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Cainam
02-13-2006, 11:58 AM
I have an "aspect ratio" question I hope someone can help with.

I have Sky Digital and a widescreen TV, so I have set the TV type to widescreen in the Sky Menu. I have set the TV aspect on my Panasonic TV to "4:3". Tivo records the Sky signal quite happily, and when I play the recording back on the TV, if the broadcast was widescreen the TV automatically switches to widescreen mode, and I get the correct picture. If the recording was in 4:3, the TV stays in 4:3 mode, and I get black bars at the side, but the picture looks 'normal'.

So far so good. But I also have a portable Archos player (AV420, great piece of kit, my second favoutite gadget buy after Tivo). And this has a 4:3 screen.

The problem is that when I record from the VCR out socket on Tivo into the Archos, the Archos auto-detects it as a 4:3 picture, and it tries to display the full picture by squashing it all up (i.e. people's faces are really long and thin). If I choose the 16:9 option, it simply tries to crop the top and bottom of the picture, so what I can see is still squashed, and I am missing part of the picture anyway.

Reading round some of the Archos forums people seems to suggest that I should change the Sky box to output letterbox 4:3. Then when it plays back it plays backs as a 4:3 image, and the Archos displays it correctly. But I do not want to do this, as most things I watch on the TV, and I want to keep them on the Tivo in a widescreen format.

The only way I have found round this is as follows:

1) Record the film from Tivo choosing the 4:3 setting on Archos. It saves it as a 512x384 resolution avi file
2) Copy the .avi file from the Archos to my PC
3) Using virtualDub, load the resize filter, and reduce the resolution to 512x288 (this stretches the picture so it is now in a 16:9 format i.e. 1.7777777778 to 1)
4) Still in the resize filter, then choose to create a letterbox image by increasing the image size back to 512x384 (so it adds the black bars at top and bottom)
5) Let virtualdub fully process the file, and save the final .avi file back to the Archos.

Now this is hard work! As an example, after recording "Blade" over the weekend, it took about 2 hours to copy from Tivo to Archos in in real time, and about another 1.5 hours to convert it to the new .avi file.

So, my questions are really:

1) Can anyone think of a better way to do what I am doing?
2) Is the way I am using VirtualDub correct?
3) Am I just being too picky? I am really not a fan of the 'squashy face syndrome'

Any advice gratefully received!

iankb
02-13-2006, 12:12 PM
I use unmentionable tools to 'archive' the file from the TiVo. You can use DVDPatcher to change the aspect ratio of an MPEG2 file, and that only takes a few seconds. The aspect ratio is then preserved through any subsequent conversion. All 'archived' TiVo files are set to 4:3 ratio, irrespective of how they were displayed.

I don't have an Archos, but this method works with both my Windows PDA, and with my Video iPod.

iankb
02-13-2006, 12:21 PM
Are you sure you have to convert the video resolution of an AVI file to change the aspect ratio? You may only need to convert the file header, since anamorphic widescreen stretches the data to fit the aspect ratio.

sanderton
02-14-2006, 07:42 AM
I don't have an Archos, but on my PDA a resize to 16:9 (320 x 180 IIRC) is all that is needed - the PDA displays it letterboxed automatically.

That's with .wmv files though.

The only way I know to record something then play it back with different aspect ratios is to use Sky+ or MCE.

Cainam
02-14-2006, 11:20 AM
Thanks for this. I tried changing the aspect ratio in the header (as per Ian's suggestion), but that did not help, it just played the file exactly the same as before.

I tried just the resize, (and not the extra expand), and I have the choice on the Archos then of how to play it: either in 4:3 mode (i.e. zoom in to fill the screen) or 16:9 mode (where it shows the full picture with the black bars. Both of these play with the correct aspect ratio.

I suppose not doing the extra expand should help with quality a bit too, as there is no need to waste bits encoding the black bars!

Thanks again for the advice. :up: