misc_support.cpp

FreeAMP(MP3播放)程序源代码-用来研究MP3解码

}

char *ID3_GetTrack(const ID3_Tag *tag)
{
  char *sTrack = NULL;
  if (NULL == tag)
  {
    return sTrack;
  }

  ID3_Frame *frame = tag->Find(ID3FID_TRACKNUM);
  if (frame != NULL)
  {
    sTrack = ID3_GetString(frame, ID3FN_TEXT);
  }
  return sTrack;
}

size_t ID3_GetTrackNum(const ID3_Tag *tag)
{
  char *sTrack = ID3_GetTrack(tag);
  size_t nTrack = 0;
  if (NULL != sTrack)
  {
    nTrack = atoi(sTrack);
    delete [] sTrack;
  }
  return nTrack;
}

ID3_Frame* ID3_AddTrack(ID3_Tag *tag, uchar trk, uchar ttl, bool replace)
{
  ID3_Frame* frame = NULL;
  if (NULL != tag && trk > 0)
  {
    if (replace)
    {
      ID3_RemoveTracks(tag);
    }
    if (replace || NULL == tag->Find(ID3FID_TRACKNUM))
    {
      frame = new ID3_Frame(ID3FID_TRACKNUM);
      if (frame)
      {
        char *sTrack = NULL;
        if (0 == ttl)
        {
          sTrack = new char[4];
          sprintf(sTrack, "%lu", (luint) trk);
        }
        else
        {
          sTrack = new char[8];
          sprintf(sTrack, "%lu/%lu", (luint) trk, (luint) ttl);
        }
        
        frame->GetField(ID3FN_TEXT)->Set(sTrack);
        tag->AttachFrame(frame);

        delete [] sTrack;
      }
    }
  }
  
  return frame;
}

size_t ID3_RemoveTracks(ID3_Tag *tag)
{
  size_t num_removed = 0;
  ID3_Frame *frame = NULL;

  if (NULL == tag)
  {
    return num_removed;
  }

  while ((frame = tag->Find(ID3FID_TRACKNUM)))
  {
    frame = tag->RemoveFrame(frame);
    delete frame;
    num_removed++;
  }

  return num_removed;
}

char *ID3_GetGenre(const ID3_Tag *tag)
{
  char *sGenre = NULL;
  if (NULL == tag)
  {
    return sGenre;
  }

  ID3_Frame *frame = tag->Find(ID3FID_CONTENTTYPE);
  if (frame != NULL)
  {
    sGenre = ID3_GetString(frame, ID3FN_TEXT);
  }

  return sGenre;
}

size_t ID3_GetGenreNum(const ID3_Tag *tag)
{
  char *sGenre = ID3_GetGenre(tag);
  size_t ulGenre = 0xFF;
  if (NULL == sGenre)
  {
    return ulGenre;
  }

  // If the genre string begins with "(ddd)", where "ddd" is a number, then 
  // "ddd" is the genre number---get it
  if (sGenre[0] == '(')
  {
    char *pCur = &sGenre[1];
    while (isdigit(*pCur))
    {
      pCur++;
    }
    if (*pCur == ')')
    {
      // if the genre number is greater than 255, its invalid.
      ulGenre = dami::min(0xFF, atoi(&sGenre[1]));
    }
  }

  delete [] sGenre;
  return ulGenre;
}

ID3_Frame* ID3_AddGenre(ID3_Tag *tag, size_t genre, bool replace)
{
  ID3_Frame* frame = NULL;
  if (NULL != tag && 0xFF != genre)
  {
    if (replace)
    {
      ID3_RemoveGenres(tag);
    }
    if (replace || NULL == tag->Find(ID3FID_CONTENTTYPE))
    {
      frame = new ID3_Frame(ID3FID_CONTENTTYPE);
      if (NULL != frame)
      {
        char sGenre[6];
        sprintf(sGenre, "(%lu)", (luint) genre);

        frame->GetField(ID3FN_TEXT)->Set(sGenre);
        tag->AttachFrame(frame);
      }
    }
  }
  
  return frame;
}

size_t ID3_RemoveGenres(ID3_Tag *tag)
{
  size_t num_removed = 0;
  ID3_Frame *frame = NULL;

  if (NULL == tag)
  {
    return num_removed;
  }

  while ((frame = tag->Find(ID3FID_CONTENTTYPE)))
  {
    frame = tag->RemoveFrame(frame);
    delete frame;
    num_removed++;
  }

  return num_removed;
}

char *ID3_GetLyrics(const ID3_Tag *tag)
{
  char *sLyrics = NULL;
  if (NULL == tag)
  {
    return sLyrics;
  }

  ID3_Frame *frame = tag->Find(ID3FID_UNSYNCEDLYRICS);
  if (frame != NULL)
  {
    sLyrics = ID3_GetString(frame, ID3FN_TEXT);
  }
  return sLyrics;
}

ID3_Frame* ID3_AddLyrics(ID3_Tag *tag, const char *text, bool replace)
{
  return ID3_AddLyrics(tag, text, "", replace);
}

ID3_Frame* ID3_AddLyrics(ID3_Tag *tag, const char *text, const char* desc, 
                         bool replace)
{
  return ID3_AddLyrics(tag, text, desc, "XXX", replace);
}

ID3_Frame* ID3_AddLyrics(ID3_Tag *tag, const char *text, const char* desc,
                         const char* lang, bool replace)
{
  ID3_Frame* frame = NULL;
  if (NULL != tag && strlen(text) > 0)
  {
    if (replace)
    {
      ID3_RemoveLyrics(tag);
    }
    if (replace || tag->Find(ID3FID_UNSYNCEDLYRICS) == NULL)
    {
      frame = new ID3_Frame(ID3FID_UNSYNCEDLYRICS);
      if (NULL != frame)
      {
        frame->GetField(ID3FN_LANGUAGE)->Set(lang);
        frame->GetField(ID3FN_DESCRIPTION)->Set(desc);
        frame->GetField(ID3FN_TEXT)->Set(text);
        tag->AttachFrame(frame);
      }
    }
  }
  
  return frame;
}

size_t ID3_RemoveLyrics(ID3_Tag *tag)
{
  size_t num_removed = 0;
  ID3_Frame *frame = NULL;

  if (NULL == tag)
  {
    return num_removed;
  }

  while ((frame = tag->Find(ID3FID_UNSYNCEDLYRICS)))
  {
    frame = tag->RemoveFrame(frame);
    delete frame;
    num_removed++;
  }

  return num_removed;
}

char *ID3_GetLyricist(const ID3_Tag *tag)
{
  char *sLyricist = NULL;
  if (NULL == tag)
  {
    return sLyricist;
  }

  ID3_Frame *frame = tag->Find(ID3FID_LYRICIST);
  if (frame != NULL)
  {
    sLyricist = ID3_GetString(frame, ID3FN_TEXT);
  }
  return sLyricist;
}

ID3_Frame* ID3_AddLyricist(ID3_Tag *tag, const char *text, bool replace)
{
  ID3_Frame* frame = NULL;
  if (NULL != tag && NULL != text && strlen(text) > 0)
  {
    if (replace)
    {
      ID3_RemoveLyricist(tag);
    }
    if (replace || (tag->Find(ID3FID_LYRICIST) == NULL))
    {    
      frame = new ID3_Frame(ID3FID_LYRICIST);
      if (frame)
      {
        frame->GetField(ID3FN_TEXT)->Set(text);
        tag->AttachFrame(frame);
      }
    }
  }

  return frame;
}

size_t ID3_RemoveLyricist(ID3_Tag *tag)
{
  size_t num_removed = 0;
  ID3_Frame *frame = NULL;

  if (NULL == tag)
  {
    return num_removed;
  }

  while ((frame = tag->Find(ID3FID_LYRICIST)))
  {
    frame = tag->RemoveFrame(frame);
    delete frame;
    num_removed++;
  }

  return num_removed;
}

ID3_Frame* ID3_AddSyncLyrics(ID3_Tag *tag, const uchar *data, size_t datasize,
                             ID3_TimeStampFormat format, bool replace)
{
  return ID3_AddSyncLyrics(tag, data, datasize, format, "", replace);
}

ID3_Frame* ID3_AddSyncLyrics(ID3_Tag *tag, const uchar *data, size_t datasize,
                             ID3_TimeStampFormat format, const char *desc, 
                             bool replace)
{
  return ID3_AddSyncLyrics(tag, data, datasize, format, desc, "XXX", replace);
}

ID3_Frame* ID3_AddSyncLyrics(ID3_Tag *tag, const uchar *data, size_t datasize,
                             ID3_TimeStampFormat format, const char *desc, 
                             const char *lang, bool replace)
{
  return ID3_AddSyncLyrics(tag, data, datasize, format, desc, lang, 
                           ID3CT_LYRICS, replace);
}

ID3_Frame* ID3_AddSyncLyrics(ID3_Tag *tag, const uchar *data, size_t datasize,
                             ID3_TimeStampFormat format, const char *desc, 
                             const char *lang, ID3_ContentType type, 
                             bool replace)
{
  ID3_Frame* frame = NULL;
  // language and descriptor should be mandatory
  if ((NULL == lang) || (NULL == desc))
  {
    return NULL;
  }

  // check if a SYLT frame of this language or descriptor already exists
  ID3_Frame* frmExist = tag->Find(ID3FID_SYNCEDLYRICS, ID3FN_LANGUAGE, lang);
  if (!frmExist)
  {
    frmExist = tag->Find(ID3FID_SYNCEDLYRICS, ID3FN_DESCRIPTION, desc);
  }

  if (NULL != tag && NULL != data)
  {
    if (replace && frmExist)
    {
      frmExist = tag->RemoveFrame (frmExist);
      delete frmExist;
      frmExist = NULL;
    }

    // if the frame still exist, cannot continue
    if (frmExist)
    {
      return NULL;
    }

    ID3_Frame* frame = new ID3_Frame(ID3FID_SYNCEDLYRICS);

    frame->GetField(ID3FN_LANGUAGE)->Set(lang);
    frame->GetField(ID3FN_DESCRIPTION)->Set(desc);
    frame->GetField(ID3FN_TIMESTAMPFORMAT)->Set(format);
    frame->GetField(ID3FN_CONTENTTYPE)->Set(type);
    frame->GetField(ID3FN_DATA)->Set(data, datasize);
    tag->AttachFrame(frame);
  }

  return frame;
}

ID3_Frame *ID3_GetSyncLyricsInfo(const ID3_Tag *tag, const char *desc, 
                                 const char *lang,
                                 ID3_TimeStampFormat& format, 
                                 ID3_ContentType& type, size_t& size)
{
  // check if a SYLT frame of this language or descriptor exists
  ID3_Frame* frmExist = NULL;
  if (NULL != lang)
  {
    // search through language
    frmExist = tag->Find(ID3FID_SYNCEDLYRICS, ID3FN_LANGUAGE, lang);
  }
  else if (NULL != desc)
  {
    // search through descriptor
    frmExist = tag->Find(ID3FID_SYNCEDLYRICS, ID3FN_DESCRIPTION, desc);
  }
  else
  {
    // both language and description not specified, search the first SYLT frame
    frmExist = tag->Find(ID3FID_SYNCEDLYRICS);
  }
  
  if (!frmExist)
  {
    return NULL;
  }
  
  // get the lyrics time stamp format
  format = static_cast<ID3_TimeStampFormat>(frmExist->GetField(ID3FN_TIMESTAMPFORMAT)->Get ());
  
  // get the lyrics content type
  type = static_cast<ID3_ContentType>(frmExist->GetField(ID3FN_CONTENTTYPE)->Get ());
  
  // get the lyrics size
  size = frmExist->GetField (ID3FN_DATA)->Size ();
  
  // return the frame pointer for further uses
  return frmExist;
}

ID3_Frame *ID3_GetSyncLyrics(const ID3_Tag *tag, const char *lang, 
                             const char *desc, const uchar *pData, size_t& size)
{
  // check if a SYLT frame of this language or descriptor exists
  ID3_Frame* frmExist = NULL;
  if (NULL != lang)
  {
    // search through language
    frmExist = tag->Find(ID3FID_SYNCEDLYRICS, ID3FN_LANGUAGE, lang);
  }
  else if (NULL != desc)
  {
    // search through descriptor
    frmExist = tag->Find(ID3FID_SYNCEDLYRICS, ID3FN_DESCRIPTION, desc);
  }
  else
  {
    // both language and description not specified, search the first SYLT frame
    frmExist = tag->Find(ID3FID_SYNCEDLYRICS);
  }

  if (NULL == frmExist)
  {
    return NULL;
  }
  
  // get the lyrics size
  size = dami::min(size, frmExist->GetField(ID3FN_DATA)->Size());

  // get the lyrics data
  pData = frmExist->GetField (ID3FN_DATA)->GetRawBinary();

  // return the frame pointer for further uses
  return frmExist;
}