[FFmpeg-devel] [PATCH] rmdec.c: correctly skip indexes

[Reimar Döffinger]

On Mon, Mar 09, 2009 at 12:39:16PM -0400, Ronald S. Bultje wrote:
> -                len = get_be16(pb) - 6;
> +                int size, n_pkts;
> +                size = get_be32(pb);
> +                url_fskip(pb, 2);
> +                n_pkts = get_be32(pb);
> +                if (size == 0x14) {
> +                    /* some files don't add index entries to total size... */
> +                    len = size - 14 + n_pkts * 14;
> +                } else {
> +                    len = size - 14;
> +                    if (size - 0x14 != n_pkts * 14)
> +                        av_log(s, AV_LOG_WARNING,
> +                               "Index size %d (%d pkts) looks broken.\n",
> +                               size, n_pkts);
> +                }

Why not reusing the len variable? Also the -14 is common etc.
I consider e.g. this simpler:
len = get_be16(pb);
url_fskip(pb, 2);
n_pkts = get_be32(pb);
if (len == 20) // only index header
  ///  add probably forgotten size of index entries
  len += npkts * 14;
else if (len != 20 + n_ptks * 14)
  av_log...
// skip index and not yet read parts of header
len -= 14;