Universal builds of gstreamer on macosx and osxvideosrc

[Dan Kegel]

On Tue, Oct 1, 2013 at 3:49 AM, Andoni Morales <ylatuya at gmail.com> wrote:
>> This plugin uses the QuickTime framework, which is only available for
>> 32bits. There is the qtkitvidesrc element (applemedia plugin) which can be
>> used as source element too in OS X using the QTKit framework, available for
>> i386 and x86_64.
>
> Right now for OS X, we only ship the QTKit based source element in
> applemedia, but at some point we should switch to avfvideosrc, based on the
> AVFoundation framework, since this pugin can be used both in OS X and iOS.
> None of these elements support device probing yet.

Thanks, I didn't know about qtkitvideosrc or avfvideosrc.  (I've
never actually used gstreamer, I'm just building it for some other folks,
and they said they needed osxvideosrc.)

http://gstreamer-devel.966125.n4.nabble.com/video-capture-on-Mac-OSX-td4659487.html
gives me pause; it says

"I have found that qtkitvideosrc is very finicky...
With gstreamer 1.0 I have never managed to get a direct pipeline with
both the video source and any displaying video sink to work.
ximagesink always hangs on one frame, osxvideosink gives the spinning
beach ball and doesn't show any frame.
With gstreamer 0.10 it sometimes worked if you inserted an extra ! queue.
What does work is to run two gstreamer processes: one to grab the
camera, then transmit over a socket to a second process, then display
there.
And if you are using qtkitvideosrc programmatically you *must* run
your gst/gobject main loop in the main thread.
...
My experience on pre 1.0 is still images were the result of an
incompatibility in the audio frequency (ie my video device versus my
audio device).  For instance since video can have audio, but say I
chose not to use it but rather used another audio input, and the
video's audio rate was 44khz, and my audio I was choosing externally
was 48khz, voila everything seemed to work fine, except I'd have a
still image on video.   Not yet tried 1.0.   Frankly, I was hoping a
rework as I think qtkit is now deprecated in 10.8?  Also, the qtkit
plug-in seemed hardwired for 640x480 video."

I guess we have some experimenting to do.

(Also: we're hoping to move to 1.2 soonish, but I'm trying to clean up
our 0.10 story in the meantime,
and that might mean osxvideosrc is more likely to be in a working state.)
- Dan