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ZLMediaKit
Commit 3acfb15c by xiongziliang
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完善H264 rtp解包打包相关代码

parent c0fde624
正在显示 包含 44 行增加 和 66 行删除
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
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{
......
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