Screenshots: 2-phase (HTTPS-proxy resolve + plain media-proxy chunked download + local ffmpeg)

app.py

@@ -109,6 +109,14 @@ def _resolve_proxy() -> str | None:
     return proxy or None
 
 
+def _resolve_media_proxy() -> str | None:
+    """Plain HTTP proxy for large media (googlevideo.com) downloads. The TLS YT_PROXY
+    can't sustain multi-MB transfers, so screenshots use this instead; falls back to
+    YT_PROXY when unset."""
+    mp = os.environ.get("YT_MEDIA_PROXY", "").strip()
+    return mp or None
+
+
 def _resolve_api_key(ui_key: str | None) -> str | None:
     key = (ui_key or "").strip() or os.environ.get("YOUTUBE_API_KEY", "").strip()
     return key or None
@@ -122,6 +130,8 @@ def check_access():
     proxies = {"http": proxy, "https": proxy} if proxy else None
     lines = [
         f"- **Proxy** (`YT_PROXY`): {'set ✅' if proxy else 'not set ⚪'}",
+        f"- **Media proxy** (`YT_MEDIA_PROXY`, screenshots): "
+        f"{'set ✅' if _resolve_media_proxy() else 'not set ⚪ (falls back to YT_PROXY)'}",
         f"- **Cookies** (`YT_COOKIES`): {'set ✅' if os.environ.get('YT_COOKIES') else 'not set ⚪'}",
         f"- **Data API key** (`YOUTUBE_API_KEY`): {'set ✅' if os.environ.get('YOUTUBE_API_KEY') else 'not set ⚪'}",
     ]
@@ -285,7 +295,8 @@ def run_pipeline(topic, hf_token, yt_api_key, llm_model, vlm_model,
             yield status(f"🎞️ Capturing {len(times)} screenshots at weighted timestamps…"), ranking, gr.update(value=transcript), gr.update()
             try:
                 selected = frames_mod.capture_shots(
-                    times, best["video_id"], frames_dir, cookiefile, proxy, progress)
+                    times, best["video_id"], frames_dir, cookiefile, proxy,
+                    _resolve_media_proxy(), progress)
             except Exception as exc:
                 yield (status(f"⚠️ Couldn't fetch screenshots — text-only tutorial. "
                               f"`{type(exc).__name__}: {str(exc)[:400]}`"),