16:9 flags

[StoryDonut]

My widescreen TV is programmed to display 4:3 images and 16:9 images in their proper dimensions as the incoming signal dictates. I had always assumed that, when needed, a 16:9 flag was somehow digitally encoded into the video signal but separate from the picture information. But recently I taped to VHS a series of DVD 16:9 episodes with the DVD player set to 16:9 widescreen. I expected on playing back the VHS to have to manually tell the TV to stretch the picture back out to widescreen. But the TV is doing it automatically instead! Which means that it knows that the VHS tape is putting out 16:9 picture.

Am I correct in concluding then that 16:9 flags are embedded in the picture information somewhere (like Closed Caption signals are)? If VHS tapes are capable of this, have any film distributors taken avantage of it?

[guns1inger]

With mpeg is it embedded digitally, as mpeg is a digital format. But I have noticed similar effects when taping from my PVR to VHS. If I have the PVR on 16:9 mode, the VHS version will also cause my TV to switch into 16:9 mode on playback. I have to switch the PVR to letterbox mode to prevent this.