gecko/media/libmkv/EbmlBufferWriter.c

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// #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_Serialize(EbmlGlobal *glob, const void *buffer_in, int buffer_size, unsigned long len)
{
/* buffer_size:
* 1 - int8_t;
* 2 - int16_t;
* 3 - int32_t;
* 4 - int64_t;
*/
long i;
for(i = len-1; i >= 0; i--) {
unsigned char x;
if (buffer_size == 1) {
x = (char)(*(const int8_t *)buffer_in >> (i * 8));
} else if (buffer_size == 2) {
x = (char)(*(const int16_t *)buffer_in >> (i * 8));
} else if (buffer_size == 4) {
x = (char)(*(const int32_t *)buffer_in >> (i * 8));
} else if (buffer_size == 8) {
x = (char)(*(const int64_t *)buffer_in >> (i * 8));
}
Ebml_Write(glob, &x, 1);
}
}
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;
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) {
unsigned long long unknownLen = 0x01FFFFFFFFFFFFFFLL;
Ebml_WriteID(glob, class_id);
ebmlLoc->offset = glob->offset;
// todo this is always taking 8 bytes, this may need later optimization
Ebml_Serialize(glob, (void *)&unknownLen,sizeof(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 |= 0x0100000000000000LL;
Ebml_Serialize(glob, &size,sizeof(size), 8);
glob->offset = curOffset;
}