From b0e2ae8e8316b983b7c8d97a2c03ea5390d4516d Mon Sep 17 00:00:00 2001
From: pstruebi <struebin.patrick@gmail.com>
Date: Sat, 7 Jun 2025 11:50:11 +0200
Subject: [PATCH] add saving to wav file for test purposes

---
 .gitignore                              |  1 +
 src/auracast/server/multicast_server.py | 57 ++++++++++++++++++++++---
 2 files changed, 51 insertions(+), 7 deletions(-)

diff --git a/.gitignore b/.gitignore
index 6479242..e0a7689 100644
--- a/.gitignore
+++ b/.gitignore
@@ -38,3 +38,4 @@ __pycache__/
 */.env
 
 wg_config/wg_confs/
+records/
diff --git a/src/auracast/server/multicast_server.py b/src/auracast/server/multicast_server.py
index e11b727..346a169 100644
--- a/src/auracast/server/multicast_server.py
+++ b/src/auracast/server/multicast_server.py
@@ -1,6 +1,10 @@
 import glob
+import os
 import logging as log
 import uuid
+
+import numpy as np
+from pydantic import BaseModel
 from fastapi import FastAPI, HTTPException
 from fastapi.middleware.cors import CORSMiddleware
 from auracast import multicast_control, auracast_config
@@ -8,7 +12,6 @@ from aiortc import RTCPeerConnection, RTCSessionDescription, MediaStreamTrack
 import av
 import av.audio.layout
 from typing import List, Set
-from pydantic import BaseModel
 import traceback
 
 app = FastAPI()
@@ -120,6 +123,9 @@ async def offer(offer: Offer):
     id_ = uuid.uuid4().hex[:8]
     log.info(f"{id_}: new PeerConnection")
 
+    # create directory for records - only for testing
+    os.makedirs("./records", exist_ok=True)
+
     @pc.on("track")
     async def on_track(track: MediaStreamTrack):
         log.info(f"{id_}: track {track.kind} received")
@@ -134,14 +140,51 @@ async def offer(offer: Offer):
                         f"{id_}: frame sample_rate={frame.sample_rate}, samples_per_channel={frame.samples}, planes={frame.planes}"
                     )
                     first = False
-                    array = frame.to_ndarray()
-                    log.info(f"array.shape{array.shape}")
-                    log.info(f"array.dtype{array.dtype}")
-                    log.info(f"frame.to_ndarray(){array}")
+                    # in stereo case this is interleaved data format
+                    frame_array = frame.to_ndarray()
+                    log.info(f"array.shape{frame_array.shape}")
+                    log.info(f"array.dtype{frame_array.dtype}")
+                    log.info(f"frame.to_ndarray(){frame_array}")
                     
-                # TODO: write to file, pipe to ASR, etc.
+                frame_array = frame.to_ndarray()
+                log.info(f"frame_array.shape: {frame_array.shape}")
+
+                # Flatten in case it's (1, N) or (N,)
+                samples = frame_array.reshape(-1)
+                log.info(f"samples.shape: {samples.shape}")
+
+                if frame.layout.name == 'stereo':
+                    # Interleaved stereo: [L0, R0, L1, R1, ...]
+                    mono_array = samples[::2]  # Take left channel
+                else:
+                    mono_array = samples
+
+                log.info(f"mono_array.shape: {mono_array.shape}")
+
+                # Save to WAV file - only for testing
+                # if not hasattr(pc, 'wav_writer'):
+                #     import wave
+                #     wav_path = f"./records/auracast_{id_}.wav"
+                #     pc.wav_writer = wave.open(wav_path, "wb")
+                #     pc.wav_writer.setnchannels(1)  # mono
+                #     pc.wav_writer.setsampwidth(2)  # 16-bit PCM
+                #     pc.wav_writer.setframerate(frame.sample_rate)
+
+                # pcm_data = mono_array.astype(np.int16).tobytes()
+                # pc.wav_writer.writeframes(pcm_data)
+                
+
+                
         except Exception as e:
             log.error(f"{id_}: Exception in on_track: {e}")
+        finally:
+            # Always close the wav file when the track ends or on error
+            if hasattr(pc, 'wav_writer'):
+                try:
+                    pc.wav_writer.close()
+                except Exception:
+                    pass
+                del pc.wav_writer
 
     # --- SDP negotiation ---
     log.info(f"{id_}: setting remote description")
@@ -175,7 +218,7 @@ async def shutdown():
 if __name__ == '__main__':
     import uvicorn
     log.basicConfig(
-        level=log.DEBUG,
+        level=log.INFO,
         format='%(module)s.py:%(lineno)d %(levelname)s: %(message)s'
     )
     uvicorn.run(app, host="0.0.0.0", port=5000)
\ No newline at end of file