使用C++(OO)编写高性能程序的可能
最近在使用C++编写真正的OO，解析RTMP协议，并将RTMP流保存为flv文件。所谓真正的OO，是用标准OO的思维和编程方式写代码，用类和对象解决问题；而不是将函数组织成类的本质上还是c的思维方式。
sample1_1500kbps.f4v和sample1_1000kbps.f4v都是fms自带的测试文件。
rtmpdump-2.2e是c写的，和rtmpdump做了比较，性能和内存占用都比rtmpdump要好（在没有优化的前提下比rtmpdump都要好），可读性和可维护性一个天上一个地下，读rtmpdump的代码就像进十八层地狱。
rtmpdump-2.2e代码量是14009，自己写的是12883（只实现了client段必须的rtmp包协议）。代码确实比rtmpdump会多，其中包括很多rtmp协议文档的注释，所以也相差不大（重用性估计会高）不会是数量级的差别。
我一直很看好OO的可读性和可维护性，比较担心性能，现在有点安慰了。我知不是所有的c都性能低下，只是一般而言，对于普通人而言，经过同等的训练，用c++写出来的性能更高（规模增长会让OO的思维方式有利）。
性能比较：
可读性，上层调用的代码比较：
rtmp的download主处理函数是这么写的，我不愿看这个难懂的代码：
int
Download(RTMP * rtmp, // connected RTMP object
FILE * file, uint32_t dSeek, uint32_t dStopOffset, double duration, bool bResume, char *metaHeader, uint32_t nMetaHeaderSize, char *initialFrame, int initialFrameType, uint32_t nInitialFrameSize, int nSkipKeyFrames, bool bStdoutMode, bool bLiveStream, bool bHashes, bool bOverrideBufferTime, uint32_t bufferTime, double *percent) // percentage downloaded [out]
{
int32_t now, lastUpdate;
int bufferSize = 64 * 1024;
char *buffer = (char *) malloc(bufferSize);
int nRead = 0;
off_t size = ftello(file);
unsigned long lastPercent = 0;
rtmp->m_read.timestamp = dSeek;
*percent = 0.0;
if (rtmp->m_read.timestamp)
{
RTMP_Log(RTMP_LOGDEBUG, "Continuing at TS: %d ms\n", rtmp->m_read.timestamp);
}
if (bLiveStream)
{
RTMP_LogPrintf("Starting Live Stream\n");
}
else
{
// print initial status
// Workaround to exit with 0 if the file is fully (> 99.9%) downloaded
if (duration > 0)
{
if ((double) rtmp->m_read.timestamp >= (double) duration * 999.0)
{
RTMP_LogPrintf("Already Completed at: %.3f sec Duration=%.3f sec\n",
(double) rtmp->m_read.timestamp / 1000.0,
(double) duration / 1000.0);
return RD_SUCCESS;
}
else
{
*percent = ((double) rtmp->m_read.timestamp) / (duration * 1000.0) * 100.0;
*percent = ((double) (int) (*percent * 10.0)) / 10.0;
RTMP_LogPrintf("%s download at: %.3f kB / %.3f sec (%.1f%%)\n",
bResume ? "Resuming" : "Starting",
(double) size / 1024.0, (double) rtmp->m_read.timestamp / 1000.0,
*percent);
}
}
else
{
RTMP_LogPrintf("%s download at: %.3f kB\n",
bResume ? "Resuming" : "Starting",
(double) size / 1024.0);
}
}
if (dStopOffset > 0)
RTMP_LogPrintf("For duration: %.3f sec\n", (double) (dStopOffset - dSeek) / 1000.0);
if (bResume && nInitialFrameSize > 0)
rtmp->m_read.flags |= RTMP_READ_RESUME;
rtmp->m_read.initialFrameType = initialFrameType;
rtmp->m_read.nResumeTS = dSeek;
rtmp->m_read.metaHeader = metaHeader;
rtmp->m_read.initialFrame = initialFrame;
rtmp->m_read.nMetaHeaderSize = nMetaHeaderSize;
rtmp->m_read.nInitialFrameSize = nInitialFrameSize;
now = RTMP_GetTime();
lastUpdate = now - 1000;
do
{
nRead = RTMP_Read(rtmp, buffer, bufferSize);
//RTMP_LogPrintf("nRead: %d\n", nRead);
if (nRead > 0)
{
if (fwrite(buffer, sizeof(unsigned char), nRead, file) !=
(size_t) nRead)
{
RTMP_Log(RTMP_LOGERROR, "%s: Failed writing, exiting!", __FUNCTION__);
free(buffer);
return RD_FAILED;
}
size += nRead;
//RTMP_LogPrintf("write %dbytes (%.1f kB)\n", nRead, nRead/1024.0);
if (duration <= 0) // if duration unknown try to get it from the stream (onMetaData)
duration = RTMP_GetDuration(rtmp);
if (duration > 0)
{
// make sure we claim to have enough buffer time!
if (!bOverrideBufferTime && bufferTime < (duration * 1000.0))
{
bufferTime = (uint32_t) (duration * 1000.0) + 5000; // extra 5sec to make sure we've got enough
RTMP_Log(RTMP_LOGDEBUG,
"Detected that buffer time is less than duration, resetting to: %dms",
bufferTime);
RTMP_SetBufferMS(rtmp, bufferTime);
RTMP_UpdateBufferMS(rtmp);
}
*percent = ((double) rtmp->m_read.timestamp) / (duration * 1000.0) * 100.0;
*percent = ((double) (int) (*percent * 10.0)) / 10.0;
if (bHashes)
{
if (lastPercent + 1 <= *percent)
{
RTMP_LogStatus("#");
lastPercent = (unsigned long) *percent;
}
}
else
{
now = RTMP_GetTime();
if (abs(now - lastUpdate) > 200)
{
RTMP_LogStatus("\r%.3f kB / %.2f sec (%.1f%%)",
(double) size / 1024.0,
(double) (rtmp->m_read.timestamp) / 1000.0, *percent);
lastUpdate = now;
}
}
}
else
{
now = RTMP_GetTime();
if (abs(now - lastUpdate) > 200)
{
if (bHashes)
RTMP_LogStatus("#");
else
RTMP_LogStatus("\r%.3f kB / %.2f sec", (double) size / 1024.0,
(double) (rtmp->m_read.timestamp) / 1000.0);
lastUpdate = now;
}
}
}
#ifdef _DEBUG
else
{
RTMP_Log(RTMP_LOGDEBUG, "zero read!");
}
#endif
}
while (!RTMP_ctrlC && nRead > -1 && RTMP_IsConnected(rtmp));
free(buffer);
if (nRead < 0)
nRead = rtmp->m_read.status;
/* Final status update */
if (!bHashes)
{
if (duration > 0)
{
*percent = ((double) rtmp->m_read.timestamp) / (duration * 1000.0) * 100.0;
*percent = ((double) (int) (*percent * 10.0)) / 10.0;
RTMP_LogStatus("\r%.3f kB / %.2f sec (%.1f%%)",
(double) size / 1024.0,
(double) (rtmp->m_read.timestamp) / 1000.0, *percent);
}
else
{
RTMP_LogStatus("\r%.3f kB / %.2f sec", (double) size / 1024.0,
(double) (rtmp->m_read.timestamp) / 1000.0);
}
}
RTMP_Log(RTMP_LOGDEBUG, "RTMP_Read returned: %d", nRead);
if (bResume && nRead == -2)
{
RTMP_LogPrintf("Couldn't resume FLV file, try --skip %d\n\n",
nSkipKeyFrames + 1);
return RD_FAILED;
}
if (nRead == -3)
return RD_SUCCESS;
if ((duration > 0 && *percent < 99.9) || RTMP_ctrlC || nRead < 0
|| RTMP_IsTimedout(rtmp))
{
return RD_INCOMPLETE;
}
return RD_SUCCESS;
}
OO的这么写：
void Rtmp2FLV::Dump(RtmpClient* rtmp_client, string host, int port, string app, string stream){
u_int32_t ret;
RtmpClient& rtmp = *rtmp_client;
if((ret = rtmp.HandShake()) != ErrorCode::Success){
exit(-1);
}
if((ret = rtmp.ConnectApp(host.c_str(), port, app.c_str())) != ErrorCode::Success){
exit(-1);
}
if((ret = rtmp.SetWindowAcknowledgementSize(2500000)) != ErrorCode::Success){
exit(-1);
}
if((ret = Helper::ConsumeAllMessage(&rtmp, 300, MessageCallback, this)) != ErrorCode::Success){
exit(-1);
}
if((ret = rtmp.Play(stream.c_str(), 0, -1, true)) != ErrorCode::Success){
exit(-1);
}
if((ret = rtmp.SetBufferLength(36000000)) != ErrorCode::Success){
exit(-1);
}
if((ret = Helper::ConsumeAllMessage(&rtmp, 10000, MessageCallback, this)) != ErrorCode::Success){
exit(-1);
}
}
void Rtmp2FLV::MessageCallback(MessagePacket* packet, void* pRtmp2FLV){
RtmpAssert(pRtmp2FLV != NULL);
Rtmp2FLV* p = (Rtmp2FLV*)pRtmp2FLV;
p->OnMessage(packet);
}
void Rtmp2FLV::OnMessage(MessagePacket* packet){
switch(packet->GetPayload()->GetType()){
case RtmpClassType::MessageVideo:{
cout << "[debug] handler mux video message packet" << endl;
MessageVideo* msg = dynamic_cast<MessageVideo*>(packet->GetPayload());
RtmpAssert(msg != NULL);
muxer.WriteVideo(fs, msg, packet->GetHeader());
break;
}
case RtmpClassType::MessageAudio:{
cout << "[debug] handler mux audio message packet" << endl;
MessageAudio* msg = dynamic_cast<MessageAudio*>(packet->GetPayload());
RtmpAssert(msg != NULL);
muxer.WriteAudio(fs, msg, packet->GetHeader());
break;
}
case RtmpClassType::MessageAggregate:{
MessageAggregate* msg = dynamic_cast<MessageAggregate*>(packet->GetPayload());
RtmpAssert(msg != NULL);
u_int32_t count = msg->GetMessageCount();
cout << "[debug] handler get " << count << " aggregate messages packet" << endl;
for(u_int32_t i = 0; i < count; i++){
MessageAggregateSub* sub = msg->GetMessageSubAt(i);
OnMessage(sub->GetMessage());
}
break;
}
case RtmpClassType::MessageAMF0CallRequest:{
cout << "[debug] handler amf0 call packet" << endl;
MessageAMF0CallRequest* msg = dynamic_cast<MessageAMF0CallRequest*>(packet->GetPayload());
RtmpAssert(msg != NULL);
if(msg->GetCommandName()->Equals("onStatus")){
AMF0Object* args = dynamic_cast<AMF0Object*>(msg->GetCommandArguments()->GetValue());
// if the args is a object, discovery the stop event
if(args != NULL){
u_int32_t count = args->GetPropertiesCount();
for(u_int32_t i = 0; i < count; i++){
AMF0ObjectProperty* prop = args->GetPropertyAt(i);
if(prop->GetName()->Equals("code")){
AMF0String* code = dynamic_cast<AMF0String*>(prop->GetValue());
if(code->Equals("NetStream.Play.Stop")){
// TODO: exit in more gentel way.
cout << "[debug] get a stream stop event, exit normally." << endl;
exit(0);
}
}
}
}
}
break;
}
case RtmpClassType::MessageAMF0Data:{
cout << "[debug] handler mux video message packet" << endl;
MessageAMF0Data* msg = dynamic_cast<MessageAMF0Data*>(packet->GetPayload());
RtmpAssert(msg != NULL);
if(msg->GetDataName()->Equals("onMetaData") && msg->GetParameterCount() > 0){
muxer.WriteMetaData(fs, msg->GetParameterAt(0));
}
break;
}
default:{
cout << "[debug] handler ignore packet: " << packet->GetPayload()->GetDescriptionTitle() << endl;
}
}
}
除了一个回调函数之外，熟悉OO的知道这个代码是在干什么。
主调用类的头文件：
/**
* the flv header at the beginning at flv file.
*/
class FLVHeader
{
public:
/**
* Signature: 'F','L','V'
*/
u_int8_t signature[3]; // 3bytes
/**
* File version (for example, 0x01 for FLV version 1)
*/
u_int8_t version; // 1byte
u_int8_t type_flags_reserved0; // 5bits
u_int8_t type_flags_audio; // 1bits
u_int8_t type_flags_reserved1; // 1bits
u_int8_t type_flags_video; // 1bits
/**
* The length of this header in bytes
* The DataOffset field usually has a value of 9 for FLV version 1.
* This field is present to accommodate larger headers in future versions.
*/
u_int32_t data_offset; //4bytes
private:
/**
* disable the copy constructor and operator=, donot allow directly copy.
*/
FLVHeader(const FLVHeader&);
FLVHeader& operator=(const FLVHeader&);
public:
FLVHeader();
virtual ~FLVHeader();
public:
u_int32_t GetSize();
public:
void Write(ostream& os);
};
/**
* the flv tag header at the beginning at flv tag. fixed 11(0xb) bytes.
*/
class FLVTagHeader
{
public:
/**
* Reserved for FMS, should be 0
*/
u_int8_t reserved; // 2bits
/**
* Indicates if packets are filtered.
* 0 = No pre-processing required.
* 1 = Pre-processing (such as decryption) of the packet is required before it can be rendered.
* Shall be 0 in unencrypted files, and 1 for encrypted tags.
* See Annex F. FLV Encryption for the use of filters.
*/
u_int8_t filter; // 1bit
/**
* Type of contents in this tag. The following types are defined:
* 8 = audio 9 = video 18 = script data
*/
u_int8_t tag_type; // 5bits.
/**
* Length of the message. Number of bytes after StreamID to end of tag (Equal to length of the tag – 11)
*/
u_int32_t data_size; //3bytes
/**
* Time in milliseconds at which the data in this tag applies.
* This value is relative to the first tag in the FLV file, which always has a timestamp of 0.
*/
u_int32_t timestamp; //3bytes
/**
* Extension of the Timestamp field to form a SI32 value. This field represents the upper 8 bits, while the previous
* Timestamp field represents the lower 24 bits of the time in milliseconds.
*/
u_int8_t timestamp_extended; //1bytes
/**
* Always 0.
*/
u_int32_t stream_id; //3bytes
private:
/**
* disable the copy constructor and operator=, donot allow directly copy.
*/
FLVTagHeader(const FLVTagHeader&);
FLVTagHeader& operator=(const FLVTagHeader&);
public:
FLVTagHeader();
virtual ~FLVTagHeader();
public:
u_int32_t GetSize();
public:
void Write(ostream& os);
};
/**
* the flv tag after flv header, consists of pre_tag_size|tag_header|data.
*/
class FLVTag
{
public:
/**
* Size of previous tag, including its header, in bytes. For FLV version
* 1, this value is 11 plus the DataSize of the previous tag.
*/
u_int32_t previous_tag_size;
/**
* the common flv tag header, fixed 11 bytes size.
*/
FLVTagHeader tag_header;
/**
* the tag header:
* AudioTagHeader // IF TagType == 8
* VideoTagHeader // IF TagType == 9
* EncryptionHeader // IF Filter == 1
* FilterParams // IF Filter == 1
*
* Data specific for each media type.
* Data // IF TagType == 8 AUDIODATA
* // IF TagType == 9 VIDEODATA
* // IF TagType == 18 SCRIPTDATA
*/
int8_t* data; // data from the rtmp.
private:
/**
* disable the copy constructor and operator=, donot allow directly copy.
*/
FLVTag(const FLVTag&);
FLVTag& operator=(const FLVTag&);
public:
FLVTag();
virtual ~FLVTag();
public:
/**
* total tag size=4+header+data
*/
u_int32_t GetSize();
/**
* total tag size=header+data
*/
u_int32_t GetTagSize();
public:
void Write(ostream& os);
public:
void SetData(int8_t* v, u_int32_t size);
};
/**
* used to mux packets in flv stream.
*/
class FLVMuxer
{
private:
FLVHeader header;
FLVTag* previous_tag;
private:
/**
* disable the copy constructor and operator=, donot allow directly copy.
*/
FLVMuxer(const FLVMuxer&);
FLVMuxer& operator=(const FLVMuxer&);
public:
FLVMuxer();
virtual ~FLVMuxer();
public:
void Open(std::ostream& os);
void WriteVideo(std::ostream& os, MessageVideo* packet, MessageHeader* pheader);
void WriteAudio(std::ostream& os, MessageAudio* packet, MessageHeader* pheader);
void WriteMetaData(std::ostream& os, AMF0Any* metadata);
/**
* close muxer, writer file header.
*/
void Close(std::ostream& os);
private:
/**
* disconvery metadata from source to pool
*/
void DiscoveryMetaData(AMF0Any* source, IBytesPool* pool);
};
/**
* mux the rtmp video/audio/data to flv file.
*/
class Rtmp2FLV
{
private:
FLVMuxer muxer;
std::fstream fs;
private:
/**
* disable the copy constructor and operator=, donot allow directly copy.
*/
Rtmp2FLV(const Rtmp2FLV&);
Rtmp2FLV& operator=(const Rtmp2FLV&);
public:
Rtmp2FLV();
virtual ~Rtmp2FLV();
public:
void Initialize(const char* flv_file_name);
void Dump(RtmpClient* rtmp_client, std::string host, int port, std::string app, std::string stream);
private:
static void MessageCallback(MessagePacket* packet, void* pRtmp2FLV);
void OnMessage(MessagePacket* packet);主调用类的实现：
#define FixedTagHeaderSize 11
FLVHeader::FLVHeader(){
signature[0] = 'F';
signature[1] = 'L';
signature[2] = 'V';
version = 1;
type_flags_reserved0 = 0;
type_flags_audio = 0;
type_flags_reserved1 = 0;
type_flags_video = 0;
data_offset = 0x09;
}
FLVHeader::~FLVHeader(){
}
u_int32_t FLVHeader::GetSize(){
return data_offset;
}
void FLVHeader::Write(ostream& os){
SimpleBytesPool pool(GetSize());
pool.WriteUInt8(signature[0]);
pool.WriteUInt8(signature[1]);
pool.WriteUInt8(signature[2]);
pool.WriteUInt8(version);
u_int8_t flag = type_flags_video;
flag |= (type_flags_reserved1 << 1);
flag |= (type_flags_audio << 2);
flag |= (type_flags_reserved0 << 7);
pool.WriteUInt8(flag);
pool.WriteUInt32(data_offset);
pool.SetPosition(0);
os.write((const char*)pool.GetBytes(), (streamsize)pool.GetLength());
//os.flush();
}
FLVTagHeader::FLVTagHeader(){
reserved = 0;
filter = 0;
tag_type = 0;
data_size = 0;
timestamp = 0;
timestamp_extended = 0;
stream_id = 0;
}
FLVTagHeader::~FLVTagHeader(){
}
u_int32_t FLVTagHeader::GetSize(){
return FixedTagHeaderSize;
}
void FLVTagHeader::Write(ostream& os){
SimpleBytesPool pool(GetSize());
u_int8_t flag = tag_type;
flag |= (filter << 5);
flag |= (reserved << 7);
pool.WriteUInt8(flag);
pool.WriteUInt24(data_size);
pool.WriteUInt24(timestamp);
pool.WriteUInt8(timestamp_extended);
pool.WriteUInt24(stream_id);
pool.SetPosition(0);
os.write((const char*)pool.GetBytes(), (streamsize)pool.GetLength());
//os.flush();
}
FLVTag::FLVTag(){
data = NULL;
previous_tag_size = 0x00;
}
FLVTag::~FLVTag(){
}
u_int32_t FLVTag::GetSize(){
return sizeof(u_int32_t) + tag_header.GetSize() + tag_header.data_size;
}
u_int32_t FLVTag::GetTagSize(){
return tag_header.GetSize() + tag_header.data_size;
}
void FLVTag::Write(ostream& os){
SimpleBytesPool pool(sizeof(u_int32_t));
pool.WriteUInt32(previous_tag_size);
pool.SetPosition(0);
os.write((const char*)pool.GetBytes(), (streamsize)pool.GetLength());
tag_header.Write(os);
if(data != NULL && tag_header.data_size > 0){
os.write((const char*)data, (streamsize)tag_header.data_size);
}
//os.flush();
}
void FLVTag::SetData(int8_t* v, u_int32_t size){
RtmpAssert(size > 0);
RtmpAssert(v != NULL);
data = v;
tag_header.data_size = size;
}
FLVMuxer::FLVMuxer(){
previous_tag = NULL;
}
FLVMuxer::~FLVMuxer(){
RtmpFree(FLVTag, previous_tag, false);
}
void FLVMuxer::Open(std::ostream& os){
os.seekp(0);
header.Write(os);
}
void FLVMuxer::WriteVideo(std::ostream& os, MessageVideo* packet, MessageHeader* pheader){
// ignore the empty audio packet.
if(packet->GetVideoLength() == 0){
cout << "[debug] ignore the empty video packet" << endl;
return;
}
header.type_flags_video = 1;
FLVTag* tag = new FLVTag();
tag->SetData(packet->GetVideoData(), packet->GetVideoLength());
if(previous_tag != NULL){
tag->previous_tag_size = previous_tag->GetTagSize();
}
tag->tag_header.tag_type = 0x09; // video.
tag->tag_header.timestamp = pheader->GetTimestampLow24bits();
tag->tag_header.timestamp_extended = pheader->GetTimestampHigh8bits();
tag->Write(os);
RtmpFree(FLVTag, previous_tag, false);
previous_tag = tag;
}
void FLVMuxer::WriteAudio(std::ostream& os, MessageAudio* packet, MessageHeader* pheader){
// ignore the empty audio packet.
if(packet->GetAudioLength() == 0){
cout << "[debug] ignore the empty audio packet" << endl;
return;
}
header.type_flags_audio = 1;
FLVTag* tag = new FLVTag();
tag->SetData(packet->GetAudioData(), packet->GetAudioLength());
if(previous_tag != NULL){
tag->previous_tag_size = previous_tag->GetTagSize();
}
tag->tag_header.tag_type = 0x08; // audio.
tag->tag_header.timestamp = pheader->GetTimestampLow24bits();
tag->tag_header.timestamp_extended = pheader->GetTimestampHigh8bits();
tag->Write(os);
RtmpFree(FLVTag, previous_tag, false);
previous_tag = tag;
}
void FLVMuxer::WriteMetaData(std::ostream& os, AMF0Any* metadata){
FLVTag* tag = new FLVTag();
SimpleBytesPool pool(0);
DiscoveryMetaData(metadata, &pool);
pool.SetPosition(0);
tag->SetData(pool.GetBytes(), pool.GetLength());
if(previous_tag != NULL){
tag->previous_tag_size = previous_tag->GetTagSize();
}
tag->tag_header.tag_type = 0x12; // 18: script data.
tag->Write(os);
RtmpFree(FLVTag, previous_tag, false);
previous_tag = tag;
}
void FLVMuxer::DiscoveryMetaData(AMF0Any* source, IBytesPool* pool){
if(true){
AMF0String command;
command.SetString("onMetaData");
SimpleBytesPool p(command.GetSize());
command.WritePacket(&p);
p.SetPosition(0);
pool->AppendBytes(p.GetBytes(), p.GetLength());
}
// the onMetaData command object must be a ECMA array.
AMF0ECMAArray* source_arr = dynamic_cast<AMF0ECMAArray*>(source->GetValue());
RtmpAssert(source_arr != NULL);
u_int32_t count = source_arr->GetPropertiesCount();
AMF0ECMAArray arr;
for(u_int32_t i = 0; i < count; i++){
AMF0ObjectProperty* prop = source_arr->GetPropertyAt(i);
AMF0UTF8* name = prop->GetName();
if(name->Equals("duration") || name->Equals("width") || name->Equals("height")
|| name->Equals("videodatarate") || name->Equals("framerate") || name->Equals("videoframerate")
){
// we only copy the number or string property.
AMF0Base* dest_value = NULL;
AMF0Number* source_value = dynamic_cast<AMF0Number*>(prop->GetValue());
if(source_value != NULL){
dest_value = new AMF0Number(source_value->GetValue());
}
else{
AMF0String* source_str = dynamic_cast<AMF0String*>(prop->GetValue());
if(source_str == NULL){
cout << "[debug] ignore the metadata if not number or string" << endl;
continue;
}
dest_value = new AMF0String(source_str->GetString());
arr.AddProperty(Factory::Instance()->CreateAMF0ObjectProperty(name->GetString(), dest_value));
}
arr.AddProperty(Factory::Instance()->CreateAMF0ObjectProperty(name->GetString(), dest_value));
}
}
if(true){
SimpleBytesPool p(arr.GetSize());
arr.WritePacket(&p);
p.SetPosition(0);
pool->AppendBytes(p.GetBytes(), p.GetLength());
}
}
void FLVMuxer::Close(std::ostream& os){
os.seekp(0);
header.Write(os);
}
Rtmp2FLV::Rtmp2FLV(){
}
Rtmp2FLV::~Rtmp2FLV(){
muxer.Close(fs);
fs.close();
}
void Rtmp2FLV::Initialize(const char* flv_file_name){
fs.open(flv_file_name, ios::trunc|ios::out|ios::binary);
RtmpAssert(fs.is_open());
muxer.Open(fs);
}
void Rtmp2FLV::Dump(RtmpClient* rtmp_client, string host, int port, string app, string stream){
u_int32_t ret;
RtmpClient& rtmp = *rtmp_client;
if((ret = rtmp.HandShake()) != ErrorCode::Success){
exit(-1);
}
if((ret = rtmp.ConnectApp(host.c_str(), port, app.c_str())) != ErrorCode::Success){
exit(-1);
}
if((ret = rtmp.SetWindowAcknowledgementSize(2500000)) != ErrorCode::Success){
exit(-1);
}
if((ret = Helper::ConsumeAllMessage(&rtmp, 300, MessageCallback, this)) != ErrorCode::Success){
exit(-1);
}
if((ret = rtmp.Play(stream.c_str(), 0, -1, true)) != ErrorCode::Success){
exit(-1);
}
if((ret = rtmp.SetBufferLength(36000000)) != ErrorCode::Success){
exit(-1);
}
if((ret = Helper::ConsumeAllMessage(&rtmp, 10000, MessageCallback, this)) != ErrorCode::Success){
exit(-1);
}
}
void Rtmp2FLV::MessageCallback(MessagePacket* packet, void* pRtmp2FLV){
RtmpAssert(pRtmp2FLV != NULL);
Rtmp2FLV* p = (Rtmp2FLV*)pRtmp2FLV;
p->OnMessage(packet);
}
void Rtmp2FLV::OnMessage(MessagePacket* packet){
switch(packet->GetPayload()->GetType()){
case RtmpClassType::MessageVideo:{
cout << "[debug] handler mux video message packet" << endl;
MessageVideo* msg = dynamic_cast<MessageVideo*>(packet->GetPayload());
RtmpAssert(msg != NULL);
muxer.WriteVideo(fs, msg, packet->GetHeader());
break;
}
case RtmpClassType::MessageAudio:{
cout << "[debug] handler mux audio message packet" << endl;
MessageAudio* msg = dynamic_cast<MessageAudio*>(packet->GetPayload());
RtmpAssert(msg != NULL);
muxer.WriteAudio(fs, msg, packet->GetHeader());
break;
}
case RtmpClassType::MessageAggregate:{
MessageAggregate* msg = dynamic_cast<MessageAggregate*>(packet->GetPayload());
RtmpAssert(msg != NULL);
u_int32_t count = msg->GetMessageCount();
cout << "[debug] handler get " << count << " aggregate messages packet" << endl;
for(u_int32_t i = 0; i < count; i++){
MessageAggregateSub* sub = msg->GetMessageSubAt(i);
OnMessage(sub->GetMessage());
}
break;
}
case RtmpClassType::MessageAMF0CallRequest:{
cout << "[debug] handler amf0 call packet" << endl;
MessageAMF0CallRequest* msg = dynamic_cast<MessageAMF0CallRequest*>(packet->GetPayload());
RtmpAssert(msg != NULL);
if(msg->GetCommandName()->Equals("onStatus")){
AMF0Object* args = dynamic_cast<AMF0Object*>(msg->GetCommandArguments()->GetValue());
// if the args is a object, discovery the stop event
if(args != NULL){
u_int32_t count = args->GetPropertiesCount();
for(u_int32_t i = 0; i < count; i++){
AMF0ObjectProperty* prop = args->GetPropertyAt(i);
if(prop->GetName()->Equals("code")){
AMF0String* code = dynamic_cast<AMF0String*>(prop->GetValue());
if(code->Equals("NetStream.Play.Stop")){
// TODO: exit in more gentel way.
cout << "[debug] get a stream stop event, exit normally." << endl;
exit(0);
}
}
}
}
}
break;
}
case RtmpClassType::MessageAMF0Data:{
cout << "[debug] handler mux video message packet" << endl;
MessageAMF0Data* msg = dynamic_cast<MessageAMF0Data*>(packet->GetPayload());
RtmpAssert(msg != NULL);
if(msg->GetDataName()->Equals("onMetaData") && msg->GetParameterCount() > 0){
muxer.WriteMetaData(fs, msg->GetParameterAt(0));
}
break;
}
default:{
cout << "[debug] handler ignore packet: " << packet->GetPayload()->GetDescriptionTitle() << endl;
}
}
}
另外，rtmpdump使用的librtmp使用同步socket收发数据：
[winlin@dev6 rtmpdump-2.2e]$ find . -name "*.c"|xargs grep --color -in "recv("
./librtmp/rtmp.c:3417: nBytes = recv(sb->sb_socket, sb->sb_start + sb->sb_size, nBytes, 0);
./rtmpgw.c:370: nRead = recv(sockfd, header, 2047, 0);
[winlin@dev6 rtmpdump-2.2e]$ find . -name "*.c"|xargs grep --color -in " send("
./librtmp/rtmp.c:3460: rc = send(sb->sb_socket, buf, len, 0);
./rtmpgw.c:381: send(sockfd, buf, len, 0);
./rtmpgw.c:530: send(sockfd, buf, len, 0);
./rtmpgw.c:584: if ((nWritten = send(sockfd, buffer, nRead, 0)) < 0)
./rtmpgw.c:646: send(sockfd, buf, len, 0);