diff --git a/README.md b/README.md
index b5bb6b1..29ebc24 100644
--- a/README.md
+++ b/README.md
@@ -68,6 +68,11 @@ ctest --test-dir build --output-on-failure
 # 流式后端
 ./build/live-caption-cli --asr-backend sherpa --asr-model zipformer-zh-2025
 ./build/live-caption-cli --asr-backend sherpa --asr-model nemotron35-560ms --language ja
+
+# 辅助
+./build/live-caption-cli --list-devices                       # 列出可选采集设备
+./build/live-caption-cli --cli-live --device <sink>           # 指定采集源
+./build/live-caption-cli --verify-model <id>                  # 校验模型完整性
 ```
 
 ## 代码结构
diff --git a/apps/cli/main.cpp b/apps/cli/main.cpp
index e0c9c1c..48a86ed 100644
--- a/apps/cli/main.cpp
+++ b/apps/cli/main.cpp
@@ -95,11 +95,12 @@ int runStreamFile(lc::IAsr & asr, const QString & path, const lc::StreamOptions
     return 0;
 }
 
-int runCliLive(lc::IAsr & asr, const lc::StreamOptions & sop)
+int runCliLive(lc::IAsr & asr, const lc::StreamOptions & sop, const QString & device)
 {
     lc::LivePipelineOptions popt;
     popt.stream = sop;
 
+    popt.captureDevice = device.toStdString();
     lc::LivePipeline pipeline(asr, popt);
     pipeline.setCaptionCallback([](const std::string & committed, const std::string & tail,
                                    const std::string & lang) {
@@ -140,11 +141,36 @@ int main(int argc, char ** argv)
     parser.addOption(QCommandLineOption("file", "转写一个 wav 文件后退出", "path"));
     parser.addOption(QCommandLineOption("stream-file", "以流式模式转写 wav 文件后退出", "path"));
     parser.addOption(QCommandLineOption("cli-live", "实时转写字幕，只用命令行输出（不开窗口）"));
+    parser.addOption(QCommandLineOption("device", "采集源（sink 名）；留空=跟随系统默认输出", "sink"));
+    parser.addOption(QCommandLineOption("verify-model", "校验模型文件完整性后退出", "id"));
+    parser.addOption(QCommandLineOption("list-devices", "列出可选的采集设备后退出"));
     parser.process(app);
 
     const lc::AsrOptions asrOpt = lc::app::asrOptions(parser);
     lc::StreamOptions sop = lc::app::streamOptions(parser);
 
+    if (parser.isSet("list-devices")) {
+        for (const auto & d : lc::listOutputDevices()) {
+            std::printf("  %-60s %s%s\n", d.sink.c_str(), d.description.c_str(),
+                        d.isDefault ? "  [默认]" : "");
+        }
+        return 0;
+    }
+
+    if (parser.isSet("verify-model")) {
+        const auto * m = lc::models::ModelStore::find(parser.value("verify-model"));
+        if (!m) { std::fprintf(stderr, "注册表里没有模型: %s\n", qUtf8Printable(parser.value("verify-model"))); return 1; }
+        QStringList bad;
+        const bool ok = lc::models::ModelStore::verify(*m, &bad, [](int done, int total) {
+            std::fprintf(stderr, "\r校验中 %d/%d", done, total);
+        });
+        std::fprintf(stderr, "\n");
+        if (ok) { std::printf("✅ %s 校验通过\n", qUtf8Printable(m->name)); return 0; }
+        std::printf("❌ %s 校验失败，损坏: %s\n", qUtf8Printable(m->name),
+                    qUtf8Printable(bad.join(QStringLiteral(", "))));
+        return 1;
+    }
+
     std::string err;
     std::unique_ptr<lc::IAsr> asr = lc::app::makeAsr(parser, asrOpt, &err);
     if (!asr) {
@@ -159,5 +185,5 @@ int main(int argc, char ** argv)
     if (parser.isSet("file"))        return runFile(*asr, parser.value("file"));
     if (parser.isSet("stream-file")) return runStreamFile(*asr, parser.value("stream-file"), sop);
 
-    return runCliLive(*asr, sop);
+    return runCliLive(*asr, sop, parser.value("device"));
 }
diff --git a/apps/gui/main.cpp b/apps/gui/main.cpp
index 3abd15d..30d4518 100644
--- a/apps/gui/main.cpp
+++ b/apps/gui/main.cpp
@@ -12,6 +12,7 @@
 #include <QMessageBox>
 #include <QPainter>
 #include <QPixmap>
+#include <QPushButton>
 #include <QSystemTrayIcon>
 #include <QTimer>
 
@@ -72,6 +73,10 @@ int main(int argc, char ** argv)
     QGuiApplication::setHighDpiScaleFactorRoundingPolicy(
         Qt::HighDpiScaleFactorRoundingPolicy::PassThrough);
     QApplication app(argc, argv);
+    // 关键：本程序常驻托盘，"最后一个窗口关闭"不等于退出。
+    // 否则首次启动时设置对话框一关（那时它是唯一窗口），Qt 就会把主事件循环也结束掉，
+    // 表现为"点了确定程序就自己退出"。
+    QApplication::setQuitOnLastWindowClosed(false);
     QCoreApplication::setApplicationName(QStringLiteral("live-caption"));
     QCoreApplication::setOrganizationName(QStringLiteral("live-caption"));
 
@@ -90,6 +95,8 @@ int main(int argc, char ** argv)
     parser.addOption(QCommandLineOption("screenshot-delay", "截图前等待秒数", "sec", "6"));
     parser.addOption(QCommandLineOption("no-tray", "不创建托盘图标（测试用）"));
     parser.addOption(QCommandLineOption("screenshot-settings", "打开设置对话框截图后退出", "path"));
+    parser.addOption(QCommandLineOption("settings-autoclose", "复现用：自动关闭设置对话框（reject|close|accept|ok）", "how"));
+    parser.addOption(QCommandLineOption("quit-after", "运行若干秒后优雅退出（测试退出路径用）", "sec"));
     parser.process(app);
 
     if (parser.isSet("asr-model")) cfg.modelId = parser.value("asr-model");
@@ -100,19 +107,37 @@ int main(int argc, char ** argv)
     // 仅用于验证渲染：打开设置对话框截图后退出
     if (parser.isSet("screenshot-settings")) {
         const QString path = parser.value("screenshot-settings");
-        auto * dlg = new lc::SettingsDialog(!hasUsableModel());
-        dlg->show();
-        QTimer::singleShot(1200, dlg, [dlg, path] {
-            dlg->grab().save(path);
+        lc::SettingsDialog dlg(!hasUsableModel());
+        dlg.show();
+        QTimer::singleShot(1200, &dlg, [&dlg, path] {
+            dlg.grab().save(path);
             std::fprintf(stderr, "设置对话框截图: %s\n", qUtf8Printable(path));
-            QCoreApplication::quit();
+            dlg.accept();
         });
-        return QCoreApplication::exec();
+        dlg.exec();
+        return 0;
     }
 
+    // 复现用：把"点 ✕ / 点确定"自动化，用来定位崩溃
+    const QString autoclose = parser.value("settings-autoclose");
+    const auto scheduleAutoclose = [&autoclose](QDialog & dlg) {
+        if (autoclose.isEmpty()) return;
+        QTimer::singleShot(700, &dlg, [&dlg, &autoclose] {
+            if (autoclose == QLatin1String("reject"))      dlg.reject();
+            else if (autoclose == QLatin1String("close"))  dlg.close();   // 标题栏 ✕
+            else if (autoclose == QLatin1String("accept")) dlg.accept();
+            else if (autoclose == QLatin1String("ok")) {                  // 真的点「确定」
+                for (auto * b : dlg.findChildren<QPushButton *>()) {
+                    if (b->text() == QObject::tr("确定")) { b->click(); break; }
+                }
+            }
+        });
+    };
+
     // ---- 启动：没有可用模型就先开设置 ----
     if (!hasUsableModel()) {
         lc::SettingsDialog dlg(true);
+        scheduleAutoclose(dlg);
         if (dlg.exec() != QDialog::Accepted || !hasUsableModel()) return 0;
     }
 
@@ -130,6 +155,7 @@ int main(int argc, char ** argv)
     const auto startTranscriber = [&]() -> bool {
         live.stop();
         asr.reset();
+        live.setCaptureDevice(cfg.captureDevice);
 
         const lc::models::ModelInfo * m = lc::models::ModelStore::find(cfg.modelId);
         if (!m) {
@@ -189,7 +215,7 @@ int main(int argc, char ** argv)
     if (!parser.isSet("no-tray")) {
         tray = new QSystemTrayIcon(makeTrayIcon(), &app);
         tray->setToolTip(QObject::tr("实时字幕"));
-        trayMenu = new QMenu;
+        trayMenu = new QMenu(&window);   // 必须有归属，否则退出时是悬空顶层窗口
         auto * showAct = trayMenu->addAction(QObject::tr("显示/隐藏字幕"));
         auto * setAct  = trayMenu->addAction(QObject::tr("设置…"));
         trayMenu->addSeparator();
@@ -239,6 +265,19 @@ int main(int argc, char ** argv)
 
     window.show();
 
+    // 复现用：程序起来后再开一次设置并自动关闭（模拟从语言标签/托盘进设置）
+    if (!autoclose.isEmpty() && hasUsableModel()) {
+        QTimer::singleShot(2500, &window, [&] {
+            lc::SettingsDialog dlg(false);
+            scheduleAutoclose(dlg);
+            if (dlg.exec() == QDialog::Accepted) {
+                applyAppearance(window, cfg);
+                if (!startTranscriber()) qWarning("重启转写失败");
+            }
+            QTimer::singleShot(500, qApp, &QCoreApplication::quit);
+        });
+    }
+
     // 自截图（验证渲染用）
     if (parser.isSet("screenshot")) {
         const QString path = parser.value("screenshot");
@@ -255,6 +294,11 @@ int main(int argc, char ** argv)
                            });
     }
 
+    if (parser.isSet("quit-after")) {
+        QTimer::singleShot(parser.value("quit-after").toInt() * 1000, qApp,
+                           &QCoreApplication::quit);
+    }
+
     const int rc = QCoreApplication::exec();
     // 显式收尾，确保工作线程停下来之后再释放后端
     live.stop();
diff --git a/data/models.json b/data/models.json
index 0e7420e..aa7b905 100644
--- a/data/models.json
+++ b/data/models.json
@@ -6,17 +6,32 @@
       "id": "qwen3-asr-0.6b-q8",
       "name": "Qwen3-ASR 0.6B（通用，52 语言）",
       "backend": "llama-cpp",
-      "languages": ["zh", "en", "ja", "ko", "fr", "de", "es", "ru", "ar", "auto"],
+      "languages": [
+        "zh",
+        "en",
+        "ja",
+        "ko",
+        "fr",
+        "de",
+        "es",
+        "ru",
+        "ar",
+        "auto"
+      ],
       "license": "Apache-2.0",
       "note": "973MB，准确率高、语言最全、自带语言识别；但每步成本随句子增长（CPU 约为流式后端的 35 倍）",
       "files": {
         "model": {
           "name": "Qwen3-ASR-0.6B-Q8_0.gguf",
-          "url": "https://hf-mirror.com/ggml-org/Qwen3-ASR-0.6B-GGUF/resolve/main/Qwen3-ASR-0.6B-Q8_0.gguf"
+          "url": "https://hf-mirror.com/ggml-org/Qwen3-ASR-0.6B-GGUF/resolve/main/Qwen3-ASR-0.6B-Q8_0.gguf",
+          "size": 804749248,
+          "sha256": "bca259818b50ca7c4c05e9bdb35a5dc04fa039653a6d6f3f0f331f96f6aa1971"
         },
         "mmproj": {
           "name": "mmproj-Qwen3-ASR-0.6B-Q8_0.gguf",
-          "url": "https://hf-mirror.com/ggml-org/Qwen3-ASR-0.6B-GGUF/resolve/main/mmproj-Qwen3-ASR-0.6B-Q8_0.gguf"
+          "url": "https://hf-mirror.com/ggml-org/Qwen3-ASR-0.6B-GGUF/resolve/main/mmproj-Qwen3-ASR-0.6B-Q8_0.gguf",
+          "size": 214392480,
+          "sha256": "41a342b5e4c514e968cb756de6cd1b7be39eff43c44c57a2ef5fc6522e36603d"
         }
       },
       "options": {}
@@ -25,25 +40,35 @@
       "id": "zipformer-zh-2025",
       "name": "中文流式（k2-fsa 官方 2025-06-30）",
       "backend": "sherpa-online",
-      "languages": ["zh"],
+      "languages": [
+        "zh"
+      ],
       "license": "Apache-2.0",
       "note": "154MB，实测中文逐字正确；首个字幕 0.48s，约 0.10 核·秒/秒音频",
       "files": {
         "encoder": {
           "name": "encoder.int8.onnx",
-          "url": "https://hf-mirror.com/csukuangfj/sherpa-onnx-streaming-zipformer-zh-int8-2025-06-30/resolve/main/encoder.int8.onnx"
+          "url": "https://hf-mirror.com/csukuangfj/sherpa-onnx-streaming-zipformer-zh-int8-2025-06-30/resolve/main/encoder.int8.onnx",
+          "size": 161141793,
+          "sha256": "5ac51e27981bb4dab01bb9be4958453ba50c3b61c063ddda0eab23fd3671aa4f"
         },
         "decoder": {
           "name": "decoder.onnx",
-          "url": "https://hf-mirror.com/csukuangfj/sherpa-onnx-streaming-zipformer-zh-int8-2025-06-30/resolve/main/decoder.onnx"
+          "url": "https://hf-mirror.com/csukuangfj/sherpa-onnx-streaming-zipformer-zh-int8-2025-06-30/resolve/main/decoder.onnx",
+          "size": 5165083,
+          "sha256": "06522ad63cec0fdf6809f4e1db9bb4f7d710c34582e3b35db62ac60eccafac7e"
         },
         "joiner": {
           "name": "joiner.int8.onnx",
-          "url": "https://hf-mirror.com/csukuangfj/sherpa-onnx-streaming-zipformer-zh-int8-2025-06-30/resolve/main/joiner.int8.onnx"
+          "url": "https://hf-mirror.com/csukuangfj/sherpa-onnx-streaming-zipformer-zh-int8-2025-06-30/resolve/main/joiner.int8.onnx",
+          "size": 1033416,
+          "sha256": "b34584dc6f561089e1d747fedebb3765f2caa72c927ef54d7ca55e5ae40a814b"
         },
         "tokens": {
           "name": "tokens.txt",
-          "url": "https://hf-mirror.com/csukuangfj/sherpa-onnx-streaming-zipformer-zh-int8-2025-06-30/resolve/main/tokens.txt"
+          "url": "https://hf-mirror.com/csukuangfj/sherpa-onnx-streaming-zipformer-zh-int8-2025-06-30/resolve/main/tokens.txt",
+          "size": 20628,
+          "sha256": "6193c7ea1c96d0d9a1e9652789b40d13a8a913b434a5451e93158f5a09fd6652"
         }
       },
       "options": {}
@@ -52,25 +77,36 @@
       "id": "xasr-zh-en-480",
       "name": "中英流式（X-ASR-zh-en, 480ms）",
       "backend": "sherpa-online",
-      "languages": ["zh", "en"],
+      "languages": [
+        "zh",
+        "en"
+      ],
       "license": "Apache-2.0",
       "note": "587MB，实测中英准确率与 Qwen3-ASR 持平；首个字幕 1.44s",
       "files": {
         "encoder": {
           "name": "encoder-480ms.onnx",
-          "url": "https://hf-mirror.com/GilgameshWind/X-ASR-zh-en/resolve/main/deployment/models/chunk-480ms-model/encoder-480ms.onnx"
+          "url": "https://hf-mirror.com/GilgameshWind/X-ASR-zh-en/resolve/main/deployment/models/chunk-480ms-model/encoder-480ms.onnx",
+          "size": 592968361,
+          "sha256": "0c3454033d249081df124ddcd7adaf3deca07d0b999b26f2ee5d2475d37abc74"
         },
         "decoder": {
           "name": "decoder-480ms.onnx",
-          "url": "https://hf-mirror.com/GilgameshWind/X-ASR-zh-en/resolve/main/deployment/models/chunk-480ms-model/decoder-480ms.onnx"
+          "url": "https://hf-mirror.com/GilgameshWind/X-ASR-zh-en/resolve/main/deployment/models/chunk-480ms-model/decoder-480ms.onnx",
+          "size": 11309084,
+          "sha256": "3658368d274a5d5fd39a7ac20c46bed0ad9cfea1f0feddef30d5d89797c1f499"
         },
         "joiner": {
           "name": "joiner-480ms.onnx",
-          "url": "https://hf-mirror.com/GilgameshWind/X-ASR-zh-en/resolve/main/deployment/models/chunk-480ms-model/joiner-480ms.onnx"
+          "url": "https://hf-mirror.com/GilgameshWind/X-ASR-zh-en/resolve/main/deployment/models/chunk-480ms-model/joiner-480ms.onnx",
+          "size": 10260467,
+          "sha256": "03781c98165a2385024c9cecdd2b6b13310d81db23a62c7da420782c2915cf81"
         },
         "tokens": {
           "name": "tokens.txt",
-          "url": "https://hf-mirror.com/GilgameshWind/X-ASR-zh-en/resolve/main/deployment/models/chunk-480ms-model/tokens.txt"
+          "url": "https://hf-mirror.com/GilgameshWind/X-ASR-zh-en/resolve/main/deployment/models/chunk-480ms-model/tokens.txt",
+          "size": 58806,
+          "sha256": "b818a60878b9aae978cbb8ad594acbd403d76d1af2e31ef4197c84e2dbdba27c"
         }
       },
       "options": {}
@@ -79,29 +115,54 @@
       "id": "nemotron35-560ms",
       "name": "多语言流式（Nemotron 3.5, 560ms, 含日语）",
       "backend": "sherpa-online",
-      "languages": ["en", "ja", "ko", "vi", "ru", "ar", "hi", "fr", "de", "es", "it", "pt", "nl", "tr", "uk", "zh"],
+      "languages": [
+        "en",
+        "ja",
+        "ko",
+        "vi",
+        "ru",
+        "ar",
+        "hi",
+        "fr",
+        "de",
+        "es",
+        "it",
+        "pt",
+        "nl",
+        "tr",
+        "uk",
+        "zh"
+      ],
       "license": "OpenMDW-1.1",
-      "note": "651MB，40 种语言 + 内置语言识别；实测中英日都可用但都有瑕疵", 
+      "note": "651MB，40 种语言 + 内置语言识别；实测中英日都可用但都有瑕疵",
       "optionsHint": "language",
       "files": {
         "encoder": {
           "name": "encoder.int8.onnx",
-          "url": "https://hf-mirror.com/csukuangfj2/sherpa-onnx-nemotron-3.5-asr-streaming-0.6b-560ms-int8-2026-06-11/resolve/main/encoder.int8.onnx"
+          "url": "https://hf-mirror.com/csukuangfj2/sherpa-onnx-nemotron-3.5-asr-streaming-0.6b-560ms-int8-2026-06-11/resolve/main/encoder.int8.onnx",
+          "size": 657601403,
+          "sha256": "012e9321373af99021415e0b0eb3ec827b4be3153be6f30d9b448fe65e896e68"
         },
         "decoder": {
           "name": "decoder.int8.onnx",
-          "url": "https://hf-mirror.com/csukuangfj2/sherpa-onnx-nemotron-3.5-asr-streaming-0.6b-560ms-int8-2026-06-11/resolve/main/decoder.int8.onnx"
+          "url": "https://hf-mirror.com/csukuangfj2/sherpa-onnx-nemotron-3.5-asr-streaming-0.6b-560ms-int8-2026-06-11/resolve/main/decoder.int8.onnx",
+          "size": 14978075,
+          "sha256": "19f9c98fc6d0a2c33a65a43b36fdb2e914c26c0aa9764be3aebc502a1e982fb0"
         },
         "joiner": {
           "name": "joiner.int8.onnx",
-          "url": "https://hf-mirror.com/csukuangfj2/sherpa-onnx-nemotron-3.5-asr-streaming-0.6b-560ms-int8-2026-06-11/resolve/main/joiner.int8.onnx"
+          "url": "https://hf-mirror.com/csukuangfj2/sherpa-onnx-nemotron-3.5-asr-streaming-0.6b-560ms-int8-2026-06-11/resolve/main/joiner.int8.onnx",
+          "size": 9504438,
+          "sha256": "4101c7c679a0bc30483794b27a059e34e79232aa2068d78d51231a22c8b0d7ce"
         },
         "tokens": {
           "name": "tokens.txt",
-          "url": "https://hf-mirror.com/csukuangfj2/sherpa-onnx-nemotron-3.5-asr-streaming-0.6b-560ms-int8-2026-06-11/resolve/main/tokens.txt"
+          "url": "https://hf-mirror.com/csukuangfj2/sherpa-onnx-nemotron-3.5-asr-streaming-0.6b-560ms-int8-2026-06-11/resolve/main/tokens.txt",
+          "size": 131440,
+          "sha256": "729cc103155bafa785f9cd45746cd41cabe97eab7182fc04d594129587958f8a"
         }
       },
       "options": {}
     }
   ]
-}
+}
\ No newline at end of file
diff --git a/docs/asr-backends.md b/docs/asr-backends.md
index 0ee2b69..04c7c9d 100644
--- a/docs/asr-backends.md
+++ b/docs/asr-backends.md
@@ -63,6 +63,26 @@ IAsr（src/core/iasr.h）
 > 同步/自旋开销会让它更慢（8 线程比 1 线程慢 2.6 倍、CPU 高 28 倍）。所以适配器里固定
 > `threads = 1`。
 
+## 采集设备选择
+
+默认跟随系统默认输出；也可以在设置里指定某个输出设备（`--list-devices` 可列出）：
+
+```bash
+./build/live-caption-cli --list-devices
+./build/live-caption-cli --cli-live --device alsa_output...HiFi__HDMI1__sink
+```
+
+## 完整性校验
+
+注册表里每个文件都记了 `size` 与 `sha256`：
+
+- 快速检查（打开/选择模型时）：文件存在且**大小**对得上；
+- 完整校验（设置里「校验完整性」或 `--verify-model <id>`）：逐个**重算 sha256**，损坏的文件名会列出来。
+
+```bash
+./build/live-caption-cli --verify-model zipformer-zh-2025
+```
+
 ## 两个坑
 
 1. **sherpa-onnx 的预编译库是旧 C++ ABI**（`_GLIBCXX_USE_CXX11_ABI=0`），和 Qt 的新 ABI 冲突，
diff --git a/src/core/audio.cpp b/src/core/audio.cpp
index 112a930..58cd165 100644
--- a/src/core/audio.cpp
+++ b/src/core/audio.cpp
@@ -149,7 +149,106 @@ bool readWavMono(const std::string & path, int targetRate,
 }
 
 // ---------------------------------------------------------------------------
-// 实时采集：默认 sink 的 monitor
+// 枚举输出设备
+// ---------------------------------------------------------------------------
+namespace {
+
+// 枚举时用的上下文。注意：回调里**必须** signal 主循环，
+// 否则 pa_threaded_mainloop_wait 会一直等下去（这里踩过一次坑）。
+struct SinkListCtx {
+    std::vector<AudioOutputDevice> * out     = nullptr;
+    std::string *                    defaultSink = nullptr;
+    pa_threaded_mainloop *           ml      = nullptr;
+};
+
+void sinkInfoCb(pa_context * /*c*/, const pa_sink_info * info, int /*eol*/, void * userdata)
+{
+    auto * ctx = static_cast<SinkListCtx *>(userdata);
+    if (info && ctx->out) {
+        AudioOutputDevice d;
+        d.sink        = info->name ? info->name : "";
+        d.description = info->description ? info->description : d.sink;
+        ctx->out->push_back(d);
+    }
+    if (ctx->ml) pa_threaded_mainloop_signal(ctx->ml, 0);
+}
+
+void serverInfoCb(pa_context * /*c*/, const pa_server_info * info, void * userdata)
+{
+    auto * ctx = static_cast<SinkListCtx *>(userdata);
+    if (info && info->default_sink_name && ctx->defaultSink) {
+        *ctx->defaultSink = info->default_sink_name;
+    }
+    if (ctx->ml) pa_threaded_mainloop_signal(ctx->ml, 0);
+}
+
+// 有界等待：避免任何情况下卡死
+void waitOp(pa_threaded_mainloop * ml, pa_operation * op)
+{
+    for (int i = 0; i < 200 && pa_operation_get_state(op) == PA_OPERATION_RUNNING; ++i) {
+        pa_threaded_mainloop_wait(ml);
+    }
+}
+
+} // namespace
+
+std::vector<AudioOutputDevice> listOutputDevices(std::string * error)
+{
+    std::vector<AudioOutputDevice> out;
+    pa_threaded_mainloop * ml = pa_threaded_mainloop_new();
+    if (!ml) { if (error) *error = "pa_threaded_mainloop_new 失败"; return out; }
+    pa_context * ctx = pa_context_new(pa_threaded_mainloop_get_api(ml), "live-caption-list");
+    if (!ctx) { pa_threaded_mainloop_free(ml); if (error) *error = "pa_context_new 失败"; return out; }
+    pa_context_set_state_callback(ctx, [](pa_context * c, void * ud) {
+        auto * m = static_cast<pa_threaded_mainloop *>(ud);
+        const pa_context_state_t st = pa_context_get_state(c);
+        if (st == PA_CONTEXT_READY || st == PA_CONTEXT_FAILED || st == PA_CONTEXT_TERMINATED)
+            pa_threaded_mainloop_signal(m, 0);
+    }, ml);
+
+    pa_threaded_mainloop_start(ml);
+    pa_threaded_mainloop_lock(ml);
+    if (pa_context_connect(ctx, nullptr, PA_CONTEXT_NOFLAGS, nullptr) < 0) {
+        pa_threaded_mainloop_unlock(ml);
+        pa_context_unref(ctx); pa_threaded_mainloop_stop(ml); pa_threaded_mainloop_free(ml);
+        if (error) *error = "连接 PulseAudio/PipeWire 失败";
+        return out;
+    }
+    for (;;) {
+        const pa_context_state_t st = pa_context_get_state(ctx);
+        if (st == PA_CONTEXT_READY) break;
+        if (!PA_CONTEXT_IS_GOOD(st)) {
+            pa_threaded_mainloop_unlock(ml);
+            pa_context_unref(ctx); pa_threaded_mainloop_stop(ml); pa_threaded_mainloop_free(ml);
+            if (error) *error = "无法连接到音频服务";
+            return out;
+        }
+        pa_threaded_mainloop_wait(ml);
+    }
+
+    std::string defaultSink;
+    SinkListCtx lctx{&out, &defaultSink, ml};
+
+    pa_operation * opDefault = pa_context_get_server_info(ctx, serverInfoCb, &lctx);
+    waitOp(ml, opDefault);
+    pa_operation_unref(opDefault);
+
+    pa_operation * opSinks = pa_context_get_sink_info_list(ctx, sinkInfoCb, &lctx);
+    waitOp(ml, opSinks);
+    pa_operation_unref(opSinks);
+
+    for (auto & d : out) d.isDefault = (d.sink == defaultSink);
+
+    pa_context_disconnect(ctx);
+    pa_context_unref(ctx);
+    pa_threaded_mainloop_unlock(ml);
+    pa_threaded_mainloop_stop(ml);
+    pa_threaded_mainloop_free(ml);
+    return out;
+}
+
+// ---------------------------------------------------------------------------
+// 实时采集：某个输出设备的 monitor（默认跟随系统默认输出）
 // ---------------------------------------------------------------------------
 struct MonitorCapture::Impl {
     pa_threaded_mainloop * ml      = nullptr;
@@ -250,7 +349,8 @@ MonitorCapture::~MonitorCapture()
 
 std::string MonitorCapture::deviceName() const { return d->deviceName; }
 
-bool MonitorCapture::start(int targetRate, ChunkCallback callback, std::string * error)
+bool MonitorCapture::start(int targetRate, ChunkCallback callback, std::string * error,
+                           const std::string & device)
 {
     const auto fail = [error](const std::string & m) {
         if (error) *error = m;
@@ -288,17 +388,21 @@ bool MonitorCapture::start(int targetRate, ChunkCallback callback, std::string *
         pa_threaded_mainloop_wait(d->ml);
     }
 
-    // 查默认 sink，拼出它的 monitor 源
-    d->deviceName.clear();
-    pa_operation * op = pa_context_get_server_info(d->ctx, storeMonitor, d);
-    while (pa_operation_get_state(op) == PA_OPERATION_RUNNING) {
-        pa_threaded_mainloop_wait(d->ml);
-    }
-    pa_operation_unref(op);
-
-    if (d->deviceName.empty()) {
-        pa_threaded_mainloop_unlock(d->ml);
-        return fail("拿不到默认输出设备名");
+    if (device.empty()) {
+        // 跟随系统默认输出
+        d->deviceName.clear();
+        pa_operation * op = pa_context_get_server_info(d->ctx, storeMonitor, d);
+        while (pa_operation_get_state(op) == PA_OPERATION_RUNNING) {
+            pa_threaded_mainloop_wait(d->ml);
+        }
+        pa_operation_unref(op);
+        if (d->deviceName.empty()) {
+            pa_threaded_mainloop_unlock(d->ml);
+            return fail("拿不到默认输出设备名");
+        }
+    } else {
+        // 指定设备（sink 名）
+        d->deviceName = device + ".monitor";
     }
 
     // 以设备实际速率请求（默认 48k）
diff --git a/src/core/audio.h b/src/core/audio.h
index 4be3d07..4abbc5b 100644
--- a/src/core/audio.h
+++ b/src/core/audio.h
@@ -7,6 +7,16 @@
 
 namespace lc {
 
+// 一个可选的采集源（输出设备的 monitor）
+struct AudioOutputDevice {
+    std::string sink;       // 设备名
+    std::string description; // 人类可读描述
+    bool        isDefault = false;
+};
+
+// 列出所有输出设备（供设置界面选择采集源）
+std::vector<AudioOutputDevice> listOutputDevices(std::string * error = nullptr);
+
 // 读取 WAV（PCM 16/24/32 位或 float32），降混为单声道并重采样到 targetRate。
 bool readWavMono(const std::string & path, int targetRate,
                  std::vector<float> & out, std::string * error);
@@ -23,7 +33,9 @@ public:
     MonitorCapture(const MonitorCapture &) = delete;
     MonitorCapture & operator=(const MonitorCapture &) = delete;
 
-    bool start(int targetRate, ChunkCallback callback, std::string * error);
+    // device: 空 = 跟随系统默认输出；否则是 sink 名（见 listOutputDevices）
+    bool start(int targetRate, ChunkCallback callback, std::string * error,
+               const std::string & device = std::string());
     void stop();
 
     // 实际采集的 monitor 源名（start 成功后有效）
diff --git a/src/core/livepipeline.cpp b/src/core/livepipeline.cpp
index 18ffc7c..af4af2a 100644
--- a/src/core/livepipeline.cpp
+++ b/src/core/livepipeline.cpp
@@ -32,7 +32,8 @@ bool LivePipeline::start(std::string * error)
             }
             cv_.notify_one();
         },
-        error);
+        error,
+        opt_.captureDevice);
     if (!ok) return false;
 
     worker_ = std::thread([this] { workerLoop(); });
diff --git a/src/core/livepipeline.h b/src/core/livepipeline.h
index dc26370..9f037ce 100644
--- a/src/core/livepipeline.h
+++ b/src/core/livepipeline.h
@@ -17,6 +17,7 @@ namespace lc {
 
 struct LivePipelineOptions {
     StreamOptions stream;
+    std::string captureDevice;        // 空 = 跟随系统默认输出；否则是 sink 名
     double silenceTimeoutSec = 0.8;   // 静音多久算一句结束
     double prerollSec        = 0.25;  // 语音开始前保留的一段，避免吃掉词头
 };
diff --git a/src/models/modeldownloader.cpp b/src/models/modeldownloader.cpp
index 042bc4d..b8cccaa 100644
--- a/src/models/modeldownloader.cpp
+++ b/src/models/modeldownloader.cpp
@@ -44,7 +44,11 @@ void ModelDownloader::start(const ModelInfo & model)
 void ModelDownloader::cancel()
 {
     cancel_ = true;
+    running_ = false;
     if (reply_) {
+        // 先彻底断开，再 abort：否则 abort 会同步触发 finished，
+        // 而这时对话框可能正在析构、那些控件已经没了。
+        disconnect(reply_, nullptr, this, nullptr);
         reply_->abort();
         reply_->deleteLater();
         reply_ = nullptr;
@@ -144,4 +148,5 @@ void ModelDownloader::cleanup()
     Q_EMIT finished(false, QStringLiteral("已取消"));
 }
 
+
 } // namespace lc::models
diff --git a/src/models/modelstore.cpp b/src/models/modelstore.cpp
index 0a422fa..7c56bf5 100644
--- a/src/models/modelstore.cpp
+++ b/src/models/modelstore.cpp
@@ -1,5 +1,6 @@
 #include "modelstore.h"
 
+#include <QCryptographicHash>
 #include <QDir>
 #include <QFile>
 #include <QFileInfo>
@@ -43,9 +44,13 @@ const std::vector<ModelInfo> & parseRegistry()
         const QJsonObject files = o.value(QStringLiteral("files")).toObject();
         for (auto it = files.begin(); it != files.end(); ++it) {
             const QJsonObject fo = it.value().toObject();
-            m.files.push_back({it.key(),
-                               fo.value(QStringLiteral("name")).toString(),
-                               fo.value(QStringLiteral("url")).toString()});
+            ModelFile mf;
+            mf.key    = it.key();
+            mf.name   = fo.value(QStringLiteral("name")).toString();
+            mf.url    = fo.value(QStringLiteral("url")).toString();
+            mf.size   = (qint64) fo.value(QStringLiteral("size")).toDouble();
+            mf.sha256 = fo.value(QStringLiteral("sha256")).toString();
+            m.files.push_back(std::move(mf));
         }
         cache.push_back(std::move(m));
     }
@@ -90,7 +95,9 @@ bool ModelStore::isInstalled(const ModelInfo & m, QStringList * missing)
     bool ok = true;
     for (const ModelFile & f : m.files) {
         const QString p = ModelStore::dirFor(m.id) + QLatin1Char('/') + f.name;
-        if (!QFileInfo::exists(p) || QFileInfo(p).size() == 0) {
+        const QFileInfo fi(p);
+        const bool badSize = (f.size > 0) && (fi.size() != f.size);
+        if (!fi.exists() || fi.size() == 0 || badSize) {
             ok = false;
             if (missing) *missing << f.name;
         }
@@ -98,6 +105,41 @@ bool ModelStore::isInstalled(const ModelInfo & m, QStringList * missing)
     return ok;
 }
 
+bool ModelStore::verify(const ModelInfo & m, QStringList * bad,
+                        const std::function<void(int, int)> & progress)
+{
+    bool ok = true;
+    int i = 0;
+    for (const ModelFile & f : m.files) {
+        if (progress) progress(i, (int) m.files.size());
+        ++i;
+        const QString p = ModelStore::dirFor(m.id) + QLatin1Char('/') + f.name;
+        QFile file(p);
+        if (!file.open(QIODevice::ReadOnly)) {
+            ok = false;
+            if (bad) *bad << f.name;
+            continue;
+        }
+        if (!f.sha256.isEmpty()) {
+            QCryptographicHash h(QCryptographicHash::Sha256);
+            if (!h.addData(&file)) {
+                ok = false;
+                if (bad) *bad << f.name;
+                continue;
+            }
+            if (QString::fromLatin1(h.result().toHex()) != f.sha256) {
+                ok = false;
+                if (bad) *bad << f.name;
+            }
+        } else if (f.size > 0 && file.size() != f.size) {
+            ok = false;
+            if (bad) *bad << f.name;
+        }
+    }
+    if (progress) progress(i, (int) m.files.size());
+    return ok;
+}
+
 const ModelInfo * ModelStore::pickForLanguage(const QString & lang)
 {
     // 先找语言列表里明确包含该语言、且已安装的
diff --git a/src/models/modelstore.h b/src/models/modelstore.h
index 3e33ae0..618d1fc 100644
--- a/src/models/modelstore.h
+++ b/src/models/modelstore.h
@@ -3,6 +3,7 @@
 #include <QString>
 #include <QStringList>
 
+#include <functional>
 #include <vector>
 
 // 模型注册表与存储。
@@ -18,9 +19,11 @@ enum class Backend {
 };
 
 struct ModelFile {
-    QString key;    // encoder / decoder / joiner / tokens / model / mmproj
-    QString name;   // 文件名
-    QString url;    // 下载地址
+    QString key;     // encoder / decoder / joiner / tokens / model / mmproj
+    QString name;    // 文件名
+    QString url;     // 下载地址
+    qint64  size = 0;   // 字节数（0 = 注册表没写）
+    QString sha256;     // 期望的 sha256（空 = 不校验）
 };
 
 struct ModelInfo {
@@ -43,9 +46,13 @@ public:
     static const std::vector<ModelInfo> & registry();
     static const ModelInfo * find(const QString & id);
 
-    // 文件是否齐全；missing 返回缺失文件名
+    // 快速检查：文件齐全且大小对得上（注册表里写了 size 时）
     static bool isInstalled(const ModelInfo & m, QStringList * missing = nullptr);
 
+    // 完整校验：逐个重算 sha256。bad 返回有问题的文件；progress(done,total) 可选
+    static bool verify(const ModelInfo & m, QStringList * bad = nullptr,
+                       const std::function<void(int, int)> & progress = {});
+
     // 按语言挑一个已安装的模型（优先语言列表里排前的）
     static const ModelInfo * pickForLanguage(const QString & lang);
 
diff --git a/src/ui/appsettings.cpp b/src/ui/appsettings.cpp
index e866667..868931b 100644
--- a/src/ui/appsettings.cpp
+++ b/src/ui/appsettings.cpp
@@ -30,6 +30,8 @@ void AppSettings::load()
                            s.value(QStringLiteral("windowY")).toInt());
     }
 
+    captureDevice = s.value(QStringLiteral("captureDevice")).toString();
+
     mirrorBase = s.value(QStringLiteral("mirrorBase"),
                          QStringLiteral("https://hf-mirror.com")).toString();
     proxyMode  = s.value(QStringLiteral("proxyMode"), 0).toInt();
@@ -62,6 +64,7 @@ void AppSettings::save()
         s.setValue(QStringLiteral("windowY"), windowPos.y());
     }
 
+    s.setValue(QStringLiteral("captureDevice"), captureDevice);
     s.setValue(QStringLiteral("mirrorBase"), mirrorBase);
     s.setValue(QStringLiteral("proxyMode"), proxyMode);
     s.setValue(QStringLiteral("proxyHost"), proxyHost);
diff --git a/src/ui/appsettings.h b/src/ui/appsettings.h
index aa8b8f1..2194c55 100644
--- a/src/ui/appsettings.h
+++ b/src/ui/appsettings.h
@@ -27,6 +27,9 @@ public:
     QPoint  windowPos;           // 空 = 默认（屏幕下方居中）
     bool    hasWindowPos = false;
 
+    // 采集
+    QString captureDevice;       // 空 = 跟随系统默认输出
+
     // 下载
     QString mirrorBase = QStringLiteral("https://hf-mirror.com");
     int     proxyMode  = 0;      // 0=不使用 1=跟随系统 2=手动
diff --git a/src/ui/captionwindow.cpp b/src/ui/captionwindow.cpp
index d27f0e7..135e73a 100644
--- a/src/ui/captionwindow.cpp
+++ b/src/ui/captionwindow.cpp
@@ -18,6 +18,7 @@ namespace {
 constexpr int kCollapsedLines = 2;
 constexpr int kExpandedLines  = 8;
 constexpr int kMargin         = 12;
+constexpr int kTopRowHeight   = 30;   // 与关闭按钮一致
 constexpr int kRadius         = 10;
 
 QString escapeHtml(const QString & s)
@@ -52,9 +53,10 @@ CaptionWindow::CaptionWindow(QWidget * parent)
     connect(langPill_, &QPushButton::clicked, this, &CaptionWindow::languageClicked);
 
     closeBtn_ = new QPushButton(QStringLiteral("\u2715"), this);   // ✕
+    closeBtn_->setObjectName(QStringLiteral("closeBtn"));
     closeBtn_->setCursor(Qt::PointingHandCursor);
     closeBtn_->setFocusPolicy(Qt::NoFocus);
-    closeBtn_->setFixedSize(22, 22);
+    closeBtn_->setFixedSize(30, 30);      // 原来 22×22 太小，不好点
     connect(closeBtn_, &QPushButton::clicked, this, &CaptionWindow::closed);
 
     top->addWidget(langPill_);
@@ -124,6 +126,13 @@ void CaptionWindow::applyStyle()
             padding: 1px 10px;
         }
         #toggleBtn { color: #bbbbbb; font-size: 15px; padding: 0px; }
+        #closeBtn {
+            color: #e8e8e8;
+            font-size: 16px;
+            padding: 0px;
+            border-radius: 15px;
+        }
+        #closeBtn:hover { background-color: rgba(255,90,90,120); }
         QTextEdit {
             color: #ffffff;
             background: transparent;
@@ -192,7 +201,8 @@ void CaptionWindow::relayout()
     toggleBtn_->setText(collapsed_ ? QStringLiteral("\u2304")     // ⌄
                                    : QStringLiteral("\u2303"));   // ⌃
     toggleBtn_->setToolTip(collapsed_ ? tr("展开") : tr("收起"));
-    const int h = kMargin * 2 + 22 + 6 + textHeight() + 6 + 24;
+    // 顶部那行的高度要跟着关闭按钮走，否则会挤到字幕
+    const int h = kMargin * 2 + kTopRowHeight + 6 + textHeight() + 6 + 24;
     setFixedHeight(h);
     setMinimumWidth(320);
     scrollToEnd();
diff --git a/src/ui/livetranscriber.cpp b/src/ui/livetranscriber.cpp
index 76b7bed..208676f 100644
--- a/src/ui/livetranscriber.cpp
+++ b/src/ui/livetranscriber.cpp
@@ -21,7 +21,8 @@ bool LiveTranscriber::start(IAsr & asr, const StreamOptions & opts, QString * er
     stop();
 
     LivePipelineOptions popt;
-    popt.stream = opts;
+    popt.stream        = opts;
+    popt.captureDevice = captureDevice_;
 
     pipeline_ = std::make_unique<LivePipeline>(asr, popt);
 
diff --git a/src/ui/livetranscriber.h b/src/ui/livetranscriber.h
index 70398ca..4745a1c 100644
--- a/src/ui/livetranscriber.h
+++ b/src/ui/livetranscriber.h
@@ -22,6 +22,9 @@ public:
     ~LiveTranscriber() override;
 
     // 后端在 start 时注入：设置里换了模型就 stop() 再 start()
+    // 采集源：空 = 跟随系统默认输出
+    void setCaptureDevice(const QString & sink) { captureDevice_ = sink.toStdString(); }
+
     bool start(IAsr & asr, const StreamOptions & opts, QString * error = nullptr);
     void stop();
 
@@ -33,6 +36,7 @@ Q_SIGNALS:
     void failed(const QString & message);
 
 private:
+    std::string                   captureDevice_;
     std::unique_ptr<LivePipeline> pipeline_;
 };
 
diff --git a/src/ui/settingsdialog.cpp b/src/ui/settingsdialog.cpp
index 5cebc2c..6de4ef3 100644
--- a/src/ui/settingsdialog.cpp
+++ b/src/ui/settingsdialog.cpp
@@ -1,5 +1,6 @@
 #include "settingsdialog.h"
 
+#include <QApplication>
 #include <QCheckBox>
 #include <QComboBox>
 #include <QDesktopServices>
@@ -24,6 +25,7 @@
 #include <QVBoxLayout>
 
 #include "appsettings.h"
+#include "audio.h"
 #include "modeldownloader.h"
 #include "modelstore.h"
 
@@ -98,14 +100,17 @@ QWidget * SettingsDialog::buildModelPage()
     auto * btnRow = new QHBoxLayout;
     downloadBtn_ = new QPushButton(tr("下载"), page);
     deleteBtn_   = new QPushButton(tr("删除"), page);
+    verifyBtn_   = new QPushButton(tr("校验完整性"), page);
     auto * openBtn = new QPushButton(tr("打开模型目录"), page);
     btnRow->addWidget(downloadBtn_);
+    btnRow->addWidget(verifyBtn_);
     btnRow->addWidget(deleteBtn_);
     btnRow->addWidget(openBtn);
     btnRow->addStretch(1);
     root->addLayout(btnRow);
 
     connect(downloadBtn_, &QPushButton::clicked, this, &SettingsDialog::onDownload);
+    connect(verifyBtn_, &QPushButton::clicked, this, &SettingsDialog::onVerify);
     connect(deleteBtn_,   &QPushButton::clicked, this, &SettingsDialog::onDelete);
     connect(openBtn,      &QPushButton::clicked, this, &SettingsDialog::onOpenDir);
 
@@ -116,6 +121,22 @@ QWidget * SettingsDialog::buildModelPage()
     root->addWidget(statusLabel_);
 
     auto * form = new QFormLayout;
+    captureCombo_ = new QComboBox(page);
+    captureCombo_->addItem(tr("跟随系统默认输出"), QString());
+    {
+        std::string derr;
+        for (const auto & dev : lc::listOutputDevices(&derr)) {
+            captureCombo_->addItem(QString::fromStdString(dev.description) +
+                                       (dev.isDefault ? tr("（默认）") : QString()),
+                                   QString::fromStdString(dev.sink));
+        }
+    }
+    {
+        const int idx = captureCombo_->findData(AppSettings::instance().captureDevice);
+        if (idx >= 0) captureCombo_->setCurrentIndex(idx);
+    }
+    form->addRow(tr("采集设备"), captureCombo_);
+
     activeCombo_ = new QComboBox(page);
     form->addRow(tr("当前使用"), activeCombo_);
 
@@ -372,6 +393,35 @@ void SettingsDialog::onDelete()
     refreshActiveCombo();
 }
 
+void SettingsDialog::onVerify()
+{
+    const int row = table_->currentRow();
+    if (row < 0) { statusLabel_->setText(tr("请先在上面选一个模型")); return; }
+    const QString id = table_->item(row, 0)->data(Qt::UserRole).toString();
+    const ModelInfo * m = ModelStore::find(id);
+    if (!m) return;
+
+    statusLabel_->setText(tr("正在校验 %1 …").arg(m->name));
+    progress_->setVisible(true);
+    progress_->setRange(0, 100);
+    QApplication::setOverrideCursor(Qt::WaitCursor);
+
+    QStringList bad;
+    const bool ok = ModelStore::verify(*m, &bad, [this](int done, int total) {
+        progress_->setValue(total > 0 ? done * 100 / total : 0);
+        QApplication::processEvents();
+    });
+
+    QApplication::restoreOverrideCursor();
+    progress_->setVisible(false);
+    if (ok) {
+        statusLabel_->setText(tr("✅ %1 校验通过").arg(m->name));
+    } else {
+        statusLabel_->setText(tr("❌ 校验失败，损坏的文件: %1（可删除后重新下载）")
+                                  .arg(bad.join(QStringLiteral(", "))));
+    }
+}
+
 void SettingsDialog::onOpenDir()
 {
     QDir().mkpath(ModelStore::root());
@@ -401,6 +451,9 @@ void SettingsDialog::onApply()
     cfg.proxyUser = proxyUser_->text();
     cfg.proxyPass = proxyPass_->text();
     cfg.language  = languageCombo_->currentData().toString();
+    if (captureCombo_->currentIndex() >= 0) {
+        cfg.captureDevice = captureCombo_->currentData().toString();
+    }
 
     cfg.fontSize         = fontSpin_->value();
     cfg.showUnstableTail = showTailCheck_->isChecked();
diff --git a/src/ui/settingsdialog.h b/src/ui/settingsdialog.h
index fcbec7f..3ddff85 100644
--- a/src/ui/settingsdialog.h
+++ b/src/ui/settingsdialog.h
@@ -38,6 +38,7 @@ private:
     void refreshModelTable();
     void refreshActiveCombo();
     void onDownload();
+    void onVerify();
     void onDelete();
     void onOpenDir();
     void onApply();
@@ -46,6 +47,8 @@ private:
     QTableWidget * table_      = nullptr;
     QComboBox *    activeCombo_ = nullptr;
     QComboBox *    languageCombo_ = nullptr;
+    QComboBox *    captureCombo_ = nullptr;
+    QPushButton *  verifyBtn_   = nullptr;
     QPushButton *  downloadBtn_ = nullptr;
     QPushButton *  deleteBtn_   = nullptr;
     QProgressBar * progress_    = nullptr;