/*
* MIT License
*
* Copyright (c) 2016-2019 xiongziliang <771730766@qq.com>
* Copyright (c) 2019 火宣 <459502659@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.
*/
#include "H264RtpCodec.h"
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;
unsigned R :1;
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;
fu.R = (in >> 5) & 0x01;
fu.type = in & 0x1f;
if (fu.R != 0) {
return false;
}
return true;
}
H264RtpDecoder::H264RtpDecoder() {
_h264frame = obtainFrame();
}
H264Frame::Ptr H264RtpDecoder::obtainFrame() {
//从缓存池重新申请对象，防止覆盖已经写入环形缓存的对象
auto frame = ResourcePoolHelper<H264Frame>::obtainObj();
frame->buffer.clear();
frame->iPrefixSize = 4;
return frame;
}
bool H264RtpDecoder::inputRtp(const RtpPacket::Ptr &rtp, bool key_pos) {
key_pos = decodeRtp(rtp);
RtpCodec::inputRtp(rtp, key_pos);
return key_pos;
}
bool H264RtpDecoder::decodeRtp(const RtpPacket::Ptr &rtppack) {
/**
* 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
*/
const uint8_t *frame = (uint8_t *) rtppack->data() + rtppack->offset;
int length = rtppack->size() - rtppack->offset;
NALU nal;
MakeNalu(*frame, nal);
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->type = nal.type;
_h264frame->timeStamp = rtppack->timeStamp;
_h264frame->sequence = rtppack->sequence;
auto isIDR = _h264frame->type == H264Frame::NAL_IDR;
onGetH264(_h264frame);
return (isIDR); //i frame
}
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){
int off = ptr - frame;
if (off >= length) {
break;
}
//获取当前nalu的大小
uint16_t len = *ptr++;
len <<= 8;
len |= *ptr++;
if (off + len > length) {
break;
}
if(len >= 10){
//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->type = nal.type;
_h264frame->timeStamp = rtppack->timeStamp;
_h264frame->sequence = rtppack->sequence;
if(nal.type == H264Frame::NAL_IDR){
haveIDR = true;
}
onGetH264(_h264frame);
}
ptr += len;
}
return haveIDR;
}
case 28:{
//FU-A
FU fu;
MakeFU(frame[1], fu);
if (fu.S == 1) {
//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->type = fu.type;
_h264frame->timeStamp = rtppack->timeStamp;
_h264frame->sequence = rtppack->sequence;
return (_h264frame->type == H264Frame::NAL_IDR); //i frame
}
if (rtppack->sequence != (uint16_t)(_h264frame->sequence + 1)) {
_h264frame->buffer.clear();
WarnL << "丢包,帧废弃:" << rtppack->sequence << "," << _h264frame->sequence;
return false;
}
_h264frame->sequence = rtppack->sequence;
if (fu.E == 1) {
//FU-A end
_h264frame->buffer.append((char *)frame + 2, length - 2);
_h264frame->timeStamp = rtppack->timeStamp;
auto isIDR = _h264frame->type == H264Frame::NAL_IDR;
onGetH264(_h264frame);
return isIDR;
}
//FU-A mid
_h264frame->buffer.append((char *)frame + 2, length - 2);
return false;
}
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
// 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 << " " << rtppack->sequence;
return false;
}
}
}
void H264RtpDecoder::onGetH264(const H264Frame::Ptr &frame) {
//写入环形缓存
auto lastSeq = _h264frame->sequence;
RtpCodec::inputFrame(frame);
_h264frame = obtainFrame();
_h264frame->sequence = lastSeq;
}
////////////////////////////////////////////////////////////////////////
H264RtpEncoder::H264RtpEncoder(uint32_t ui32Ssrc,
uint32_t ui32MtuSize,
uint32_t ui32SampleRate,
uint8_t ui8PlayloadType,
uint8_t ui8Interleaved) :
RtpInfo(ui32Ssrc,
ui32MtuSize,
ui32SampleRate,
ui8PlayloadType,
ui8Interleaved) {
}
void H264RtpEncoder::inputFrame(const Frame::Ptr &frame) {
RtpCodec::inputFrame(frame);
GET_CONFIG(uint32_t,cycleMS,Rtp::kCycleMS);
auto pcData = frame->data() + frame->prefixSize();
auto uiStamp = frame->stamp();
auto iLen = frame->size() - frame->prefixSize();
unsigned char naluType = H264_TYPE(pcData[0]); //获取NALU的5bit 帧类型
uiStamp %= cycleMS;
int iSize = _ui32MtuSize - 2;
if (iLen > iSize) { //超过MTU
const unsigned char s_e_r_Start = 0x80;
const unsigned char s_e_r_Mid = 0x00;
const unsigned char s_e_r_End = 0x40;
//获取帧头数据，1byte
unsigned char nal_ref_idc = *((unsigned char *) pcData) & 0x60; //获取NALU的2bit 帧重要程度 00 可以丢 11不能丢
//nal_ref_idc = 0x60;
//组装FU-A帧头数据 2byte
unsigned char f_nri_type = nal_ref_idc + 28;//F为0 1bit,nri上面获取到2bit,28为FU-A分片类型5bit
unsigned char s_e_r_type = naluType;
bool bFirst = true;
bool mark = false;
int nOffset = 1;
while (!mark) {
if (iLen < nOffset + iSize) { //是否拆分结束
iSize = iLen - nOffset;
mark = true;
s_e_r_type = s_e_r_End + naluType;
} else if (bFirst) {
s_e_r_type = s_e_r_Start + naluType;
} else {
s_e_r_type = s_e_r_Mid + naluType;
}
memcpy(_aucSectionBuf, &f_nri_type, 1);
memcpy(_aucSectionBuf + 1, &s_e_r_type, 1);
memcpy(_aucSectionBuf + 2, (unsigned char *) pcData + nOffset, iSize);
nOffset += iSize;
makeH264Rtp(naluType,_aucSectionBuf, iSize + 2, mark,bFirst, uiStamp);
bFirst = false;
}
} else {
makeH264Rtp(naluType,pcData, iLen, true, true, uiStamp);
}
}
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);
}
}//namespace mediakit