Just to point out an issue with your approach: If you were simply looking for a specific sequence of 24 bytes within up to 20,000,000,000 bytes, what about false positives? To avoid that, you'd actually have to parse the file and only look in the appropriate places for that flag. Which, if you were to DIY, would be a lot of reading specs and writing code, so it really is best to use an existing tool.

You're in luck! Someone actually submitted a patch for MP4::Info to add support for the HDVD tag: https://rt.cpan.org/Public/Bug/Display.html?id=101016

There's a quick & really dirty way to patch the module on your system: "wget -nv https://rt.cpan.org/Ticket/Attachment/1444239/767837/0001-add-support-for-HDVD-tag.patch -O- | patch `perldoc -l MP4::Info`" (you'll probably need to do this as root). However, a somewhat cleaner way would be to patch the module before installation:

# in the shell:
$ cd /tmp
$ wget http://www.cpan.org/authors/id/J/JH/JHAR/MP4-Info-1.13.tar.gz
$ tar xzf MP4-Info-1.13.tar.gz
$ cd MP4-Info-1.13/
$ wget -nv https://rt.cpan.org/Ticket/Attachment/1444239/767837/0001-a
+dd-support-for-HDVD-tag.patch -O- | patch

[download]

... and then install to a local module repository separate from your system's modules. For example, see the instructions under "I don't have permission to install a module on the system!" in A Guide to Installing Modules.

In reply to Re: Search hex string in vary large binary file by Anonymous Monk
in thread Search hex string in vary large binary file by westrock2000

Title:
Use:  <p> text here (a paragraph) </p>
and:  <code> code here </code>
to format your post, it's "PerlMonks-approved HTML":


  • Posts are HTML formatted. Put <p> </p> tags around your paragraphs. Put <code> </code> tags around your code and data!
  • Titles consisting of a single word are discouraged, and in most cases are disallowed outright.
  • Read Where should I post X? if you're not absolutely sure you're posting in the right place.
  • Please read these before you post! —
  • Posts may use any of the Perl Monks Approved HTML tags:
    a, abbr, b, big, blockquote, br, caption, center, col, colgroup, dd, del, details, div, dl, dt, em, font, h1, h2, h3, h4, h5, h6, hr, i, ins, li, ol, p, pre, readmore, small, span, spoiler, strike, strong, sub, summary, sup, table, tbody, td, tfoot, th, thead, tr, tt, u, ul, wbr
  • You may need to use entities for some characters, as follows. (Exception: Within code tags, you can put the characters literally.)
            For:     Use:
    & &amp;
    < &lt;
    > &gt;
    [ &#91;
    ] &#93;
  • Link using PerlMonks shortcuts! What shortcuts can I use for linking?
  • See Writeup Formatting Tips and other pages linked from there for more info.