TV Channels have different aspect ratios??

[yoda]

Hi all,

I'm using a hauppauge nova s-plus watching dvb-s freeview satalite in New Zealand and most things are now working but...

...Channel 3 and ch4 seem to change the aspect ratio depending on different programs :confused:

I have set the aspect to 16:9 and have tried using different cedecs i.e. MVP, GPL, Hauppauge etc. but still the same result.

Ch1, Ch2, seem to be pretty stable but the others seem to change according to the what program is broadcast i.e. if i watch the news on ch3 then the studio coverage is fine but if they break away to a clip that clip will show as a pillar box. and other shows are completely pillar box. changing aspect with F7 only serves to screw up the other channels if i change back to Ch1 or Ch2.

Am i missing something or is this a broadcast issue??

[sub]

This is related to the way the channels are broadcast on freeview. TV1/TV2 are always transmitted as 4:3 video. TV3/TV4 are always transimitted as 16:9. On the 1st August, TVNZ will switch TV1/TV2 to 16:9 in the same way that TV3/TV4 are currently transmitted.

When I say "always transimitted as 16:9" above, I mean exactly that. Even when an old 4:3 show or advert is being played, its transmitted as 16:9, with black bars on the left/right being part of the video. It would have been nice if 16:9 video was transmitted as 16:9 and 4:3 video was transmitted as 4:3, but thats not what they've done.

If you have a 16:9 TV then this is no problem, just set the TV Shape setting in the config app to 16:9 and you get full widescreen when widescreen 16:9 video is being transmitted, and 4:3 will pillar box.

If you have a 4:3 TV, then you'll have more problems. To display a 16:9 picture on a 4:3 display it'll letterbox the content, meaning it'll add black bars at the top and the bottom of the 16:9 picture. Annoyingly because Canwest a transmitting their 4:3 video as 16:9 (with black bars left/right as part of the picture), this means you end up with black bars on all four sides (top/bottom added by GB-PVR, left/right added by canwest). Your only real option is to manually change aspect ratios, or hope Canwest start transmitting the real aspect ratio of their video. GB-PVR's 'center cut' aspect ratio is what the set top boxes do to get around this.

This isnt a GB-PVR problems, and effects people using Freeview set top boxes, and Sky boxes as well. On these boxes with a 4:3 TV, its not possible to have 16:9 video letterboxed and 4:3 video is shown fullscreen. The problem has been getting a fair bit of attention recently. Hopefully they'll fix it.

[stustunz]

yeah tv3 news is dumb how they do that why not fix that at the studio then broadcast it pisses me off to
i added f7 to my remote in the end mce remote using program HIP to add

[yoda]

Geez! i thought i was clasping at strws suggesting that it may be the broadcasters but your right stustunz thats just dumb.

So sub does that mean as of 1st of August that the problem will go away, or be made worse....

. On the 1st August, TVNZ will switch TV1/TV2 to 16:9 in the same way that TV3/TV4 are currently transmitted.

... if one and two do the same as three and four then it will get worse won't it?

[sub]

... if one and two do the same as three and four then it will get worse won't it?

Correct, unless they give us the real aspect ratio, ie 16x9 as 16x9 and 4x3 as 4x3. We'll just have to wait and see.

TVNZ have also had longer to get 16x9 content, so you may find they have more real 16x9 content and adverts, so even without real aspect ratio the problem may not be as obvious.

I may have the date wrong. It might have been 31st August. I cant remember for sure.

[yoda]

Surely they've got to get there act together before going live with DVB-T or is that a separate broadcast.

[sub]

I wouldnt count on it changing. Apparently its a fairly common approach used worldwide on DVB systems. It favours those with widescreen TVs which are becoming the norm these days. People with 4:3 TVs usually have to leave their set top boxes to center cut (often called 4:3 pan&scan).

[mvallevand]

Although I haven't seen it myself on livetv here in Canada, I think this is what the WSS feature of mvpmc is designed to address. The aspect ratio changes based on the information in the mpeg file.

Martin

[sub]

Although I haven't seen it myself on livetv here in Canada, I think this is what the WSS feature of mvpmc is designed to address. The aspect ratio changes based on the information in the mpeg file.

Unfortunately that is not in this case in this specific problem. If they had been setting the WSS flags, or the digital equivalent (changing the aspect ratio flags in the MPEG system header), then this problem wouldnt exist. If this header were to dynamically change during playback playback to identify real aspect ratio, then GB-PVR would automatically adjust to accomodate the aspect ratio.

The problem arises because the channel is always transmitted as 16:9, and if its showing content that was originally 4:3 then it has had black bars were added to the left/right of the picture before transmission.

Because of this, trying to display 16:9 letterboxed on a 4:3 display, ends up with black bars on all four sides.