diff --git a/tools/cabana/streams/replaystream.cc b/tools/cabana/streams/replaystream.cc
index 550e2be6a3..8a6b806a8a 100644
--- a/tools/cabana/streams/replaystream.cc
+++ b/tools/cabana/streams/replaystream.cc
@@ -40,6 +40,7 @@ bool ReplayStream::loadRoute(const QString &route, const QString &data_dir, uint
   replay->installEventFilter(event_filter, this);
   QObject::connect(replay.get(), &Replay::seekedTo, this, &AbstractStream::seekedTo);
   QObject::connect(replay.get(), &Replay::segmentsMerged, this, &ReplayStream::mergeSegments);
+  QObject::connect(replay.get(), &Replay::qLogLoaded, this, &ReplayStream::qLogLoaded, Qt::QueuedConnection);
   return replay->load();
 }
 
diff --git a/tools/cabana/streams/replaystream.h b/tools/cabana/streams/replaystream.h
index de69d9e86c..3f301d2ce2 100644
--- a/tools/cabana/streams/replaystream.h
+++ b/tools/cabana/streams/replaystream.h
@@ -32,6 +32,9 @@ public:
   inline const std::vector<std::tuple<double, double, TimelineType>> getTimeline() override { return replay->getTimeline(); }
   static AbstractOpenStreamWidget *widget(AbstractStream **stream);
 
+signals:
+  void qLogLoaded(int segnum, std::shared_ptr<LogReader> qlog);
+
 private:
   void mergeSegments();
   std::unique_ptr<Replay> replay = nullptr;
diff --git a/tools/cabana/videowidget.cc b/tools/cabana/videowidget.cc
index 7e051ef3b9..3e22464d06 100644
--- a/tools/cabana/videowidget.cc
+++ b/tools/cabana/videowidget.cc
@@ -1,8 +1,6 @@
 #include "tools/cabana/videowidget.h"
 
 #include <algorithm>
-#include <memory>
-#include <string>
 #include <utility>
 
 #include <QButtonGroup>
@@ -11,7 +9,6 @@
 #include <QPainter>
 #include <QStackedLayout>
 #include <QStyleOptionSlider>
-#include <QTimer>
 #include <QVBoxLayout>
 #include <QtConcurrent>
 
@@ -125,6 +122,7 @@ QWidget *VideoWidget::createCameraWidget() {
   QObject::connect(slider, &QSlider::valueChanged, [=](int value) { time_label->setText(utils::formatSeconds(slider->currentSecond())); });
   QObject::connect(slider, &Slider::updateMaximumTime, this, &VideoWidget::setMaximumTime, Qt::QueuedConnection);
   QObject::connect(cam_widget, &CameraWidget::clicked, []() { can->pause(!can->isPaused()); });
+  QObject::connect(static_cast<ReplayStream*>(can), &ReplayStream::qLogLoaded, slider, &Slider::parseQLog);
   QObject::connect(can, &AbstractStream::updated, this, &VideoWidget::updateState);
   return w;
 }
@@ -165,29 +163,9 @@ void VideoWidget::updatePlayBtnState() {
 
 Slider::Slider(QWidget *parent) : thumbnail_label(parent), QSlider(Qt::Horizontal, parent) {
   setMouseTracking(true);
-  auto timer = new QTimer(this);
-  timer->callOnTimeout([this]() {
-    timeline = can->getTimeline();
-    std::sort(timeline.begin(), timeline.end(), [](auto &l, auto &r) { return std::get<2>(l) < std::get<2>(r); });
-    update();
-  });
-  timer->start(2000);
-  QObject::connect(can, &AbstractStream::eventsMerged, [this]() {
-    if (!qlog_future) {
-      qlog_future = std::make_unique<QFuture<void>>(QtConcurrent::run(this, &Slider::parseQLog));
-    }
-  });
-  QObject::connect(qApp, &QApplication::aboutToQuit, [this]() {
-    abort_parse_qlog = true;
-    if (qlog_future && qlog_future->isRunning()) {
-      qDebug() << "stopping thumbnail thread";
-      qlog_future->waitForFinished();
-    }
-  });
 }
 
 AlertInfo Slider::alertInfo(double seconds) {
-  std::lock_guard lk(thumbnail_lock);
   uint64_t mono_time = (seconds + can->routeStartTime()) * 1e9;
   auto alert_it = alerts.lower_bound(mono_time);
   bool has_alert = (alert_it != alerts.end()) && ((alert_it->first - mono_time) <= 1e8);
@@ -195,7 +173,6 @@ AlertInfo Slider::alertInfo(double seconds) {
 }
 
 QPixmap Slider::thumbnail(double seconds)  {
-  std::lock_guard lk(thumbnail_lock);
   uint64_t mono_time = (seconds + can->routeStartTime()) * 1e9;
   auto it = thumbnails.lowerBound(mono_time);
   return it != thumbnails.end() ? it.value() : QPixmap();
@@ -206,36 +183,32 @@ void Slider::setTimeRange(double min, double max) {
   setRange(min * factor, max * factor);
 }
 
-void Slider::parseQLog() {
-  const auto &segments = can->route()->segments();
-  for (auto it = segments.rbegin(); it != segments.rend() && !abort_parse_qlog; ++it) {
-    LogReader log;
-    std::string qlog = it->second.qlog.toStdString();
-    if (!qlog.empty() && log.load(qlog, &abort_parse_qlog, {cereal::Event::Which::THUMBNAIL, cereal::Event::Which::CONTROLS_STATE}, true, 0, 3)) {
-      if (it == segments.rbegin() && !log.events.empty()) {
-        double max_time = log.events.back()->mono_time / 1e9 - can->routeStartTime();
-        emit updateMaximumTime(max_time);
+void Slider::parseQLog(int segnum, std::shared_ptr<LogReader> qlog) {
+ const auto &segments = qobject_cast<ReplayStream *>(can)->route()->segments();
+  if (segments.size() > 0 && segnum == segments.rbegin()->first && !qlog->events.empty()) {
+    emit updateMaximumTime(qlog->events.back()->mono_time / 1e9 - can->routeStartTime());
+  }
+
+  std::mutex mutex;
+  QtConcurrent::blockingMap(qlog->events.cbegin(), qlog->events.cend(), [&mutex, this](const Event *e) {
+    if (e->which == cereal::Event::Which::THUMBNAIL) {
+      auto thumb = e->event.getThumbnail();
+      auto data = thumb.getThumbnail();
+      if (QPixmap pm; pm.loadFromData(data.begin(), data.size(), "jpeg")) {
+        QPixmap scaled = pm.scaledToHeight(MIN_VIDEO_HEIGHT - THUMBNAIL_MARGIN * 2, Qt::SmoothTransformation);
+        std::lock_guard lk(mutex);
+        thumbnails[thumb.getTimestampEof()] = scaled;
       }
-      for (auto ev = log.events.cbegin(); ev != log.events.cend() && !abort_parse_qlog; ++ev) {
-        if ((*ev)->which == cereal::Event::Which::THUMBNAIL) {
-          auto thumb = (*ev)->event.getThumbnail();
-          auto data = thumb.getThumbnail();
-          if (QPixmap pm; pm.loadFromData(data.begin(), data.size(), "jpeg")) {
-            pm = pm.scaledToHeight(MIN_VIDEO_HEIGHT - THUMBNAIL_MARGIN * 2, Qt::SmoothTransformation);
-            std::lock_guard lk(thumbnail_lock);
-            thumbnails[thumb.getTimestampEof()] = pm;
-          }
-        } else if ((*ev)->which == cereal::Event::Which::CONTROLS_STATE) {
-          auto cs = (*ev)->event.getControlsState();
-          if (cs.getAlertType().size() > 0 && cs.getAlertText1().size() > 0 &&
-              cs.getAlertSize() != cereal::ControlsState::AlertSize::NONE) {
-            std::lock_guard lk(thumbnail_lock);
-            alerts.emplace((*ev)->mono_time, AlertInfo{cs.getAlertStatus(), cs.getAlertText1().cStr(), cs.getAlertText2().cStr()});
-          }
-        }
+    } else if (e->which == cereal::Event::Which::CONTROLS_STATE) {
+      auto cs = e->event.getControlsState();
+      if (cs.getAlertType().size() > 0 && cs.getAlertText1().size() > 0 &&
+          cs.getAlertSize() != cereal::ControlsState::AlertSize::NONE) {
+        std::lock_guard lk(mutex);
+        alerts.emplace(e->mono_time, AlertInfo{cs.getAlertStatus(), cs.getAlertText1().cStr(), cs.getAlertText2().cStr()});
       }
     }
-  }
+  });
+  update();
 }
 
 void Slider::paintEvent(QPaintEvent *ev) {
@@ -245,7 +218,7 @@ void Slider::paintEvent(QPaintEvent *ev) {
   double min = minimum() / factor;
   double max = maximum() / factor;
 
-  for (auto [begin, end, type] : timeline) {
+  for (auto [begin, end, type] : qobject_cast<ReplayStream *>(can)->getTimeline()) {
     if (begin > max || end < min)
       continue;
     r.setLeft(((std::max(min, begin) - min) / (max - min)) * width());
diff --git a/tools/cabana/videowidget.h b/tools/cabana/videowidget.h
index aca44d0ac1..12961cd061 100644
--- a/tools/cabana/videowidget.h
+++ b/tools/cabana/videowidget.h
@@ -1,19 +1,14 @@
 #pragma once
 
-#include <atomic>
 #include <map>
 #include <memory>
-#include <mutex>
-#include <tuple>
-#include <vector>
 
-#include <QFuture>
 #include <QLabel>
 #include <QSlider>
 #include <QToolButton>
 
 #include "selfdrive/ui/qt/widgets/cameraview.h"
-#include "tools/cabana/streams/abstractstream.h"
+#include "tools/cabana/streams/replaystream.h"
 
 struct AlertInfo {
   cereal::ControlsState::AlertStatus status;
@@ -42,6 +37,7 @@ public:
   void setTimeRange(double min, double max);
   AlertInfo alertInfo(double sec);
   QPixmap thumbnail(double sec);
+  void parseQLog(int segnum, std::shared_ptr<LogReader> qlog);
 
 signals:
   void updateMaximumTime(double);
@@ -51,15 +47,10 @@ private:
   void mouseMoveEvent(QMouseEvent *e) override;
   bool event(QEvent *event) override;
   void paintEvent(QPaintEvent *ev) override;
-  void parseQLog();
 
   const double factor = 1000.0;
-  std::vector<std::tuple<double, double, TimelineType>> timeline;
-  std::mutex thumbnail_lock;
-  std::atomic<bool> abort_parse_qlog = false;
   QMap<uint64_t, QPixmap> thumbnails;
   std::map<uint64_t, AlertInfo> alerts;
-  std::unique_ptr<QFuture<void>> qlog_future;
   InfoLabel thumbnail_label;
 };
 
diff --git a/tools/replay/replay.cc b/tools/replay/replay.cc
index d3a32a2651..b83f657e39 100644
--- a/tools/replay/replay.cc
+++ b/tools/replay/replay.cc
@@ -153,12 +153,10 @@ void Replay::buildTimeline() {
 
   const auto &route_segments = route_->segments();
   for (auto it = route_segments.cbegin(); it != route_segments.cend() && !exit_; ++it) {
-    LogReader log;
-    if (!log.load(it->second.qlog.toStdString(), &exit_,
-                  {cereal::Event::Which::CONTROLS_STATE, cereal::Event::Which::USER_FLAG},
-                  !hasFlag(REPLAY_FLAG_NO_FILE_CACHE), 0, 3)) continue;
+    std::shared_ptr<LogReader> log(new LogReader());
+    if (!log->load(it->second.qlog.toStdString(), &exit_, {}, !hasFlag(REPLAY_FLAG_NO_FILE_CACHE), 0, 3)) continue;
 
-    for (const Event *e : log.events) {
+    for (const Event *e : log->events) {
       if (e->which == cereal::Event::Which::CONTROLS_STATE) {
         auto cs = e->event.getControlsState();
 
@@ -186,6 +184,8 @@ void Replay::buildTimeline() {
         timeline.push_back({toSeconds(e->mono_time), toSeconds(e->mono_time), TimelineType::UserFlag});
       }
     }
+    std::sort(timeline.begin(), timeline.end(), [](auto &l, auto &r) { return std::get<2>(l) < std::get<2>(r); });
+    emit qLogLoaded(it->first, log);
   }
 }
 
diff --git a/tools/replay/replay.h b/tools/replay/replay.h
index 5ed4ff11b5..01969b0a9f 100644
--- a/tools/replay/replay.h
+++ b/tools/replay/replay.h
@@ -44,6 +44,7 @@ enum class FindFlag {
 
 enum class TimelineType { None, Engaged, AlertInfo, AlertWarning, AlertCritical, UserFlag };
 typedef bool (*replayEventFilter)(const Event *, void *);
+Q_DECLARE_METATYPE(std::shared_ptr<LogReader>);
 
 class Replay : public QObject {
   Q_OBJECT
@@ -91,6 +92,7 @@ signals:
   void streamStarted();
   void segmentsMerged();
   void seekedTo(double sec);
+  void qLogLoaded(int segnum, std::shared_ptr<LogReader> qlog);
 
 protected slots:
   void segmentLoadFinished(bool success);