Widescreen

[Chris]

Normal is 4:3
Widescreen is 16:9

---------------

The new widescreen support is supposed to enable:

Viewing a 16:9 programme on a 16:9 TV
Viewing a 4:3 programme on a 16:9 TV

An extra complication when the TV is 16:9 format is that the TV needs to know the aspect ratio of the incoming picture in order to stretch / squash / display it properly. For correctness, the TV should be informed the aspect ratio and do the following: When the picture is in 16:9 format the TV correctly displays all the picture over all the screen. When the picture is in 4:3 mode the TV should display black bars at left and right of the picture, the 4:3 picture will be in its correct aspect ratio in the middle of the screen. (I realise most people will then get their TV to strech/zoom a 4:3 picture to fit, but that is not relevant here. The aspect ratio information still has to be present even for that to work properly). On SCART TVs a SCART control line can be used to tell the TV the incoming aspect ratio. This poll is basically, does this work?

Also, to any American users (Hoochster!).. How is this widescreen switching done for you? As far as I know there is no system of sending control signals through composite signals, S-Video signals, or seperate RGB cable signals.

---------------

The new widescreen support has nothing to do with:

Viewing a 16:9 programme on a 4:3 TV

Viewing a 4:3 programme on a 4:3 TV has always worked. Viewing a 16:9 programme on a 4:3 TV -- currently the sides are chopped off and the middle of the picture is drawn on all of the TV screen. The other way to do this is to letterbox the picture with black bars at top and bottom. Unfortunately, while the MVP will letterbox a picture, it then draws the picture at the top of the screen with all the black bars at the bottom. If anyone fancies playing with ioctls etc to try to guess-fix this, be my guest.

[torsten]

Hi Chris,

I don't know the details, but the switching of the tv-sets aspect ratio in pal country is done via a teletext signal called WPS. This signal will be decoded by the tv set. So it will be transmitted via SVHS or Composite signal to the set. It isn't necessary to use a scart cable. Our DV camera does support this via SVHS too.

Yours

Torsten

[riban]

Chris

Setting the mvp option to 16:9 now allows me to see all of the picture of all recordings / channels. Previously, the image was displayed as 4:3 image with left and right portions cut off. The TV is not however switching to the right mode via the signalling in the SCART connector automatically. I can force my TV to the right aspect ratio so dongle 0.0.10 is a great improvement but still not working fully in this 'aspect'.

There are two means of signalling aspect ratio to a TV. One is to place a specific voltage on the signal pin of the SCART. The other is data embedded in an out of view line of the picture. (From memory, I think it may be line 23.) Given my TV remains locked firmly to 4:3 from the mvp, I assume either the SCART is asserting 4:3 and overriding the video signalling or that this signalling is not being encoded by UK broadcasters on digital feeds. I know my TV handles line 23 switching because it switches aspect from a VHS source via UHF (aerial) input and I am quite sure that UK broadcasters are using this method.

There are also a few different aspect ratios that can be signalled. 4:3 & 16:9 are the most commonly known but BBC are fond of 14:9 as an effort to compromise between both conventional and widescreen viewers. My Panasonic TV will switch to 16:9 on receiving a 14:9 signal.