snd_pcm_plug_client_channels_buf
frames1 = snd_pcm_plug_client_channels_buf(substream, (char *)buf, frames, &channels);
frames1 = snd_pcm_plug_client_channels_buf(substream, buf, frames, &channels);
snd_pcm_sframes_t snd_pcm_plug_client_channels_buf(struct snd_pcm_substream *handle,