diff --git a/selfdrive/ui/replay/main.cc b/selfdrive/ui/replay/main.cc
index 1bb4344956..196672d9b2 100644
--- a/selfdrive/ui/replay/main.cc
+++ b/selfdrive/ui/replay/main.cc
@@ -46,24 +46,24 @@ void keyboardThread(Replay *replay) {
       try {
         if (r[0] == '#') {
           r.erase(0, 1);
-          replay->seekTo(std::stoi(r) * 60);
+          replay->seekTo(std::stoi(r) * 60, false);
         } else {
-          replay->seekTo(std::stoi(r));
+          replay->seekTo(std::stoi(r), false);
         }
       } catch (std::invalid_argument) {
         qDebug() << "invalid argument";
       }
       getch();  // remove \n from entering seek
     } else if (c == 'm') {
-      replay->relativeSeek(+60);
+      replay->seekTo(+60, true);
     } else if (c == 'M') {
-      replay->relativeSeek(-60);
+      replay->seekTo(-60, true);
     } else if (c == 's') {
-      replay->relativeSeek(+10);
+      replay->seekTo(+10, true);
     } else if (c == 'S') {
-      replay->relativeSeek(-10);
+      replay->seekTo(-10, true);
     } else if (c == 'G') {
-      replay->relativeSeek(0);
+      replay->seekTo(0, true);
     } else if (c == ' ') {
       replay->pause(!replay->isPaused());
     }
@@ -97,10 +97,10 @@ int main(int argc, char *argv[]){
   QStringList block = parser.value("block").isEmpty() ? QStringList{} : parser.value("block").split(",");
 
   Replay *replay = new Replay(route, allow, block, nullptr, parser.isSet("dcam"), parser.isSet("ecam"), &app);
-  if (replay->load()) {
-    replay->start(parser.value("start").toInt());
+  if (!replay->load()) {
+    return 0;  
   }
-
+  replay->start(parser.value("start").toInt());
   // start keyboard control thread
   QThread *t = QThread::create(keyboardThread, replay);
   QObject::connect(t, &QThread::finished, t, &QThread::deleteLater);
diff --git a/selfdrive/ui/replay/replay.cc b/selfdrive/ui/replay/replay.cc
index d977b56752..dec204b7b3 100644
--- a/selfdrive/ui/replay/replay.cc
+++ b/selfdrive/ui/replay/replay.cc
@@ -3,8 +3,8 @@
 #include <QApplication>
 #include <QDebug>
 
+#include <capnp/dynamic.h>
 #include "cereal/services.h"
-#include "selfdrive/camerad/cameras/camera_common.h"
 #include "selfdrive/common/timing.h"
 #include "selfdrive/hardware/hw.h"
 #include "selfdrive/ui/replay/util.h"
@@ -27,16 +27,15 @@ Replay::Replay(QString route, QStringList allow, QStringList block, SubMaster *s
   if (sm == nullptr) {
     pm = new PubMaster(s);
   }
-
   route_ = std::make_unique<Route>(route);
   events_ = new std::vector<Event *>();
-  // queueSegment is always executed in the main thread
+  // doSeek & queueSegment are always executed in the same thread
+  connect(this, &Replay::seekTo, this, &Replay::doSeek);
   connect(this, &Replay::segmentChanged, this, &Replay::queueSegment);
 }
 
 Replay::~Replay() {
   qDebug() << "shutdown: in progress...";
-
   exit_ = true;
   updating_events_ = true;
   if (stream_thread_) {
@@ -53,18 +52,27 @@ Replay::~Replay() {
 }
 
 bool Replay::load() {
-  if (!route_->load() || route_->size() == 0) {
-    qDebug() << "failed load route" << route_->name() << "from server";
+  if (!route_->load()) {
+    qDebug() << "failed to load route" << route_->name() << "from server";
     return false;
   }
 
-  qDebug() << "load route" << route_->name() << route_->size() << "segments";
-  segments_.resize(route_->size());
+  for (int i = 0; i < route_->size(); ++i) {
+    const SegmentFile &f = route_->at(i);
+    if ((!f.rlog.isEmpty() || !f.qlog.isEmpty()) && (!f.road_cam.isEmpty() || !f.qcamera.isEmpty())) {
+      segments_[i] = nullptr;
+    }
+  }
+  if (segments_.empty()) {
+    qDebug() << "no valid segments in route" << route_->name();
+    return false;
+  }
+  qDebug() << "load route" << route_->name() << "with" << segments_.size() << "valid segments";
   return true;
 }
 
 void Replay::start(int seconds) {
-  seekTo(seconds);
+  seekTo(seconds, false);
 
   camera_server_ = std::make_unique<CameraServer>();
   // start stream thread
@@ -84,35 +92,24 @@ void Replay::updateEvents(const std::function<bool()> &lambda) {
   stream_cv_.notify_one();
 }
 
-void Replay::seekTo(int seconds, bool relative) {
-  if (segments_.empty()) return;
-
-  bool segment_loaded = false;
-  bool segment_changed = false;
+void Replay::doSeek(int seconds, bool relative) {
   updateEvents([&]() {
     if (relative) {
-      seconds += ((cur_mono_time_ - route_start_ts_) * 1e-9);
+      seconds += currentSeconds();
     }
     qInfo() << "seeking to" << seconds;
-
-    cur_mono_time_ = route_start_ts_ + std::clamp(seconds, 0, (int)segments_.size() * 60) * 1e9;
-    int segment = std::min(seconds / 60, (int)segments_.size() - 1);
-    segment_changed = current_segment_.exchange(segment) != segment;
-    segment_loaded = std::find(segments_merged_.begin(), segments_merged_.end(), segment) != segments_merged_.end();
-    return segment_loaded;
+    cur_mono_time_ = route_start_ts_ + std::clamp(seconds, 0, (int)segments_.rbegin()->first * 60) * 1e9;
+    current_segment_ = std::min(seconds / 60, (int)segments_.rbegin()->first - 1);
+    return false;
   });
-
-  if (segment_changed || !segment_loaded) {
-    emit segmentChanged();
-  }
+  queueSegment();
 }
 
 void Replay::pause(bool pause) {
   updateEvents([=]() {
     qDebug() << (pause ? "paused..." : "resuming");
     if (pause) {
-      float current_ts = (cur_mono_time_ - route_start_ts_) / 1e9;
-      qInfo() << "at " << current_ts << "s";
+      qInfo() << "at " << currentSeconds() << "s";
     }
     paused_ = pause;
     return true;
@@ -127,43 +124,36 @@ void Replay::setCurrentSegment(int n) {
 
 // maintain the segment window
 void Replay::queueSegment() {
-  // fetch segments forward
-  int cur_seg = current_segment_.load();
-  int end_idx = cur_seg;
-  for (int i = cur_seg, fwd = 0; i < segments_.size() && fwd <= FORWARD_SEGS; ++i) {
-    if (!segments_[i]) {
-      segments_[i] = std::make_unique<Segment>(i, route_->at(i), load_dcam, load_ecam);
-      QObject::connect(segments_[i].get(), &Segment::loadFinished, this, &Replay::queueSegment);
-    }
-    end_idx = i;
-    // skip invalid segment
-    if (segments_[i]->isValid()) {
-      ++fwd;
-    } else if (i == cur_seg) {
-      ++cur_seg;
+  // forward fetch segments
+  SegmentMap::iterator begin, end;
+  begin = end = segments_.lower_bound(current_segment_);
+  for (int fwd = 0; end != segments_.end() && fwd <= FORWARD_SEGS; ++end, ++fwd) {
+    auto &[n, seg] = *end;
+    if (!seg) {
+      seg = std::make_unique<Segment>(n, route_->at(n), load_dcam, load_ecam);
+      QObject::connect(seg.get(), &Segment::loadFinished, this, &Replay::queueSegment);
     }
   }
-
-  mergeSegments(std::min(cur_seg, (int)segments_.size() - 1), end_idx);
+  // merge segments
+  mergeSegments(begin, end);
+  // free segments out of current semgnt window.
+  for (auto it = segments_.begin(); it != begin; ++it) {
+    it->second.reset(nullptr);
+  }
+  for (auto it = end; it != segments_.end(); ++it) {
+    it->second.reset(nullptr);
+  }
 }
 
-void Replay::mergeSegments(int cur_seg, int end_idx) {
+void Replay::mergeSegments(const SegmentMap::iterator &begin, const SegmentMap::iterator &end) {
   // segments must be merged in sequence.
   std::vector<int> segments_need_merge;
-  const int begin_idx = std::max(cur_seg - BACKWARD_SEGS, 0);
-  for (int i = begin_idx; i <= end_idx; ++i) {
-    if (segments_[i] && segments_[i]->isLoaded()) {
-      segments_need_merge.push_back(i);
-    } else if (i >= cur_seg && segments_[i] && segments_[i]->isValid()) {
-      // segment is valid,but still loading. can't skip it to merge the next one.
-      // otherwise the stream thread may jump to the next segment.
-      break;
-    }
+  for (auto it = begin; it != end && it->second->isLoaded(); ++it) {
+    segments_need_merge.push_back(it->first);
   }
 
   if (segments_need_merge != segments_merged_) {
     qDebug() << "merge segments" << segments_need_merge;
-
     // merge & sort events
     std::vector<Event *> *new_events = new std::vector<Event *>();
     new_events->reserve(std::accumulate(segments_need_merge.begin(), segments_need_merge.end(), 0,
@@ -173,7 +163,6 @@ void Replay::mergeSegments(int cur_seg, int end_idx) {
       auto middle = new_events->insert(new_events->end(), log->events.begin(), log->events.end());
       std::inplace_merge(new_events->begin(), middle, new_events->end(), Event::lessThan());
     }
-
     // update events
     auto prev_events = events_;
     updateEvents([&]() {
@@ -182,7 +171,7 @@ void Replay::mergeSegments(int cur_seg, int end_idx) {
         auto it = std::find_if(new_events->begin(), new_events->end(), [=](auto e) { return e->which == cereal::Event::Which::INIT_DATA; });
         if (it != new_events->end()) {
           route_start_ts_ = (*it)->mono_time;
-          // cur_mono_time_ is set by seekTo int start() before get route_start_ts_
+          // cur_mono_time_ is set by seekTo in start() before get route_start_ts_
           cur_mono_time_ += route_start_ts_;
         }
       }
@@ -193,22 +182,16 @@ void Replay::mergeSegments(int cur_seg, int end_idx) {
     });
     delete prev_events;
   } else {
-    updateEvents([]() { return true; });
-  }
-
-  // free segments out of current semgnt window.
-  for (int i = 0; i < segments_.size(); i++) {
-    if ((i < begin_idx || i > end_idx) && segments_[i]) {
-      segments_[i].reset(nullptr);
-    }
+    updateEvents([=]() { return begin->second->isLoaded(); });
   }
 }
 
 void Replay::publishFrame(const Event *e) {
   auto publish = [=](CameraType cam_type, const cereal::EncodeIndex::Reader &eidx) {
-    auto &seg = segments_[eidx.getSegmentNum()];
-    if (seg && seg->isLoaded() && seg->frames[cam_type] && eidx.getType() == cereal::EncodeIndex::Type::FULL_H_E_V_C) {
-      camera_server_->pushFrame(cam_type, seg->frames[cam_type].get(), eidx);
+    int n = eidx.getSegmentNum();
+    bool segment_loaded = std::find(segments_merged_.begin(), segments_merged_.end(), n) != segments_merged_.end();
+    if (segment_loaded && segments_[n]->frames[cam_type] && eidx.getType() == cereal::EncodeIndex::Type::FULL_H_E_V_C) {
+      camera_server_->pushFrame(cam_type, segments_[n]->frames[cam_type].get(), eidx);
     }
   };
   if (e->which == cereal::Event::ROAD_ENCODE_IDX) {
@@ -238,22 +221,21 @@ void Replay::stream() {
       continue;
     }
 
-    uint64_t evt_start_ts = cur_mono_time_;
-    uint64_t loop_start_ts = nanos_since_boot();
+    const uint64_t evt_start_ts = cur_mono_time_;
+    const uint64_t loop_start_ts = nanos_since_boot();
 
     for (auto end = events_->end(); !updating_events_ && eit != end; ++eit) {
       const Event *evt = (*eit);
       cur_which = evt->which;
       cur_mono_time_ = evt->mono_time;
+      const int current_ts = currentSeconds();
+      if (last_print > current_ts || (current_ts - last_print) > 5.0) {
+        last_print = current_ts;
+        qInfo() << "at " << current_ts << "s";
+      }
+      setCurrentSegment(current_ts / 60);
 
       if (cur_which < sockets_.size() && sockets_[cur_which] != nullptr) {
-        int current_ts = (cur_mono_time_ - route_start_ts_) / 1e9;
-        if ((current_ts - last_print) > 5.0) {
-          last_print = current_ts;
-          qInfo() << "at " << current_ts << "s";
-        }
-        setCurrentSegment(current_ts / 60);
-
         // keep time
         long etime = cur_mono_time_ - evt_start_ts;
         long rtime = nanos_since_boot() - loop_start_ts;
diff --git a/selfdrive/ui/replay/replay.h b/selfdrive/ui/replay/replay.h
index 65f4cc5cfc..e6243bdf27 100644
--- a/selfdrive/ui/replay/replay.h
+++ b/selfdrive/ui/replay/replay.h
@@ -2,8 +2,6 @@
 
 #include <QThread>
 
-#include <capnp/dynamic.h>
-#include "cereal/visionipc/visionipc_server.h"
 #include "selfdrive/ui/replay/camera.h"
 #include "selfdrive/ui/replay/route.h"
 
@@ -18,23 +16,25 @@ public:
   ~Replay();
   bool load();
   void start(int seconds = 0);
-  void seekTo(int seconds, bool relative = false);
-  void relativeSeek(int seconds) { seekTo(seconds, true); }
   void pause(bool pause);
   bool isPaused() const { return paused_; }
 
 signals:
  void segmentChanged();
+ void seekTo(int seconds, bool relative);
 
 protected slots:
   void queueSegment();
+  void doSeek(int seconds, bool relative);
 
 protected:
+  typedef std::map<int, std::unique_ptr<Segment>> SegmentMap;
   void stream();
   void setCurrentSegment(int n);
-  void mergeSegments(int begin_idx, int end_idx);
+  void mergeSegments(const SegmentMap::iterator &begin, const SegmentMap::iterator &end);
   void updateEvents(const std::function<bool()>& lambda);
   void publishFrame(const Event *e);
+  inline int currentSeconds() const { return (cur_mono_time_ - route_start_ts_) / 1e9; }
 
   QThread *stream_thread_ = nullptr;
 
@@ -43,7 +43,7 @@ protected:
   std::condition_variable stream_cv_;
   std::atomic<bool> updating_events_ = false;
   std::atomic<int> current_segment_ = -1;
-  std::vector<std::unique_ptr<Segment>> segments_;
+  SegmentMap segments_;
   // the following variables must be protected with stream_lock_
   bool exit_ = false;
   bool paused_ = false;
diff --git a/selfdrive/ui/replay/route.cc b/selfdrive/ui/replay/route.cc
index 0d574d1140..f43bd47f23 100644
--- a/selfdrive/ui/replay/route.cc
+++ b/selfdrive/ui/replay/route.cc
@@ -77,9 +77,7 @@ Segment::Segment(int n, const SegmentFile &segment_files, bool load_dcam, bool l
   // fallback to qcamera/qlog
   road_cam_path_ = files_.road_cam.isEmpty() ? files_.qcamera : files_.road_cam;
   log_path_ = files_.rlog.isEmpty() ? files_.qlog : files_.rlog;
-
-  valid_ = !log_path_.isEmpty() && !road_cam_path_.isEmpty();
-  if (!valid_) return;
+  assert (!log_path_.isEmpty() && !road_cam_path_.isEmpty());
 
   if (!load_dcam) {
     files_.driver_cam = "";
@@ -151,7 +149,7 @@ void Segment::load() {
   }
 
   int success_cnt = std::accumulate(futures.begin(), futures.end(), 0, [=](int v, auto &f) { return f.get() + v; });
-  loaded_ = valid_ = (success_cnt == futures.size());
+  loaded_ = (success_cnt == futures.size());
   emit loadFinished();
 }
 
diff --git a/selfdrive/ui/replay/route.h b/selfdrive/ui/replay/route.h
index 0cce753414..2ece59c48f 100644
--- a/selfdrive/ui/replay/route.h
+++ b/selfdrive/ui/replay/route.h
@@ -25,17 +25,14 @@ class Route {
 public:
   Route(const QString &route);
   bool load();
-
   inline const QString &name() const { return route_; };
   inline int size() const { return segments_.size(); }
   inline SegmentFile &at(int n) { return segments_[n]; }
 
-  // public for unit tests
-  std::vector<SegmentFile> segments_;
-
 protected:
   bool loadFromJson(const QString &json);
   QString route_;
+  std::vector<SegmentFile> segments_;
 };
 
 class Segment : public QObject {
@@ -44,7 +41,6 @@ class Segment : public QObject {
 public:
   Segment(int n, const SegmentFile &segment_files, bool load_dcam, bool load_ecam);
   ~Segment();
-  inline bool isValid() const { return valid_; };
   inline bool isLoaded() const { return loaded_; }
 
   std::unique_ptr<LogReader> log;
@@ -58,7 +54,7 @@ protected:
   void downloadFile(const QString &url);
   QString localPath(const QUrl &url);
 
-  std::atomic<bool> loaded_ = false, valid_ = false;
+  std::atomic<bool> loaded_ = false;
   std::atomic<bool> aborting_ = false;
   std::atomic<int> downloading_ = 0;
   int seg_num_ = 0;
diff --git a/selfdrive/ui/replay/tests/test_replay.cc b/selfdrive/ui/replay/tests/test_replay.cc
index 91b5742067..b374239f36 100644
--- a/selfdrive/ui/replay/tests/test_replay.cc
+++ b/selfdrive/ui/replay/tests/test_replay.cc
@@ -1,38 +1,12 @@
 #include <QCryptographicHash>
 #include <QDebug>
 #include <QEventLoop>
-#include <QString>
-#include <set>
-#include <future>
 
 #include "catch2/catch.hpp"
-#include "selfdrive/common/util.h"
-#include "selfdrive/ui/replay/framereader.h"
 #include "selfdrive/ui/replay/replay.h"
-#include "selfdrive/ui/replay/route.h"
 #include "selfdrive/ui/replay/util.h"
 
-const char *stream_url = "https://commadataci.blob.core.windows.net/openpilotci/0c94aa1e1296d7c6/2021-05-05--19-48-37/0/fcamera.hevc";
-
-// TEST_CASE("FrameReader") {
-//   SECTION("process&get") {
-//     FrameReader fr;
-//     REQUIRE(fr.load(stream_url) == true);
-//     REQUIRE(fr.valid() == true);
-//     REQUIRE(fr.getFrameCount() == 1200);
-//     // random get 50 frames
-//     // srand(time(NULL));
-//     // for (int i = 0; i < 50; ++i) {
-//     //   int idx = rand() % (fr.getFrameCount() - 1);
-//     //   REQUIRE(fr.get(idx) != nullptr);
-//     // }
-//     // sequence get 50 frames {
-//     for (int i = 0; i < 50; ++i) {
-//       REQUIRE(fr.get(i) != nullptr);
-//     }
-//   }
-// }
-
+const QString DEMO_ROUTE = "4cf7a6ad03080c90|2021-09-29--13-46-36";
 std::string sha_256(const QString &dat) {
   return QString(QCryptographicHash::hash(dat.toUtf8(), QCryptographicHash::Sha256).toHex()).toStdString();
 }
@@ -43,6 +17,7 @@ TEST_CASE("httpMultiPartDownload") {
   REQUIRE(fd != -1);
   close(fd);
 
+  const char *stream_url = "https://commadataci.blob.core.windows.net/openpilotci/0c94aa1e1296d7c6/2021-05-05--19-48-37/0/fcamera.hevc";
   SECTION("http 200") {
     REQUIRE(httpMultiPartDownload(stream_url, filename, 5));
     std::string content = util::read_file(filename);
@@ -76,8 +51,6 @@ bool is_events_ordered(const std::vector<Event *> &events) {
   return true;
 }
 
-const QString DEMO_ROUTE = "4cf7a6ad03080c90|2021-09-29--13-46-36";
-
 TEST_CASE("Segment") {
   Route demo_route(DEMO_ROUTE);
   REQUIRE(demo_route.load());
@@ -85,43 +58,46 @@ TEST_CASE("Segment") {
 
   QEventLoop loop;
   Segment segment(0, demo_route.at(0), false, false);
-  REQUIRE(segment.isValid() == true);
-  REQUIRE(segment.isLoaded() == false);
   QObject::connect(&segment, &Segment::loadFinished, [&]() {
     REQUIRE(segment.isLoaded() == true);
     REQUIRE(segment.log != nullptr);
-    REQUIRE(segment.log->events.size() > 0);
-    REQUIRE(is_events_ordered(segment.log->events));
     REQUIRE(segment.frames[RoadCam] != nullptr);
-    REQUIRE(segment.frames[RoadCam]->getFrameCount() > 0);
     REQUIRE(segment.frames[DriverCam] == nullptr);
     REQUIRE(segment.frames[WideRoadCam] == nullptr);
+
+    // LogReader & FrameReader
+    REQUIRE(segment.log->events.size() > 0);
+    REQUIRE(is_events_ordered(segment.log->events));
+    // sequence get 50 frames {
+    REQUIRE(segment.frames[RoadCam]->getFrameCount() == 1200);
+    for (int i = 0; i < 50; ++i) {
+      REQUIRE(segment.frames[RoadCam]->get(i));
+    }
     loop.quit();
   });
   loop.exec();
 }
-/*
+
 // helper class for unit tests
 class TestReplay : public Replay {
 public:
   TestReplay(const QString &route) : Replay(route, {}, {}) {}
   void test_seek();
-
-protected:
-  void testSeekTo(int seek_to, const std::set<int> &invalid_segments = {});
+  void testSeekTo(int seek_to);
 };
 
-void TestReplay::testSeekTo(int seek_to, const std::set<int> &invalid_segments) {
-  seekTo(seek_to);
+void TestReplay::testSeekTo(int seek_to) {
+  seekTo(seek_to, false);
 
-  // wait for seek finish
+  // wait for the seek to finish
   while (true) {
     std::unique_lock lk(stream_lock_);
     stream_cv_.wait(lk, [=]() { return events_updated_ == true; });
     events_updated_ = false;
-
-    // verify result
-    REQUIRE(uint64_t(route_start_ts_ + seek_to * 1e9) == cur_mono_time_);
+    if (cur_mono_time_ != route_start_ts_ + seek_to * 1e9) {
+      // wake up by the previous merging, skip it.
+      continue;
+    }
 
     Event cur_event(cereal::Event::Which::INIT_DATA, cur_mono_time_);
     auto eit = std::upper_bound(events_->begin(), events_->end(), &cur_event, Event::lessThan());
@@ -130,26 +106,15 @@ void TestReplay::testSeekTo(int seek_to, const std::set<int> &invalid_segments)
       continue;
     }
 
-    INFO("seek to [" << seek_to << "s segment " << seek_to / 60 << "]");
-    REQUIRE(!events_->empty());
     REQUIRE(is_events_ordered(*events_));
-
-    REQUIRE(eit != events_->end());
     const int seek_to_segment = seek_to / 60;
     const int event_seconds = ((*eit)->mono_time - route_start_ts_) / 1e9;
     current_segment_ = event_seconds / 60;
-    INFO("event [" << event_seconds << "s segment " << current_segment_ << "]");
+    INFO("seek to [" << seek_to << "s segment " << seek_to_segment << "], events [" << event_seconds << "s segment" << current_segment_ << "]");
     REQUIRE(event_seconds >= seek_to);
-    if (invalid_segments.find(seek_to_segment) == invalid_segments.end()) {
-      REQUIRE(event_seconds == seek_to); // at the same time
-    } else {
-      if (current_segment_ == seek_to_segment) {
-        // seek cross-boundary. e.g. seek_to 60s(segment 1), but segment 0 end at 60.021 and segemnt 1 is invalid.
-        REQUIRE(event_seconds == seek_to);
-      } else {
-        REQUIRE(current_segment_ > seek_to_segment);
-        REQUIRE(invalid_segments.find(current_segment_) == invalid_segments.end());
-      }
+    if (event_seconds > seek_to) {
+      auto it = segments_.lower_bound(seek_to_segment);
+      REQUIRE(it->first == current_segment_);
     }
     break;
   }
@@ -157,29 +122,21 @@ void TestReplay::testSeekTo(int seek_to, const std::set<int> &invalid_segments)
 
 void TestReplay::test_seek() {
   QEventLoop loop;
-
   std::thread thread = std::thread([&]() {
-    const int loop_count = 100;
-    // random seek in one segment
-    for (int i = 0; i < loop_count; ++i) {
-      testSeekTo(random_int(0, 60));
+    // random seek 50 times in 3 segments
+    for (int i = 0; i < 50; ++i) {
+      testSeekTo(random_int(0, 3 * 60));
     }
-    // random seek in 3 segments
-    for (int i = 0; i < loop_count; ++i) {
-      testSeekTo(random_int(0, 60 * 3));
+    // random seek 50 times in routes with invalid segments
+    for (int n : {5, 6, 8}) {
+      segments_.erase(n);
     }
-    // random seek in invalid segments
-    std::set<int> invalid_segments{5, 6, 7, 9};
-    for (int i : invalid_segments) {
-      route_->segments_[i].rlog = route_->segments_[i].qlog = "";
-      route_->segments_[i].road_cam = route_->segments_[i].qcamera = "";
-    }
-    for (int i = 0; i < loop_count; ++i) {
-      testSeekTo(random_int(4 * 60, 60 * 10), invalid_segments);
+    for (int i =0; i < 50; ++i) {
+      testSeekTo(520);
+      testSeekTo(random_int(4 * 60, 9 * 60));
     }
     loop.quit();
   });
-
   loop.exec();
   thread.join();
 }
@@ -189,4 +146,3 @@ TEST_CASE("Replay") {
   REQUIRE(replay.load());
   replay.test_seek();
 }
-*/