diff --git a/configure.cmake b/configure.cmake
index 8f30b34..bbd934e 100644
--- a/configure.cmake
+++ b/configure.cmake
@@ -209,25 +209,6 @@ int main(void){
 }"
 )

-qt_config_compile_test(libavformat
-    LABEL "libavformat"
-    LIBRARIES
-        PkgConfig::FFMPEG
-    CODE
-"
-#include \"libavformat/version.h\"
-extern \"C\" {
-#include \"libavformat/avformat.h\"
-}
-int main(void) {
-#if LIBAVFORMAT_VERSION_MAJOR >= 59
-    AVStream stream;
-    auto first_dts = av_stream_get_first_dts(&stream);
-#endif
-    return 0;
-}"
-)
-
 #### Features

 qt_feature("qtwebengine-build" PUBLIC
@@ -563,11 +544,6 @@ add_check_for_support(
    CONDITION NOT LINUX OR DBUS_FOUND
    MESSAGE "Build requires dbus."
 )
-add_check_for_support(
-    MODULES QtWebEngine
-    CONDITION NOT LINUX OR NOT QT_FEATURE_webengine_system_ffmpeg OR TEST_libavformat
-    MESSAGE "Unmodified ffmpeg >= 5.0 is not supported."
-)
 # FIXME: This prevents non XCB Linux builds from building:
 set(xcbSupport X11 LIBDRM XCOMPOSITE XCURSOR XRANDR XI XPROTO XSHMFENCE XTST)
 foreach(xs ${xcbSupport})
diff --git a/src/3rdparty/chromium/AUTHORS b/src/3rdparty/chromium/AUTHORS
index ff6abe8..0fd7937 100644
--- a/src/3rdparty/chromium/AUTHORS
+++ b/src/3rdparty/chromium/AUTHORS
@@ -99,6 +99,7 @@ Andra Paraschiv <andra.paraschiv@intel.com>
 Andras Tokodi <a.tokodi@eyeo.com>
 Andreas Nazlidis <andreas221b@gmail.com>
 Andreas Papacharalampous <andreas@apap04.com>
+Andreas Schneider <asn@cryptomilk.org>
 Andrei Borza <andrei.borza@gmail.com>
 Andrei Parvu <andrei.prv@gmail.com>
 Andrei Parvu <parvu@adobe.com>
diff --git a/src/3rdparty/chromium/media/filters/ffmpeg_demuxer.cc b/src/3rdparty/chromium/media/filters/ffmpeg_demuxer.cc
index f41464b..3aa3918 100644
--- a/src/3rdparty/chromium/media/filters/ffmpeg_demuxer.cc
+++ b/src/3rdparty/chromium/media/filters/ffmpeg_demuxer.cc
@@ -59,7 +59,7 @@ namespace media {

 namespace {

-constexpr int64_t kInvalidPTSMarker = static_cast<int64_t>(0x8000000000000000);
+constexpr int64_t kRelativeTsBase = static_cast<int64_t>(0x7ffeffffffffffff);

 void SetAVStreamDiscard(AVStream* stream, AVDiscard discard) {
   DCHECK(stream);
@@ -97,7 +97,7 @@ static base::TimeDelta FramesToTimeDelta(int frames, double sample_rate) {
                             sample_rate);
 }

-static base::TimeDelta ExtractStartTime(AVStream* stream) {
+static base::TimeDelta ExtractStartTime(AVStream* stream, int64_t first_dts) {
   // The default start time is zero.
   base::TimeDelta start_time;

@@ -107,12 +107,12 @@ static base::TimeDelta ExtractStartTime(AVStream* stream) {

   // Next try to use the first DTS value, for codecs where we know PTS == DTS
   // (excludes all H26x codecs). The start time must be returned in PTS.
-  if (av_stream_get_first_dts(stream) != kInvalidPTSMarker &&
+  if (first_dts != AV_NOPTS_VALUE &&
       stream->codecpar->codec_id != AV_CODEC_ID_HEVC &&
       stream->codecpar->codec_id != AV_CODEC_ID_H264 &&
       stream->codecpar->codec_id != AV_CODEC_ID_MPEG4) {
     const base::TimeDelta first_pts =
-        ConvertFromTimeBase(stream->time_base, av_stream_get_first_dts(stream));
+        ConvertFromTimeBase(stream->time_base, first_dts);
     if (first_pts < start_time)
       start_time = first_pts;
   }
@@ -270,6 +270,7 @@ FFmpegDemuxerStream::FFmpegDemuxerStream(
       fixup_negative_timestamps_(false),
       fixup_chained_ogg_(false),
       num_discarded_packet_warnings_(0),
+      first_dts_(AV_NOPTS_VALUE),
       last_packet_pos_(AV_NOPTS_VALUE),
       last_packet_dts_(AV_NOPTS_VALUE) {
   DCHECK(demuxer_);
@@ -336,6 +337,11 @@ void FFmpegDemuxerStream::EnqueuePacket(ScopedAVPacket packet) {
   int64_t packet_dts =
       packet->dts == AV_NOPTS_VALUE ? packet->pts : packet->dts;

+  if (first_dts_ == AV_NOPTS_VALUE && packet->dts != AV_NOPTS_VALUE &&
+      last_packet_dts_ != AV_NOPTS_VALUE) {
+    first_dts_ = packet->dts - (last_packet_dts_ + kRelativeTsBase);
+  }
+
   // Chained ogg files have non-monotonically increasing position and time stamp
   // values, which prevents us from using them to determine if a packet should
   // be dropped. Since chained ogg is only allowed on single track audio only
@@ -683,6 +689,7 @@ void FFmpegDemuxerStream::FlushBuffers(bool preserve_packet_position) {
   ResetBitstreamConverter();

   if (!preserve_packet_position) {
+    first_dts_ = AV_NOPTS_VALUE;
     last_packet_pos_ = AV_NOPTS_VALUE;
     last_packet_dts_ = AV_NOPTS_VALUE;
   }
@@ -1452,7 +1459,8 @@ void FFmpegDemuxer::OnFindStreamInfoDone(int result) {

     max_duration = std::max(max_duration, streams_[i]->duration());

-    base::TimeDelta start_time = ExtractStartTime(stream);
+    base::TimeDelta start_time =
+        ExtractStartTime(stream, streams_[i]->first_dts());

     // Note: This value is used for seeking, so we must take the true value and
     // not the one possibly clamped to zero below.
@@ -1609,7 +1617,7 @@ FFmpegDemuxerStream* FFmpegDemuxer::FindStreamWithLowestStartTimestamp(
   for (const auto& stream : streams_) {
     if (!stream || stream->IsEnabled() != enabled)
       continue;
-    if (av_stream_get_first_dts(stream->av_stream()) == kInvalidPTSMarker)
+    if (stream->first_dts() == AV_NOPTS_VALUE)
       continue;
     if (!lowest_start_time_stream ||
         stream->start_time() < lowest_start_time_stream->start_time()) {
@@ -1630,7 +1638,7 @@ FFmpegDemuxerStream* FFmpegDemuxer::FindPreferredStreamForSeeking(
     if (stream->type() != DemuxerStream::VIDEO)
       continue;

-    if (av_stream_get_first_dts(stream->av_stream()) == kInvalidPTSMarker)
+    if (stream->first_dts() == AV_NOPTS_VALUE)
       continue;

     if (!stream->IsEnabled())
diff --git a/src/3rdparty/chromium/media/filters/ffmpeg_demuxer.h b/src/3rdparty/chromium/media/filters/ffmpeg_demuxer.h
index 086a795..ba9c665 100644
--- a/src/3rdparty/chromium/media/filters/ffmpeg_demuxer.h
+++ b/src/3rdparty/chromium/media/filters/ffmpeg_demuxer.h
@@ -145,6 +145,8 @@ class MEDIA_EXPORT FFmpegDemuxerStream : public DemuxerStream {
   base::TimeDelta start_time() const { return start_time_; }
   void set_start_time(base::TimeDelta time) { start_time_ = time; }

+  int64_t first_dts() const { return first_dts_; }
+
  private:
   friend class FFmpegDemuxerTest;

@@ -202,6 +204,7 @@ class MEDIA_EXPORT FFmpegDemuxerStream : public DemuxerStream {
   bool fixup_chained_ogg_;

   int num_discarded_packet_warnings_;
+  int64_t first_dts_;
   int64_t last_packet_pos_;
   int64_t last_packet_dts_;
   // Requested buffer count. The actual returned buffer count could be less
