noop_convert(j_decompress_ptr cinfo, JSAMPIMAGE input_buf,
             JDIMENSION input_row, JSAMPARRAY output_buf, int num_rows)
{
}
noop_convert(j_decompress_ptr cinfo, JSAMPIMAGE input_buf,
             JDIMENSION input_row, JSAMPARRAY output_buf, int num_rows)
{
}