[OT] TOTPs not offered in HD (720p)

RS richard22j at zoho.com
Thu Dec 29 05:27:04 PST 2016

>From: Owen Smith

>Sent: Thursday, December 29, 2016 11:43
>Freeview HD uses AAC sound, either in stereo or 5.1 (sometimes with another 
>AAC stream for audio described). It is never in AC3 aka Dolby Digital. Many 
> >set top boxes (including mine) transcode the AAC to Dolby Digital so that 
>amps can play it, this leads to confusion on what format is being 

>I am aware that Freesat sometimes uses AC3 sound but I don't keep up with 
>details as I don't have satellite.

>It is probably more pertinent to the discussion to say the broadcast stream 
>sometimes includes 5.1 sound which the iPlayer version never does. It's the 
> >stereo vs. multi channel sound aspect that is important here.

I only have one receiver which can receive Freeview HD.  That does not have 
a surround sound receiver connected, and I have not tried to record from it, 
so I can't comment on Freeview.

I do most of my viewing from satellite.  This page
shows that APIDs 5401, 5501 and 5301 use AC3.  When the AC3 encoder is 
switched on VLC shows an AC3 stream and a stereo stream are usually 
transmitted.  In some films I have seen the DTS indicator on my surround 
sound receiver light but not, I think, on the BBC.  Dolby Digital is more 
usual.  Many broadcasters use Dolby ProLogic on their stereo streams.

When HD transmission first started the AC3 encoder was switched on for every 
BBC continuity announcement.  There was a short clip which exercised all 5.1 

The discussion was about non-HD material on HD channels.  The same applies 
with AC3.  Turning on the AC3 encoder does not mean there is surround sound 
material.  Many sporting events are broadcast with an AC3 stream.

Most coverage of the Proms is particularly disappointing.  In order to allow 
the vision editor to change camera angles every few seconds there is usually 
a very narrow sound stage heavily band limited, with almost nothing on the 
sub-woofer channel.  I much to prefer to listen to a concert with a fairly 
static vision image and proper use of surround sound even if I can only have 
Dolby ProLogic on a SD channel.

I agree that I have not seen any use of AC3 on the iPlayer.

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