EbmlWriter.c

/*
 *  Copyright (c) 2010 The WebM project authors. All Rights Reserved.
 *
 *  Use of this source code is governed by a BSD-style license
 *  that can be found in the LICENSE file in the root of the source
 *  tree. An additional intellectual property rights grant can be found
 *  in the file PATENTS.  All contributing project authors may
 *  be found in the AUTHORS file in the root of the source tree.
 */
#include "EbmlWriter.h"
#include <stdlib.h>
#include <wchar.h>
#include <string.h>
#include <limits.h>
#if defined(_MSC_VER)
#define LITERALU64(n) n
#else
#define LITERALU64(n) n##LLU
#endif

void Ebml_WriteLen(EbmlGlobal *glob, int64_t val) {
  /* TODO check and make sure we are not > than 0x0100000000000000LLU */
  unsigned char size = 8; /* size in bytes to output */

  /* mask to compare for byte size */
  int64_t minVal = 0xff;

  for (size = 1; size < 8; size ++) {
    if (val < minVal)
      break;

    minVal = (minVal << 7);
  }

  val |= (((uint64_t)0x80) << ((size - 1) * 7));

  Ebml_Serialize(glob, (void *) &val, sizeof(val), size);
}

void Ebml_WriteString(EbmlGlobal *glob, const char *str) {
  const size_t size_ = strlen(str);
  const uint64_t  size = size_;
  Ebml_WriteLen(glob, size);
  /* TODO: it's not clear from the spec whether the nul terminator
   * should be serialized too.  For now we omit the null terminator.
   */
  Ebml_Write(glob, str, (unsigned long)size);
}

void Ebml_WriteUTF8(EbmlGlobal *glob, const wchar_t *wstr) {
  const size_t strlen = wcslen(wstr);

  /* TODO: it's not clear from the spec whether the nul terminator
   * should be serialized too.  For now we include it.
   */
  const uint64_t  size = strlen;

  Ebml_WriteLen(glob, size);
  Ebml_Write(glob, wstr, (unsigned long)size);
}

void Ebml_WriteID(EbmlGlobal *glob, unsigned long class_id) {
  int len;

  if (class_id >= 0x01000000)
    len = 4;
  else if (class_id >= 0x00010000)
    len = 3;
  else if (class_id >= 0x00000100)
    len = 2;