feat: YouTube support via yt-proxy helper Space

- YouTube URLs detected by regex, routed to HeshamHaroon/yt-proxy Space
- Proxy runs on free CPU, downloads video, returns file via Gradio Client
- ZeroGPU Space connects via huggingface.co API (DNS accessible)
- Non-YouTube URLs still use direct yt-dlp download
- Updated UI labels to reflect YouTube support

app.py

@@ -283,11 +283,11 @@ with gr.Blocks(
             gr.Markdown("### SOURCE")
             source_url = gr.Textbox(
                 label="Video URL",
-                placeholder="Direct video/audio URL (or YouTube if network allows)...",
+                placeholder="YouTube URL or direct video/audio link...",
                 lines=1,
                 max_lines=2,
             )
-            gr.Markdown("<center style='color:var(--text-secondary);font-size:0.85rem'>Upload recommended — YouTube may be blocked on ZeroGPU</center>")
+            gr.Markdown("<center style='color:var(--text-secondary);font-size:0.85rem'>YouTube links download via proxy — or upload directly</center>")
             source_upload = gr.File(
                 label="Upload video or audio",
                 file_types=["video", "audio"],

pipeline_runner.py

@@ -14,11 +14,15 @@ import time
 from typing import Any, Generator
 
 import spaces  # provided by HF ZeroGPU runtime
+import re
 
 # ---------------------------------------------------------------------------
 # Constants
 # ---------------------------------------------------------------------------
 
+YT_PROXY_SPACE = "HeshamHaroon/yt-proxy"
+_YT_RE = re.compile(r'(?:youtube\.com/watch\?v=|youtu\.be/|youtube\.com/shorts/)([a-zA-Z0-9_-]{11})')
+
 HF_TOKEN: str = os.environ.get("HF_TOKEN", "")
 LLM_BASE_URL: str = "https://router.huggingface.co/v1"
 LLM_MODEL_TEXT: str = "Qwen/Qwen2.5-72B-Instruct"
@@ -68,6 +72,20 @@ def _make_client(model: str = LLM_MODEL_TEXT):
     return build_client(api_key=HF_TOKEN, base_url=LLM_BASE_URL)
 
 
+def _is_youtube_url(url: str) -> bool:
+    return bool(_YT_RE.search(url))
+
+
+def _download_via_proxy(url: str, output_path: str) -> str:
+    """Download a YouTube video via the yt-proxy helper Space."""
+    from gradio_client import Client
+    client = Client(YT_PROXY_SPACE, hf_token=HF_TOKEN)
+    result = client.predict(url=url, api_name="/download_video")
+    # result is a file path on the proxy; gradio_client downloads it locally
+    shutil.copy2(result, output_path)
+    return output_path
+
+
 # ---------------------------------------------------------------------------
 # Helper: call with exponential backoff on 429
 # ---------------------------------------------------------------------------
@@ -285,7 +303,12 @@ def run_pipeline(
 
     try:
         if download.is_url(source):
-            download.download_video(source, proj.video)
+            if _is_youtube_url(source):
+                # YouTube: use proxy Space (ZeroGPU blocks youtube.com DNS)
+                yield stage, f"[{STAGE_NAMES[stage - 1]}] Downloading via YouTube proxy...", {}
+                _download_via_proxy(source, proj.video)
+            else:
+                download.download_video(source, proj.video)
             download.extract_audio(proj.video, proj.audio)
         elif download.is_audio_file(source):
             download.ingest_local_audio(source, proj.audio)