#212 ID3_Tag::Link() takes long time on WAV files

[dreamlayers]

ID3_Tag::Link() takes a long time for WAV files. I'm just using this code, the 1.68 MB 10 second silent WAV file in the attached ZIP and id3lib from id3lib-3.8.3binaries.zip:

#define ID3LIB_LINKOPTION 3
#include <id3/tag.h>

int main(int argc, char* argv[])
{
    ID3_Tag myTag;
    myTag.Link("d:\\10s_silence.wav");
    return 0;
}

There is no tag in the WAV file and I have no interest in working with WAV tags. I ran into this bug while trying to play a WAV file in Winamp. The Toaster plugin uses id3lib and runs into this problem.

[dreamlayers]

The time is being spent in void src/tag_parse.cpp in ID3_TagImpl::ParseReader(ID3_Reader &reader), in the following loop. It reads the file character by character looking for a possible MPEG sync byte. This problem should not occur if the WAV file has some 0xFF bytes early on.

        // loop until first possible sync byte
        if (!wr.atEnd() && wr.peekChar() != 0xFF)
        {
          do
          {
            last = cur;
            cur = wr.getCur() + 1;
            wr.setCur(cur);
          } while (!wr.atEnd() &&  cur > last && wr.peekChar() != 0xFF);
        }