In message <
q5bm6d-...@wschwanke.de>, Wolfgang Schwanke
>
news:6pednZcT1JEX5AXK...@brightview.co.uk:
>
>>> HD is 16:9 by definition. You can't have 4:3 HD.
>>
>> Yes, I thought we were all talking about SD in this thread. The very
>> fact that I've referred to 704 or 720 pixels horizontal resolution
>> makes it obvious that it's SD, rather than HD which is 1920x1080.
>
>Sorry, I read that as 720p. My error.
>
>>> Really? That shouldn't really be possible. Are sure those are not SD
>>> channels? Obviusly you can have 576i 4:3, and that's how such
>>> material should always be handled (sadly it isn't often).
>>
>> Are you saying that it's correct to broadcast 4:3 SD in a 16:9 frame
>> (with widescreen turned on)
>
>No, I hate that. It is only excusable if a short 4:3 clip is shown in
I'm not sure what you (both) mean here. IMO, it's _never_ acceptable to
cause the image seen to be _distorted_. If by "with widescreen turned
on" you mean set so that the full horizontal resolution of the
transmission system is used, but with the relevant flags so that the
displaying equipment knows it is 4:3, then that's fair enough [if the
_user_ has set their equipment to mangle the image, that's not the
broadcaster's fault].
>the framwork of a programme that is otherwhise widescreen. You can't
IMO, such material should always appear pillarboxed when viewed on a
shortscreen display, however it is actually encoded; for a _short_ clip,
it might be acceptable to encode some black sides rather than switch
flags.
>switch aspect ratio mid-programme; even if it was technically possible
>(which I guess it isn't) you wouldn't want to.
I think it is; the only reason you wouldn't want to is because of
possible delays in receiving (displaying) equipment as it gets round to
doing the switching. Even with such, I think for a clip of a reasonable
length (a minute or more perhaps?), I think the switching should be
done, to use the maximum resolution/bandwidth/whatever available from
the channel.
>
>> or are you saying that it's correct to
>> broadcast it as 4:3 with all the frame allocated to the broadcast
>> material (ie no black borders) and with widescreen turned off?
If it's just raw video, then yes, no black borders but with relevant
flags would maximise the horizontal resolution; however, where data
compression/encoding is involved, it probably doesn't matter that much,
in that as others have said black compresses to near enough zero anyway.
>
>Yes absolutely. That way you get the full resolution, and you retain
>compatibility with 4:3 screens.
>
(What bugged me when I started this thread was, indeed, the tendency of
broadcasters to show vertical-strip material - which I accept may be
what's available - with a blown-up and blurred version _of the same
content_ filling the sides. Whatever the _source_ of this weird
presentation [done in the 'phone, or whatever], I don't see the _point_
of it. I just find it distracting.)
--
J. P. Gilliver. UMRA: 1960/<1985 MB++G()AL-IS-Ch++(p)Ar@T+H+Sh0!:`)DNAf
... each generation tends to imagine that its attitude to sex strikes just
about the right balance; that by comparison its predecessors were prim and
embarrassed, its successors sex-obsessed and pornified. - Julian Barnes, Radio
Times 9-15 March 2013