Add multiple gated streams

Anyone have an idea how I can sum (add_ff) multiple, gated streams into
a single stream? For example, the gr-dsd block gates it’s output when
there is nothing to decode. I can sum multiple decoders together for a
single audio stream, but the add_ff only processes when ALL inputs have
a sample. So what I need is a block that passes all samples, and
outputs zeros (or repeats last sample) when input has halted. Maybe
there is a trick to do that with an existing block.

Thanks,
Lou

Hi Lou,

gr-eventstream[1] as invented by Tim [2] seems to fit your description
pretty exactly!

Best regards,
Marcus

[1] https://github.com/osh/gr-eventstream
[2] http://oshearesearch.com/tag/gr-eventstream/