> I'm looking to enhance video input/output enumeration support in > GStreamer using VIDIOC_ENUMINPUT/VIDIOC_ENUMOUTPUT ioctls and after some > discussions we wonder if the input/output list can change dynamically at > runtime or not. > > So, is v4l2 allow this input/output list to be dynamic ? I sure how the spec allows it, because I've done it in the past. I have cards which have an onboard header for external A/V inputs, and I am able to tell if the breakout cable is attached due to a dedicated pin tied to a GPIO. Thus, I am able to dictate whether the card has the A/V breakout cable attached and thus whether to expose only the first input or all three inputs. That said, in this case the inputs in the list never moved around because the optional entries were at the end of the list - the list just got longer if those inputs were available. I'm not sure what would happen if you had a configuration where you needed to remove entries other than those at the end of the list. For example, if you had a card with four possible inputs and you removed input 2, does the list stay the same length and input 2 is now marked as invalid, or does the length of the list become 3 and inputs 3 and 4 turn into inputs 2 and 3? Devin -- Devin J. Heitmueller - Kernel Labs http://www.kernellabs.com -- To unsubscribe from this list: send the line "unsubscribe linux-media" in the body of a message to majordomo@xxxxxxxxxxxxxxx More majordomo info at http://vger.kernel.org/majordomo-info.html
