Re: [gphoto-devel] Canon Digital IXUS 400 in PTP mode

[Till K. <til...@gm...>]

Mariusz Woloszyn wrote:
> On Thu, 28 Aug 2003, Till Kamppeter wrote:
> 
> 
>>One additional remark: In Canon mode "gphoto2 --get-all-thumbnails"
>>produces correct thumbnails also for video files. The thumbnails contain
>>the first image of the videos. On the card there is no extra file for
>>that, it seems that the camera extracts the image from the beginning of
>>the video file.
>>
> 
> OH, BTW: I commited just mentioned change to CVS, could you test whether
> it works, please?
> 

I have tested now and have the following results:

"gphoto2 --get-all-thumbnails"

behaves worse: It downloads the whole files again and after downloading 
the video it stops with the error message "*** Error (-6: 'Unsupported 
operation') ***" and does not continue with the rest of the files. When 
there is one file for which no thumbnail is available, it should not be 
stopped with a fatal error but continued with a warning and the 
remaining files. Could one not make the driver skip files without 
thumbnails with a warning?

In addition, it seems that Canon's PTP mode seems not to support the 
thumbnail in the .thm file. Or is this a problem of the PTP driver?

Debug output is here:

http://www.linuxprinting.org/till/tmp/Canon-Digital_IXUS_400-ptp2-thumbnails-20030829-log.txt.bz2

Now I tested flphoto again in PTP mode and the thumbnail download still 
loads the entire files (including the video) instead of only thumbnails. 
So the thumbnail retrieval is as slow as before. At least flphoto 
continues retrieving thumbnails after the video. For the video (and also 
sound files) the thumbnail area stays blank.

GTKam is as slow in getting thumbnails, so it also seems to download the 
entire pictures. Right-clicking on the camera entry in the left part of 
the windows opens a context menu and there is a grayed "Capture" (though 
capture works) and an active "Preferences" entry (was gray in 2.1.2). 
The "Preferences" entry gives only an error message "Could not get 
configuration". "gphoto2 --config" gives the error "-6: Unsupported 
operation".

My suggestion for gphoto2 and other frontends is to allow two different 
modes of thumbnail loading: One quick mode where only those thumbnails 
are loaded which one gets without loading the entire file and one "slow" 
mode where thumbnail search in the whole file and/or thumbnail 
generation by downloading the whole original image and downscaling it is 
allowed. GUIs should have a cache so that if entire files were loaded 
for obtaining thumbnails that they do not get loaded again for obtaining 
the images themselves.

On the "canon" driver noone changed anything in the CVS, it behaves 
exactly as the released 2.1.2 version.

    Till