while (buf_ptr < buf_end) {
start_code = ff_mjpeg_find_marker(jpg, &buf_ptr, buf_end,
&unescaped_buf_ptr, &unescaped_buf_size);
while (buf_ptr < buf_end) {
start_code = ff_mjpeg_find_marker(jpg, &buf_ptr, buf_end,
&unescaped_buf_ptr, &unescaped_buf_size);