Video tab: modalita 'Solo audio' (estrazione MP3)

Aggiunto toggle Video/Solo audio nella tab Video. In modalita audio
yt-dlp scarica solo bestaudio ed estrae in MP3 al bitrate impostato
in Impostazioni (default 320 kbps), con embed thumbnail come la tab
Scarica.

- core/downloader.py: download_video() accetta audio_only e
  audio_bitrate; quando True usa format 'bestaudio/best' e
  --extract-audio --audio-format mp3
- api/bridge.py: start_video_download passa audio_only nel worker;
  log mostra 'Solo audio MP3 320K' vs 'Video 1080p'
- webui: segmented control 'Video (MP4)' / 'Solo audio (MP3)' rosa,
  selettore qualita nascosto in modalita audio, hint aggiornato

Co-Authored-By: Claude Opus 4.7 <noreply@anthropic.com>

api/bridge.py

@@ -640,6 +640,7 @@ class Api:
         urls = payload.get("urls") or []
         output_dir = (payload.get("output_dir") or "").strip()
         quality = payload.get("quality") or "1080p"
+        audio_only = bool(payload.get("audio_only", False))
 
         if not urls:
             return {"ok": False, "error": "Nessun URL fornito"}
@@ -648,7 +649,7 @@ class Api:
 
         self._video_thread = threading.Thread(
             target=self._video_worker,
-            args=(list(urls), output_dir, quality),
+            args=(list(urls), output_dir, quality, audio_only),
             daemon=True,
         )
         self._video_thread.start()
@@ -659,10 +660,12 @@ class Api:
         self._log("video", "[INFO] Interruzione richiesta...")
         return {"ok": True}
 
-    def _video_worker(self, urls: list, output_dir: str, quality: str) -> None:
+    def _video_worker(self, urls: list, output_dir: str, quality: str,
+                       audio_only: bool = False) -> None:
         reset_download_stop()
         cfg = load_config()
         cookies_path = cfg.get("cookies_path", "")
+        bitrate = cfg.get("bitrate", "320K")
         total_urls = len(urls)
         multi = total_urls > 1
         view = "video"
@@ -718,9 +721,11 @@ class Api:
 
                 self._emit("video:progress", payload_evt)
 
-            self._log(view, f"[INFO] Video: {url}")
+            mode_lbl = f"Solo audio MP3 {bitrate}" if audio_only else f"Video {quality}"
+            self._log(view, f"[INFO] {mode_lbl}: {url}")
             try:
-                download_video(url, output_dir, quality, cookies_path, progress_cb)
+                download_video(url, output_dir, quality, cookies_path, progress_cb,
+                               audio_only=audio_only, audio_bitrate=bitrate)
             except Exception as e:
                 self._log(view, f"[ERRORE] {e}")
                 continue

core/downloader.py

@@ -418,10 +418,14 @@ def download_video(
     quality: str = "1080p",
     cookies_path: Optional[str] = None,
     progress_callback: Optional[Callable] = None,
+    audio_only: bool = False,
+    audio_bitrate: str = "320K",
 ) -> None:
-    """Scarica video (con audio) da YouTube/TikTok/Instagram/Facebook/etc.
+    """Scarica video (con audio) o solo audio da YouTube/TikTok/Instagram/Facebook/etc.
 
-    quality: "best" | "1080p" | "720p" | "480p"
+    quality: "best" | "1080p" | "720p" | "480p" (ignorato se audio_only=True)
+    audio_only: True -> estrae solo audio in MP3
+    audio_bitrate: bitrate MP3 quando audio_only=True
     Per Instagram/Facebook privati servono cookies validi.
     """
     global _current_process
@@ -461,7 +465,7 @@ def download_video(
         return
 
     total = len(entries)
-    fmt = _video_format(quality)
+    fmt = _video_format(quality) if not audio_only else "bestaudio/best"
 
     for i, entry in enumerate(entries):
         if is_stopped():
@@ -483,6 +487,21 @@ def download_video(
         if progress_callback:
             progress_callback(i, total, title, "downloading", 0)
 
+        if audio_only:
+            cmd = [
+                ytdlp,
+                "-f", fmt,
+                "--extract-audio",
+                "--audio-format", "mp3",
+                "--audio-quality", audio_bitrate.rstrip("Kk"),
+                "--embed-thumbnail",
+                "--add-metadata",
+                "--no-check-certificates",
+                "--newline",
+                "--output", str(Path(output_dir) / "%(title)s [%(id)s].%(ext)s"),
+                entry_url,
+            ]
+        else:
             cmd = [
                 ytdlp,
                 "-f", fmt,

webui/css/style.css

@@ -615,6 +615,36 @@ input[type="number"]::-webkit-inner-spin-button {
 .log .l-warn { color: #FDCB6E; }
 .log .l-muted { color: var(--text-3); }
 
+/* ===============================
+   SEGMENTED CONTROL
+   =============================== */
+.segmented {
+  display: inline-flex;
+  background: var(--bg-input);
+  padding: 4px;
+  border-radius: var(--r-pill);
+  gap: 2px;
+}
+
+.seg-btn {
+  border: none;
+  background: transparent;
+  color: var(--text-2);
+  padding: 8px 18px;
+  border-radius: var(--r-pill);
+  cursor: pointer;
+  font-weight: 700;
+  font-size: 13px;
+  transition: background-color 0.15s, color 0.15s;
+}
+
+.seg-btn:hover:not(.active) { color: var(--text); }
+
+.seg-btn.active {
+  background: var(--pink);
+  color: #fff;
+}
+
 /* ===============================
    HINT BOX
    =============================== */

webui/index.html

@@ -144,6 +144,14 @@
           </div>
 
           <div class="field inline">
+            <label class="field-label">Modalità</label>
+            <div class="segmented" id="videoMode">
+              <button type="button" class="seg-btn active" data-mode="video">🎬 Video (MP4)</button>
+              <button type="button" class="seg-btn" data-mode="audio">🎵 Solo audio (MP3)</button>
+            </div>
+          </div>
+
+          <div class="field inline" id="videoQualityField">
             <label class="field-label">Qualità</label>
             <select id="videoQuality" class="input pill input-sm">
               <option value="best">Migliore disponibile</option>
@@ -155,9 +163,12 @@
 
           <div class="hint">
             <span class="hint-ico">ⓘ</span>
+            <div>
+              In modalità <strong>Solo audio</strong> il file viene salvato in MP3 al bitrate impostato in Impostazioni → Download.<br>
               Per Instagram/Facebook privati serve un file <strong>cookies.txt</strong> valido (Impostazioni → Percorsi).
             </div>
           </div>
+        </div>
 
         <div class="card actions">
           <button class="btn btn-pink pill btn-lg" id="videoDownloadBtn">

webui/js/app.js

@@ -375,6 +375,17 @@ $("#videoBrowseBtn").addEventListener("click", async () => {
   }
 });
 
+let videoMode = "video";  // "video" | "audio"
+
+$$("#videoMode .seg-btn").forEach((b) => {
+  b.addEventListener("click", () => {
+    $$("#videoMode .seg-btn").forEach((x) => x.classList.remove("active"));
+    b.classList.add("active");
+    videoMode = b.dataset.mode;
+    $("#videoQualityField").style.display = videoMode === "audio" ? "none" : "";
+  });
+});
+
 $("#videoDownloadBtn").addEventListener("click", async () => {
   const url = $("#videoUrlInput").value.trim();
   if (!url) {
@@ -396,6 +407,7 @@ $("#videoDownloadBtn").addEventListener("click", async () => {
     urls: [url],
     output_dir: state.videoOutputDir,
     quality: $("#videoQuality").value,
+    audio_only: videoMode === "audio",
   });
   if (!res.ok) {
     toast(res.error || "Errore", "error");