On Tue, 6 Jun 2023 18:20:08 +0100, John Williamson
<johnwilliamson@btinternet.com> wrote:

>On 06/06/2023 16:51, Max Demian wrote:
>> On 06/06/2023 12:00, Mark Carver wrote:
>
>> To apply compression before transmission would require a new radio
>> standard to specify it, and for bog standard radios to have expanders,
>> unless it's assumed that most people will want everything to be compressed.
>>
>That is, indeed, the assumption that Classic FM make. There definitely
>seems to be an Optimod or software equivalent somewhere in their signal
>chain.

Does Classic FM vary the compression through the day (according to
predicted listening environment, eg cars during commute)? I believe
the BBC used to do this.

On 06/06/2023 18:32, Scott wrote:

> Does Classic FM vary the compression through the day (according to
> predicted listening environment, eg cars during commute)? I believe
> the BBC used to do this.
>
I've not listened enough to tell and apparently they run different
ratios on FM and DAB. Radio 3 is not noticeable compressed, though.

--
Tciao for Now!

John.

On Tue 06/06/2023 18:48, John Williamson wrote:
> On 06/06/2023 18:32, Scott wrote:
>
>> Does Classic FM vary the compression through the day (according to
>> predicted listening environment, eg cars during commute)?  I believe
>> the BBC used to do this.
>>
> I've not listened enough to tell and apparently they run different
> ratios on FM and DAB. Radio 3 is not noticeable compressed, though.
>

AIUI BBC R3 runs through Optimod during the rush hours - something like
07h-09h and 17h-19h but at all other times send it plain at 192kb. IMSMC
they do however drop the data rate when one of the occasional stations
such as 5LSX/TMS or 4LW is on air or at least they used to. Marky will
be along shortly to put me right no doubt!

On 06/06/2023 19:26, Woody wrote:
> On Tue 06/06/2023 18:48, John Williamson wrote:
>> On 06/06/2023 18:32, Scott wrote:
>>
>>> Does Classic FM vary the compression through the day (according to
>>> predicted listening environment, eg cars during commute)?  I believe
>>> the BBC used to do this.
>>>
>> I've not listened enough to tell and apparently they run different
>> ratios on FM and DAB. Radio 3 is not noticeable compressed, though.
>>
>
> AIUI BBC R3 runs through Optimod during the rush hours - something
> like 07h-09h and 17h-19h but at all other times send it plain at
> 192kb. IMSMC they do however drop the data rate when one of the
> occasional stations such as 5LSX/TMS or 4LW is on air or at least they
> used to. Marky will be along shortly to put me right no doubt!
Wohnort is our friend

http://www.wohnort.org/dab/uknat.html#BBC

On 06/06/2023 19:35, Mark Carver wrote:
> On 06/06/2023 19:26, Woody wrote:
>> On Tue 06/06/2023 18:48, John Williamson wrote:
>>> On 06/06/2023 18:32, Scott wrote:
>>>
>>>> Does Classic FM vary the compression through the day (according to
>>>> predicted listening environment, eg cars during commute)? I believe
>>>> the BBC used to do this.
>>>>
>>> I've not listened enough to tell and apparently they run different
>>> ratios on FM and DAB. Radio 3 is not noticeable compressed, though.
>>>
>>
>> AIUI BBC R3 runs through Optimod during the rush hours - something
>> like 07h-09h and 17h-19h but at all other times send it plain at
>> 192kb. IMSMC they do however drop the data rate when one of the
>> occasional stations such as 5LSX/TMS or 4LW is on air or at least they
>> used to. Marky will be along shortly to put me right no doubt!
> Wohnort is our friend
>
> http://www.wohnort.org/dab/uknat.html#BBC

That shows that the bitrate varies, which alters the perceived quality,
but says nothing about analogue level compression.

The bit rate is now reduced to make room for special events such as
sports on other channels.

Optimod makes the quiet bits louder (Simplified explanation), which has
no effect on the DAB bitrate.

I have just read a report that all BBC radio channels use either am
Optimod or the earlier Omnia compressor at settings which vary to match
the channel profile.

--
Tciao for Now!

John.

On 06/06/2023 18:20, John Williamson wrote:
> That is, indeed, the assumption that Classic FM make. There definitely
> seems to be an Optimod or software equivalent somewhere in their signal
> chain.

I think most (if not everyone) with have something in the chain even if
just acting as a limiter because of the penalties for overdeviating.

On 06/06/2023 18:29, Scott wrote:
> I think there are fewer adverts at off-peak times. I have heard them
> say there will be x minutes (maybe an hour) uninterrupted.

Presumably like TV and put out more adverts when more viewers then
ensure the average complies with regulations by having few adverts when
not many viewers.

Unsurprisingly not being done for the benefit of the viewer or listener!

On Tue, 6 Jun 2023 20:14:51 +0100, John Williamson
<johnwilliamson@btinternet.com> wrote:

>On 06/06/2023 19:35, Mark Carver wrote:
>> On 06/06/2023 19:26, Woody wrote:
>>> On Tue 06/06/2023 18:48, John Williamson wrote:
>>>> On 06/06/2023 18:32, Scott wrote:
>>>>
>>>>> Does Classic FM vary the compression through the day (according to
>>>>> predicted listening environment, eg cars during commute)? I believe
>>>>> the BBC used to do this.
>>>>>
>>>> I've not listened enough to tell and apparently they run different
>>>> ratios on FM and DAB. Radio 3 is not noticeable compressed, though.
>>>>
>>>
>>> AIUI BBC R3 runs through Optimod during the rush hours - something
>>> like 07h-09h and 17h-19h but at all other times send it plain at
>>> 192kb. IMSMC they do however drop the data rate when one of the
>>> occasional stations such as 5LSX/TMS or 4LW is on air or at least they
>>> used to. Marky will be along shortly to put me right no doubt!
>> Wohnort is our friend
>>
>> http://www.wohnort.org/dab/uknat.html#BBC
>
>That shows that the bitrate varies, which alters the perceived quality,
>but says nothing about analogue level compression.
>
>The bit rate is now reduced to make room for special events such as
>sports on other channels.
>
>Optimod makes the quiet bits louder (Simplified explanation), which has
>no effect on the DAB bitrate.
>
>I have just read a report that all BBC radio channels use either am
>Optimod or the earlier Omnia compressor at settings which vary to match
>the channel profile.

I suspect 'Marky' is aware of this :-)

On Wed, 7 Jun 2023 07:44:18 +0100, MB <MB@nospam.net> wrote:

>On 06/06/2023 18:29, Scott wrote:
>> I think there are fewer adverts at off-peak times. I have heard them
>> say there will be x minutes (maybe an hour) uninterrupted.
>
>
>Presumably like TV and put out more adverts when more viewers then
>ensure the average complies with regulations by having few adverts when
>not many viewers.
>
>Unsurprisingly not being done for the benefit of the viewer or listener!
>
It benefits me as I usually listen in bed last thing at night :-)

On Wed 07/06/2023 16:37, Scott wrote:
> On Wed, 7 Jun 2023 07:44:18 +0100, MB <MB@nospam.net> wrote:
>
>> On 06/06/2023 18:29, Scott wrote:
>>> I think there are fewer adverts at off-peak times. I have heard them
>>> say there will be x minutes (maybe an hour) uninterrupted.
>>
>>
>> Presumably like TV and put out more adverts when more viewers then
>> ensure the average complies with regulations by having few adverts when
>> not many viewers.
>>
>> Unsurprisingly not being done for the benefit of the viewer or listener!
>>
> It benefits me as I usually listen in bed last thing at night :-)

Do you? I tend to use the Shipping Forecast - "......Cromaty, Forth,
Tyne, Dogger, Fisher, German Bight, etc etc... zzzzzzzzzzzzzzzzzzzzzz

On Wed, 7 Jun 2023 18:11:15 +0100, Woody <harrogate3@ntlworld.com>
wrote:

>On Wed 07/06/2023 16:37, Scott wrote:
>> On Wed, 7 Jun 2023 07:44:18 +0100, MB <MB@nospam.net> wrote:
>>
>>> On 06/06/2023 18:29, Scott wrote:
>>>> I think there are fewer adverts at off-peak times. I have heard them
>>>> say there will be x minutes (maybe an hour) uninterrupted.
>>>
>>>
>>> Presumably like TV and put out more adverts when more viewers then
>>> ensure the average complies with regulations by having few adverts when
>>> not many viewers.
>>>
>>> Unsurprisingly not being done for the benefit of the viewer or listener!
>>>
>> It benefits me as I usually listen in bed last thing at night :-)
>
>Do you? I tend to use the Shipping Forecast - "......Cromaty, Forth,
>Tyne, Dogger, Fisher, German Bight, etc etc... zzzzzzzzzzzzzzzzzzzzzz

I used to do that but it is too late for me now. I tried to imagine
the position of each of the sea areas as they circled (clockwise)
round the UK.

On 07/06/2023 18:11, Woody wrote:
> Do you? I tend to use the Shipping Forecast - "......Cromaty, Forth,
> Tyne, Dogger, Fisher, German Bight, etc etc... zzzzzzzzzzzzzzzzzzzzzz

Keeping Long Wave running is a very expensive way of helping a few
people get to sleep!

On Wed, 7 Jun 2023 21:07:36 +0100, MB <MB@nospam.net> wrote:

>On 07/06/2023 18:11, Woody wrote:
>> Do you? I tend to use the Shipping Forecast - "......Cromaty, Forth,
>> Tyne, Dogger, Fisher, German Bight, etc etc... zzzzzzzzzzzzzzzzzzzzzz
>
>Keeping Long Wave running is a very expensive way of helping a few
>people get to sleep!
>
Won't some of the shipping forecasts continue on FM? I assume this
would include the late night one.

On Tue, 6 Jun 2023 19:35:40 +0100, Mark Carver
<mark.carver@invalid.invalid> wrote:

>On 06/06/2023 19:26, Woody wrote:
>> On Tue 06/06/2023 18:48, John Williamson wrote:
>>> On 06/06/2023 18:32, Scott wrote:
>>>
>>>> Does Classic FM vary the compression through the day (according to
>>>> predicted listening environment, eg cars during commute)?  I believe
>>>> the BBC used to do this.
>>>>
>>> I've not listened enough to tell and apparently they run different
>>> ratios on FM and DAB. Radio 3 is not noticeable compressed, though.
>>>
>>
>> AIUI BBC R3 runs through Optimod during the rush hours - something
>> like 07h-09h and 17h-19h but at all other times send it plain at
>> 192kb. IMSMC they do however drop the data rate when one of the
>> occasional stations such as 5LSX/TMS or 4LW is on air or at least they
>> used to. Marky will be along shortly to put me right no doubt!
>Wohnort is our friend
>
>http://www.wohnort.org/dab/uknat.html#BBC

Returning to topic, I'm wondering if Classic FM on the Global Player
(HD audio) is compressed. My impression is that it is not.

In fact, is compression used for streaming services at all?