Corion, you are the best. I think I've got it- 
#!/usr/bin/perl
use strict;
use warnings;
use Inline 'C';
Inline->init;

my $buffer_size = 36;    # (6x6)
print "Buffer size: $buffer_size\n";

my %template = (
    "32,3" => 'f',
    "32,1" => 'I',
    "32,2" => 'i',
    "8,1"  => 'c',
    "8,2"  => 'C',
    # ... add the other formats as you need
);

my $data;
print "char* data:\n";
$data = get_char_buffer();
printf "Raw data %s\n", $data;
print_buf( $data, 8, 1 );    # unsigned ints

print "\nfloat* data:\n";
print_buf( get_float_buffer(), 32, 3 );    # floating point

sub print_buf {
    my ( $rawdata, $bps, $fmt ) = @_;
    print "Ref count: " . get_ref_count( $rawdata ) . "\n";

    my $t = $template{ "$bps,$fmt" }
        or die "Couldn't find an unpack template for $bps BPS, format 
+$fmt";
    print "Template: $t\n";
    my @samples = unpack( "${t}${buffer_size}", $rawdata );

    print "Samples:\n@samples\n";
}

1;
__DATA__
__C__

#define BUF_SIZE 36

SV* get_char_buffer() {
    void* buffer;
    SV* sv_buf;
    int i;
    buffer = malloc(sizeof(char) * BUF_SIZE);
    for (i = 65; i < 65 + BUF_SIZE; i++) {  // printable chars
        ((char*)buffer)[i-65] = (char)i;
    }
    sv_buf = newSVpv(buffer,BUF_SIZE);
    free(buffer);
    return sv_buf;
}

SV* get_float_buffer() {
    void* buffer;
    SV* sv_buf;
    int i;
    buffer = malloc(sizeof(float) * BUF_SIZE);
    for (i = 1; i <= BUF_SIZE; i++) {
        ((float*)buffer)[i-1] = (float)(i + 0.5);
    }
    sv_buf = newSVpv(buffer,32*BUF_SIZE);
    free(buffer);
    return sv_buf;
}

int get_ref_count(SV* buf) {
    return (int)(SvREFCNT(buf));
}

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In reply to Re^4: C types and SV's by blakew
in thread C types and SV's and unpack by blakew

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