libmkv/EbmlBufferWriter.c

   1 //#include <strmif.h>
   2 #include "EbmlBufferWriter.h"
   3 #include "EbmlWriter.h"
   4 //#include <cassert>
   5 //#include <limits>
   6 //#include <malloc.h>  //_alloca
   7 #include <stdlib.h>
   8 #include <wchar.h>
   9 #include <string.h>
  10
  11 void Ebml_Write(EbmlGlobal *glob, const void *buffer_in, unsigned long len)
  12 {
  13     unsigned char *src = glob->buf;
  14     src += glob->offset;
  15     memcpy(src, buffer_in, len);
  16     glob->offset += len;
  17 }
  18
  19 static void _Serialize(EbmlGlobal *glob, const unsigned char *p, const unsigned char *q)
  20 {
  21     while (q != p)
  22     {
  23         --q;
  24
  25         unsigned long cbWritten;
  26         memcpy(&(glob->buf[glob->offset]), q, 1);
  27         glob->offset ++;
  28     }
  29 }
  30
  31 void Ebml_Serialize(EbmlGlobal *glob, const void *buffer_in, unsigned long len)
  32 {
  33     //assert(buf);
  34
  35     const unsigned char *const p = (const unsigned char *)(buffer_in);
  36     const unsigned char *const q = p + len;
  37
  38     _Serialize(glob, p, q);
  39 }
  40
  41
  42 void Ebml_StartSubElement(EbmlGlobal *glob, EbmlLoc *ebmlLoc, unsigned long class_id)
  43 {
  44     Ebml_WriteID(glob, class_id);
  45     ebmlLoc->offset = glob->offset;
  46     //todo this is always taking 8 bytes, this may need later optimization
  47     unsigned long long unknownLen =  0x01FFFFFFFFFFFFFFLLU;
  48     Ebml_Serialize(glob, (void *)&unknownLen, 8); //this is a key that says lenght unknown
  49 }
  50
  51 void Ebml_EndSubElement(EbmlGlobal *glob, EbmlLoc *ebmlLoc)
  52 {
  53     unsigned long long size = glob->offset - ebmlLoc->offset - 8;
  54     unsigned long long curOffset = glob->offset;
  55     glob->offset = ebmlLoc->offset;
  56     size |=  0x0100000000000000LLU;
  57     Ebml_Serialize(glob, &size, 8);
  58     glob->offset = curOffset;
  59 }
  60