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Audio Description

"Nigel reverses his car" (August 2013)

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DV
dvboy
Couldn't find an appropriate thread to share this gem from the Radio Times letters page.

SF
Shane Forster
Audio Description doesn't even work on my Freeview set top box. There is an option to turn it on, so I tried it; but nothing.
NJ
Neil Jones Founding member
Audio Description doesn't even work on my Freeview set top box. There is an option to turn it on, so I tried it; but nothing.


Not all programmes, apparently, have it.
This is the schedule for Freeview programmes that, it is claimed, has audio description:
http://www.tvhelp.org.uk/audes/schedule.php

And a lot of boxes can't use it anyway. According to S4C. Other sites say only two or three boxes, most of which are no longer on sale, can also do AD.
OV
Orry Verducci
The problem with Audio Description implementation on Freeview is that it isn't done in a way that is backwards compatible with old receivers, as the commentary is broadcast on its own on a separate audio channel.

This means the box needs to be capable of decoding both the normal audio channel and the AD audio channel and mixing them together, which wasn't built into older receivers, and due to the way they are designed can't be enabled by software update. Sky was able to add it to old receivers by software update by choosing to broadcast a second audio channel that already had the normal audio and AD mixed together, meaning all the box has to do is switch channel rather than having to do anything more complicated.

All receivers in recent years that carry the Freeview logo will have AD support, as it is a requirement to pass the DTG testing process that is a requirement to carry the logo. I find the majority of televisions support it, whereas older Freeview boxes generally don't.
DA
davidhorman
The problem with Audio Description implementation on Freeview is that it isn't done in a way that is backwards compatible with old receivers, as the commentary is broadcast on its own on a separate audio channel.

This means the box needs to be capable of decoding both the normal audio channel and the AD audio channel and mixing them together,

Any idea why it was chosen to do it that way? It seems a bit overly complicated. If the AD is pre-mixed with programme audio you have the ability to lower the volume during things like establishing shots to allow the AD through. If that's still possible it must mean some other kind of data going along with the AD to control programme volume.
RI
Richard
The problem with Audio Description implementation on Freeview is that it isn't done in a way that is backwards compatible with old receivers, as the commentary is broadcast on its own on a separate audio channel.

This means the box needs to be capable of decoding both the normal audio channel and the AD audio channel and mixing them together,

Any idea why it was chosen to do it that way? It seems a bit overly complicated. If the AD is pre-mixed with programme audio you have the ability to lower the volume during things like establishing shots to allow the AD through. If that's still possible it must mean some other kind of data going along with the AD to control programme volume.


I imagine its to save bandwidth. Audio only can be a lower bit rate than something which includes a larger variety of noises/music and it can be in mono rather than stereo.
BA
bilky asko
All receivers in recent years that carry the Freeview logo will have AD support, as it is a requirement to pass the DTG testing process that is a requirement to carry the logo. I find the majority of televisions support it, whereas older Freeview boxes generally don't.

My 5 or 6 year old Freeview TV supports AD perfectly, yet my year old Freeview HD box doesn't have functioning AD on SD channels. Then again, the same box has automatic standby when left inactive - that cannot be turned off.
DV
DVB Cornwall
Somewhat unique, the BT Vision box has AD available via a single button push on the remote, appears to the left of the '0', directly opposite the subtitles button. Can't recall seeing the facility being so accessible on any other TV or receiver box.

Set up is a doddle too., allowing the downmix of the programme and ad audio to be customised.
SF
Shane Forster
The problem with Audio Description implementation on Freeview is that it isn't done in a way that is backwards compatible with old receivers, as the commentary is broadcast on its own on a separate audio channel.

This means the box needs to be capable of decoding both the normal audio channel and the AD audio channel and mixing them together, which wasn't built into older receivers, and due to the way they are designed can't be enabled by software update. Sky was able to add it to old receivers by software update by choosing to broadcast a second audio channel that already had the normal audio and AD mixed together, meaning all the box has to do is switch channel rather than having to do anything more complicated.

All receivers in recent years that carry the Freeview logo will have AD support, as it is a requirement to pass the DTG testing process that is a requirement to carry the logo. I find the majority of televisions support it, whereas older Freeview boxes generally don't.


If my Freeview box was too old to support it, why does it display the option to turn AD on? How odd... :S

As for old boxes, you may be correct. My box is only a couple of years old I think. But I don't need AD anyway; I was only testing it.
GO
gottago
Somewhat unique, the BT Vision box has AD available via a single button push on the remote, appears to the left of the '0', directly opposite the subtitles button. Can't recall seeing the facility being so accessible on any other TV or receiver box.
My Panasonic remote has an AD button.
WP
WillPS
Somewhat unique, the BT Vision box has AD available via a single button push on the remote, appears to the left of the '0', directly opposite the subtitles button. Can't recall seeing the facility being so accessible on any other TV or receiver box.

Set up is a doddle too., allowing the downmix of the programme and ad audio to be customised.

Every Freesat box I'm aware of has an "Audio" button which does the same thing.

Also, we know you like BT [Vision] a lot.
SF
Shane Forster
Somewhat unique, the BT Vision box has AD available via a single button push on the remote, appears to the left of the '0', directly opposite the subtitles button. Can't recall seeing the facility being so accessible on any other TV or receiver box.

Set up is a doddle too., allowing the downmix of the programme and ad audio to be customised.

Every Freesat box I'm aware of has an "Audio" button which does the same thing.

Also, we know you like BT [Vision] a lot.


Haha, I think we all know!

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