Actually, I think the format of the file has changed in version
1.0.50.
I did some sniffing, and came up with an approach that worked for me.
I've attached the modified version of makering.pl that I've
used (thanks to Tony and Stephen), as it may work better for others.
It also includes a breakdown of the header format as I understand
it to now be.
Cheers,
Jeremy
#!/usr/bin/perl
#--
# Create ringtone file for Grandstream BT100 phone, using uLaw input.
#
# Author: Tony Mountifield [EMAIL PROTECTED]
# Date: 28 May 2004
# File: makering.pl
# History:
# 28/05/2004 Initial version.
# 29/05/2004 Added checks for input file size being even and not too large.
# 30/05/2004 Phone will not accept files larger than 65536 bytes.
# 06/06/2004 Modified for the 1.05.00 firmware, probably doesn't support
# older firmware any longer
#--
#
# Usage:
# Use sox to convert any audio input file to uLaw and pipe to this prog, e.g.
#
# sox inputfile -r 8000 -c 1 -t ul - rate | makering.pl ring1.bin
#
# (try using /usr/share/sounds/phone.wav for the inputfile)
#
# Check the output file by using the following command:
#
# tail +513c ring1.bin | play -t ul -
#
# Finally, put the ring file in /tftpboot on the phone's TFTP server,
# and reboot the phone.
#
#--
#
# Credits:
# Based on analysis by Stephen R. Besch [EMAIL PROTECTED]
#
# Copyright: placed into the public domain by the author
#
# Warranty: none!
#
#--
$filename = shift or die need output filename\n;
undef $/; # slurp whole file at once...
$audio = ;# ... like this
$filesize = 512 + length $audio;
if ($filesize 1) {
# length odd, add a zero byte (should never happen)
$audio .= chr(0);
}
if ($filesize = (2 * 65536)) {
print STDERR Warning: $filesize is bigger than 2 bytes, trouble may be ahead.
}
# this is the format for the header
$headerfmt = N n C4 n C C C C a16 C C x4 n n x214 n n N x72 a176;
# get the current date and time
($min, $hour, $day, $month, $year) = (localtime)[1..5];
$year += 1900;
$month += 1;
# create the header, with zero for the checksum
$header = pack $headerfmt,
$filesize/2,# 00 - filesize/2
# FIXME: I'm guessing that the we
# always see at the beginning of
# the files are an extended file size
0, # 04 - put checksum in later
1,0,0,1,# 06 - version
$year, # 0a - year
$month, # 0c - month
$day, # 0d - day
$hour, # 0e - hour
$min, # 0f - min
ring.bin, # 10 - name, seems to always be ring.bin
# FIXME: Assumption 1: always ring.bin
# FIXME: Assumption 2: name field is 16 chars
0, # 20 - ?
0, # 21 - ? 0 (ring1.bin) or 9 (ring2.bin) - Codec?
# 22 - 4 NULL bytes, unknown
0xc8, # 26 - ? 00C8 (0 sometimes seen before)
0, # 28 - (ring2.bin) or 0001 (ring1.bin) - why?
# 2a - 214 null bytes
0, # 100 - ? 0
256,# 102 - ? 0x0100
$filesize/2,# 104 -
# Next comes an array of positions, which seems
# to be a sort of 'play until' set of instructions
# 150 - Description
Grandstream standard music ring;
# sanity check
$headerlen = length $header;
die header length wrong ($headerlen)\n unless $headerlen == 512;
# add the audio
$header .= $audio;
# compute the checksum
$checksum = unpack %16n*, $header;
printf checksum before = %04x\n, $checksum;
# insert it in the correct place
substr($header,4,2) = pack n,-$checksum;
# ensure the new checksum is zero
$checksum = unpack %16n*, $header;
printf checksum after = %04x\n, $checksum;
die checksum failed\n unless $checksum == 0;
# write the file
open F, $filename or die can't open output file $filename: $!\n;
print F $header;
close F;
# end
