aom/libmkv/EbmlBufferWriter.c

55 строки
1.5 KiB
C

// #include <strmif.h>
#include "EbmlBufferWriter.h"
#include "EbmlWriter.h"
// #include <cassert>
// #include <limits>
// #include <malloc.h> //_alloca
#include <stdlib.h>
#include <wchar.h>
#include <string.h>
void Ebml_Write(EbmlGlobal *glob, const void *buffer_in, unsigned long len) {
unsigned char *src = glob->buf;
src += glob->offset;
memcpy(src, buffer_in, len);
glob->offset += len;
}
static void _Serialize(EbmlGlobal *glob, const unsigned char *p, const unsigned char *q) {
while (q != p) {
--q;
unsigned long cbWritten;
memcpy(&(glob->buf[glob->offset]), q, 1);
glob->offset++;
}
}
void Ebml_Serialize(EbmlGlobal *glob, const void *buffer_in, unsigned long len) {
// assert(buf);
const unsigned char *const p = (const unsigned char *)(buffer_in);
const unsigned char *const q = p + len;
_Serialize(glob, p, q);
}
void Ebml_StartSubElement(EbmlGlobal *glob, EbmlLoc *ebmlLoc, unsigned long class_id) {
Ebml_WriteID(glob, class_id);
ebmlLoc->offset = glob->offset;
// todo this is always taking 8 bytes, this may need later optimization
unsigned long long unknownLen = 0x01FFFFFFFFFFFFFFLLU;
Ebml_Serialize(glob, (void *)&unknownLen, 8); // this is a key that says lenght unknown
}
void Ebml_EndSubElement(EbmlGlobal *glob, EbmlLoc *ebmlLoc) {
unsigned long long size = glob->offset - ebmlLoc->offset - 8;
unsigned long long curOffset = glob->offset;
glob->offset = ebmlLoc->offset;
size |= 0x0100000000000000LLU;
Ebml_Serialize(glob, &size, 8);
glob->offset = curOffset;
}