write_metadata_header  654 libavformat/wtvenc.c     write_metadata_header(pb, 0, key, 4);
write_metadata_header  660 libavformat/wtvenc.c     write_metadata_header(pb, 1, key, strlen(value)*2 + 2);
write_metadata_header  683 libavformat/wtvenc.c         write_metadata_header(pb, 2, "WM/Picture", attachment_value_size(&wctx->thumbnail, tag));