audio: mux: fix input buffer consumption for mixed channel counts

Fix per-source consumed byte accounting in mux_process().

When MUX inputs use different channel counts, using the first
input buffer frame size for all consumed accounting advances
other source buffers incorrectly. This causes duplicated
samples, incorrect output frequency, and capture duration
issues.

Compute consumed bytes per input buffer using each source
stream's own frame size.

Signed-off-by: Adrian Bonislawski <adrian.bonislawski@intel.com>

Author: abonislawski

src/audio/mux/mux.c

@@ -312,7 +312,6 @@ static int mux_process(struct processing_module *mod,
 	const struct audio_stream *sources_stream[MUX_MAX_STREAMS] = { NULL };
 	int frames = 0;
 	int sink_bytes;
-	int source_bytes;
 	int i, j;
 
 	comp_dbg(dev, "entry");
@@ -341,18 +340,18 @@ static int mux_process(struct processing_module *mod,
 	if (num_input_buffers == 0)
 		return 0;
 
-	source_bytes = frames * audio_stream_frame_bytes(mod->input_buffers[0].data);
 	sink_bytes = frames * audio_stream_frame_bytes(mod->output_buffers[0].data);
 	mux_prepare_active_look_up(cd, output_buffers[0].data, &sources_stream[0]);
 
 	/* produce output */
 	cd->mux(dev, output_buffers[0].data, &sources_stream[0], frames, &cd->active_lookup);
 
-	/* Update consumed and produced */
+	/* Update consumed per source using each source's own frame size */
 	j = 0;
 	comp_dev_for_each_producer(dev, source) {
 		if (comp_buffer_get_source_state(source) == dev->state)
-			mod->input_buffers[j].consumed = source_bytes;
+			mod->input_buffers[j].consumed =
+				frames * audio_stream_frame_bytes(mod->input_buffers[j].data);
 		j++;
 	}
 	mod->output_buffers[0].size = sink_bytes;