[Icecast] Delay on preroll
geoff at QuiteLikely.com
Wed Dec 4 11:44:19 UTC 2019
On Wed, 4 Dec 2019, Javier Fuentes wrote:
> I have a problem when I use the intro to send a pre-roll, the main stream
> generates a 20 second delay, when the main stream is played it has no delay.
> Is there any parameter I can use to eliminate the delay?
> with pre-rolli: https://radiomarca-rrcast.flumotion.com/radiomarca/live.mp3
> without pre-rolli:
Are you saying that the listener is further behind on the stream with the
I believe that this happens because the pre-roll is sent as quickly as
possible by Icecast to the client, rather than at the rate of the audio.
So it will take much less time to send than it does to play. Once it has
finished sending the pre-roll, it starts sending the live audio. The
player still has to play the pre-roll and will therefore be further behind
the live audio when it gets to it.
Note that I'm only guessing but it makes sense.
My advice, use a shorter pre-roll. As a listener, this will get very
annoying very quickly. 40 seconds is a long time to listen through a
pre-roll if your connection drops for a second. I would limit it to 10
BTW: At time of writing, the live audio is out of phase (see
https://www.audiocheck.net/audiotests_polaritycheck.php for explanations
and examples). this will cause the encoder to work much harder than it
has to and will not sound as good as it should. It will also cause anyone
listening through a single speaker not to be able to hear the announcer
and anything else that is panned centre (e.g. song vocals).
this is most likely caused by an incorrectly wired cable or an RTS plug
which is not fully inserted into the jack.
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