convert nodes_audio.py to V3 schema (#10798)

Author: bigcat88

comfy_api/latest/_ui.py

@@ -319,9 +319,10 @@ def save_audio(
             for key, value in metadata.items():
                 output_container.metadata[key] = value
 
+            layout = "mono" if waveform.shape[0] == 1 else "stereo"
             # Set up the output stream with appropriate properties
             if format == "opus":
-                out_stream = output_container.add_stream("libopus", rate=sample_rate)
+                out_stream = output_container.add_stream("libopus", rate=sample_rate, layout=layout)
                 if quality == "64k":
                     out_stream.bit_rate = 64000
                 elif quality == "96k":
@@ -333,7 +334,7 @@ def save_audio(
                 elif quality == "320k":
                     out_stream.bit_rate = 320000
             elif format == "mp3":
-                out_stream = output_container.add_stream("libmp3lame", rate=sample_rate)
+                out_stream = output_container.add_stream("libmp3lame", rate=sample_rate, layout=layout)
                 if quality == "V0":
                     # TODO i would really love to support V3 and V5 but there doesn't seem to be a way to set the qscale level, the property below is a bool
                     out_stream.codec_context.qscale = 1
@@ -342,12 +343,12 @@ def save_audio(
                 elif quality == "320k":
                     out_stream.bit_rate = 320000
             else:  # format == "flac":
-                out_stream = output_container.add_stream("flac", rate=sample_rate)
+                out_stream = output_container.add_stream("flac", rate=sample_rate, layout=layout)
 
             frame = av.AudioFrame.from_ndarray(
                 waveform.movedim(0, 1).reshape(1, -1).float().numpy(),
                 format="flt",
-                layout="mono" if waveform.shape[0] == 1 else "stereo",
+                layout=layout,
             )
             frame.sample_rate = sample_rate
             frame.pts = 0