Substream Number Indicates the effect of playback and simultaneous recording

When the substream number of loopback_pcm_new is 2, in the loopback_pos_update function, the value of delta_play and delta_capt will be synchronized update, then the playback of the file will not appear sound stoppage; When the number of streams of loopback_pcm_new is 1, only the value of delta_play is updated, delta_capt is always 0, and the playback file will stall.enter image description hereenter image description here