary of NAL unit types and their payload structures - Type Packet Type name Section - --------------------------------------------------------- - 0 undefined - - 1-23 NAL unit Single NAL unit packet per H.264 5.6 - 24 STAP-A Single-time aggregation packet 5.7.1 - 25 STAP-B Single-time aggregation packet 5.7.1 - 26 MTAP16 Multi-time aggregation packet 5.7.2 - 27 MTAP24 Multi-time aggregation packet 5.7.2 - 28 FU-A Fragmentation unit 5.8 - 29 FU-B Fragmentation unit 5.8 - 30-31 undefined - - */ + Type Packet Type name Section + --------------------------------------------------------- + 0 undefined - + 1-23 NAL unit Single NAL unit packet per H.264 5.6 + 24 STAP-A Single-time aggregation packet 5.7.1 + 25 STAP-B Single-time aggregation packet 5.7.1 + 26 MTAP16 Multi-time aggregation packet 5.7.2 + 27 MTAP24 Multi-time aggregation packet 5.7.2 + 28 FU-A Fragmentation unit 5.8 + 29 FU-B Fragmentation unit 5.8 + 30-31 undefined - +*/ + +bool H264RtpDecoder::decodeRtp(const RtpPacket::Ptr &rtp) { auto frame = rtp->getPayload(); auto length = rtp->getPayloadSize(); auto stamp = rtp->getStampMS(); auto seq = rtp->getSeq(); - - int nal_type = *frame & 0x1F; - int nal_suffix = *frame & (~0x1F); + auto nal_type = *frame & 0x1F; + auto nal_suffix = *frame & (~0x1F); if (nal_type >= 0 && nal_type < 24) { //a full frame - _h264frame->_buffer.assign("\x00\x00\x00\x01", 4); - _h264frame->_buffer.append((char *) frame, length); - _h264frame->_pts = stamp; - auto key = _h264frame->keyFrame(); - onGetH264(_h264frame); + _frame->_buffer.assign("\x00\x00\x00\x01", 4); + _frame->_buffer.append((char *) frame, length); + _frame->_pts = stamp; + auto key = _frame->keyFrame(); + onGetH264(_frame); return (key); //i frame } - switch (nal_type){ - case 24:{ + switch (nal_type) { + case 24: { // 24 STAP-A 单一时间的组合包 bool haveIDR = false; auto ptr = frame + 1; @@ -106,53 +103,59 @@ bool H264RtpDecoder::decodeRtp(const RtpPacket::Ptr &rtp) { } if (len > 0) { //有有效数据 - _h264frame->_buffer.assign("\x00\x00\x00\x01", 4); - _h264frame->_buffer.append((char *) ptr, len); - _h264frame->_pts = stamp; + _frame->_buffer.assign("\x00\x00\x00\x01", 4); + _frame->_buffer.append((char *) ptr, len); + _frame->_pts = stamp; if ((ptr[0] & 0x1F) == H264Frame::NAL_IDR) { haveIDR = true; } - onGetH264(_h264frame); + onGetH264(_frame); } ptr += len; } return haveIDR; } - case 28:{ + case 28: { //FU-A - FU fu; - MakeFU(frame[1], fu); - if (fu.S) { + FuFlags *fu = (FuFlags *) (frame + 1); + if (fu->start_bit) { //该帧的第一个rtp包 FU-A start - _h264frame->_buffer.assign("\x00\x00\x00\x01", 4); - _h264frame->_buffer.push_back(nal_suffix | fu.type); - _h264frame->_buffer.append((char *) frame + 2, length - 2); - _h264frame->_pts = stamp; + //预留空间，防止频繁扩容拷贝 + _frame->_buffer.reserve(_max_frame_size); + _frame->_buffer.assign("\x00\x00\x00\x01", 4); + _frame->_buffer.push_back(nal_suffix | fu->nal_type); + _frame->_buffer.append((char *) frame + 2, length - 2); + _frame->_pts = stamp; //该函数return时，保存下当前sequence,以便下次对比seq是否连续 - _lastSeq = seq; - return _h264frame->keyFrame(); + _last_seq = seq; + return _frame->keyFrame(); } - if (seq != (uint16_t)(_lastSeq + 1) && seq != 0) { + if (seq != (uint16_t) (_last_seq + 1)) { //中间的或末尾的rtp包，其seq必须连续(如果回环了则判定为连续)，否则说明rtp丢包，那么该帧不完整，必须得丢弃 - _h264frame->_buffer.clear(); - WarnL << "rtp丢包: " << seq << " != " << _lastSeq << " + 1,该帧被废弃"; + _frame->_buffer.clear(); + WarnL << "rtp丢包: " << seq << " != " << _last_seq << " + 1,该帧被废弃"; return false; } - if (!fu.E) { + if (!fu->end_bit) { //该帧的中间rtp包 FU-A mid - _h264frame->_buffer.append((char *) frame + 2, length - 2); + _frame->_buffer.append((char *) frame + 2, length - 2); //该函数return时，保存下当前sequence,以便下次对比seq是否连续 - _lastSeq = seq; + _last_seq = seq; return false; } //该帧最后一个rtp包 FU-A end - _h264frame->_buffer.append((char *) frame + 2, length - 2); - _h264frame->_pts = stamp; - onGetH264(_h264frame); + _frame->_buffer.append((char *) frame + 2, length - 2); + _frame->_pts = stamp; + //计算最大的帧 + auto frame_size = _frame->size(); + if (frame_size > _max_frame_size) { + _max_frame_size = frame_size; + } + onGetH264(_frame); return false; } @@ -161,9 +164,6 @@ bool H264RtpDecoder::decodeRtp(const RtpPacket::Ptr &rtp) { // 25 STAP-B 单一时间的组合包 // 26 MTAP16 多个时间的组合包 // 27 MTAP24 多个时间的组合包 - // 0 udef - // 30 udef - // 31 udef WarnL << "不支持的rtp类型:" << (int) nal_type << " " << seq; return false; } @@ -173,24 +173,15 @@ bool H264RtpDecoder::decodeRtp(const RtpPacket::Ptr &rtp) { void H264RtpDecoder::onGetH264(const H264Frame::Ptr &frame) { //rtsp没有dts，那么根据pts排序算法生成dts _dts_generator.getDts(frame->_pts,frame->_dts); - //写入环形缓存 RtpCodec::inputFrame(frame); - _h264frame = obtainFrame(); + _frame = obtainFrame(); } //////////////////////////////////////////////////////////////////////// -H264RtpEncoder::H264RtpEncoder(uint32_t ui32Ssrc, - uint32_t ui32MtuSize, - uint32_t ui32SampleRate, - uint8_t ui8PayloadType, - uint8_t ui8Interleaved) : - RtpInfo(ui32Ssrc, - ui32MtuSize, - ui32SampleRate, - ui8PayloadType, - ui8Interleaved) { +H264RtpEncoder::H264RtpEncoder(uint32_t ssrc, uint32_t mtu, uint32_t sample_rate, uint8_t pt, uint8_t interleaved) + : RtpInfo(ssrc, mtu, sample_rate, pt, interleaved) { } void H264RtpEncoder::inputFrame(const Frame::Ptr &frame) { @@ -198,48 +189,39 @@ void H264RtpEncoder::inputFrame(const Frame::Ptr &frame) { auto len = frame->size() - frame->prefixSize(); auto pts = frame->pts(); auto nal_type = H264_TYPE(ptr[0]); - auto max_size = getMaxSize() - 2; + auto packet_size = getMaxSize() - 2; + + //末尾5bit为nalu type，固定为28(FU-A) + auto fu_char_0 = (ptr[0] & (~0x1F)) | 28; + auto fu_char_1 = nal_type; + FuFlags *fu_flags = (FuFlags *) (&fu_char_1); + fu_flags->start_bit = 1; //超过MTU则按照FU-A模式打包 - if (len > max_size + 1) { - //最高位bit为forbidden_zero_bit, - //后面2bit为nal_ref_idc(帧重要程度),00:可以丢,11:不能丢 - //末尾5bit为nalu type，固定为28(FU-A) - unsigned char nal_fu_a = (*((unsigned char *) ptr) & (~0x1F)) | 28; - unsigned char s_e_r_flags; - bool fu_a_start = true; - bool mark_bit = false; + if (len > packet_size + 1) { size_t offset = 1; - while (!mark_bit) { - if (len <= offset + max_size) { + while (!fu_flags->end_bit) { + if (!fu_flags->start_bit && len <= offset + packet_size) { //FU-A end - mark_bit = true; - max_size = len - offset; - s_e_r_flags = (1 << 6) | nal_type; - } else if (fu_a_start) { - //FU-A start - s_e_r_flags = (1 << 7) | nal_type; - } else { - //FU-A mid - s_e_r_flags = nal_type; + packet_size = len - offset; + fu_flags->end_bit = 1; } - { - //传入nullptr先不做payload的内存拷贝 - auto rtp = makeRtp(getTrackType(), nullptr, max_size + 2, mark_bit, pts); - //rtp payload 负载部分 - uint8_t *payload = rtp->getPayload(); - //FU-A 第1个字节 - payload[0] = nal_fu_a; - //FU-A 第2个字节 - payload[1] = s_e_r_flags; - //H264 数据 - memcpy(payload + 2, (unsigned char *) ptr + offset, max_size); - //输入到rtp环形缓存 - RtpCodec::inputRtp(rtp, fu_a_start && nal_type == H264Frame::NAL_IDR); - } - offset += max_size; - fu_a_start = false; + //传入nullptr先不做payload的内存拷贝 + auto rtp = makeRtp(getTrackType(), nullptr, packet_size + 2, fu_flags->end_bit, pts); + //rtp payload 负载部分 + uint8_t *payload = rtp->getPayload(); + //FU-A 第1个字节 + payload[0] = fu_char_0; + //FU-A 第2个字节 + payload[1] = fu_char_1; + //H264 数据 + memcpy(payload + 2, (uint8_t *) ptr + offset, packet_size); + //输入到rtp环形缓存 + RtpCodec::inputRtp(rtp, fu_flags->start_bit && nal_type == H264Frame::NAL_IDR); + + offset += packet_size; + fu_flags->start_bit = 0; } } else { //如果帧长度不超过mtu, 则按照Single NAL unit packet per H.264 方式打包 diff --git a/src/Extension/H264Rtp.h b/src/Extension/H264Rtp.h index 303c77a5..d727a0c1 100644 --- a/src/Extension/H264Rtp.h +++ b/src/Extension/H264Rtp.h @@ -48,8 +48,9 @@ private: H264Frame::Ptr obtainFrame(); private: - uint16_t _lastSeq = 0; - H264Frame::Ptr _h264frame; + uint16_t _last_seq = 0; + size_t _max_frame_size = 0; + H264Frame::Ptr _frame; DtsGenerator _dts_generator; }; @@ -61,17 +62,17 @@ public: typedef std::shared_ptr Ptr; /** - * @param ui32Ssrc ssrc - * @param ui32MtuSize mtu大小 - * @param ui32SampleRate 采样率，强制为90000 - * @param ui8PayloadType pt类型 - * @param ui8Interleaved rtsp interleaved + * @param ssrc ssrc + * @param mtu mtu大小 + * @param sample_rate 采样率，强制为90000 + * @param pt pt类型 + * @param interleaved rtsp interleaved */ - H264RtpEncoder(uint32_t ui32Ssrc, - uint32_t ui32MtuSize = 1400, - uint32_t ui32SampleRate = 90000, - uint8_t ui8PayloadType = 96, - uint8_t ui8Interleaved = TrackVideo * 2); + H264RtpEncoder(uint32_t ssrc, + uint32_t mtu = 1400, + uint32_t sample_rate = 90000, + uint8_t pt = 96, + uint8_t interleaved = TrackVideo * 2); ~H264RtpEncoder() {} /**