[LAU] Need to create delay or artificial latency

[Paul Davis]

On Mon, Apr 4, 2011 at 11:31 AM, Daniel Bair
<daniel at familyfirstradio.net> wrote:
> On Sun, Apr 3, 2011 at 9:12 PM, Paul Davis <paul at linuxaudiosystems.com> wrote:
>>
>> On Sun, Apr 3, 2011 at 9:57 PM, Daniel Bair <daniel at familyfirstradio.net> wrote:
>> > I have two different sized delays that I need to create.
>> > 1.) I need a audio delay of no more than 4 seconds. All of the delay plugins
>> > for Jack-Rack create echo. I just need a pure delay or artificial latency
>> > inserted into the jack audio stream (the output needs to be delayed 4
>> > seconds from the input without mixing back the input).
>>
>> just change the dry/wet mix to 100% wet and you'll get what you want.
> I have tried that and it still makes an echo by mixing the delay back
> with the original.
> If you could give me the exact plugin name and exact settings that do
> work I would appreciate that.
>
>
>> > 2.) I need a timezone delay of no more than 4 hours. (there are no plugins
>> > for Jack-Rack that do this and my attempt to create one with csladspa
>> > doesn't work... I have plenty of hd space for looped storage.)
>>
>> more details on the use case would be appropriate. it may not be that
>> a delay in the conventional sense is the right answer. or it could be.
>> no way to tell.
>>
> I am using Rivendell Radio Automation and we have towers in Eastern,
> Central and Pacific timezones.
> We have one master output for all stations. Management wants the
> output delayed for each timezone so that for example 9am content airs
> at 9am in each timezone. Content is mastered for Eastern timezone and
> simply needs to be delayed one hour for Central and three hours for
> Pacific.
>
> I temporarly have Rotter setup recording one hour slices of the master
> output and Mplayer on a cron job playing the correct slice for the
> respective timezone. BUT there is a small break when Mplayer finishes
> the one slice and starts the next - which we want to avoid.
>
> I was thinking that if a delay plugin could be created that stored a
> max of four hours (not just four seconds) that this would be smoother.

as has been noted, this involves very large amounts of memory (plugin
delays don't write to disk in general).

i don't know rivendell, but if was doing this with playlist-based
software i'd simply set it up using a playlist with 0,1,2,3 and 4
hours of silence at the start of 4 different playlists with the same
material in each. no memory utilitization, no disk utilization. i
don't know if rivendell can do this but i'd be a bit suprised if it
could not.

--p