Stereo Tool

When using the streaming input, the audio becomes delayed by more than 10 seconds after only 2 days of running. I'm sure the delay will increase too much to be acceptable for realtime streaming. When the next song comes up the waveforms still reflect the previous song until 10 seconds later. This problem occurs on both the normal output and streaming output.

Here's my setup:

[pi running mpd]----FLAC stream (HTTP)---->[NUC running ST]--
--FLAC stream (HTTP)---->[ffmpeg transcoders on same pi]--
--icecast source streams---->[icecast on different pi]

I think it might be ST slowing down the input stream and not speeding it up. Turning off sound card sync doesn't seem to help. Any solution for this?

_________________
NKUB-FM 100.7 The Cube
We're the station for LA's cubers!

Seems no one has a solution...

I switched to using a plain UDP transport. This is how I did it:

On the pi running mpd:

ffmpeg -nostdin -loglevel quiet -i http://ip6-localhost:8001 -c:a libfdk_aac -b:a 448k -profile:a aac_low -f adts udp://nuc:4002?pkt_size=1452

And on the NUC running ST:
Set

udp://@:4002

as the stream URL

Then made sure syncing was turned on for the inputs and both the normal and FM outputs.

So far so good. Will report back if it lags badly.

_________________
NKUB-FM 100.7 The Cube
We're the station for LA's cubers!

I might have solved the issue... no more increasingly delayed audio after over a week of running

_________________
NKUB-FM 100.7 The Cube
We're the station for LA's cubers!

If you're doing the streaming outside of Stereo Tool, then the synchronization inside Stereo Tool can't do anything anymore. So ffmpeg would need to compensate in this case.

Ffmpeg sends the audio as fast as it can. I have the output buffers for both HD and FM set to 1 second. That way Stereo Tool can adjust for any frequency drifts on both sound cards. The ST GUI has brief pauses but there are no dropouts on the outputs at all. Total delay from MPD to the listener tops out at 4 seconds.

_________________
NKUB-FM 100.7 The Cube
We're the station for LA's cubers!