media/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
  12 Ebml_Serialize(EbmlGlobal *glob, const void *buffer_in, int buffer_size, unsigned long len)
  13 {
  14   /* buffer_size:
  15    * 1 - int8_t;
  16    * 2 - int16_t;
  17    * 4 - int32_t;
  18    * 8 - int64_t;
  19    */
  20   long i;
  21   for(i = len-1; i >= 0; i--) {
  22     unsigned char x;
  23     if (buffer_size == 1) {
  24       x = (char)(*(const int8_t *)buffer_in >> (i * 8));
  25     } else if (buffer_size == 2) {
  26       x = (char)(*(const int16_t *)buffer_in >> (i * 8));
  27     } else if (buffer_size == 4) {
  28       x = (char)(*(const int32_t *)buffer_in >> (i * 8));
  29     } else if (buffer_size == 8) {
  30       x = (char)(*(const int64_t *)buffer_in >> (i * 8));
  31     }
  32     Ebml_Write(glob, &x, 1);
  33   }
  34 }
  35
  36 void Ebml_Write(EbmlGlobal *glob, const void *buffer_in, unsigned long len) {
  37   unsigned char *src = glob->buf;
  38   src += glob->offset;
  39   memcpy(src, buffer_in, len);
  40   glob->offset += len;
  41 }
  42
  43 static void _Serialize(EbmlGlobal *glob, const unsigned char *p, const unsigned char *q) {
  44   while (q != p) {
  45     --q;
  46
  47     memcpy(&(glob->buf[glob->offset]), q, 1);
  48     glob->offset++;
  49   }
  50 }
  51
  52 /*
  53 void Ebml_Serialize(EbmlGlobal *glob, const void *buffer_in, unsigned long len) {
  54   // assert(buf);
  55
  56   const unsigned char *const p = (const unsigned char *)(buffer_in);
  57   const unsigned char *const q = p + len;
  58
  59   _Serialize(glob, p, q);
  60 }
  61 */
  62
  63 void Ebml_StartSubElement(EbmlGlobal *glob, EbmlLoc *ebmlLoc, unsigned long class_id) {
  64   unsigned long long unknownLen = 0x01FFFFFFFFFFFFFFLL;
  65   Ebml_WriteID(glob, class_id);
  66   ebmlLoc->offset = glob->offset;
  67   // todo this is always taking 8 bytes, this may need later optimization
  68   Ebml_Serialize(glob, (void *)&unknownLen,sizeof(unknownLen), 8); // this is a key that says length unknown
  69 }
  70
  71 void Ebml_EndSubElement(EbmlGlobal *glob, EbmlLoc *ebmlLoc) {
  72   unsigned long long size = glob->offset - ebmlLoc->offset - 8;
  73   unsigned long long curOffset = glob->offset;
  74   glob->offset = ebmlLoc->offset;
  75   size |=  0x0100000000000000LL;
  76   Ebml_Serialize(glob, &size,sizeof(size), 8);
  77   glob->offset = curOffset;
  78 }
  79