scratch team mailing list archive

[Amos Blanton <amos@xxxxxxxxxxxxxxx>]

Hi Derek,

Hrm.. Well I did some checking into the camera issue. I went back to make
sure that the compiler commands were the same before and after I changed the
makefile / build process to meet Ubuntu standards, and they were.

I went back to the previous version of the source for the camera plugin,
prior to some changes you sent to me to check in a while back.  I ran the
makefile and replaced my current CameraPlugin with the result and the new
old plugin worked. Here's the diff of the old revision and the newer one,
which is the latest.

http://www.assembla.com/code/scratchonlinux/subversion/node/diff/36/14/src/plugins/camera/sqCamera-linux.c

The comment for the new one:

Removed RGB24 to ARGB32 conversion. Now request
ARGB32 directly from V4l / lib4vl and memcpy result straight to Squeak
buffer (by Derek - checked in by Amos)

It's weird - I thought I tested that after checking in the changes, but
perhaps I was still using a previously built plugin and didn't realize it.
There were some issues with how we were compiling / overwriting the old
plugins for a bit back then, so that may be why things appeared to be
working as they had previously.

Anyway - please take a look and let me know what the best solution would be.


Thanks!
Amos



On Tue, Apr 20, 2010 at 12:46 AM, Derek O'Connell <doc@xxxxxxxxxxxxxxxxx>wrote:

> > Did you mean to say you tested on another earlier version and found that
> it worked?
>
> yep, works fine in scratch_1.4.0.debian.12_i386. I also looked at an svn
> checkout I have from around 21st Feb but the Camera plugin was missing at
> that point (I vaguely remember querying it's absence).
>
>
>
> > As to why it is failing - I have no idea. Possibly b/c of an Ubuntu
> update? I don't believe we changed anything related to the Camera plugin
> stuff.
>
> I do update Ubuntu at least once a week but since the earlier plugin still
> works that rules out problems due to OS changes. I will pull another svn
> version this week and do some digging.
>
>
>   It's true, Scratch 2.0 will likely be all Flash based. But it's also
>> likely
>>  to take a long time before we're ready to release - at least a year I'd
>>  guess. So it might be helpful to use V4L (we already do as a library,
>> right?
>>  Or do you mean a closer connection?) I expect people will continue using
>> the
>>  squeak based software for some time after 2.0 is released, depending on
>> the
>>  success of our efforts to make an offline flash based version.
>>
>
> ok, thanks for the info. Yes, I was referring to the v4l plugin that
> already exists, which would require migration of Squeak classes to be usable
> in Scratch. The two main advantages are that:
>
> 1) the Camera plugin, which on Linux is just an interface to v4l anyway,
> could be dropped = less need for a custom VM for Scratch, especially if Ian
> adopts the "Scratch" plugin (ugh, the naming is confusing, I have to read
> things myself two/three time to make sure what I write makes sense :-) ).
> Scratch protocol would remain the same, since Windows plugin still required.
>
> 2) direct use of v4l in-image makes it easier to provide more controls to
> the user, vis-à-vis directshow properties dialog on Windows, gaining
> x-platform parity.
>
> Despite the above, I know that Camera use is not a key feature or of prime
> importance to most Scratch users. Maybe it would be if costumes could be
> dynamically updated from the camera via Scratch blocks (cough, done-it,
> cough). I have a few ideas on the back-burner for Etoys projects based
> around non-contact interfacing of various cheap sensors (power monitors,
> weather stations, etc) that provide LCD displays but no easy way to directly
> connect to a computer. The camera will be used to read the LCD. Would be
> nice to do the equivalent in Scratch for others to use :-) Anyways, that's
> my reason for being nosey about the direction of future scratch releases.
>
> One final note, on last nights Etoys mtg Bert expressed a preference for a
> simpler Camera interface for Etoys based on the Scratch plugin, which I read
> to mean Ian also adopting Scratch's "Camera" plugin (Bert, correct me if I'm
> wrong). I do see the attraction but it still leaves the Scratch user at a
> disadvantage on Linux since they cannot (easily) choose the video source
> and, as stated above, have no access to video controls. GStreamer was also
> mentioned but atm my focus is to get any/all Linux AV issues resolved across
> Squeak, Etoys and Scratch.
>
> @Amos: sorry to hear about the near miss with 10.04
>
> -D
>
>
> On 20/04/10 00:07, Amos Blanton wrote:
>
>> Hmm... looks like i might need to do a little more QA before releasing.
>> Thanks for letting us know about this!
>>
>> I'd lost track of my camera for a bit, but found it and can confirm that
>> the
>> camera in Scratch is not working currently. However, I'm using
>> scratch_1.4.0.1-0ubuntu4_i386.deb -- the latest version from our PPA and
>> the
>> main Scratch download page. Did you mean to say you tested on another
>> earlier version and found that it worked?
>>
>> As to why it is failing - I have no idea. Possibly b/c of an Ubuntu
>> update?
>> I don't believe we changed anything related to the Camera plugin stuff...
>>
>> No, we did not make it into 10.04 unfortunately. I thought we might scrape
>> by but alas. :( So we'll have to stick to recommending the PPA or the
>> download page.
>>
>> btw2, I'm planning to spend a fair chunk of this week on AV issues
>> (Squeak/
>>
>>
>>> Scratch/ Etoys), first on the desktop then on the XO. This includes
>>> bringing
>>> together any/all notes into one place. Squeak's wiki seems the most
>>> appropriate place so would you be willing to replace related Scratch wiki
>>> entries with links to the Squeak wiki? Which reminds me...
>>>
>>>
>>>
>> Sure! Just let us know what / where.
>>
>>
>>
>>
>>> For the XO I need to get intimate with the V4L plugin and I was wondering
>>> if there is any value in replacing the Camera plugin in Scratch with V4L?
>>> This helps a little if you are still aiming to eventually use Ian's VM.
>>> However, I get the impression that Scratch development might soon be
>>> focused
>>> on Flash so I'm wondering what the future is for the Squeak-based version
>>> beyond the current release?
>>>
>>>
>>>
>>>
>> It's true, Scratch 2.0 will likely be all Flash based. But it's also
>> likely
>> to take a long time before we're ready to release - at least a year I'd
>> guess. So it might be helpful to use V4L (we already do as a library,
>> right?
>> Or do you mean a closer connection?) I expect people will continue using
>> the
>> squeak based software for some time after 2.0 is released, depending on
>> the
>> success of our efforts to make an offline flash based version.
>>
>> -Amos
>>
>> On Mon, Apr 19, 2010 at 12:48 PM, Derek O'Connell<doc@xxxxxxxxxxxxxxxxx
>> >wrote:
>>
>>
>>
>>> Hi Amos, John, hope you are both well.
>>>
>>> I discovered today that the camera facility is broken in this version.
>>> For
>>> comparison I checked "scratch_1.4.0.1-0ubuntu4_i386.deb" in which the
>>> camera
>>> does work. Plugin file sizes match and the latest deb still quotes libv4l
>>> as
>>> a dependency so I'm left scratching my head. Can you think of any thing
>>> that
>>> might be peculiar to this build? No bother if not, I'll try a fresh build
>>> from svn later this week.
>>>
>>> btw, Amos, I was a little confused and thought your posting meant the
>>> Scratch deb was now in the official Ubuntu/ Debian repo's. What's the
>>> score
>>> on that, did it make it into 10.04? If so does that mean it will be
>>> automatically included in Karmic "backports" or is that only done on
>>> request?
>>>
>>> btw2, I'm planning to spend a fair chunk of this week on AV issues
>>> (Squeak/
>>> Scratch/ Etoys), first on the desktop then on the XO. This includes
>>> bringing
>>> together any/all notes into one place. Squeak's wiki seems the most
>>> appropriate place so would you be willing to replace related Scratch wiki
>>> entries with links to the Squeak wiki? Which reminds me...
>>>
>>> For the XO I need to get intimate with the V4L plugin and I was wondering
>>> if there is any value in replacing the Camera plugin in Scratch with V4L?
>>> This helps a little if you are still aiming to eventually use Ian's VM.
>>> However, I get the impression that Scratch development might soon be
>>> focused
>>> on Flash so I'm wondering what the future is for the Squeak-based version
>>> beyond the current release?
>>>
>>> -D
>>>
>>>
>>>
>>> On 17/04/10 00:34, Amos Blanton wrote:
>>>
>>>
>>>
>>>> http://info.scratch.mit.edu/Scratch_1.4_Download
>>>>
>>>> Thanks to everyone who contributed their time and energy to help make
>>>> this
>>>> package possible!
>>>>
>>>> -Amos
>>>>
>>>>
>>>>
>>>>
>>>
>>>
>>>
>>
>>
>>
>
>


-- 
_____
Amos