Is this possible ?

[David Ondzes]

Is it possible to send video into the roku (say via component) and then
overlay a portion of the screen ? I am wondering if it is possible to
make my own information ticker. It would be great if I could change it
locatations and turn it off/on with the push of a button.

[Dave Dodge]

Post by David Ondzes
Is it possible to send video into the roku (say via component) and then
overlay a portion of the screen ?

If you mean you want to overlay something onto the analog video input,
then I don't believe there's any way to do that. From previous
discussions it appears that the video passthrough is just a simple
analog wiring switch: when the passthrough is enabled the video
bypasses the CPU and most other processing hardware. There's a simple
detection circuit that tests for motion in the analog input, but I
don't think there's any way to actually capture the analog video for
processing, scaling, overlay, etc.

Now, if you want to overlay something onto a _digital_ video stream,
such as an MPEG transport stream being fed from a file server, then
that should be possible from a technical standpoint. I don't know if
the Cascade API currently enables this, though.

-Dave Dodge

[David Ondzes]

Post by Dave Dodge

Post by David Ondzes
Is it possible to send video into the roku (say via component) and

then

Post by David Ondzes
overlay a portion of the screen ?

If you mean you want to overlay something onto the analog video input,
then I don't believe there's any way to do that. From previous
discussions it appears that the video passthrough is just a simple
analog wiring switch: when the passthrough is enabled the video
bypasses the CPU and most other processing hardware. There's a simple
detection circuit that tests for motion in the analog input, but I
don't think there's any way to actually capture the analog video for
processing, scaling, overlay, etc.

I had a feeling that was the case but I couldn't connect to the
archives to confirm.

Post by Dave Dodge
Now, if you want to overlay something onto a _digital_ video stream,
such as an MPEG transport stream being fed from a file server, then
that should be possible from a technical standpoint. I don't know if
the Cascade API currently enables this, though.

There an idea. I wonder if vlc can read TS file as it is being written
so I could do this with live tv. I guess it times to start looking at
the Cascade APIs, I was holding out for jvm :) If anyone know what APIs
to please let me know.

[Mike Kobb]

You can absolutely do overlay of graphics onto a video stream. Notice that
in the Photo app, when playing LiveArt, transport icons appear and so on.

In fact, you can't even really display video without painting 100% alpha
into the graphics layer. If you want an overlay, just paint some non-alpha
graphics.

Post by David Ondzes

Post by Dave Dodge

Post by David Ondzes
Is it possible to send video into the roku (say via component) and

then

Post by David Ondzes
overlay a portion of the screen ?

If you mean you want to overlay something onto the analog video input,
then I don't believe there's any way to do that. From previous
discussions it appears that the video passthrough is just a simple
analog wiring switch: when the passthrough is enabled the video
bypasses the CPU and most other processing hardware. There's a simple
detection circuit that tests for motion in the analog input, but I
don't think there's any way to actually capture the analog video for
processing, scaling, overlay, etc.

I had a feeling that was the case but I couldn't connect to the
archives to confirm.

Post by Dave Dodge
Now, if you want to overlay something onto a _digital_ video stream,
such as an MPEG transport stream being fed from a file server, then
that should be possible from a technical standpoint. I don't know if
the Cascade API currently enables this, though.

There an idea. I wonder if vlc can read TS file as it is being written
so I could do this with live tv. I guess it times to start looking at
the Cascade APIs, I was holding out for jvm :) If anyone know what APIs
to please let me know.
_______________________________________________
Roku-tech mailing list
http://lists.rokulabs.com/mailman/listinfo/roku-tech

------
Mike Kobb
Senior Software Engineer, Roku
Get more out of your high-def TV.
High-definition photos, art, music and more.
http://www.rokulabs.com
tel: [phone] x12 fax: [phone]

[David Ondzes]

Post by Mike Kobb
You can absolutely do overlay of graphics onto a video stream.
Notice that
in the Photo app, when playing LiveArt, transport icons appear and so on.
In fact, you can't even really display video without painting 100% alpha
into the graphics layer. If you want an overlay, just paint some non-alpha
graphics.

Can I do reverse of what you are saying ? I want to stream some video
to hd1000 and overlay the bottom or top portion with text, ie a ticker.

I just did a test and I able to record live tv and stream it to the
hd1000 and play it MpegPSPlay. So my next question is can I have a
second application also running and writing the text overlay ? I would
like to avoid having to modify MpegPSPlay to do the overlay...actually
I do not even have the source for the version I am using.

[Mike Kobb]

You can definitely overlay. I think you can do what you're proposing as far
as a second app, also.

Post by David Ondzes

Post by Mike Kobb
You can absolutely do overlay of graphics onto a video stream.
Notice that
in the Photo app, when playing LiveArt, transport icons appear and so on.
In fact, you can't even really display video without painting 100% alpha
into the graphics layer. If you want an overlay, just paint some non-alpha
graphics.

Can I do reverse of what you are saying ? I want to stream some video
to hd1000 and overlay the bottom or top portion with text, ie a ticker.
I just did a test and I able to record live tv and stream it to the
hd1000 and play it MpegPSPlay. So my next question is can I have a
second application also running and writing the text overlay ? I would
like to avoid having to modify MpegPSPlay to do the overlay...actually
I do not even have the source for the version I am using.
_______________________________________________
Roku-tech mailing list
http://lists.rokulabs.com/mailman/listinfo/roku-tech

------
Mike Kobb
Senior Software Engineer, Roku
Get more out of your high-def TV.
High-definition photos, art, music and more.
http://www.rokulabs.com
tel: [phone] x12 fax: [phone]

[Mike Kobb]

...oh, but it is definitely not possible to overlay graphics onto analog
video. As mentioned, it's an electrical bypass around the Xilleon, so
there's no opportunity to overlay.

--Mike

Post by David Ondzes

Post by Dave Dodge

Post by David Ondzes
Is it possible to send video into the roku (say via component) and

then

Post by David Ondzes
overlay a portion of the screen ?

If you mean you want to overlay something onto the analog video input,
then I don't believe there's any way to do that. From previous
discussions it appears that the video passthrough is just a simple
analog wiring switch: when the passthrough is enabled the video
bypasses the CPU and most other processing hardware. There's a simple
detection circuit that tests for motion in the analog input, but I
don't think there's any way to actually capture the analog video for
processing, scaling, overlay, etc.

I had a feeling that was the case but I couldn't connect to the
archives to confirm.

Post by Dave Dodge
Now, if you want to overlay something onto a _digital_ video stream,
such as an MPEG transport stream being fed from a file server, then
that should be possible from a technical standpoint. I don't know if
the Cascade API currently enables this, though.

There an idea. I wonder if vlc can read TS file as it is being written
so I could do this with live tv. I guess it times to start looking at
the Cascade APIs, I was holding out for jvm :) If anyone know what APIs
to please let me know.
_______________________________________________
Roku-tech mailing list
http://lists.rokulabs.com/mailman/listinfo/roku-tech

------
Mike Kobb
Senior Software Engineer, Roku
Get more out of your high-def TV.
High-definition photos, art, music and more.
http://www.rokulabs.com
tel: [phone] x12 fax: [phone]