71 lines
2.3 KiB
C++
71 lines
2.3 KiB
C++
#include "h264.h"
|
|
#include <cstdlib>
|
|
#include <cstring>
|
|
#include "bitfields.h"
|
|
#include "defines.h"
|
|
|
|
namespace h264 {
|
|
unsigned long toAnnexB(const char * data, unsigned long dataSize, char *& result){
|
|
//toAnnexB keeps the same size.
|
|
if (!result){
|
|
result = (char *)malloc(dataSize);
|
|
}
|
|
int offset = 0;
|
|
while (offset < dataSize){
|
|
//Read unit size
|
|
unsigned long unitSize = Bit::btohl(data + offset);
|
|
//Write annex b header
|
|
memset(result + offset, 0x00, 3);
|
|
result[offset + 3] = 0x01;
|
|
//Copy the nal unit
|
|
memcpy(result + offset + 4, data + offset + 4, unitSize);
|
|
//Update the offset
|
|
offset += 4 + unitSize;
|
|
}
|
|
return dataSize;
|
|
}
|
|
|
|
unsigned long fromAnnexB(const char * data, unsigned long dataSize, char *& result){
|
|
if (!result){
|
|
//first compute the new size. This might be the same as the annex b version, but this is not guaranteed
|
|
int offset = 0;
|
|
int newSize = 0;
|
|
while (offset < dataSize){
|
|
const char * begin = (const char*)memmem(data + offset, dataSize - offset, "\000\000\001", 3);
|
|
begin += 3;//Initialize begin after the first 0x000001 pattern.
|
|
const char * end = (const char*)memmem(begin, dataSize - (begin - data), "\000\000\001", 3);
|
|
if (end - data > dataSize){
|
|
end = data + dataSize;
|
|
}
|
|
//Check for 4-byte lead in's. Yes, we access -1 here
|
|
if (end[-1] == 0x00){
|
|
end--;
|
|
}
|
|
newSize += 4 + (end - begin);//end - begin = nalSize
|
|
offset = end - data;
|
|
}
|
|
result = (char *)malloc(newSize);
|
|
}
|
|
int offset = 0;
|
|
int newOffset = 0;
|
|
while (offset < dataSize){
|
|
const char * begin = ((const char*)memmem(data + offset, dataSize - offset, "\000\000\001", 3)) + 3;//Initialize begin after the first 0x000001 pattern.
|
|
const char * end = (const char*)memmem(begin, dataSize - (begin - data), "\000\000\001", 3);
|
|
if (end - data > dataSize){
|
|
end = data + dataSize;
|
|
}
|
|
//Check for 4-byte lead in's. Yes, we access -1 here
|
|
if (end[-1] == 0x00){
|
|
end--;
|
|
}
|
|
unsigned int nalSize = end - begin;
|
|
Bit::htobl(result + newOffset, nalSize);
|
|
memcpy(result + newOffset + 4, begin, nalSize);
|
|
|
|
newOffset += 4 + nalSize;
|
|
offset = end - data;
|
|
}
|
|
return newOffset;
|
|
}
|
|
}
|
|
|