5 ms·

Perhaps tangential, but is there any way to be certain whether the webcam light can be controlled by software? I often wonder if my MBP camera is necessarily o

Perhaps tangential, but is there any way to be certain whether the webcam light can be controlled by software? I often wonder if my MBP camera is necessarily off just because the ominous little green light isn't shining.

sillysaurus 13y ago
I don't think so. It seems like software controls whether that little green light is on. Unless the green light is on whenever the webcam is powered.
- deleted 13y ago
  [deleted]
  - mrmekon 13y ago
    Hardware-based can mean two things. 1. The CCD IC controls the LED 2. A intermediate IC has firmware that controls the CCD and LED It is safe to assume that the LED is always controlled either by an OS driver, or by an intermediate firmware. I doubt it would ever be controlled by the 'final' camera IC. This means that, for Macbooks, running the CCD without the LED is _very difficult_, but, if the camera supports firmware upgrades, it is possible. And there could be undocumented commands to enable video without the LED. If you're afraid of script-kiddies watching you read Reddit, you can probably trust the LED. If you're afraid the NSA has identified you as a special target, you probably cannot.
mrmekon 13y ago
That would be hardware-specific, but probably _always_ independently controllable. It's not like the IC manufacturer is going to link the CCD to an LED.
- Arnt 13y ago
  Why not? It's easy. Turn the LED on when there's current on the CCD's power input.
  - mrmekon 13y ago
    Certainly not arguing that it's difficult. It's extremely trivial. It just makes no business sense for the camera manufacturer. The CCD is a generic chip that spews clocked image data over some serial connection. Keep it simple and generic, and ship to any business who wants it. You can have a camera controller IC/ASIC/FPGA/µcontroller one step up from the CCD that manages the CCD and LEDs. That would have either firmware or hardware support for LEDs, but you'd still imagine that it would be configurable for cases where there is no LED installed. It's absolutely possible, and I don't know all the options out there, but I can't imagine a manufacturer shipping an off-the-shelf IC that _always_ ties an LED to CCD operation.
    - Arnt 13y ago
      Sometimes companies try to act in their customer's best interest. Or at least in such a way that they don't risk customers turning away. I noticed this story on HN quite recently: http://www.computerworld.com/s/article/9241003 http://www.computerworld.com/s/article/9241003 Perhaps not as often as one might wish.
weland 13y ago
Engineering common sense is a good way to be certain.

sillysaurus 13y ago

I don't think so. It seems like software controls whether that little green light is on. Unless the green light is on whenever the webcam is powered.

deleted 13y ago
[deleted]
- mrmekon 13y ago
  Hardware-based can mean two things. 1. The CCD IC controls the LED 2. A intermediate IC has firmware that controls the CCD and LED It is safe to assume that the LED is always controlled either by an OS driver, or by an intermediate firmware. I doubt it would ever be controlled by the 'final' camera IC. This means that, for Macbooks, running the CCD without the LED is _very difficult_, but, if the camera supports firmware upgrades, it is possible. And there could be undocumented commands to enable video without the LED. If you're afraid of script-kiddies watching you read Reddit, you can probably trust the LED. If you're afraid the NSA has identified you as a special target, you probably cannot.

mrmekon 13y ago

That would be hardware-specific, but probably _always_ independently controllable. It's not like the IC manufacturer is going to link the CCD to an LED.

Arnt 13y ago
Why not? It's easy. Turn the LED on when there's current on the CCD's power input.
- mrmekon 13y ago
  Certainly not arguing that it's difficult. It's extremely trivial. It just makes no business sense for the camera manufacturer. The CCD is a generic chip that spews clocked image data over some serial connection. Keep it simple and generic, and ship to any business who wants it. You can have a camera controller IC/ASIC/FPGA/µcontroller one step up from the CCD that manages the CCD and LEDs. That would have either firmware or hardware support for LEDs, but you'd still imagine that it would be configurable for cases where there is no LED installed. It's absolutely possible, and I don't know all the options out there, but I can't imagine a manufacturer shipping an off-the-shelf IC that _always_ ties an LED to CCD operation.
  - Arnt 13y ago
    Sometimes companies try to act in their customer's best interest. Or at least in such a way that they don't risk customers turning away. I noticed this story on HN quite recently: http://www.computerworld.com/s/article/9241003 http://www.computerworld.com/s/article/9241003 Perhaps not as often as one might wish.

weland 13y ago

Engineering common sense is a good way to be certain.