Issue 127 in mp4v2: Name and mean tags like iTunEXTC are not shown in iTunes

[mp...@googlecode.com]

Status: New
Owner: ----
Labels: Type-Defect Priority-Medium

New issue 127 by holgr.ja...@gmail.com: Name and mean tags like iTunEXTC
are not shown in iTunes
http://code.google.com/p/mp4v2/issues/detail?id=127

Hi,

I tried to tag mp4-files with name-tags like iTunEXTC. The tags are copied
to the file, but iTunes does not recognize them. When I imported the tagged
file in iTunes, iTunes doesn't show the age rating information.

I used the following code segment:

MP4ItmfItem* item = MP4ItmfItemAlloc( "----", 1 );
bogus->mean = strdup( "com.apple.iTunes" );
bogus->name = strdup( "iTunEXTC" );
const char* const fsk = "de-movie|FSK 18|500|";
MP4ItmfData* data = &item->dataList.elements[0];
data->typeCode = MP4_ITMF_BT_UTF8;
data->valueSize = strlen( fsk );
data->value = (uint8_t*)malloc( data->valueSize );
memcpy( data->value, fsk, data->valueSize );
bool result = MP4ItmfAddItem( destFile, item );

I think, that the name atoms are not stored in the correct format, but
thats only a guess.

Version 1.9.0, Mac OS X Lion 10.7.2

If needed, I can send you the tagged file to reproduce the error in iTunes.
It is to big for attachment.

Thanks

Holger

[mp...@googlecode.com]

Comment #1 on issue 127 by holgr.ja...@gmail.com: Name and mean tags like

iTunEXTC are not shown in iTunes
http://code.google.com/p/mp4v2/issues/detail?id=127

Hi,

ok, after two days of investigation I found the problem: the property
values of the mean and name tags are written as null terminated string.
The '\0' character at the end is included in the atom. That's an issue,
because iTunes expect a fixed length string without terminating zero.

I fixed it in generic.cpp by setting the fixed length parameter to the
actual sting length:

static bool
__itemModelToAtom( const MP4ItmfItem& model, MP4ItemAtom& atom )
{
if( ATOMID( atom.GetType() ) == ATOMID( "----" )) {
ASSERT( model.mean ); // mandatory
MP4MeanAtom& meanAtom = *(MP4MeanAtom*)MP4Atom::CreateAtom(
&atom, "mean" );
atom.AddChildAtom( &meanAtom );
meanAtom.value.SetValue( model.mean );
> meanAtom.value.SetFixedLength( strlen(model.mean) );

if( model.name ) {
MP4NameAtom& nameAtom = *(MP4NameAtom*)MP4Atom::CreateAtom(
&atom, "name" );
atom.AddChildAtom( &nameAtom );
nameAtom.value.SetValue( model.name );
> nameAtom.value.SetFixedLength( strlen(model.name) );
}
}

for( uint32_t i = 0; i < model.dataList.size; i++ ) {
...

[mp...@googlecode.com]

Updates:
Status: Accepted

Comment #2 on issue 127 by kid...@gmail.com: Name and mean tags like

iTunEXTC are not shown in iTunes
http://code.google.com/p/mp4v2/issues/detail?id=127

I'll work on getting this change in today; if I understand you correctly,
you're basically just telling the atom the length of the value, so existing
code that expected a NULL terminator would still work correctly?

[mp...@googlecode.com]

Comment #3 on issue 127 by kid...@gmail.com: Name and mean tags like

iTunEXTC are not shown in iTunes
http://code.google.com/p/mp4v2/issues/detail?id=127

Actually, sorry--have you tried trunk, or the current developer release?
The code that's currently there is significantly different from what's in
1.9.0 (which, actually, I'd advise against using because there's a ton of
known issues):

static bool
__itemModelToAtom( const MP4ItmfItem& model, MP4ItemAtom& atom )
{
if( ATOMID( atom.GetType() ) == ATOMID( "----" )) {
ASSERT( model.mean ); // mandatory
MP4MeanAtom& meanAtom = *(MP4MeanAtom*)MP4Atom::CreateAtom(

atom.GetFile(), &atom, "mean" );
atom.AddChildAtom( &meanAtom );
meanAtom.value.SetValue( (const uint8_t*)model.mean,
(uint32_t)strlen( model.mean ));

if( model.name ) {
MP4NameAtom& nameAtom = *(MP4NameAtom*)MP4Atom::CreateAtom(

atom.GetFile(), &atom, "name" );
atom.AddChildAtom( &nameAtom );
nameAtom.value.SetValue( (const uint8_t*)model.name,
(uint32_t)strlen( model.name ));
}
}

I want to do a release soon, and now might be as good a time as any if this
is a bug we can fix (or establish as fixed).

[mp...@googlecode.com]

Updates:
Status: WontFix

Comment #4 on issue 127 by kid...@gmail.com: Name and mean tags like

iTunEXTC are not shown in iTunes
http://code.google.com/p/mp4v2/issues/detail?id=127

Closing this bug; already fixed in trunk. Please let me know if you have
an issue w/trunk and I'll revisit the issue.