improvement(voice): 语音优先转 MP3，并完善导出/接口兜底

- 新增 _convert_silk_to_browser_audio：优先 MP3（有 ffmpeg），否则 WAV，最后回退 SILK

- /chat/voice 返回浏览器可播格式，并补充 Content-Disposition 文件名后缀

- HTML 导出按实际格式写入语音资源；音频缺失时仍保留语音气泡结构

- 测试覆盖 MP3 优先、缺失音频兜底，并在用例结束 logging.shutdown()

Author: 2977094657

src/wechat_decrypt_tool/chat_export_service.py

@@ -53,7 +53,7 @@
 )
 from .logging_config import get_logger
 from .media_helpers import (
-    _convert_silk_to_wav,
+    _convert_silk_to_browser_audio,
     _detect_image_media_type,
     _fallback_search_media_by_file_id,
     _read_and_maybe_decrypt_media,
@@ -121,9 +121,10 @@ def _resolve_ui_public_dir() -> Optional[Path]:
     if ui_dir_env:
         candidates.append(Path(ui_dir_env))
 
-    # Repo default: `frontend/.output/public` after `npm --prefix frontend run generate`.
+    # Repo defaults: generated Nuxt output or checked-in desktop UI assets.
     repo_root = Path(__file__).resolve().parents[2]
     candidates.append(repo_root / "frontend" / ".output" / "public")
+    candidates.append(repo_root / "desktop" / "resources" / "ui")
 
     for p in candidates:
         try:
@@ -622,6 +623,68 @@ def _download_remote_image_to_zip(
 .wce-audio-actions a { font-size: 0.75rem; color: #07c160; text-decoration: none; }
 .wce-audio-actions a:hover { text-decoration: underline; }
 
+/* Voice message fallback styles (keep close to `frontend/pages/chat/[[username]].vue`). */
+.wechat-voice-wrapper { display: flex; width: 100%; position: relative; }
+.wechat-voice-bubble {
+  border-radius: var(--message-radius);
+  position: relative;
+  transition: opacity 0.15s ease;
+  min-width: 80px;
+  max-width: 200px;
+  cursor: pointer;
+}
+.wechat-voice-bubble:hover { opacity: 0.85; }
+.wechat-voice-bubble:active { opacity: 0.7; }
+.wechat-voice-sent { background: #95EC69; }
+.wechat-voice-sent::after {
+  content: '';
+  position: absolute;
+  top: 50%;
+  right: -4px;
+  transform: translateY(-50%) rotate(45deg);
+  width: 10px;
+  height: 10px;
+  background: #95EC69;
+  border-radius: 2px;
+}
+.wechat-voice-received { background: #fff; }
+.wechat-voice-received::before {
+  content: '';
+  position: absolute;
+  top: 50%;
+  left: -4px;
+  transform: translateY(-50%) rotate(45deg);
+  width: 10px;
+  height: 10px;
+  background: #fff;
+  border-radius: 2px;
+}
+.wechat-voice-content { display: flex; align-items: center; padding: 8px 12px; gap: 8px; }
+.wechat-voice-icon { width: 18px; height: 18px; flex-shrink: 0; color: #1a1a1a; }
+.wechat-quote-voice-icon { width: 14px; height: 14px; color: inherit; }
+.voice-icon-sent { transform: scaleX(-1); }
+.wechat-voice-icon.voice-playing .voice-wave-2 { animation: voice-wave-2 1s infinite; }
+.wechat-voice-icon.voice-playing .voice-wave-3 { animation: voice-wave-3 1s infinite; }
+@keyframes voice-wave-2 {
+  0%, 33% { opacity: 0; }
+  34%, 100% { opacity: 1; }
+}
+@keyframes voice-wave-3 {
+  0%, 66% { opacity: 0; }
+  67%, 100% { opacity: 1; }
+}
+.wechat-voice-duration { font-size: 14px; color: #1a1a1a; }
+.wechat-voice-unread {
+  position: absolute;
+  top: 50%;
+  right: -20px;
+  transform: translateY(-50%);
+  width: 8px;
+  height: 8px;
+  border-radius: 50%;
+  background: #e75e58;
+}
+
 /* Index page helpers. */
 .wce-index { min-height: 100vh; background: #EDEDED; }
 .wce-index-container { max-width: 880px; margin: 0 auto; padding: 24px; }
@@ -4958,40 +5021,38 @@ def _mark_exported() -> None:
                         tw.write(f'                  <div class="{esc_attr(bubble_base_cls + " " + bubble_dir_cls)}">{render_text_with_emojis(msg.get("content") or "")}</div>\n')
                 elif rt == "voice":
                     voice = offline_path(msg, "voice")
+                    duration_ms = msg.get("voiceLength")
+                    width = get_voice_width(duration_ms)
+                    seconds = get_voice_duration_in_seconds(duration_ms)
+                    voice_dir_cls = "wechat-voice-sent" if is_sent else "wechat-voice-received"
+                    content_dir_cls = " flex-row-reverse" if is_sent else ""
+                    icon_dir_cls = "voice-icon-sent" if is_sent else "voice-icon-received"
+                    voice_id = str(msg.get("id") or "").strip()
+
+                    tw.write('                  <div class="wechat-voice-wrapper">\n')
+                    tw.write(
+                        f'                    <div class="wechat-voice-bubble msg-radius {esc_attr(voice_dir_cls)}" style="width: {esc_attr(width)}" data-voice-id="{esc_attr(voice_id)}">\n'
+                    )
+                    tw.write(f'                      <div class="wechat-voice-content{esc_attr(content_dir_cls)}">\n')
+                    tw.write(
+                        f'                        <svg class="wechat-voice-icon {esc_attr(icon_dir_cls)}" viewBox="0 0 32 32" fill="currentColor">\n'
+                    )
+                    tw.write(
+                        '                          <path d="M10.24 11.616l-4.224 4.192 4.224 4.192c1.088-1.056 1.76-2.56 1.76-4.192s-0.672-3.136-1.76-4.192z"></path>\n'
+                    )
+                    tw.write(
+                        '                          <path class="voice-wave-2" d="M15.199 6.721l-1.791 1.76c1.856 1.888 3.008 4.48 3.008 7.328s-1.152 5.44-3.008 7.328l1.791 1.76c2.336-2.304 3.809-5.536 3.809-9.088s-1.473-6.784-3.809-9.088z"></path>\n'
+                    )
+                    tw.write(
+                        '                          <path class="voice-wave-3" d="M20.129 1.793l-1.762 1.76c3.104 3.168 5.025 7.488 5.025 12.256s-1.921 9.088-5.025 12.256l1.762 1.76c3.648-3.616 5.887-8.544 5.887-14.016s-2.239-10.432-5.887-14.016z"></path>\n'
+                    )
+                    tw.write("                        </svg>\n")
+                    tw.write(f'                        <span class="wechat-voice-duration">{esc_text(seconds)}"</span>\n')
+                    tw.write("                      </div>\n")
+                    tw.write("                    </div>\n")
                     if voice:
-                        duration_ms = msg.get("voiceLength")
-                        width = get_voice_width(duration_ms)
-                        seconds = get_voice_duration_in_seconds(duration_ms)
-                        voice_dir_cls = "wechat-voice-sent" if is_sent else "wechat-voice-received"
-                        content_dir_cls = " flex-row-reverse" if is_sent else ""
-                        icon_dir_cls = "voice-icon-sent" if is_sent else "voice-icon-received"
-                        voice_id = str(msg.get("id") or "").strip()
-
-                        tw.write('                  <div class="wechat-voice-wrapper">\n')
-                        tw.write(
-                            f'                    <div class="wechat-voice-bubble msg-radius {esc_attr(voice_dir_cls)}" style="width: {esc_attr(width)}" data-voice-id="{esc_attr(voice_id)}">\n'
-                        )
-                        tw.write(f'                      <div class="wechat-voice-content{esc_attr(content_dir_cls)}">\n')
-                        tw.write(
-                            f'                        <svg class="wechat-voice-icon {esc_attr(icon_dir_cls)}" viewBox="0 0 32 32" fill="currentColor">\n'
-                        )
-                        tw.write(
-                            '                          <path d="M10.24 11.616l-4.224 4.192 4.224 4.192c1.088-1.056 1.76-2.56 1.76-4.192s-0.672-3.136-1.76-4.192z"></path>\n'
-                        )
-                        tw.write(
-                            '                          <path class="voice-wave-2" d="M15.199 6.721l-1.791 1.76c1.856 1.888 3.008 4.48 3.008 7.328s-1.152 5.44-3.008 7.328l1.791 1.76c2.336-2.304 3.809-5.536 3.809-9.088s-1.473-6.784-3.809-9.088z"></path>\n'
-                        )
-                        tw.write(
-                            '                          <path class="voice-wave-3" d="M20.129 1.793l-1.762 1.76c3.104 3.168 5.025 7.488 5.025 12.256s-1.921 9.088-5.025 12.256l1.762 1.76c3.648-3.616 5.887-8.544 5.887-14.016s-2.239-10.432-5.887-14.016z"></path>\n'
-                        )
-                        tw.write("                        </svg>\n")
-                        tw.write(f'                        <span class="wechat-voice-duration">{esc_text(seconds)}"</span>\n')
-                        tw.write("                      </div>\n")
-                        tw.write("                    </div>\n")
                         tw.write(f'                    <audio src="{esc_attr(voice)}" preload="none" class="hidden"></audio>\n')
-                        tw.write("                  </div>\n")
-                    else:
-                        tw.write(f'                  <div class="{esc_attr(bubble_base_cls + " " + bubble_dir_cls)}">{render_text_with_emojis(msg.get("content") or "")}</div>\n')
+                    tw.write("                  </div>\n")
                 elif rt == "file":
                     fsrc = offline_path(msg, "file")
                     title = str(msg.get("title") or msg.get("content") or "文件").strip()
@@ -5982,13 +6043,9 @@ def _materialize_voice(
     if not isinstance(data, (bytes, bytearray)):
         data = bytes(data)
 
-    wav = _convert_silk_to_wav(data)
-    if wav != data and wav[:4] == b"RIFF":
-        ext = "wav"
-        payload = wav
-    else:
-        ext = "silk"
-        payload = data
+    payload, ext, _media_type = _convert_silk_to_browser_audio(data, preferred_format="mp3")
+    if not payload:
+        return "", False
 
     arc = f"media/voices/voice_{int(server_id)}.{ext}"
     zf.writestr(arc, payload)

src/wechat_decrypt_tool/media_helpers.py

@@ -1964,6 +1964,114 @@ def _convert_silk_to_wav(silk_data: bytes) -> bytes:
         return silk_data
 
 
+def _looks_like_mp3(data: bytes) -> bool:
+    if not data:
+        return False
+    if data.startswith(b"ID3"):
+        return True
+    return len(data) >= 2 and data[0] == 0xFF and (data[1] & 0xE0) == 0xE0
+
+
+@lru_cache(maxsize=1)
+def _find_ffmpeg_executable() -> str:
+    import shutil
+
+    env_value = str(os.environ.get("WECHAT_TOOL_FFMPEG") or "").strip()
+    if env_value:
+        resolved = shutil.which(env_value)
+        if resolved:
+            return resolved
+        candidate = Path(env_value).expanduser()
+        if candidate.is_file():
+            return str(candidate)
+
+    return shutil.which("ffmpeg") or ""
+
+
+def _convert_wav_to_mp3(wav_data: bytes) -> bytes:
+    import subprocess
+    import tempfile
+
+    if not wav_data or not wav_data.startswith(b"RIFF"):
+        return b""
+
+    ffmpeg_exe = _find_ffmpeg_executable()
+    if not ffmpeg_exe:
+        return b""
+
+    try:
+        with tempfile.TemporaryDirectory() as tmp_dir:
+            tmp_path = Path(tmp_dir)
+            wav_path = tmp_path / "voice.wav"
+            mp3_path = tmp_path / "voice.mp3"
+            wav_path.write_bytes(wav_data)
+
+            proc = subprocess.run(
+                [
+                    ffmpeg_exe,
+                    "-y",
+                    "-hide_banner",
+                    "-loglevel",
+                    "error",
+                    "-i",
+                    str(wav_path),
+                    "-vn",
+                    "-codec:a",
+                    "libmp3lame",
+                    "-q:a",
+                    "4",
+                    str(mp3_path),
+                ],
+                check=False,
+                capture_output=True,
+            )
+            if proc.returncode != 0 or not mp3_path.exists():
+                err = proc.stderr.decode("utf-8", errors="ignore").strip()
+                if err:
+                    logger.warning(f"WAV to MP3 conversion failed: {err}")
+                return b""
+
+            mp3_data = mp3_path.read_bytes()
+            if _looks_like_mp3(mp3_data):
+                return mp3_data
+    except Exception as e:
+        logger.warning(f"WAV to MP3 conversion failed: {e}")
+
+    return b""
+
+
+def _convert_silk_to_browser_audio(
+    silk_data: bytes,
+    *,
+    preferred_format: str = "mp3",
+) -> tuple[bytes, str, str]:
+    """Convert SILK audio to a browser-friendly format.
+
+    Returns `(payload, ext, media_type)`.
+    Preference order:
+      1) MP3 if ffmpeg is available
+      2) WAV if SILK decoding succeeds
+      3) original SILK bytes as a last-resort fallback
+    """
+
+    data = bytes(silk_data or b"")
+    if not data:
+        return b"", "silk", "audio/silk"
+
+    if _looks_like_mp3(data):
+        return data, "mp3", "audio/mpeg"
+
+    wav_data = data if data.startswith(b"RIFF") else _convert_silk_to_wav(data)
+    if wav_data.startswith(b"RIFF"):
+        if str(preferred_format or "").strip().lower() == "mp3":
+            mp3_data = _convert_wav_to_mp3(wav_data)
+            if mp3_data:
+                return mp3_data, "mp3", "audio/mpeg"
+        return wav_data, "wav", "audio/wav"
+
+    return data, "silk", "audio/silk"
+
+
 def _resolve_media_path_for_kind(
     account_dir: Path,
     kind: str,

src/wechat_decrypt_tool/routers/chat_media.py

@@ -33,7 +33,7 @@
 )
 from ..logging_config import get_logger
 from ..media_helpers import (
-    _convert_silk_to_wav,
+    _convert_silk_to_browser_audio,
     _decrypt_emoticon_aes_cbc,
     _detect_image_extension,
     _detect_image_media_type,
@@ -1762,12 +1762,12 @@ async def get_chat_voice(server_id: int, account: Optional[str] = None):
     if not isinstance(data, (bytes, bytearray)):
         data = bytes(data)
 
-    # Try to convert SILK to WAV for browser playback
-    wav_data = _convert_silk_to_wav(data)
-    if wav_data != data:
+    payload, ext, media_type = _convert_silk_to_browser_audio(data, preferred_format="mp3")
+    if payload and ext != "silk":
         return Response(
-            content=wav_data,
-            media_type="audio/wav",
+            content=payload,
+            media_type=media_type,
+            headers={"Content-Disposition": f"inline; filename=voice_{int(server_id)}.{ext}"},
         )
 
     # Fallback to raw SILK if conversion fails
@@ -1821,11 +1821,16 @@ async def open_chat_media_folder(
         if not isinstance(data, (bytes, bytearray)):
             data = bytes(data)
 
+        payload, ext, _media_type = _convert_silk_to_browser_audio(data, preferred_format="mp3")
+        if not payload:
+            payload = data
+            ext = "silk"
+
         export_dir = account_dir / "_exports"
         export_dir.mkdir(parents=True, exist_ok=True)
-        p = export_dir / f"voice_{int(server_id)}.silk"
+        p = export_dir / f"voice_{int(server_id)}.{ext}"
         try:
-            p.write_bytes(data)
+            p.write_bytes(payload)
         except Exception as e:
             raise HTTPException(status_code=500, detail=f"Failed to export voice: {e}")
     else: