mciSendCommand is actually pretty simple. The tricky part is preparing the structure for its fourth argument, since the structure varies based on the second argument.

I imagine it would look like the following: 

package MCI;

use strict;
use warnings;

use Encode     qw( decode );
use Win32::API qw( );

use constant {
   # Messages
   MCI_INFO   => 0x80A
   MCI_RECORD => 0x80F,
   ...

   # Flags
   MCI_NOTIFY => 0x01,
   MCI_WAIT   => 0x02,
   ...
};

my $send_command = Win32::API->new(
   'Winmm.dll', 'mciSendCommandW', 'NNNP', 'N',
);

sub send_command {
   my ($device, $msg, $flags, $packed_parms) = @_;
   my $rv = $send_command->Call($device, $msg, $flags, $packed_parms);
   return 1 if $rv == 0;
   die(MCI::Error->new($rv));
}

sub info {
   my ($device, $flags, $win_handle, $max_chars) = @_;
   $max_chars ||= 256;

   my $size = $max_chars * 2;
   my $str_buf = "\0" x $size;

   # MCI_INFO_PARMS
   my $packed_params = pack("IPI",
      $win_handle,
      $str_buf,
      $size,
   );

   return undef if !send_command(
      $device,
      MCI_INFO,
      $flags,
      $packed_params,
   );

   my ($new_size) = unpack("x4x4I", $packed_params);
   return decode('UCS-2le', substr($str_buf, 0, $new_size));  # Or $ne
+w_size-2?
}


sub record {
   my ($device, $flags, $win_handle, $from, $to) = @_;

   # MCI_RECORD_PARMS
   my $packed_params = pack('III',
      $win_handle,
      $from,
      $to,
   );

   return send_command(
      $device,
      MCI_RECORD,
      $flags,
      $packed_params,
   );
}

...

1;

[download]
package MCI::Error;

use strict;
use warnings;

sub new {
   my ($class, $error) = @_;

   my $msg = ...mciGetErrorString...;

   return bless({
      code      => $error & 0xFFFF,
      driver_id => $error >> 16,
      msg       => $msg,
   }, $class);
}

...

1;

[download]

In reply to Re: Win32::API syntax for mciSendCommand? by ikegami
in thread Win32::API syntax for mciSendCommand? by slloyd

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.