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.