Originally Posted by Logic Design
What would you expect the Widescreen signaling to be on S-Video?
Here are the two bits that controls the aspect ratio and what their meaning is:
Bit 0 ------- Logic 1 is 16:9, logic 0 is 4:3.
Bit 1 ------- Logic 1 is Lettterbox, logic 0 is Normal
On the HD channels, both bits are set to logic 1. What should they be for S-Video?
I don't know what your SA box will deliver. I have heard that some SA boxes only offer letterboxed output on their S-video, which I would guess would mean Bit 0 = 0 and Bit 1 = 1.
My impression is that Bit 1 only applies when Bit 0 = 0. Bit 1 is used to override DVD player setting for "pan and scan" full screen viewing for 4x3 TV and force the DVD player to letterbox regardless of the setting choice of P&S or letterbox.
Another impression of mine is that the absence Bit 0 or Bit 1 data results in an assumption of a 0 (zero) value. Thus, a source device not providing widescreen flag signals leaves the sink (receiving) device to assume Bit 0 = 0 and Bit 1 = 0. This is the condition I experience with the output of my DirecTV HD TiVo (HR10-250).
I only set Bit 0 using my Video Filter and I get my desired control between widescreen 16x9 and standard screen 4x3 behaviors from DVD players.
My impressions come from my experiences. I hesitate to call them "understandings" because I don't have enough knowledge in this area to claim understanding. I am able to control the Bit 0 widescreen flag on my recordings to get the correct behaviors for DVD playback.
Whether or not the actual video program material is anamorphic ("tall and skinny" viewed on 4x3) or not has nothing to do with the widescreen flag settings directly. But coordinating anamorphic video with the Bit 0 = 1 widescreen flag is how I get desired results.
I am still learning and trying to confirm my impressions.