Re: [Bug-gnupod] mktunes.pl creates corrupt iTunesDB ?

[Richard van den Berg]

The results I got today were not consistent with yesterday (ok iTunesDBs 
would now be "not ok"). I learned a lot about the binary format, and 
figured out that by messing with the ArtworkDB (for the performance 
tests) the dbid_1 numbers were now out of whack. However, restoring the 
whole iPod_Control/Artwork directory from yesterday didn't help.

So I decided to clear the iPod_Control/Artwork directory and take out 
the dbid_1, artworkcnt and has_artwork parameters from my GNUtunesDB.xml 
files. I had to do a complete new binary search to find the following ok 
-> ok -> not_ok sequence:

http://richard.vdberg.org/gnupod/no_artwork/ok/11124/iTunesDB
http://richard.vdberg.org/gnupod/no_artwork/ok/11125/iTunesDB
http://richard.vdberg.org/gnupod/no_artwork/not_ok/11126/iTunesDB

This time file number 11126 seems to be the problem:

 <file addtime="3327445665" album="Love Train - The Sound Of 
Philadelphia - Disc 2" artist="Billy Paul" bitrate="215" cdnum="0" 
cds="0" comment="" compilation="1" composer="" 
desc="/d01/mp3/marcel/Love Train/The Sound Of Philadelphia/32 - Billy 
Paul - Thanks For Saving My Life.mp3" fdesc="MPEG 1 layer 3 file" 
filesize="4813000" genre="Soul" id="11152" mediatype="1" 
path=":iPod_Control:Music:f23:g0_For_Saving_My_Life.mp3" playcount="0" 
songnum="12" songs="0" soundcheck="5070" srate="44100" time="178311" 
title="Thanks For Saving My Life" volume="0" year="2008" />

On 6/13/09 12:43 PM, H. Langos wrote:
> I don't have much time this weekend but maybe you could check out what
> happens if you start giving those IDs from the highest value and decrement
> with each entry.
>   

Interesting idea. See attached patch. It does make the diff a whole lot 
easier to read. And it made a difference as well. With this patch 
applied 11126 suddenly worked.

During the binary search for the next limit I found that if an iTunesDB 
does not work right after I unplug the USB, it *might* work after a 
reset of the iPod. How weird is that? I verified that after the reboot 
the iTunesDB is exactly (cmp -bl) the same as before.

I'm now starting to think it's a RAM issue. According to 
http://ipodlinux.org/wiki/Generations#Fifth_Generation_.285G.29_.2F_Fifth_Generation_Enhanced_.285.5G.29 
my 30GB turned 240GB iPod has 32MB of RAM. Maybe I should try to get a 
hold of a 60GB/80GB version (64GB of RAM)?

Using a binary search including a reset cycle, I was able to get it to 
work with 17759 files (then I got bored):

25026442 not_ok/18053/iTunesDB-plid
25826240 not_ok/18640/iTunesDB-plid
28968870 not_ok/20987/iTunesDB-plid
42047276 not_ok/30415/iTunesDB-plid
22566800 ok/16293/iTunesDB-plid
24192148 ok/17466/iTunesDB-plid
24621122 ok/17759/iTunesDB-plid

You can find the files here: http://richard.vdberg.org/gnupod/no_artwork/
I used the "plid" extension to show I've used the decrement-plid patch 
to produce those iTunesDBs.

Cheers,

Richard

? .gnupod_version
? Makefile
? autom4te.cache
? config.log
? config.status
? configure
Index: src/ext/Mktunes.pm
===================================================================
RCS file: /sources/gnupod/gnupod/src/ext/Mktunes.pm,v
retrieving revision 1.6
diff -u -r1.6 Mktunes.pm
--- src/ext/Mktunes.pm  6 Oct 2007 07:26:52 -0000       1.6
+++ src/ext/Mktunes.pm  13 Jun 2009 17:05:41 -0000
@@ -12,7 +12,7 @@
                my($class,%args) = @_;
                
                my $self = { Connection=>$args{Connection}, Mode=>MODE_ADDFILE, 
Artwork=>$args{Artwork},
-                            ArrayFiles => [], CountFiles => 0, Sequence => 0,  
iPodName => $args{iPodName},
+                            ArrayFiles => [], CountFiles => 0, Sequence => 0, 
PlSequence => 0xFFFFFFFF, iPodName => $args{iPodName},
                             MasterPlaylist => [], Playlists => {}, 
SmartPlaylists => {},
                             FuzzyDb_Normal => {}, FuzzyDb_Lowercase => {} };
                bless($self,$class);
@@ -91,6 +91,8 @@
        sub GetFileCount        { my($self) = @_; return $self->{CountFiles};   
 }
        # Increments Sequence counter
        sub GetNextId           { my($self) = @_; return ++$self->{Sequence};   
 }
+       # Decrements PlSequence counter
+       sub GetPrevId           { my($self) = @_; return --$self->{PlSequence}; 
 }
        # Dispatch connector
        sub GetConnection       { my($self) = @_; return $self->{Connection}    
 }
        # Returns array to files
@@ -240,7 +242,7 @@
                        
                        
                        foreach my $fqid (@{$cont}) {
-                               my $current_id = $self->GetNextId;
+                               my $current_id = $self->GetPrevId;
                                my $current_mhod = 
GNUpod::iTunesDB::mk_mhod({fqid=>$fqid});
                                my $current_mhip = 
GNUpod::iTunesDB::mk_mhip({childs => 1, plid => $current_id, sid=>$fqid, 
size=>length($current_mhod)});
                                next unless (defined($current_mhod) && 
defined($current_mhip));