393 lines
14 KiB
C++
393 lines
14 KiB
C++
/// \file flv_tag.cpp
|
|
/// Holds all code for the FLV namespace.
|
|
|
|
#include "flv_tag.h"
|
|
#include <stdio.h> //for Tag::FileLoader
|
|
#include <unistd.h> //for Tag::FileLoader
|
|
#include <fcntl.h> //for Tag::FileLoader
|
|
#include <stdlib.h> //malloc
|
|
#include <string.h> //memcpy
|
|
|
|
char FLV::Header[13]; ///< Holds the last FLV header parsed.
|
|
bool FLV::Parse_Error = false; ///< This variable is set to true if a problem is encountered while parsing the FLV.
|
|
std::string FLV::Error_Str = "";
|
|
|
|
/// Checks a FLV Header for validness. Returns true if the header is valid, false
|
|
/// if the header is not. Not valid can mean:
|
|
/// - Not starting with the string "FLV".
|
|
/// - The DataOffset is not 9 bytes.
|
|
/// - The PreviousTagSize is not 0 bytes.
|
|
///
|
|
/// Note that we see PreviousTagSize as part of the FLV header, not part of the tag header!
|
|
bool FLV::check_header(char * header){
|
|
if (header[0] != 'F') return false;
|
|
if (header[1] != 'L') return false;
|
|
if (header[2] != 'V') return false;
|
|
if (header[5] != 0) return false;
|
|
if (header[6] != 0) return false;
|
|
if (header[7] != 0) return false;
|
|
if (header[8] != 0x09) return false;
|
|
if (header[9] != 0) return false;
|
|
if (header[10] != 0) return false;
|
|
if (header[11] != 0) return false;
|
|
if (header[12] != 0) return false;
|
|
return true;
|
|
}//FLV::check_header
|
|
|
|
/// Checks the first 3 bytes for the string "FLV". Implementing a basic FLV header check,
|
|
/// returning true if it is, false if not.
|
|
bool FLV::is_header(char * header){
|
|
if (header[0] != 'F') return false;
|
|
if (header[1] != 'L') return false;
|
|
if (header[2] != 'V') return false;
|
|
return true;
|
|
}//FLV::is_header
|
|
|
|
|
|
/// Returns a std::string describing the tag in detail.
|
|
/// The string includes information about whether the tag is
|
|
/// audio, video or metadata, what encoding is used, and the details
|
|
/// of the encoding itself.
|
|
std::string FLV::Tag::tagType(){
|
|
std::string R = "";
|
|
switch (data[0]){
|
|
case 0x09:
|
|
switch (data[11] & 0x0F){
|
|
case 1: R += "JPEG"; break;
|
|
case 2: R += "H263"; break;
|
|
case 3: R += "ScreenVideo1"; break;
|
|
case 4: R += "VP6"; break;
|
|
case 5: R += "VP6Alpha"; break;
|
|
case 6: R += "ScreenVideo2"; break;
|
|
case 7: R += "AVC"; break;
|
|
default: R += "unknown"; break;
|
|
}
|
|
R += " video ";
|
|
switch (data[11] & 0xF0){
|
|
case 0x10: R += "keyframe"; break;
|
|
case 0x20: R += "iframe"; break;
|
|
case 0x30: R += "disposableiframe"; break;
|
|
case 0x40: R += "generatedkeyframe"; break;
|
|
case 0x50: R += "videoinfo"; break;
|
|
}
|
|
if ((data[11] & 0x0F) == 7){
|
|
switch (data[12]){
|
|
case 0: R += " header"; break;
|
|
case 1: R += " NALU"; break;
|
|
case 2: R += " endofsequence"; break;
|
|
}
|
|
}
|
|
break;
|
|
case 0x08:
|
|
switch (data[11] & 0xF0){
|
|
case 0x00: R += "linear PCM PE"; break;
|
|
case 0x10: R += "ADPCM"; break;
|
|
case 0x20: R += "MP3"; break;
|
|
case 0x30: R += "linear PCM LE"; break;
|
|
case 0x40: R += "Nelly16kHz"; break;
|
|
case 0x50: R += "Nelly8kHz"; break;
|
|
case 0x60: R += "Nelly"; break;
|
|
case 0x70: R += "G711A-law"; break;
|
|
case 0x80: R += "G711mu-law"; break;
|
|
case 0x90: R += "reserved"; break;
|
|
case 0xA0: R += "AAC"; break;
|
|
case 0xB0: R += "Speex"; break;
|
|
case 0xE0: R += "MP38kHz"; break;
|
|
case 0xF0: R += "DeviceSpecific"; break;
|
|
default: R += "unknown"; break;
|
|
}
|
|
switch (data[11] & 0x0C){
|
|
case 0x0: R += " 5.5kHz"; break;
|
|
case 0x4: R += " 11kHz"; break;
|
|
case 0x8: R += " 22kHz"; break;
|
|
case 0xC: R += " 44kHz"; break;
|
|
}
|
|
switch (data[11] & 0x02){
|
|
case 0: R += " 8bit"; break;
|
|
case 2: R += " 16bit"; break;
|
|
}
|
|
switch (data[11] & 0x01){
|
|
case 0: R += " mono"; break;
|
|
case 1: R += " stereo"; break;
|
|
}
|
|
R += " audio";
|
|
if ((data[12] == 0) && ((data[11] & 0xF0) == 0xA0)){
|
|
R += " initdata";
|
|
}
|
|
break;
|
|
case 0x12:
|
|
R += "(meta)data";
|
|
break;
|
|
default:
|
|
R += "unknown";
|
|
break;
|
|
}
|
|
return R;
|
|
}//FLV::Tag::tagtype
|
|
|
|
/// Returns the 32-bit timestamp of this tag.
|
|
unsigned int FLV::Tag::tagTime(){
|
|
return (data[4] << 16) + (data[5] << 8) + data[6] + (data[7] << 24);
|
|
}//tagTime getter
|
|
|
|
/// Sets the 32-bit timestamp of this tag.
|
|
void FLV::Tag::tagTime(unsigned int T){
|
|
data[4] = ((T >> 16) & 0xFF);
|
|
data[5] = ((T >> 8) & 0xFF);
|
|
data[6] = (T & 0xFF);
|
|
data[7] = ((T >> 24) & 0xFF);
|
|
}//tagTime setter
|
|
|
|
/// Constructor for a new, empty, tag.
|
|
/// The buffer length is initialized to 0, and later automatically
|
|
/// increased if neccesary.
|
|
FLV::Tag::Tag(){
|
|
len = 0; buf = 0; data = 0; isKeyframe = false; done = true; sofar = 0;
|
|
}//empty constructor
|
|
|
|
/// Copy constructor, copies the contents of an existing tag.
|
|
/// The buffer length is initialized to the actual size of the tag
|
|
/// that is being copied, and later automaticallt increased if
|
|
/// neccesary.
|
|
FLV::Tag::Tag(const Tag& O){
|
|
done = true;
|
|
sofar = 0;
|
|
buf = O.len;
|
|
len = buf;
|
|
if (len > 0){
|
|
data = (char*)malloc(len);
|
|
memcpy(data, O.data, len);
|
|
}else{
|
|
data = 0;
|
|
}
|
|
isKeyframe = O.isKeyframe;
|
|
}//copy constructor
|
|
|
|
/// Assignment operator - works exactly like the copy constructor.
|
|
/// This operator checks for self-assignment.
|
|
FLV::Tag & FLV::Tag::operator= (const FLV::Tag& O){
|
|
if (this != &O){//no self-assignment
|
|
len = O.len;
|
|
if (len > 0){
|
|
if (!data){
|
|
data = (char*)malloc(len);
|
|
buf = len;
|
|
}else{
|
|
if (buf < len){
|
|
data = (char*)realloc(data, len);
|
|
buf = len;
|
|
}
|
|
}
|
|
memcpy(data, O.data, len);
|
|
}
|
|
isKeyframe = O.isKeyframe;
|
|
}
|
|
return *this;
|
|
}//assignment operator
|
|
|
|
/// Helper function for FLV::MemLoader.
|
|
/// This function will try to read count bytes from data buffer D into buffer.
|
|
/// This function should be called repeatedly until true.
|
|
/// P and sofar are not the same value, because D may not start with the current tag.
|
|
/// \param buffer The target buffer.
|
|
/// \param count Amount of bytes to read.
|
|
/// \param sofar Current amount read.
|
|
/// \param D The location of the data buffer.
|
|
/// \param S The size of the data buffer.
|
|
/// \param P The current position in the data buffer. Will be updated to reflect new position.
|
|
/// \return True if count bytes are read succesfully, false otherwise.
|
|
bool FLV::Tag::MemReadUntil(char * buffer, unsigned int count, unsigned int & sofar, char * D, unsigned int S, unsigned int & P){
|
|
if (sofar >= count){return true;}
|
|
int r = 0;
|
|
if (P+(count-sofar) > S){r = S-P;}else{r = count-sofar;}
|
|
memcpy(buffer+sofar, D+P, r);
|
|
P += r;
|
|
sofar += r;
|
|
if (sofar >= count){return true;}
|
|
return false;
|
|
}//Tag::MemReadUntil
|
|
|
|
|
|
/// Try to load a tag from a data buffer in memory.
|
|
/// This is a stateful function - if fed incorrect data, it will most likely never return true again!
|
|
/// While this function returns false, the Tag might not contain valid data.
|
|
/// \param D The location of the data buffer.
|
|
/// \param S The size of the data buffer.
|
|
/// \param P The current position in the data buffer. Will be updated to reflect new position.
|
|
/// \return True if a whole tag is succesfully read, false otherwise.
|
|
bool FLV::Tag::MemLoader(char * D, unsigned int S, unsigned int & P){
|
|
if (buf < 15){data = (char*)realloc(data, 15); buf = 15;}
|
|
if (done){
|
|
//read a header
|
|
if (MemReadUntil(data, 11, sofar, D, S, P)){
|
|
//if its a correct FLV header, throw away and read tag header
|
|
if (FLV::is_header(data)){
|
|
if (MemReadUntil(data, 13, sofar, D, S, P)){
|
|
if (FLV::check_header(data)){
|
|
sofar = 0;
|
|
memcpy(FLV::Header, data, 13);
|
|
}else{FLV::Parse_Error = true; Error_Str = "Invalid header received."; return false;}
|
|
}
|
|
}else{
|
|
//if a tag header, calculate length and read tag body
|
|
len = data[3] + 15;
|
|
len += (data[2] << 8);
|
|
len += (data[1] << 16);
|
|
if (buf < len){data = (char*)realloc(data, len); buf = len;}
|
|
if (data[0] > 0x12){FLV::Parse_Error = true; Error_Str = "Invalid Tag received."; return false;}
|
|
done = false;
|
|
}
|
|
}
|
|
}else{
|
|
//read tag body
|
|
if (MemReadUntil(data, len, sofar, D, S, P)){
|
|
//calculate keyframeness, next time read header again, return true
|
|
if ((data[0] == 0x09) && (((data[11] & 0xf0) >> 4) == 1)){isKeyframe = true;}else{isKeyframe = false;}
|
|
done = true;
|
|
sofar = 0;
|
|
return true;
|
|
}
|
|
}
|
|
return false;
|
|
}//Tag::MemLoader
|
|
|
|
|
|
/// Helper function for FLV::SockLoader.
|
|
/// This function will try to read count bytes from socket sock into buffer.
|
|
/// This function should be called repeatedly until true.
|
|
/// \param buffer The target buffer.
|
|
/// \param count Amount of bytes to read.
|
|
/// \param sofar Current amount read.
|
|
/// \param sock Socket to read from.
|
|
/// \return True if count bytes are read succesfully, false otherwise.
|
|
bool FLV::Tag::SockReadUntil(char * buffer, unsigned int count, unsigned int & sofar, Socket::Connection & sock){
|
|
if (sofar == count){return true;}
|
|
if (!sock.read(buffer + sofar,count-sofar)){
|
|
if (errno != EWOULDBLOCK){
|
|
FLV::Parse_Error = true;
|
|
Error_Str = "Error reading from socket.";
|
|
}
|
|
return false;
|
|
}
|
|
sofar += count-sofar;
|
|
if (sofar == count){return true;}
|
|
if (sofar > count){
|
|
FLV::Parse_Error = true;
|
|
Error_Str = "Socket buffer overflow.";
|
|
}
|
|
return false;
|
|
}//Tag::SockReadUntil
|
|
|
|
/// Try to load a tag from a socket.
|
|
/// This is a stateful function - if fed incorrect data, it will most likely never return true again!
|
|
/// While this function returns false, the Tag might not contain valid data.
|
|
/// \param sock The socket to read from.
|
|
/// \return True if a whole tag is succesfully read, false otherwise.
|
|
bool FLV::Tag::SockLoader(Socket::Connection sock){
|
|
if (buf < 15){data = (char*)realloc(data, 15); buf = 15;}
|
|
if (done){
|
|
if (SockReadUntil(data, 11, sofar, sock)){
|
|
//if its a correct FLV header, throw away and read tag header
|
|
if (FLV::is_header(data)){
|
|
if (SockReadUntil(data, 13, sofar, sock)){
|
|
if (FLV::check_header(data)){
|
|
sofar = 0;
|
|
memcpy(FLV::Header, data, 13);
|
|
}else{FLV::Parse_Error = true; Error_Str = "Invalid header received."; return false;}
|
|
}
|
|
}else{
|
|
//if a tag header, calculate length and read tag body
|
|
len = data[3] + 15;
|
|
len += (data[2] << 8);
|
|
len += (data[1] << 16);
|
|
if (buf < len){data = (char*)realloc(data, len); buf = len;}
|
|
if (data[0] > 0x12){FLV::Parse_Error = true; Error_Str = "Invalid Tag received."; return false;}
|
|
done = false;
|
|
}
|
|
}
|
|
}else{
|
|
//read tag body
|
|
if (SockReadUntil(data, len, sofar, sock)){
|
|
//calculate keyframeness, next time read header again, return true
|
|
if ((data[0] == 0x09) && (((data[11] & 0xf0) >> 4) == 1)){isKeyframe = true;}else{isKeyframe = false;}
|
|
done = true;
|
|
sofar = 0;
|
|
return true;
|
|
}
|
|
}
|
|
return false;
|
|
}//Tag::SockLoader
|
|
|
|
/// Try to load a tag from a socket.
|
|
/// This is a stateful function - if fed incorrect data, it will most likely never return true again!
|
|
/// While this function returns false, the Tag might not contain valid data.
|
|
/// \param sock The socket to read from.
|
|
/// \return True if a whole tag is succesfully read, false otherwise.
|
|
bool FLV::Tag::SockLoader(int sock){
|
|
return SockLoader(Socket::Connection(sock));
|
|
}//Tag::SockLoader
|
|
|
|
/// Helper function for FLV::FileLoader.
|
|
/// This function will try to read count bytes from file f into buffer.
|
|
/// This function should be called repeatedly until true.
|
|
/// \param buffer The target buffer.
|
|
/// \param count Amount of bytes to read.
|
|
/// \param sofar Current amount read.
|
|
/// \param f File to read from.
|
|
/// \return True if count bytes are read succesfully, false otherwise.
|
|
bool FLV::Tag::FileReadUntil(char * buffer, unsigned int count, unsigned int & sofar, FILE * f){
|
|
if (sofar >= count){return true;}
|
|
int r = 0;
|
|
r = fread(buffer + sofar,1,count-sofar,f);
|
|
if (r < 0){FLV::Parse_Error = true; Error_Str = "File reading error."; return false;}
|
|
sofar += r;
|
|
if (sofar >= count){return true;}
|
|
return false;
|
|
}
|
|
|
|
/// Try to load a tag from a file.
|
|
/// This is a stateful function - if fed incorrect data, it will most likely never return true again!
|
|
/// While this function returns false, the Tag might not contain valid data.
|
|
/// \param f The file to read from.
|
|
/// \return True if a whole tag is succesfully read, false otherwise.
|
|
bool FLV::Tag::FileLoader(FILE * f){
|
|
int preflags = fcntl(fileno(f), F_GETFL, 0);
|
|
int postflags = preflags | O_NONBLOCK;
|
|
fcntl(fileno(f), F_SETFL, postflags);
|
|
if (buf < 15){data = (char*)realloc(data, 15); buf = 15;}
|
|
|
|
if (done){
|
|
//read a header
|
|
if (FileReadUntil(data, 11, sofar, f)){
|
|
//if its a correct FLV header, throw away and read tag header
|
|
if (FLV::is_header(data)){
|
|
if (FileReadUntil(data, 13, sofar, f)){
|
|
if (FLV::check_header(data)){
|
|
sofar = 0;
|
|
memcpy(FLV::Header, data, 13);
|
|
}else{FLV::Parse_Error = true; Error_Str = "Invalid header received."; return false;}
|
|
}
|
|
}else{
|
|
//if a tag header, calculate length and read tag body
|
|
len = data[3] + 15;
|
|
len += (data[2] << 8);
|
|
len += (data[1] << 16);
|
|
if (buf < len){data = (char*)realloc(data, len); buf = len;}
|
|
if (data[0] > 0x12){FLV::Parse_Error = true; Error_Str = "Invalid Tag received."; return false;}
|
|
done = false;
|
|
}
|
|
}
|
|
}else{
|
|
//read tag body
|
|
if (FileReadUntil(data, len, sofar, f)){
|
|
//calculate keyframeness, next time read header again, return true
|
|
if ((data[0] == 0x09) && (((data[11] & 0xf0) >> 4) == 1)){isKeyframe = true;}else{isKeyframe = false;}
|
|
done = true;
|
|
sofar = 0;
|
|
fcntl(fileno(f), F_SETFL, preflags);
|
|
return true;
|
|
}
|
|
}
|
|
fcntl(fileno(f), F_SETFL, preflags);
|
|
return false;
|
|
}//FLV_GetPacket
|