revert(video): back to simple send_file for video serving (RPi3 can't transcode)

Co-authored-by: Copilot <[email protected]>

app.py

@@ -1,6 +1,6 @@
 from flask import Flask, render_template, make_response, json, jsonify, request, send_file, Response
 from modules import app_gps, app_events, app_car, app_account, app_gps,app_obd, app_sql, app_dash, app_upload, app_video, app_health, app_alerts, app_settings, app_network
-import os, time, subprocess
+import os, time
 from gevent.pywsgi import WSGIServer
 
 
@@ -149,33 +149,7 @@ def local_video_file():
         return jsonify(error=str(error)), 400
     except FileNotFoundError:
         return jsonify(error=f"Local video not found: {relative_path}"), 404
-
-    # Stream via ffmpeg: copy video, transcode audio to AAC (PCM not supported
-    # in MP4), output as fragmented MP4 so browser plays without full download.
-    def generate_stream():
-        cmd = [
-            "ffmpeg", "-nostdin", "-loglevel", "error",
-            "-i", path,
-            "-c:v", "copy",
-            "-c:a", "aac",
-            "-movflags", "frag_keyframe+empty_moov",
-            "-f", "mp4",
-            "pipe:1",
-        ]
-        proc = subprocess.Popen(cmd, stdout=subprocess.PIPE, stderr=subprocess.DEVNULL)
-        try:
-            while True:
-                chunk = proc.stdout.read(65536)
-                if not chunk:
-                    break
-                yield chunk
-        finally:
-            proc.stdout.close()
-            proc.wait()
-
-    resp = Response(generate_stream(), 200, mimetype="video/mp4", direct_passthrough=True)
-    resp.headers["Cache-Control"] = "no-cache"
-    return resp
+    return send_file(path, conditional=True, as_attachment=False)
 
 @app.route('/api/local-video/thumbnail')
 def local_video_thumbnail():