iSight issue with Black screen

[Herb K.]

Hi,

I'm evaluating the software for use, and I've encountered the infamous 'black screen' mentioned by others in this support forum when I try to activate my external (not built-in) iSight camera.

I've read several similar posts, but none match my situation exactly. Here are my details:
- PowerMac G5, 10.4.9, most recent security patches (all up-to-date)
- iChat is turned off
- iSight is "on" (turned internal white lens cap to 'open' state)
- Miglia AlchemyTV card installed (not running)
- I've tried restarting the program several times
- I've tried unplugging and plugging the camera back in
- I've tried different Firewire ports
- In iChat, I can activate the camera (it is working; no connection problems); then I quit iChat
- I've looked at the console log, and see nothing suspicious

When I am in "add" mode in Bookpedia, I click on the "iSight" button, and I get a black screen with the red bar (indicating where the bar code should show up for a proper scan).

I do have the AlchemyTV software running with the Miglia card installed in my G5. This TV tuner works great, but I have done all these tests with that tuner card software NOT running (trying to isolate the problem)

I saw one person mention that they got an error message if the iSight camera was not connected. So, I tried that approach, just to try to replicate that result. And, I got a surprise -- right inside the iSight window was my television screen! No audio, of course. However, the last channel I used when the AlchemyTV software was active (ch 5) was not showing inside the iSight window!

This suggests to me that there is something "strange" in how Bookpedia accesses the various video streams available inside the Mac. I had no idea that my TV tuner was "always on" and tuning TV when my Mac was on (but the Alchemy TV software was OFF), so I was surprised to see "live TV" showing up in the Bookpedia iSight window.

FYI -- inside the AlchemyTV tuner software preferences, they have a drop-down menu where I can select audio from the iSight (not sure why I'd want to, but I just tested it, and it did accept the iSight microphone input and put it with the television image).

Is there a programming flag or other setting where you can select the video input stream, or make it a preferences option for the end-user to select in a case like this?

One other question that came to mind -- perhaps the iSight feature is disabled during the trial period?

I've successfully entered ISBN numbers during my test of your software, and I really like what I see (much more than my eval of DL). Hopefully we can figure this out so I won't have to only use it on my MacBook (which I haven't tested yet).

Thanks,
Herb

ps -- I have a screen capture showing the television news I can send you if you are interested.

[Nora]

It does seem that your TV card has a constant stream. We use the sample code provided by Apple to access the iSight. (OpenDefaultComponent(SeqGrabComponentType, 0)). You will find a new version of DVDpedia at:
http://www.bruji.com/temp/DVDpediaHerb.zip,
this version tries to limit the search of the stream to that which comes from
Apple hardware first before opening the default stream.

Let me know if that helps solve the issue.

[Herb K.]

Hi,

I downloaded the DVDpediaHerb.zip file, and just tested it.

At first, all I got was the black screen. Then, I decided to start the AlchemyTV application, to see if it captured that video. To my surprise, as the TV started up, the iSight camera in DVDpedia started working!

I pointed it to a nearby DVD case, and it registered the bar code, and loaded the data in about 2 seconds! Very cool to see this work!

So, to test some more, I quit DVDpedia, and also quit the AlchemyTV application. When I restarted DVDpedia, the iSight view presented me with the television image. Sigh...

I tried quiting and restarting; and I tried turning off the camera and then turning it back on. Neither worked -- all I got was the TV video again.

So, after successfully scanning one DVD, the application no longer sees the iSight camera.

Herb

[Conor]

I'll keep looking to see if there is a better way to determine the stream; but all documentation points to the current method that we are now using.