From 3acfb15c9930a378cafc53af367d3dad4de68bdd Mon Sep 17 00:00:00 2001 From: xiongziliang <771730766@qq.com> Date: Sun, 26 Jul 2020 19:56:39 +0800 Subject: [PATCH] =?UTF-8?q?=E5=AE=8C=E5=96=84H264=20rtp=E8=A7=A3=E5=8C=85?= =?UTF-8?q?=E6=89=93=E5=8C=85=E7=9B=B8=E5=85=B3=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 | 108 +++++++++++++++----------------------- src/Extension/H264Rtp.h | 2 +- 2 files changed, 44 insertions(+), 66 deletions(-) diff --git a/src/Extension/H264Rtp.cpp b/src/Extension/H264Rtp.cpp index 76958147..986cf3ef 100644 --- a/src/Extension/H264Rtp.cpp +++ b/src/Extension/H264Rtp.cpp @@ -12,13 +12,6 @@ namespace mediakit{ - -typedef struct { - unsigned forbidden_zero_bit :1; - unsigned nal_ref_idc :2; - unsigned type :5; -} NALU; - typedef struct { unsigned S :1; unsigned E :1; @@ -26,15 +19,6 @@ typedef struct { unsigned type :5; } FU; -static bool MakeNalu(uint8_t in, NALU &nal) { - nal.forbidden_zero_bit = in >> 7; - if (nal.forbidden_zero_bit) { - return false; - } - nal.nal_ref_idc = (in & 0x60) >> 5; - nal.type = in & 0x1f; - return true; -} static bool MakeFU(uint8_t in, FU &fu) { fu.S = in >> 7; fu.E = (in >> 6) & 0x01; @@ -86,30 +70,28 @@ bool H264RtpDecoder::decodeRtp(const RtpPacket::Ptr &rtppack) { 28 FU-A Fragmentation unit 5.8 29 FU-B Fragmentation unit 5.8 30-31 undefined - - - */ const uint8_t *frame = (uint8_t *) rtppack->data() + rtppack->offset; int length = rtppack->size() - rtppack->offset; - NALU nal; - MakeNalu(*frame, nal); + int nal_type = *frame & 0x1F; + int nal_suffix = *frame & (~0x1F); - if (nal.type >= 0 && nal.type < 24) { + if (nal_type >= 0 && nal_type < 24) { //a full frame _h264frame->_buffer.assign("\x0\x0\x0\x1", 4); - _h264frame->_buffer.append((char *)frame, length); + _h264frame->_buffer.append((char *) frame, length); _h264frame->_pts = rtppack->timeStamp; auto key = _h264frame->keyFrame(); onGetH264(_h264frame); return (key); //i frame } - switch (nal.type){ + switch (nal_type){ case 24:{ // 24 STAP-A 单一时间的组合包 bool haveIDR = false; auto ptr = frame + 1; - while(true){ + while (true) { int off = ptr - frame; if (off >= length) { break; @@ -121,14 +103,12 @@ bool H264RtpDecoder::decodeRtp(const RtpPacket::Ptr &rtppack) { if (off + len > length) { break; } - if(len >= 10){ + if (len > 4) { //过小的帧丢弃 - NALU nal; - MakeNalu(ptr[0], nal); _h264frame->_buffer.assign("\x0\x0\x0\x1", 4); - _h264frame->_buffer.append((char *)ptr, len); + _h264frame->_buffer.append((char *) ptr, len); _h264frame->_pts = rtppack->timeStamp; - if(nal.type == H264Frame::NAL_IDR){ + if ((ptr[0] & 0x1F) == H264Frame::NAL_IDR) { haveIDR = true; } onGetH264(_h264frame); @@ -144,10 +124,9 @@ bool H264RtpDecoder::decodeRtp(const RtpPacket::Ptr &rtppack) { MakeFU(frame[1], fu); if (fu.S) { //该帧的第一个rtp包 FU-A start - char tmp = (nal.forbidden_zero_bit << 7 | nal.nal_ref_idc << 5 | fu.type); _h264frame->_buffer.assign("\x0\x0\x0\x1", 4); - _h264frame->_buffer.push_back(tmp); - _h264frame->_buffer.append((char *)frame + 2, length - 2); + _h264frame->_buffer.push_back(nal_suffix | fu.type); + _h264frame->_buffer.append((char *) frame + 2, length - 2); _h264frame->_pts = rtppack->timeStamp; //该函数return时，保存下当前sequence,以便下次对比seq是否连续 _lastSeq = rtppack->sequence; @@ -163,20 +142,20 @@ bool H264RtpDecoder::decodeRtp(const RtpPacket::Ptr &rtppack) { if (!fu.E) { //该帧的中间rtp包 FU-A mid - _h264frame->_buffer.append((char *)frame + 2, length - 2); + _h264frame->_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 = rtppack->sequence; return false; } //该帧最后一个rtp包 FU-A end - _h264frame->_buffer.append((char *)frame + 2, length - 2); + _h264frame->_buffer.append((char *) frame + 2, length - 2); _h264frame->_pts = rtppack->timeStamp; onGetH264(_h264frame); return false; } - default:{ + default: { // 29 FU-B 单NAL单元B模式 // 25 STAP-B 单一时间的组合包 // 26 MTAP16 多个时间的组合包 @@ -184,7 +163,7 @@ bool H264RtpDecoder::decodeRtp(const RtpPacket::Ptr &rtppack) { // 0 udef // 30 udef // 31 udef - WarnL << "不支持的rtp类型:" << (int)nal.type << " " << rtppack->sequence; + WarnL << "不支持的rtp类型:" << (int) nal_type << " " << rtppack->sequence; return false; } } @@ -215,63 +194,62 @@ H264RtpEncoder::H264RtpEncoder(uint32_t ui32Ssrc, void H264RtpEncoder::inputFrame(const Frame::Ptr &frame) { GET_CONFIG(uint32_t,cycleMS,Rtp::kCycleMS); - auto pcData = frame->data() + frame->prefixSize(); - auto uiStamp = frame->pts(); - auto iLen = frame->size() - frame->prefixSize(); - //获取NALU的5bit 帧类型 - unsigned char naluType = H264_TYPE(pcData[0]); + auto ptr = frame->data() + frame->prefixSize(); + auto pts = frame->pts() % cycleMS; + auto len = frame->size() - frame->prefixSize(); + auto nal_type = H264_TYPE(ptr[0]); + auto max_rtp_size = _ui32MtuSize - 2; - uiStamp %= cycleMS; - int iSize = _ui32MtuSize - 2; //超过MTU则按照FU-A模式打包 - if (iLen > iSize) { + if (len > max_rtp_size) { //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 f_nri_flags = (*((unsigned char *) pcData) & 0x60) | 28; + unsigned char nal_fu_a = (*((unsigned char *) ptr) & (~0x1F)) | 28; unsigned char s_e_r_flags; - bool bFirst = true; - bool mark = false; - int nOffset = 1; - while (!mark) { - if (iLen <= nOffset + iSize) { + bool fu_a_start = true; + bool mark_bit = false; + int offset = 1; + while (!mark_bit) { + if (len <= offset + max_rtp_size) { //已经拆分结束 - iSize = iLen - nOffset; - mark = true; + max_rtp_size = len - offset; + mark_bit = true; //FU-A end - s_e_r_flags = (1 << 6) | naluType; - } else if (bFirst) { + s_e_r_flags = (1 << 6) | nal_type; + } else if (fu_a_start) { //FU-A start - s_e_r_flags = (1 << 7) | naluType; + s_e_r_flags = (1 << 7) | nal_type; } else { //FU-A mid - s_e_r_flags = naluType; + s_e_r_flags = nal_type; } { //传入nullptr先不做payload的内存拷贝 - auto rtp = makeRtp(getTrackType(), nullptr, iSize + 2, mark, uiStamp); + auto rtp = makeRtp(getTrackType(), nullptr, max_rtp_size + 2, mark_bit, pts); //rtp payload 负载部分 uint8_t *payload = (uint8_t*)rtp->data() + rtp->offset; //FU-A 第1个字节 - payload[0] = f_nri_flags; + 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 *) pcData + nOffset, iSize); + memcpy(payload + 2, (unsigned char *) ptr + offset, max_rtp_size); //输入到rtp环形缓存 - RtpCodec::inputRtp(rtp,bFirst && naluType == H264Frame::NAL_IDR); + RtpCodec::inputRtp(rtp, fu_a_start && nal_type == H264Frame::NAL_IDR); } - nOffset += iSize; - bFirst = false; + offset += max_rtp_size; + fu_a_start = false; } } else { - makeH264Rtp(naluType,pcData, iLen, true, true, uiStamp); + //如果帧长度不超过mtu, 则按照Single NAL unit packet per H.264 方式打包 + makeH264Rtp(ptr, len, false, false, pts); } } -void H264RtpEncoder::makeH264Rtp(int nal_type,const void* data, unsigned int len, bool mark, bool first_packet, uint32_t uiStamp) { - RtpCodec::inputRtp(makeRtp(getTrackType(),data,len,mark,uiStamp),first_packet && nal_type == H264Frame::NAL_IDR); +void H264RtpEncoder::makeH264Rtp(const void* data, unsigned int len, bool mark, bool gop_pos, uint32_t uiStamp) { + RtpCodec::inputRtp(makeRtp(getTrackType(), data, len, mark, uiStamp), gop_pos); } }//namespace mediakit diff --git a/src/Extension/H264Rtp.h b/src/Extension/H264Rtp.h index 2b5038b1..89e09c59 100644 --- a/src/Extension/H264Rtp.h +++ b/src/Extension/H264Rtp.h @@ -78,7 +78,7 @@ public: */ void inputFrame(const Frame::Ptr &frame) override; private: - void makeH264Rtp(int nal_type,const void *pData, unsigned int uiLen, bool bMark, bool first_packet, uint32_t uiStamp); + void makeH264Rtp(const void *pData, unsigned int uiLen, bool bMark, bool gop_pos, uint32_t uiStamp); }; }//namespace mediakit{