stl->unitsize = logic_channel_unitsize(sdi->channels);
stl->prev_sample = g_malloc0(stl->unitsize);
stl->pre_trigger_size = stl->unitsize * pre_trigger_samples;
stl->unitsize = logic_channel_unitsize(sdi->channels);
stl->prev_sample = g_malloc0(stl->unitsize);
stl->pre_trigger_size = stl->unitsize * pre_trigger_samples;