JV
Someone's trying to be box clever!
James Vertigan
Founding member
Alexia posted:
So if you're using your set-top box to watch the boxing on the box on Boxing Day and you want to see a letterbox picture don't choose the pillarbox because if you have a window box it's letterboxed and pillar boxed?
Someone's trying to be box clever!
NG
All BBC channels currently do this on Freeview - but they send something called an AFD (Active Format Descriptor) in the data stream that tells set top boxes whether the signal they are receiving is 16:9 full frame or 4:3 pillarboxed into a 16:9 frame. If the latter is sent the set top box can do a central cut out, and convert the pillarbox into a 4:3 full frame signal for output.
Sky boxes don't support AFDs - so the BBC have to do the centre cut before they code the signal, and signal that the video stream itself has changed aspect ratio from 16:9 to 4:3. (This signal is not frame accurate, unlike the AFD which can be, so there can be a jump where a few frames of the wrong shape pictures are signalled)
noggin
Founding member
nodnirG kraM posted:
Carlton Cinema used to broadcast 4:3 programming on ONdigital in a pillarboxed 16:9 signal. Was bloody annoying, especially as my box was set to letterbox by default.
All BBC channels currently do this on Freeview - but they send something called an AFD (Active Format Descriptor) in the data stream that tells set top boxes whether the signal they are receiving is 16:9 full frame or 4:3 pillarboxed into a 16:9 frame. If the latter is sent the set top box can do a central cut out, and convert the pillarbox into a 4:3 full frame signal for output.
Sky boxes don't support AFDs - so the BBC have to do the centre cut before they code the signal, and signal that the video stream itself has changed aspect ratio from 16:9 to 4:3. (This signal is not frame accurate, unlike the AFD which can be, so there can be a jump where a few frames of the wrong shape pictures are signalled)
NH
Get back in your box!
Nick Harvey
Founding member
Alexia posted:
So if you're using your set-top box to watch the boxing on the box on Boxing Day and you want to see a letterbox picture don't choose the pillarbox because if you have a window box it's letterboxed and pillar boxed?
Get back in your box!
SP
All BBC channels currently do this on Freeview - but they send something called an AFD (Active Format Descriptor) in the data stream that tells set top boxes whether the signal they are receiving is 16:9 full frame or 4:3 pillarboxed into a 16:9 frame. If the latter is sent the set top box can do a central cut out, and convert the pillarbox into a 4:3 full frame signal for output.
Sky boxes don't support AFDs - so the BBC have to do the centre cut before they code the signal, and signal that the video stream itself has changed aspect ratio from 16:9 to 4:3. (This signal is not frame accurate, unlike the AFD which can be, so there can be a jump where a few frames of the wrong shape pictures are signalled)
Did ITV take a while to start using AFDs in the early days of DTT? I remember watching TV via a friend's OnDigital box not long after it launched, and 4:3 pictures on ITV (London) were pillarboxed, but those on the BBC were full screen.
noggin posted:
nodnirG kraM posted:
Carlton Cinema used to broadcast 4:3 programming on ONdigital in a pillarboxed 16:9 signal. Was bloody annoying, especially as my box was set to letterbox by default.
All BBC channels currently do this on Freeview - but they send something called an AFD (Active Format Descriptor) in the data stream that tells set top boxes whether the signal they are receiving is 16:9 full frame or 4:3 pillarboxed into a 16:9 frame. If the latter is sent the set top box can do a central cut out, and convert the pillarbox into a 4:3 full frame signal for output.
Sky boxes don't support AFDs - so the BBC have to do the centre cut before they code the signal, and signal that the video stream itself has changed aspect ratio from 16:9 to 4:3. (This signal is not frame accurate, unlike the AFD which can be, so there can be a jump where a few frames of the wrong shape pictures are signalled)
Did ITV take a while to start using AFDs in the early days of DTT? I remember watching TV via a friend's OnDigital box not long after it launched, and 4:3 pictures on ITV (London) were pillarboxed, but those on the BBC were full screen.
MA
Did ITV take a while to start using AFDs in the early days of DTT? I remember watching TV via a friend's OnDigital box not long after it launched, and 4:3 pictures on ITV (London) were pillarboxed, but those on the BBC were full screen.
The Beeb were the first to use AFDs on DTT, and that was from March 2000 as they rolled out English regional opts on DTT. That required OnD to send OTA upgrades to enable AFD reading on their boxes. I seem to recall the Pioneer box never got enabled. Until March 2000, no DTT broadcasters used AFDs. For 4:3 broadcasts an ARC was inserted at the broadcaster's end, and the MPEG header changed accordingly.
The Beeb started using 16:9 permanent coded frame from March 2000, and AFD signalled 4:3 broadcasts. This made regional opting easier for them.
ITV/4/5 carried on not using AFDs for a few more years.
However, DTT broadcasts in the London and Meridian (and other areas) was permanent 16:9 coded frame from Oct 1998 until sometime mid 1999, when LNN's new playout facility was brought on line. In fact Meridian normally just broadcast a PAL derived 4:3 image on DTT but they would manually patch an anamorphic component version for special occasions !
Spencer For Hire posted:
Did ITV take a while to start using AFDs in the early days of DTT? I remember watching TV via a friend's OnDigital box not long after it launched, and 4:3 pictures on ITV (London) were pillarboxed, but those on the BBC were full screen.
The Beeb were the first to use AFDs on DTT, and that was from March 2000 as they rolled out English regional opts on DTT. That required OnD to send OTA upgrades to enable AFD reading on their boxes. I seem to recall the Pioneer box never got enabled. Until March 2000, no DTT broadcasters used AFDs. For 4:3 broadcasts an ARC was inserted at the broadcaster's end, and the MPEG header changed accordingly.
The Beeb started using 16:9 permanent coded frame from March 2000, and AFD signalled 4:3 broadcasts. This made regional opting easier for them.
ITV/4/5 carried on not using AFDs for a few more years.
However, DTT broadcasts in the London and Meridian (and other areas) was permanent 16:9 coded frame from Oct 1998 until sometime mid 1999, when LNN's new playout facility was brought on line. In fact Meridian normally just broadcast a PAL derived 4:3 image on DTT but they would manually patch an anamorphic component version for special occasions !
NG
Did ITV take a while to start using AFDs in the early days of DTT? I remember watching TV via a friend's OnDigital box not long after it launched, and 4:3 pictures on ITV (London) were pillarboxed, but those on the BBC were full screen.
The Beeb were the first to use AFDs on DTT, and that was from March 2000 as they rolled out English regional opts on DTT. That required OnD to send OTA upgrades to enable AFD reading on their boxes. I seem to recall the Pioneer box never got enabled. Until March 2000, no DTT broadcasters used AFDs. For 4:3 broadcasts an ARC was inserted at the broadcaster's end, and the MPEG header changed accordingly.
The Beeb started using 16:9 permanent coded frame from March 2000, and AFD signalled 4:3 broadcasts. This made regional opting easier for them.
ITV/4/5 carried on not using AFDs for a few more years.
However, DTT broadcasts in the London and Meridian (and other areas) was permanent 16:9 coded frame from Oct 1998 until sometime mid 1999, when LNN's new playout facility was brought on line. In fact Meridian normally just broadcast a PAL derived 4:3 image on DTT but they would manually patch an anamorphic component version for special occasions !
Markymark - weren't both DTT and DSat BBC One permanently coded 16:9 at launch in 1998 - with the ARCs for 4:3 swiftly introduced on DSat once the complaints came from letterbox 4:3 viewers complaining about postage stamp stuff?
The complaints calmed down a bit - apart from during Grandstand which was a 16:9 show that contained 4:3 pillarboxed inserts - but as they were within the show the aspect ratio headers and ARCs weren't adjusted.
ISTR that Five went from AFDs to aspect ratio switching when they moved coding centres - at the same time as they introduced their current, horrid, long GOP encoding.
noggin
Founding member
Markymark posted:
Spencer For Hire posted:
Did ITV take a while to start using AFDs in the early days of DTT? I remember watching TV via a friend's OnDigital box not long after it launched, and 4:3 pictures on ITV (London) were pillarboxed, but those on the BBC were full screen.
The Beeb were the first to use AFDs on DTT, and that was from March 2000 as they rolled out English regional opts on DTT. That required OnD to send OTA upgrades to enable AFD reading on their boxes. I seem to recall the Pioneer box never got enabled. Until March 2000, no DTT broadcasters used AFDs. For 4:3 broadcasts an ARC was inserted at the broadcaster's end, and the MPEG header changed accordingly.
The Beeb started using 16:9 permanent coded frame from March 2000, and AFD signalled 4:3 broadcasts. This made regional opting easier for them.
ITV/4/5 carried on not using AFDs for a few more years.
However, DTT broadcasts in the London and Meridian (and other areas) was permanent 16:9 coded frame from Oct 1998 until sometime mid 1999, when LNN's new playout facility was brought on line. In fact Meridian normally just broadcast a PAL derived 4:3 image on DTT but they would manually patch an anamorphic component version for special occasions !
Markymark - weren't both DTT and DSat BBC One permanently coded 16:9 at launch in 1998 - with the ARCs for 4:3 swiftly introduced on DSat once the complaints came from letterbox 4:3 viewers complaining about postage stamp stuff?
The complaints calmed down a bit - apart from during Grandstand which was a 16:9 show that contained 4:3 pillarboxed inserts - but as they were within the show the aspect ratio headers and ARCs weren't adjusted.
ISTR that Five went from AFDs to aspect ratio switching when they moved coding centres - at the same time as they introduced their current, horrid, long GOP encoding.
MA
Markymark - weren't both DTT and DSat BBC One permanently coded 16:9 at launch in 1998 - with the ARCs for 4:3 swiftly introduced on DSat once the complaints came from letterbox 4:3 viewers complaining about postage stamp stuff?
Ah yes, you're right ! I think it took the 'Nations' a little longer to have ARCs installed too ? In those days it was BBC 1 and BBC Choice that had 'Nation' versions on D-Sat.
noggin posted:
Markymark - weren't both DTT and DSat BBC One permanently coded 16:9 at launch in 1998 - with the ARCs for 4:3 swiftly introduced on DSat once the complaints came from letterbox 4:3 viewers complaining about postage stamp stuff?
Ah yes, you're right ! I think it took the 'Nations' a little longer to have ARCs installed too ? In those days it was BBC 1 and BBC Choice that had 'Nation' versions on D-Sat.