FU-A分包方式,以及从RTP包里面得到H.264数据和AAC数据的方法
2012-11-06 10:59
423 查看
RFC3984是H.264的baseline码流在RTP方式下传输的规范,这里只讨论FU-A分包方式,以及从RTP包里面得到H.264数据和AAC数据的方法。
1、单个NAL包单元
12字节的RTP头后面的就是音视频数据,比较简单。一个封装单个NAL单元包到RTP的NAL单元流的RTP序号必须符合NAL单元的解码顺序。
2、FU-A的分片格式
数据比较大的H264视频包,被RTP分片发送。12字节的RTP头后面跟随的就是FU-A分片:
FU indicator有以下格式:
+---------------+
|0|1|2|3|4|5|6|7|
+-+-+-+-+-+-+-+-+
|F|NRI| Type |
+---------------+
FU指示字节的类型域 Type=28表示FU-A。。NRI域的值必须根据分片NAL单元的NRI域的值设置。
FU header的格式如下:
+---------------+
|0|1|2|3|4|5|6|7|
+-+-+-+-+-+-+-+-+
|S|E|R| Type |
+---------------+
S: 1 bit
当设置成1,开始位指示分片NAL单元的开始。当跟随的FU荷载不是分片NAL单元荷载的开始,开始位设为0。
E: 1 bit
当设置成1, 结束位指示分片NAL单元的结束,即, 荷载的最后字节也是分片NAL单元的最后一个字节。当跟随的FU荷载不是分片NAL单元的最后分片,结束位设置为0。
R: 1 bit
保留位必须设置为0,接收者必须忽略该位。
Type: 5 bits
NAL单元荷载类型定义见下表
表1. 单元类型以及荷载结构总结
Type Packet Type name
---------------------------------------------------------
0 undefined -
1-23 NAL unit Single NAL unit packet per H.264
24 STAP-A Single-time aggregation packet
25 STAP-B Single-time aggregation packet
26 MTAP16 Multi-time aggregation packet
27 MTAP24 Multi-time aggregation packet
28 FU-A Fragmentation unit
29 FU-B Fragmentation unit
30-31 undefined -
3、拆包和解包
拆包:当编码器在编码时需要将原有一个NAL按照FU-A进行分片,原有的NAL的单元头与分片后的FU-A的单元头有如下关系:
原始的NAL头的前三位为FU indicator的前三位,原始的NAL头的后五位为FU header的后五位,FU indicator与FU header的剩余位数根据实际情况决定。
解包:当接收端收到FU-A的分片数据,需要将所有的分片包组合还原成原始的NAl包时,FU-A的单元头与还原后的NAL的关系如下:
还原后的NAL头的八位是由FU indicator的前三位加FU header的后五位组成,即:
nal_unit_type = (fu_indicator & 0xe0) | (fu_header & 0x1f)
4、代码实现
从RTP包里面得到H264视频数据的方法:
![](http://www.cnweblog.com/Images/OutliningIndicators/None.gif)
![](http://www.cnweblog.com/Images/OutliningIndicators/None.gif)
// 功能:解码RTP H.264视频
![](http://www.cnweblog.com/Images/OutliningIndicators/None.gif)
// 参数:1.RTP包缓冲地址 2.RTP包数据大小 3.H264输出地址 4.输出数据大小
![](http://www.cnweblog.com/Images/OutliningIndicators/None.gif)
// 返回:true:表示一帧结束 false:FU-A分片未结束或帧未结束
![](http://www.cnweblog.com/Images/OutliningIndicators/None.gif)
#define RTP_HEADLEN 12
![](http://www.cnweblog.com/Images/OutliningIndicators/None.gif)
bool UnpackRTPH264(
void
* bufIn,
int len,
void ** pBufOut,
int
* pOutLen)
![](http://www.cnweblog.com/Images/OutliningIndicators/ExpandedBlockStart.gif)
![](http://www.cnweblog.com/Images/OutliningIndicators/ContractedBlock.gif)
![](http://www.cnweblog.com/Images/dot.gif)
{
![](http://www.cnweblog.com/Images/OutliningIndicators/InBlock.gif)
* pOutLen
= 0
;
![](http://www.cnweblog.com/Images/OutliningIndicators/InBlock.gif)
if (len
< RTP_HEADLEN)
![](http://www.cnweblog.com/Images/OutliningIndicators/ExpandedSubBlockStart.gif)
![](http://www.cnweblog.com/Images/OutliningIndicators/ContractedSubBlock.gif)
![](http://www.cnweblog.com/Images/dot.gif)
{
![](http://www.cnweblog.com/Images/OutliningIndicators/InBlock.gif)
return
false ;
![](http://www.cnweblog.com/Images/OutliningIndicators/ExpandedSubBlockEnd.gif)
}
![](http://www.cnweblog.com/Images/OutliningIndicators/InBlock.gif)
![](http://www.cnweblog.com/Images/OutliningIndicators/InBlock.gif)
unsigned
char *
src = (unsigned
char *
)bufIn + RTP_HEADLEN;
![](http://www.cnweblog.com/Images/OutliningIndicators/InBlock.gif)
unsigned
char head1
=
* src; //
获取第一个字节
![](http://www.cnweblog.com/Images/OutliningIndicators/InBlock.gif)
unsigned
char head2
= *
(src +
1 ); //
获取第二个字节
![](http://www.cnweblog.com/Images/OutliningIndicators/InBlock.gif)
unsigned
char nal
= head1 &
0x1f
; // 获取FU indicator的类型域,
![](http://www.cnweblog.com/Images/OutliningIndicators/InBlock.gif)
unsigned
char flag
= head2 &
0xe0
; // 获取FU header的前三位,判断当前是分包的开始、中间或结束
![](http://www.cnweblog.com/Images/OutliningIndicators/InBlock.gif)
unsigned
char nal_fua
= (head1
& 0xe0
) |
(head2 &
0x1f );
// FU_A nal
![](http://www.cnweblog.com/Images/OutliningIndicators/InBlock.gif)
bool
bFinishFrame =
false
;
![](http://www.cnweblog.com/Images/OutliningIndicators/InBlock.gif)
if (nal
== 0x1c )
// 判断NAL的类型为0x1c=28,说明是FU-A分片
![](http://www.cnweblog.com/Images/OutliningIndicators/ExpandedSubBlockStart.gif)
![](http://www.cnweblog.com/Images/OutliningIndicators/ContractedSubBlock.gif)
![](http://www.cnweblog.com/Images/dot.gif)
{
// fu-a
![](http://www.cnweblog.com/Images/OutliningIndicators/InBlock.gif)
if
(flag ==
0x80 ) //
开始
![](http://www.cnweblog.com/Images/OutliningIndicators/ExpandedSubBlockStart.gif)
![](http://www.cnweblog.com/Images/OutliningIndicators/ContractedSubBlock.gif)
![](http://www.cnweblog.com/Images/dot.gif)
{
![](http://www.cnweblog.com/Images/OutliningIndicators/InBlock.gif)
* pBufOut
= src -
3 ;
![](http://www.cnweblog.com/Images/OutliningIndicators/InBlock.gif)
* ((
int * )(
* pBufOut))
=
0x01000000 ;
// zyf:大模式会有问题
![](http://www.cnweblog.com/Images/OutliningIndicators/InBlock.gif)
* (( char
* )(
* pBufOut)
+ 4 )
= nal_fua;
![](http://www.cnweblog.com/Images/OutliningIndicators/InBlock.gif)
* pOutLen
= len
- RTP_HEADLEN
+ 3
;
![](http://www.cnweblog.com/Images/OutliningIndicators/ExpandedSubBlockEnd.gif)
}
![](http://www.cnweblog.com/Images/OutliningIndicators/InBlock.gif)
else
if (flag ==
0x40 )
// 结束
![](http://www.cnweblog.com/Images/OutliningIndicators/ExpandedSubBlockStart.gif)
![](http://www.cnweblog.com/Images/OutliningIndicators/ContractedSubBlock.gif)
![](http://www.cnweblog.com/Images/dot.gif)
{
![](http://www.cnweblog.com/Images/OutliningIndicators/InBlock.gif)
* pBufOut
= src +
2 ;
![](http://www.cnweblog.com/Images/OutliningIndicators/InBlock.gif)
* pOutLen
= len
- RTP_HEADLEN
- 2
;
![](http://www.cnweblog.com/Images/OutliningIndicators/ExpandedSubBlockEnd.gif)
}
![](http://www.cnweblog.com/Images/OutliningIndicators/InBlock.gif)
else //
中间
![](http://www.cnweblog.com/Images/OutliningIndicators/ExpandedSubBlockStart.gif)
![](http://www.cnweblog.com/Images/OutliningIndicators/ContractedSubBlock.gif)
![](http://www.cnweblog.com/Images/dot.gif)
{
![](http://www.cnweblog.com/Images/OutliningIndicators/InBlock.gif)
* pBufOut
= src +
2 ;
![](http://www.cnweblog.com/Images/OutliningIndicators/InBlock.gif)
* pOutLen
= len
- RTP_HEADLEN
- 2
;
![](http://www.cnweblog.com/Images/OutliningIndicators/ExpandedSubBlockEnd.gif)
}
![](http://www.cnweblog.com/Images/OutliningIndicators/ExpandedSubBlockEnd.gif)
}
![](http://www.cnweblog.com/Images/OutliningIndicators/InBlock.gif)
else //
单包数据
![](http://www.cnweblog.com/Images/OutliningIndicators/ExpandedSubBlockStart.gif)
![](http://www.cnweblog.com/Images/OutliningIndicators/ContractedSubBlock.gif)
![](http://www.cnweblog.com/Images/dot.gif)
{
![](http://www.cnweblog.com/Images/OutliningIndicators/InBlock.gif)
* pBufOut
= src -
4 ;
![](http://www.cnweblog.com/Images/OutliningIndicators/InBlock.gif)
* ((
int * )(
* pBufOut))
=
0x01000000 ;
// zyf:大模式会有问题
![](http://www.cnweblog.com/Images/OutliningIndicators/InBlock.gif)
*
pOutLen =
len -
RTP_HEADLEN +
4 ;
![](http://www.cnweblog.com/Images/OutliningIndicators/ExpandedSubBlockEnd.gif)
}
![](http://www.cnweblog.com/Images/OutliningIndicators/InBlock.gif)
![](http://www.cnweblog.com/Images/OutliningIndicators/InBlock.gif)
unsigned
char *
bufTmp =
(unsigned char
* )bufIn;
![](http://www.cnweblog.com/Images/OutliningIndicators/InBlock.gif)
if (bufTmp[
1 ]
& 0x80
)
![](http://www.cnweblog.com/Images/OutliningIndicators/ExpandedSubBlockStart.gif)
![](http://www.cnweblog.com/Images/OutliningIndicators/ContractedSubBlock.gif)
![](http://www.cnweblog.com/Images/dot.gif)
{
![](http://www.cnweblog.com/Images/OutliningIndicators/InBlock.gif)
bFinishFrame
=
true ; //
rtp mark
![](http://www.cnweblog.com/Images/OutliningIndicators/ExpandedSubBlockEnd.gif)
}
![](http://www.cnweblog.com/Images/OutliningIndicators/InBlock.gif)
else
![](http://www.cnweblog.com/Images/OutliningIndicators/ExpandedSubBlockStart.gif)
![](http://www.cnweblog.com/Images/OutliningIndicators/ContractedSubBlock.gif)
![](http://www.cnweblog.com/Images/dot.gif)
{
![](http://www.cnweblog.com/Images/OutliningIndicators/InBlock.gif)
bFinishFrame
=
false ;
![](http://www.cnweblog.com/Images/OutliningIndicators/ExpandedSubBlockEnd.gif)
}
![](http://www.cnweblog.com/Images/OutliningIndicators/InBlock.gif)
return bFinishFrame;
![](http://www.cnweblog.com/Images/OutliningIndicators/ExpandedBlockEnd.gif)
}
![](http://www.cnweblog.com/Images/OutliningIndicators/None.gif)
![](http://www.cnweblog.com/Images/OutliningIndicators/None.gif)
从RTP包里面得到AAC音频数据的方法:
![](http://www.cnweblog.com/Images/OutliningIndicators/None.gif)
![](http://www.cnweblog.com/Images/OutliningIndicators/None.gif)
//功能:解RTP AAC音频包,声道和采样频率必须知道。
![](http://www.cnweblog.com/Images/OutliningIndicators/None.gif)
//参数:1.RTP包缓冲地址 2.RTP包数据大小 3.H264输出地址 4.输出数据大小
![](http://www.cnweblog.com/Images/OutliningIndicators/None.gif)
//返回:true:表示一帧结束 false:帧未结束 一般AAC音频包比较小,没有分片。
![](http://www.cnweblog.com/Images/OutliningIndicators/None.gif)
bool UnpackRTPAAC(void * bufIn, int recvLen, void** pBufOut, int* pOutLen)
![](http://www.cnweblog.com/Images/OutliningIndicators/ExpandedBlockStart.gif)
![](http://www.cnweblog.com/Images/OutliningIndicators/ContractedBlock.gif)
![](http://www.cnweblog.com/Images/dot.gif)
{
![](http://www.cnweblog.com/Images/OutliningIndicators/InBlock.gif)
unsigned char* bufRecv = (unsigned char*)bufIn;
![](http://www.cnweblog.com/Images/OutliningIndicators/InBlock.gif)
//char strFileName[20];
![](http://www.cnweblog.com/Images/OutliningIndicators/InBlock.gif)
![](http://www.cnweblog.com/Images/OutliningIndicators/ExpandedSubBlockStart.gif)
![](http://www.cnweblog.com/Images/OutliningIndicators/ContractedSubBlock.gif)
unsigned char ADTS[] =
![](http://www.cnweblog.com/Images/dot.gif)
{0xFF, 0xF1, 0x00, 0x00, 0x00, 0x00, 0xFC};
![](http://www.cnweblog.com/Images/OutliningIndicators/InBlock.gif)
int audioSamprate = 32000;//音频采样率
![](http://www.cnweblog.com/Images/OutliningIndicators/InBlock.gif)
int audioChannel = 2;//音频声道 1或2
![](http://www.cnweblog.com/Images/OutliningIndicators/InBlock.gif)
int audioBit = 16;//16位 固定
![](http://www.cnweblog.com/Images/OutliningIndicators/InBlock.gif)
switch(audioSamprate)
![](http://www.cnweblog.com/Images/OutliningIndicators/ExpandedSubBlockStart.gif)
![](http://www.cnweblog.com/Images/OutliningIndicators/ContractedSubBlock.gif)
![](http://www.cnweblog.com/Images/dot.gif)
{
![](http://www.cnweblog.com/Images/OutliningIndicators/InBlock.gif)
case 16000:
![](http://www.cnweblog.com/Images/OutliningIndicators/InBlock.gif)
ADTS[2] = 0x60;
![](http://www.cnweblog.com/Images/OutliningIndicators/InBlock.gif)
break;
![](http://www.cnweblog.com/Images/OutliningIndicators/InBlock.gif)
case 32000:
![](http://www.cnweblog.com/Images/OutliningIndicators/InBlock.gif)
ADTS[2] = 0x54;
![](http://www.cnweblog.com/Images/OutliningIndicators/InBlock.gif)
break;
![](http://www.cnweblog.com/Images/OutliningIndicators/InBlock.gif)
case 44100:
![](http://www.cnweblog.com/Images/OutliningIndicators/InBlock.gif)
ADTS[2] = 0x50;
![](http://www.cnweblog.com/Images/OutliningIndicators/InBlock.gif)
break;
![](http://www.cnweblog.com/Images/OutliningIndicators/InBlock.gif)
case 48000:
![](http://www.cnweblog.com/Images/OutliningIndicators/InBlock.gif)
ADTS[2] = 0x4C;
![](http://www.cnweblog.com/Images/OutliningIndicators/InBlock.gif)
break;
![](http://www.cnweblog.com/Images/OutliningIndicators/InBlock.gif)
case 96000:
![](http://www.cnweblog.com/Images/OutliningIndicators/InBlock.gif)
ADTS[2] = 0x40;
![](http://www.cnweblog.com/Images/OutliningIndicators/InBlock.gif)
break;
![](http://www.cnweblog.com/Images/OutliningIndicators/InBlock.gif)
default:
![](http://www.cnweblog.com/Images/OutliningIndicators/InBlock.gif)
break;
![](http://www.cnweblog.com/Images/OutliningIndicators/ExpandedSubBlockEnd.gif)
}
![](http://www.cnweblog.com/Images/OutliningIndicators/InBlock.gif)
ADTS[3] = (audioChannel==2)?0x80:0x40;
![](http://www.cnweblog.com/Images/OutliningIndicators/InBlock.gif)
![](http://www.cnweblog.com/Images/OutliningIndicators/InBlock.gif)
int len = recvLen - 16 + 7;
![](http://www.cnweblog.com/Images/OutliningIndicators/InBlock.gif)
len <<= 5;//8bit * 2 - 11 = 5(headerSize 11bit)
![](http://www.cnweblog.com/Images/OutliningIndicators/InBlock.gif)
len |= 0x1F;//5 bit 1
![](http://www.cnweblog.com/Images/OutliningIndicators/InBlock.gif)
ADTS[4] = len>>8;
![](http://www.cnweblog.com/Images/OutliningIndicators/InBlock.gif)
ADTS[5] = len & 0xFF;
![](http://www.cnweblog.com/Images/OutliningIndicators/InBlock.gif)
*pBufOut = (char*)bufIn+16-7;
![](http://www.cnweblog.com/Images/OutliningIndicators/InBlock.gif)
memcpy(*pBufOut, ADTS, sizeof(ADTS));
![](http://www.cnweblog.com/Images/OutliningIndicators/InBlock.gif)
*pOutLen = recvLen - 16 + 7;
![](http://www.cnweblog.com/Images/OutliningIndicators/InBlock.gif)
![](http://www.cnweblog.com/Images/OutliningIndicators/InBlock.gif)
unsigned char* bufTmp = (unsigned char*)bufIn;
![](http://www.cnweblog.com/Images/OutliningIndicators/InBlock.gif)
bool bFinishFrame = false;
![](http://www.cnweblog.com/Images/OutliningIndicators/InBlock.gif)
if (bufTmp[1] & 0x80)
![](http://www.cnweblog.com/Images/OutliningIndicators/ExpandedSubBlockStart.gif)
![](http://www.cnweblog.com/Images/OutliningIndicators/ContractedSubBlock.gif)
![](http://www.cnweblog.com/Images/dot.gif)
{
![](http://www.cnweblog.com/Images/OutliningIndicators/InBlock.gif)
//DebugTrace::D("Marker");
![](http://www.cnweblog.com/Images/OutliningIndicators/InBlock.gif)
bFinishFrame = true;
![](http://www.cnweblog.com/Images/OutliningIndicators/ExpandedSubBlockEnd.gif)
}
![](http://www.cnweblog.com/Images/OutliningIndicators/InBlock.gif)
else
![](http://www.cnweblog.com/Images/OutliningIndicators/ExpandedSubBlockStart.gif)
![](http://www.cnweblog.com/Images/OutliningIndicators/ContractedSubBlock.gif)
![](http://www.cnweblog.com/Images/dot.gif)
{
![](http://www.cnweblog.com/Images/OutliningIndicators/InBlock.gif)
bFinishFrame = false;
![](http://www.cnweblog.com/Images/OutliningIndicators/ExpandedSubBlockEnd.gif)
}
![](http://www.cnweblog.com/Images/OutliningIndicators/InBlock.gif)
return true;
![](http://www.cnweblog.com/Images/OutliningIndicators/ExpandedBlockEnd.gif)
}
![](http://www.cnweblog.com/Images/OutliningIndicators/None.gif)
来自http://www.cnweblog.com/fly2700/archive/2012/02/23/319718.html
1、单个NAL包单元
12字节的RTP头后面的就是音视频数据,比较简单。一个封装单个NAL单元包到RTP的NAL单元流的RTP序号必须符合NAL单元的解码顺序。
2、FU-A的分片格式
数据比较大的H264视频包,被RTP分片发送。12字节的RTP头后面跟随的就是FU-A分片:
FU indicator有以下格式:
+---------------+
|0|1|2|3|4|5|6|7|
+-+-+-+-+-+-+-+-+
|F|NRI| Type |
+---------------+
FU指示字节的类型域 Type=28表示FU-A。。NRI域的值必须根据分片NAL单元的NRI域的值设置。
FU header的格式如下:
+---------------+
|0|1|2|3|4|5|6|7|
+-+-+-+-+-+-+-+-+
|S|E|R| Type |
+---------------+
S: 1 bit
当设置成1,开始位指示分片NAL单元的开始。当跟随的FU荷载不是分片NAL单元荷载的开始,开始位设为0。
E: 1 bit
当设置成1, 结束位指示分片NAL单元的结束,即, 荷载的最后字节也是分片NAL单元的最后一个字节。当跟随的FU荷载不是分片NAL单元的最后分片,结束位设置为0。
R: 1 bit
保留位必须设置为0,接收者必须忽略该位。
Type: 5 bits
NAL单元荷载类型定义见下表
表1. 单元类型以及荷载结构总结
Type Packet Type name
---------------------------------------------------------
0 undefined -
1-23 NAL unit Single NAL unit packet per H.264
24 STAP-A Single-time aggregation packet
25 STAP-B Single-time aggregation packet
26 MTAP16 Multi-time aggregation packet
27 MTAP24 Multi-time aggregation packet
28 FU-A Fragmentation unit
29 FU-B Fragmentation unit
30-31 undefined -
3、拆包和解包
拆包:当编码器在编码时需要将原有一个NAL按照FU-A进行分片,原有的NAL的单元头与分片后的FU-A的单元头有如下关系:
原始的NAL头的前三位为FU indicator的前三位,原始的NAL头的后五位为FU header的后五位,FU indicator与FU header的剩余位数根据实际情况决定。
解包:当接收端收到FU-A的分片数据,需要将所有的分片包组合还原成原始的NAl包时,FU-A的单元头与还原后的NAL的关系如下:
还原后的NAL头的八位是由FU indicator的前三位加FU header的后五位组成,即:
nal_unit_type = (fu_indicator & 0xe0) | (fu_header & 0x1f)
4、代码实现
从RTP包里面得到H264视频数据的方法:
![](http://www.cnweblog.com/Images/OutliningIndicators/None.gif)
![](http://www.cnweblog.com/Images/OutliningIndicators/None.gif)
// 功能:解码RTP H.264视频
![](http://www.cnweblog.com/Images/OutliningIndicators/None.gif)
// 参数:1.RTP包缓冲地址 2.RTP包数据大小 3.H264输出地址 4.输出数据大小
![](http://www.cnweblog.com/Images/OutliningIndicators/None.gif)
// 返回:true:表示一帧结束 false:FU-A分片未结束或帧未结束
![](http://www.cnweblog.com/Images/OutliningIndicators/None.gif)
#define RTP_HEADLEN 12
![](http://www.cnweblog.com/Images/OutliningIndicators/None.gif)
bool UnpackRTPH264(
void
* bufIn,
int len,
void ** pBufOut,
int
* pOutLen)
![](http://www.cnweblog.com/Images/OutliningIndicators/ExpandedBlockStart.gif)
![](http://www.cnweblog.com/Images/OutliningIndicators/ContractedBlock.gif)
![](http://www.cnweblog.com/Images/dot.gif)
{
![](http://www.cnweblog.com/Images/OutliningIndicators/InBlock.gif)
* pOutLen
= 0
;
![](http://www.cnweblog.com/Images/OutliningIndicators/InBlock.gif)
if (len
< RTP_HEADLEN)
![](http://www.cnweblog.com/Images/OutliningIndicators/ExpandedSubBlockStart.gif)
![](http://www.cnweblog.com/Images/OutliningIndicators/ContractedSubBlock.gif)
![](http://www.cnweblog.com/Images/dot.gif)
{
![](http://www.cnweblog.com/Images/OutliningIndicators/InBlock.gif)
return
false ;
![](http://www.cnweblog.com/Images/OutliningIndicators/ExpandedSubBlockEnd.gif)
}
![](http://www.cnweblog.com/Images/OutliningIndicators/InBlock.gif)
![](http://www.cnweblog.com/Images/OutliningIndicators/InBlock.gif)
unsigned
char *
src = (unsigned
char *
)bufIn + RTP_HEADLEN;
![](http://www.cnweblog.com/Images/OutliningIndicators/InBlock.gif)
unsigned
char head1
=
* src; //
获取第一个字节
![](http://www.cnweblog.com/Images/OutliningIndicators/InBlock.gif)
unsigned
char head2
= *
(src +
1 ); //
获取第二个字节
![](http://www.cnweblog.com/Images/OutliningIndicators/InBlock.gif)
unsigned
char nal
= head1 &
0x1f
; // 获取FU indicator的类型域,
![](http://www.cnweblog.com/Images/OutliningIndicators/InBlock.gif)
unsigned
char flag
= head2 &
0xe0
; // 获取FU header的前三位,判断当前是分包的开始、中间或结束
![](http://www.cnweblog.com/Images/OutliningIndicators/InBlock.gif)
unsigned
char nal_fua
= (head1
& 0xe0
) |
(head2 &
0x1f );
// FU_A nal
![](http://www.cnweblog.com/Images/OutliningIndicators/InBlock.gif)
bool
bFinishFrame =
false
;
![](http://www.cnweblog.com/Images/OutliningIndicators/InBlock.gif)
if (nal
== 0x1c )
// 判断NAL的类型为0x1c=28,说明是FU-A分片
![](http://www.cnweblog.com/Images/OutliningIndicators/ExpandedSubBlockStart.gif)
![](http://www.cnweblog.com/Images/OutliningIndicators/ContractedSubBlock.gif)
![](http://www.cnweblog.com/Images/dot.gif)
{
// fu-a
![](http://www.cnweblog.com/Images/OutliningIndicators/InBlock.gif)
if
(flag ==
0x80 ) //
开始
![](http://www.cnweblog.com/Images/OutliningIndicators/ExpandedSubBlockStart.gif)
![](http://www.cnweblog.com/Images/OutliningIndicators/ContractedSubBlock.gif)
![](http://www.cnweblog.com/Images/dot.gif)
{
![](http://www.cnweblog.com/Images/OutliningIndicators/InBlock.gif)
* pBufOut
= src -
3 ;
![](http://www.cnweblog.com/Images/OutliningIndicators/InBlock.gif)
* ((
int * )(
* pBufOut))
=
0x01000000 ;
// zyf:大模式会有问题
![](http://www.cnweblog.com/Images/OutliningIndicators/InBlock.gif)
* (( char
* )(
* pBufOut)
+ 4 )
= nal_fua;
![](http://www.cnweblog.com/Images/OutliningIndicators/InBlock.gif)
* pOutLen
= len
- RTP_HEADLEN
+ 3
;
![](http://www.cnweblog.com/Images/OutliningIndicators/ExpandedSubBlockEnd.gif)
}
![](http://www.cnweblog.com/Images/OutliningIndicators/InBlock.gif)
else
if (flag ==
0x40 )
// 结束
![](http://www.cnweblog.com/Images/OutliningIndicators/ExpandedSubBlockStart.gif)
![](http://www.cnweblog.com/Images/OutliningIndicators/ContractedSubBlock.gif)
![](http://www.cnweblog.com/Images/dot.gif)
{
![](http://www.cnweblog.com/Images/OutliningIndicators/InBlock.gif)
* pBufOut
= src +
2 ;
![](http://www.cnweblog.com/Images/OutliningIndicators/InBlock.gif)
* pOutLen
= len
- RTP_HEADLEN
- 2
;
![](http://www.cnweblog.com/Images/OutliningIndicators/ExpandedSubBlockEnd.gif)
}
![](http://www.cnweblog.com/Images/OutliningIndicators/InBlock.gif)
else //
中间
![](http://www.cnweblog.com/Images/OutliningIndicators/ExpandedSubBlockStart.gif)
![](http://www.cnweblog.com/Images/OutliningIndicators/ContractedSubBlock.gif)
![](http://www.cnweblog.com/Images/dot.gif)
{
![](http://www.cnweblog.com/Images/OutliningIndicators/InBlock.gif)
* pBufOut
= src +
2 ;
![](http://www.cnweblog.com/Images/OutliningIndicators/InBlock.gif)
* pOutLen
= len
- RTP_HEADLEN
- 2
;
![](http://www.cnweblog.com/Images/OutliningIndicators/ExpandedSubBlockEnd.gif)
}
![](http://www.cnweblog.com/Images/OutliningIndicators/ExpandedSubBlockEnd.gif)
}
![](http://www.cnweblog.com/Images/OutliningIndicators/InBlock.gif)
else //
单包数据
![](http://www.cnweblog.com/Images/OutliningIndicators/ExpandedSubBlockStart.gif)
![](http://www.cnweblog.com/Images/OutliningIndicators/ContractedSubBlock.gif)
![](http://www.cnweblog.com/Images/dot.gif)
{
![](http://www.cnweblog.com/Images/OutliningIndicators/InBlock.gif)
* pBufOut
= src -
4 ;
![](http://www.cnweblog.com/Images/OutliningIndicators/InBlock.gif)
* ((
int * )(
* pBufOut))
=
0x01000000 ;
// zyf:大模式会有问题
![](http://www.cnweblog.com/Images/OutliningIndicators/InBlock.gif)
*
pOutLen =
len -
RTP_HEADLEN +
4 ;
![](http://www.cnweblog.com/Images/OutliningIndicators/ExpandedSubBlockEnd.gif)
}
![](http://www.cnweblog.com/Images/OutliningIndicators/InBlock.gif)
![](http://www.cnweblog.com/Images/OutliningIndicators/InBlock.gif)
unsigned
char *
bufTmp =
(unsigned char
* )bufIn;
![](http://www.cnweblog.com/Images/OutliningIndicators/InBlock.gif)
if (bufTmp[
1 ]
& 0x80
)
![](http://www.cnweblog.com/Images/OutliningIndicators/ExpandedSubBlockStart.gif)
![](http://www.cnweblog.com/Images/OutliningIndicators/ContractedSubBlock.gif)
![](http://www.cnweblog.com/Images/dot.gif)
{
![](http://www.cnweblog.com/Images/OutliningIndicators/InBlock.gif)
bFinishFrame
=
true ; //
rtp mark
![](http://www.cnweblog.com/Images/OutliningIndicators/ExpandedSubBlockEnd.gif)
}
![](http://www.cnweblog.com/Images/OutliningIndicators/InBlock.gif)
else
![](http://www.cnweblog.com/Images/OutliningIndicators/ExpandedSubBlockStart.gif)
![](http://www.cnweblog.com/Images/OutliningIndicators/ContractedSubBlock.gif)
![](http://www.cnweblog.com/Images/dot.gif)
{
![](http://www.cnweblog.com/Images/OutliningIndicators/InBlock.gif)
bFinishFrame
=
false ;
![](http://www.cnweblog.com/Images/OutliningIndicators/ExpandedSubBlockEnd.gif)
}
![](http://www.cnweblog.com/Images/OutliningIndicators/InBlock.gif)
return bFinishFrame;
![](http://www.cnweblog.com/Images/OutliningIndicators/ExpandedBlockEnd.gif)
}
![](http://www.cnweblog.com/Images/OutliningIndicators/None.gif)
![](http://www.cnweblog.com/Images/OutliningIndicators/None.gif)
从RTP包里面得到AAC音频数据的方法:
![](http://www.cnweblog.com/Images/OutliningIndicators/None.gif)
![](http://www.cnweblog.com/Images/OutliningIndicators/None.gif)
//功能:解RTP AAC音频包,声道和采样频率必须知道。
![](http://www.cnweblog.com/Images/OutliningIndicators/None.gif)
//参数:1.RTP包缓冲地址 2.RTP包数据大小 3.H264输出地址 4.输出数据大小
![](http://www.cnweblog.com/Images/OutliningIndicators/None.gif)
//返回:true:表示一帧结束 false:帧未结束 一般AAC音频包比较小,没有分片。
![](http://www.cnweblog.com/Images/OutliningIndicators/None.gif)
bool UnpackRTPAAC(void * bufIn, int recvLen, void** pBufOut, int* pOutLen)
![](http://www.cnweblog.com/Images/OutliningIndicators/ExpandedBlockStart.gif)
![](http://www.cnweblog.com/Images/OutliningIndicators/ContractedBlock.gif)
![](http://www.cnweblog.com/Images/dot.gif)
{
![](http://www.cnweblog.com/Images/OutliningIndicators/InBlock.gif)
unsigned char* bufRecv = (unsigned char*)bufIn;
![](http://www.cnweblog.com/Images/OutliningIndicators/InBlock.gif)
//char strFileName[20];
![](http://www.cnweblog.com/Images/OutliningIndicators/InBlock.gif)
![](http://www.cnweblog.com/Images/OutliningIndicators/ExpandedSubBlockStart.gif)
![](http://www.cnweblog.com/Images/OutliningIndicators/ContractedSubBlock.gif)
unsigned char ADTS[] =
![](http://www.cnweblog.com/Images/dot.gif)
{0xFF, 0xF1, 0x00, 0x00, 0x00, 0x00, 0xFC};
![](http://www.cnweblog.com/Images/OutliningIndicators/InBlock.gif)
int audioSamprate = 32000;//音频采样率
![](http://www.cnweblog.com/Images/OutliningIndicators/InBlock.gif)
int audioChannel = 2;//音频声道 1或2
![](http://www.cnweblog.com/Images/OutliningIndicators/InBlock.gif)
int audioBit = 16;//16位 固定
![](http://www.cnweblog.com/Images/OutliningIndicators/InBlock.gif)
switch(audioSamprate)
![](http://www.cnweblog.com/Images/OutliningIndicators/ExpandedSubBlockStart.gif)
![](http://www.cnweblog.com/Images/OutliningIndicators/ContractedSubBlock.gif)
![](http://www.cnweblog.com/Images/dot.gif)
{
![](http://www.cnweblog.com/Images/OutliningIndicators/InBlock.gif)
case 16000:
![](http://www.cnweblog.com/Images/OutliningIndicators/InBlock.gif)
ADTS[2] = 0x60;
![](http://www.cnweblog.com/Images/OutliningIndicators/InBlock.gif)
break;
![](http://www.cnweblog.com/Images/OutliningIndicators/InBlock.gif)
case 32000:
![](http://www.cnweblog.com/Images/OutliningIndicators/InBlock.gif)
ADTS[2] = 0x54;
![](http://www.cnweblog.com/Images/OutliningIndicators/InBlock.gif)
break;
![](http://www.cnweblog.com/Images/OutliningIndicators/InBlock.gif)
case 44100:
![](http://www.cnweblog.com/Images/OutliningIndicators/InBlock.gif)
ADTS[2] = 0x50;
![](http://www.cnweblog.com/Images/OutliningIndicators/InBlock.gif)
break;
![](http://www.cnweblog.com/Images/OutliningIndicators/InBlock.gif)
case 48000:
![](http://www.cnweblog.com/Images/OutliningIndicators/InBlock.gif)
ADTS[2] = 0x4C;
![](http://www.cnweblog.com/Images/OutliningIndicators/InBlock.gif)
break;
![](http://www.cnweblog.com/Images/OutliningIndicators/InBlock.gif)
case 96000:
![](http://www.cnweblog.com/Images/OutliningIndicators/InBlock.gif)
ADTS[2] = 0x40;
![](http://www.cnweblog.com/Images/OutliningIndicators/InBlock.gif)
break;
![](http://www.cnweblog.com/Images/OutliningIndicators/InBlock.gif)
default:
![](http://www.cnweblog.com/Images/OutliningIndicators/InBlock.gif)
break;
![](http://www.cnweblog.com/Images/OutliningIndicators/ExpandedSubBlockEnd.gif)
}
![](http://www.cnweblog.com/Images/OutliningIndicators/InBlock.gif)
ADTS[3] = (audioChannel==2)?0x80:0x40;
![](http://www.cnweblog.com/Images/OutliningIndicators/InBlock.gif)
![](http://www.cnweblog.com/Images/OutliningIndicators/InBlock.gif)
int len = recvLen - 16 + 7;
![](http://www.cnweblog.com/Images/OutliningIndicators/InBlock.gif)
len <<= 5;//8bit * 2 - 11 = 5(headerSize 11bit)
![](http://www.cnweblog.com/Images/OutliningIndicators/InBlock.gif)
len |= 0x1F;//5 bit 1
![](http://www.cnweblog.com/Images/OutliningIndicators/InBlock.gif)
ADTS[4] = len>>8;
![](http://www.cnweblog.com/Images/OutliningIndicators/InBlock.gif)
ADTS[5] = len & 0xFF;
![](http://www.cnweblog.com/Images/OutliningIndicators/InBlock.gif)
*pBufOut = (char*)bufIn+16-7;
![](http://www.cnweblog.com/Images/OutliningIndicators/InBlock.gif)
memcpy(*pBufOut, ADTS, sizeof(ADTS));
![](http://www.cnweblog.com/Images/OutliningIndicators/InBlock.gif)
*pOutLen = recvLen - 16 + 7;
![](http://www.cnweblog.com/Images/OutliningIndicators/InBlock.gif)
![](http://www.cnweblog.com/Images/OutliningIndicators/InBlock.gif)
unsigned char* bufTmp = (unsigned char*)bufIn;
![](http://www.cnweblog.com/Images/OutliningIndicators/InBlock.gif)
bool bFinishFrame = false;
![](http://www.cnweblog.com/Images/OutliningIndicators/InBlock.gif)
if (bufTmp[1] & 0x80)
![](http://www.cnweblog.com/Images/OutliningIndicators/ExpandedSubBlockStart.gif)
![](http://www.cnweblog.com/Images/OutliningIndicators/ContractedSubBlock.gif)
![](http://www.cnweblog.com/Images/dot.gif)
{
![](http://www.cnweblog.com/Images/OutliningIndicators/InBlock.gif)
//DebugTrace::D("Marker");
![](http://www.cnweblog.com/Images/OutliningIndicators/InBlock.gif)
bFinishFrame = true;
![](http://www.cnweblog.com/Images/OutliningIndicators/ExpandedSubBlockEnd.gif)
}
![](http://www.cnweblog.com/Images/OutliningIndicators/InBlock.gif)
else
![](http://www.cnweblog.com/Images/OutliningIndicators/ExpandedSubBlockStart.gif)
![](http://www.cnweblog.com/Images/OutliningIndicators/ContractedSubBlock.gif)
![](http://www.cnweblog.com/Images/dot.gif)
{
![](http://www.cnweblog.com/Images/OutliningIndicators/InBlock.gif)
bFinishFrame = false;
![](http://www.cnweblog.com/Images/OutliningIndicators/ExpandedSubBlockEnd.gif)
}
![](http://www.cnweblog.com/Images/OutliningIndicators/InBlock.gif)
return true;
![](http://www.cnweblog.com/Images/OutliningIndicators/ExpandedBlockEnd.gif)
}
![](http://www.cnweblog.com/Images/OutliningIndicators/None.gif)
来自http://www.cnweblog.com/fly2700/archive/2012/02/23/319718.html
相关文章推荐
- FU-A分包方式,以及从RTP包里面得到H.264数据和AAC数据的方法
- FU-A分包方式,以及从RTP包里面得到H.264数据和AAC数据的方法
- FU-A分包方式,以及从RTP包里面得到H.264数据和AAC数据的方法
- FU-A分包方式,以及从RTP包里面得到H.264数据和AAC数据的方法
- FU-A分包方式,以及从RTP包里面得到H.264数据和AAC数据的方法
- FU-A分包方式,以及从RTP包里面得到H.264数据和AAC数据的方法
- FU-A分包方式,以及从RTP包里面得到H.264数据和AAC数据的方法
- FU-A分包方式,以及从RTP包里面得到H.264数据和AAC数据的方法。。
- FU-A分包方式,以及从RTP包里面得到H.264数据和AAC数据的方法
- FU-A分包方式,以及从RTP包里面得到H.264数据和AAC数据的方法
- FU-A分包方式,以及从RTP包里面得到H.264数据和AAC数据的方法
- FU-A分包方式,以及从RTP包里面得到H.264数据和AAC数据的方法
- FU-A分包方式,以及从RTP包里面得到H.264数据和AAC数据的方法
- FU-A分包方式,以及从RTP包里面得到H.264数据和AAC数据的方法
- FU-A分包方式,以及从RTP包里面得到H.264数据和AAC数据的方法
- FU-A分包方式,以及从RTP包里面得到H.264数据和AAC数据的方法
- FU-A分包方式,以及从RTP包里面得到H.264数据和AAC数据的方法
- FU-A分包方式,以及从RTP包里面得到H.264数据和AAC数据的方法
- FU-A分包方式,以及从RTP包里面得到H.264数据和AAC数据的方法
- RTP包里面得到H.264数据和AAC数据的方法