Re: [Libexif-devel] Need some help with adding support for extra canon makernotes

[Jef D. <jef...@ho...>]

Marcus Meissner wrote:
> On Wed, Sep 06, 2006 at 03:39:30PM +0200, Jef Driesen wrote:
>> Jan Patera wrote:
>>>> case MNOTE_CANON_TAG_FOCAL_LENGTH:
>>>>     CF (entry->format, EXIF_FORMAT_SHORT, val, maxlen);
>>>>     n = exif_get_short (data, entry->order) / 2;
>>>>     if (t >= n) return NULL;
>>>>     CC (entry->components, n, val, maxlen);
>>>>     vs = exif_get_short (entry->data + 2 + t * 2, entry->order);
>>>>     snprintf (buf, sizeof (buf), "0x%04x", vs);
>>>>     strncpy (val, buf, maxlen - strlen (val));
>>>>     break;
>>>>
>>>> But when I run the exif commandline utility, an error is reported for
>>>> the new tag:
>>>>
>>>> Focal type          |Invalid number of components (4, expected 1).
>>>>
>>>> What am I doing wrong here?
>>>
>>> this message is printed by the CC macro. It checks whether
>>> 1st & 2nd arguments are equal. apparently entry->components is 4,
>>> but n is only 1.
>> I knew it was reported by the CC macro, but I don't understand why it is
>> happening. It is exactly the same code as is used for
>> MNOTE_CANON_TAG_SETTINGS_1 (which also has multiple components), but no
>> error there! Probably I forgot to add some code somewhere else, but I
>> don't see it.
> 
> Just a wild guess:
> Did you adjust mnote_canon_entry_count_values() too?

I added an extra 'case MNOTE_CANON_TAG_FOCAL_LENGTH:' between the others.