diff --git a/.github/ci/Dockerfile b/.github/ci/Dockerfile
index bd9ccfc2..be2a56f2 100644
--- a/.github/ci/Dockerfile
+++ b/.github/ci/Dockerfile
@@ -1,7 +1,7 @@
 ARG DOCKER_ARCH
 ARG DEBIAN_VERSION
 ARG DOCKER_REPO
-FROM --platform=linux/${DOCKER_ARCH} ${DOCKER_REPO}debian:${DEBIAN_VERSION} as build_env
+FROM --platform=linux/${DOCKER_ARCH} ${DOCKER_REPO}debian:${DEBIAN_VERSION} AS build_env
 
 RUN apt-get -y update && apt-get -y install gnupg2
 
@@ -11,8 +11,9 @@ ARG BUILD_TYPE="generic"
 RUN [ "$BUILD_TYPE" != "raspi" ] || \
   ( \
     ( [ "$(dpkg --print-architecture)" != "armhf" ] || echo "deb http://raspbian.raspberrypi.org/raspbian/ $DEBIAN_VERSION main contrib non-free rpi" > /etc/apt/sources.list ) && \
+    gpg --keyserver keyserver.ubuntu.com --recv-keys 9165938D90FDDD2E 82B129927FA3303E && \
+    gpg --export 9165938D90FDDD2E 82B129927FA3303E > /etc/apt/trusted.gpg.d/raspi.gpg && \
     echo "deb http://archive.raspberrypi.org/debian/ $DEBIAN_VERSION main" > /etc/apt/sources.list.d/raspi.list && \
-    apt-key adv --keyserver keyserver.ubuntu.com --recv-keys 9165938D90FDDD2E 82B129927FA3303E && \
     apt-get -y update && \
     apt-get -y install libcamera-dev liblivemedia-dev \
   )
@@ -21,14 +22,14 @@ RUN [ "$BUILD_TYPE" != "raspi" ] || \
 RUN apt-get -y install build-essential xxd cmake ccache git-core pkg-config \
   libavformat-dev libavutil-dev libavcodec-dev libssl-dev v4l-utils debhelper
 
-FROM build_env as build
+FROM build_env AS build
 ADD / /src
 WORKDIR /src
 RUN git clean -ffdx
 RUN git submodule update --init --recursive --recommend-shallow
 RUN git submodule foreach --recursive git clean -ffdx
 
-FROM build as deb_make
+FROM build AS deb_make
 ARG GIT_VERSION
 ARG BUILD_TYPE="generic"
 ENV DEB_BUILD_PROFILES="$BUILD_TYPE"
diff --git a/.github/ci/arm32-cross b/.github/ci/arm32-cross
new file mode 100755
index 00000000..8d5dc52f
--- /dev/null
+++ b/.github/ci/arm32-cross
@@ -0,0 +1,6 @@
+#!/bin/bash
+
+apt install -y g{cc,++}-arm-linux-gnueabihf
+export CC=arm-linux-gnueabihf-gcc
+export CXX=arm-linux-gnueabihf-g++
+exec "$@"
diff --git a/.github/ci/build-env b/.github/ci/build-env
index 0163ad6b..44ff2be3 100755
--- a/.github/ci/build-env
+++ b/.github/ci/build-env
@@ -1,7 +1,7 @@
 #!/bin/bash
 
-if [[ $# -lt 3 ]]; then
-  echo "usage: $0 <generic|raspi> <bullseye|bookworm> <amd64|arm32v7|arm64v8>"
+if [[ $# -lt 2 ]]; then
+  echo "usage: $0 <generic|raspi> <bookworm|trixie> [amd64|arm32v7|arm64v8] [cmdline args]"
   exit 1
 fi
 
@@ -9,12 +9,36 @@ docker_image="camera_streamer_build_env"
 
 build_type="raspi"
 [[ -n "$1" ]] && build_type="$1"
+shift
 
 debian_version="bookworm"
-[[ -n "$2" ]] && debian_version="$2" && docker_image="${docker_image}_${2}"
-
-docker_arch=""
-[[ -n "$3" ]] && docker_arch="$3" && docker_image="${docker_image}_${3}"
+[[ -n "$1" ]] && debian_version="$1" && docker_image="${docker_image}_${1}"
+shift
+
+arch=${1:-$(dpkg --print-architecture)}
+shift
+
+case "$arch" in
+  amd64)
+    docker_arch="amd64"
+    docker_repo="amd64/"
+    ;;
+
+  armhf|arm32v7)
+    docker_arch="arm/v7"
+    docker_repo="arm32v7/"
+    ;;
+
+  arm64|arm64v8)
+    docker_arch="arm64/v8"
+    docker_repo="arm64v8/"
+    ;;
+
+  *)
+    echo "Unsupported architecture: $arch"
+    exit 1
+    ;;
+esac
 
 PWD=$(pwd)
 ROOT=$(cd -- "$( dirname -- "${BASH_SOURCE[0]}" )/../.." &> /dev/null && pwd)
@@ -23,8 +47,9 @@ set -xeo pipefail
 
 DOCKER_BUILDKIT=1 docker build -t "$docker_image" \
   --build-arg "DOCKER_ARCH=$docker_arch" \
+  --build-arg "DOCKER_REPO=$docker_repo" \
   --build-arg "DEBIAN_VERSION=$debian_version" \
   --build-arg "BUILD_TYPE=$build_type" \
   --target build_env - < .github/ci/Dockerfile
 
-exec docker run --rm -it -u "$UID" -e "CCACHE_DIR=$ROOT/tmp/ccache" -v "$ROOT:$ROOT" -w "$ROOT" "$docker_image"
+exec docker run --rm -it -u "$UID" -e "CCACHE_DIR=$ROOT/tmp/ccache" -v "$ROOT:$ROOT" -w "$ROOT" "$docker_image" "$@"
diff --git a/.github/workflows/build_release.yaml b/.github/workflows/build_release.yaml
index 93556144..b2242b5c 100644
--- a/.github/workflows/build_release.yaml
+++ b/.github/workflows/build_release.yaml
@@ -8,7 +8,7 @@ jobs:
       contents: write
     strategy:
       matrix:
-        debian_version: [bullseye, bookworm]
+        debian_version: [bookworm, trixie]
         arch:
           - docker: amd64
             runner: ubuntu-24.04
diff --git a/.github/workflows/build_test.yaml b/.github/workflows/build_test.yaml
index 00f4482c..729c9d2d 100644
--- a/.github/workflows/build_test.yaml
+++ b/.github/workflows/build_test.yaml
@@ -18,7 +18,7 @@ jobs:
     strategy:
       fail-fast: false
       matrix:
-        debian_version: [bullseye, bookworm]
+        debian_version: [bookworm, trixie]
         arch:
           - docker: amd64
             variant: amd64
diff --git a/Makefile b/Makefile
index 7c5290dd..0e9c5657 100644
--- a/Makefile
+++ b/Makefile
@@ -14,6 +14,7 @@ CFLAGS += -Wno-error=cpp
 
 # LOG_*(this, ...)
 CFLAGS += -Wno-error=nonnull-compare
+CFLAGS += -Wno-nonnull-compare
 
 # libdatachannel deprecations on bookworm
 # error: 'HMAC_Init_ex' is deprecated: Since OpenSSL 3.0
@@ -24,6 +25,7 @@ CCACHE ?= ccache
 endif
 
 LIBDATACHANNEL_PATH ?= third_party/libdatachannel
+LIBDATACHANNEL_VERSION ?= $(LIBDATACHANNEL_PATH)/v0.23.222529eb2c8ae44
 
 USE_HW_H264 ?= 1
 USE_FFMPEG ?= $(shell pkg-config libavutil libavformat libavcodec && echo 1)
@@ -116,6 +118,10 @@ html/%.c: html/%
 	xxd -i $< > $@.tmp
 	mv $@.tmp $@
 
-$(LIBDATACHANNEL_PATH)/build/libdatachannel-static.a: $(LIBDATACHANNEL_PATH)
+$(LIBDATACHANNEL_VERSION):
+
+$(LIBDATACHANNEL_PATH)/build/libdatachannel-static.a: $(LIBDATACHANNEL_PATH) $(LIBDATACHANNEL_VERSION)
+	git submodule update --init --recursive $(LIBDATACHANNEL_PATH)
 	[ -e $</build/Makefile ] || cmake -S $< -B $</build
 	$(MAKE) -C $</build datachannel-static
+	touch $(LIBDATACHANNEL_VERSION) $@
diff --git a/README.md b/README.md
index c1e658c9..7d2761f1 100644
--- a/README.md
+++ b/README.md
@@ -22,9 +22,13 @@ To clone this repository be sure to use the following command:
 
 ## Requirements
 
-1. Debian Bullseye, with at least 5.15 kernel
+1. Debian Bookworm, with at least 6.1 kernel
 1. Best: Raspberry PI for hardware acceleration
 
+Older systems:
+
+1. Debian Bullseye. Use version `v0.3.x` from [stable-0.3](https://github.com/ayufan/camera-streamer/tree/stable-0.3).
+
 ## Install
 
 1. [Use precompiled debian package](https://github.com/ayufan/camera-streamer/releases/latest) (recommended)
diff --git a/RELEASE.md b/RELEASE.md
index 002f992f..269a482d 100644
--- a/RELEASE.md
+++ b/RELEASE.md
@@ -4,8 +4,8 @@ Download correct version for your platform:
 
 - Variant: **raspi**: Raspberry PI compatible build with USB, CSI, WebRTC, RTSP support
 - Variant: **generic**: All other platforms with USB and MJPEG support only for time being
-- System: **bullseye**: Debian Bullseye (11) compatible build
 - System: **bookworm**: Debian Bookworm (12) compatible build
+- System: **trixie**: Debian Trixie (13) compatible build
 - Platform: **amd64**: x86/64 compatible build
 - Platform: **arm32**: ARM 32-bit kernel: PIs 0.2W, 2B, and higher, Orange PIs, Rock64, etc. No support for RPI0.
 - Platform: **arm64**: ARM 64-bit kernel: PIs 0.2W, 3B, and higher, Orange PIs, Rock64, etc. No support for RPI0 and RPI2B.
diff --git a/VERSION b/VERSION
index be586341..bd73f470 100644
--- a/VERSION
+++ b/VERSION
@@ -1 +1 @@
-0.3
+0.4
diff --git a/device/dummy/buffer_list.c b/device/dummy/buffer_list.c
index 0f45e2d2..855fa515 100644
--- a/device/dummy/buffer_list.c
+++ b/device/dummy/buffer_list.c
@@ -4,6 +4,7 @@
 #include "util/opts/log.h"
 
 #include <stdlib.h>
+#include <inttypes.h>
 #include <sys/types.h>
 #include <sys/stat.h>
 
@@ -36,12 +37,12 @@ int dummy_buffer_list_open(buffer_list_t *buf_list)
 
   buf_list->dummy->data = malloc(st.st_size);
   if (!buf_list->dummy->data) {
-		LOG_ERROR(buf_list, "Can't allocate %ld bytes for %s", st.st_size, buf_list->dev->path);
+		LOG_ERROR(buf_list, "Can't allocate %" PRId64 " bytes for %s", (off64_t)st.st_size, buf_list->dev->path);
   }
 
   buf_list->dummy->length = read(fd, buf_list->dummy->data, st.st_size);
   if (!buf_list->dummy->data) {
-		LOG_ERROR(buf_list, "Can't read %ld bytes for %s. Only read %zu.", st.st_size, buf_list->dev->path, buf_list->dummy->length);
+		LOG_ERROR(buf_list, "Can't read %" PRId64 " bytes for %s. Only read %zu.", (off64_t)st.st_size, buf_list->dev->path, buf_list->dummy->length);
   }
 
   close(fd);
diff --git a/output/http_ffmpeg.c b/output/http_ffmpeg.c
index bf5a7643..ac924ab4 100644
--- a/output/http_ffmpeg.c
+++ b/output/http_ffmpeg.c
@@ -49,7 +49,7 @@ static int http_ffmpeg_read_from_buf(void *opaque, uint8_t *buf, int buf_size)
   return buf_size;
 }
 
-static int http_ffmpeg_write_to_stream(void *opaque, uint8_t *buf, int buf_size)
+static int http_ffmpeg_write_to_stream(void *opaque, const uint8_t *buf, int buf_size)
 {
   http_ffmpeg_status_t *status = opaque;
   if (!status->stream)
diff --git a/output/webrtc/webrtc.cc b/output/webrtc/webrtc.cc
index 211c8332..05aff9ae 100644
--- a/output/webrtc/webrtc.cc
+++ b/output/webrtc/webrtc.cc
@@ -32,7 +32,6 @@ extern "C" {
 #include <rtc/peerconnection.hpp>
 #include <rtc/rtcpsrreporter.hpp>
 #include <rtc/h264rtppacketizer.hpp>
-#include <rtc/h264packetizationhandler.hpp>
 #include <rtc/rtcpnackresponder.hpp>
 
 #include "third_party/magic_enum/include/magic_enum.hpp"
@@ -62,9 +61,6 @@ struct ClientTrackData
 
   void startStreaming()
   {
-    double currentTime_s = get_monotonic_time_us(NULL, NULL)/(1000.0*1000.0);
-    sender->rtpConfig->setStartTime(currentTime_s, rtc::RtpPacketizationConfig::EpochStart::T1970);
-    sender->startRecording();
   }
 
   void sendTime()
@@ -75,7 +71,7 @@ struct ClientTrackData
     uint32_t elapsedTimestamp = rtpConfig->secondsToTimestamp(currentTime_s);
 
     sender->rtpConfig->timestamp = sender->rtpConfig->startTimestamp + elapsedTimestamp;
-    auto reportElapsedTimestamp = sender->rtpConfig->timestamp - sender->previousReportedTimestamp;
+    auto reportElapsedTimestamp = sender->rtpConfig->timestamp - sender->lastReportedTimestamp();
     if (sender->rtpConfig->timestampToSeconds(reportElapsedTimestamp) > 1) {
       sender->setNeedsToReport();
     }
@@ -248,14 +244,13 @@ static std::shared_ptr<ClientTrackData> webrtc_add_video(const std::shared_ptr<r
   video.setBitrate(1000);
   video.addSSRC(ssrc, cname, msid, cname);
   auto track = pc->addTrack(video);
-  auto rtpConfig = std::make_shared<rtc::RtpPacketizationConfig>(ssrc, cname, payloadType, rtc::H264RtpPacketizer::defaultClockRate);
+  auto rtpConfig = std::make_shared<rtc::RtpPacketizationConfig>(ssrc, cname, payloadType, rtc::H264RtpPacketizer::ClockRate);
   auto packetizer = std::make_shared<rtc::H264RtpPacketizer>(rtc::H264RtpPacketizer::Separator::LongStartSequence, rtpConfig);
-  auto h264Handler = std::make_shared<rtc::H264PacketizationHandler>(packetizer);
   auto srReporter = std::make_shared<rtc::RtcpSrReporter>(rtpConfig);
-  h264Handler->addToChain(srReporter);
+  packetizer->addToChain(srReporter);
   auto nackResponder = std::make_shared<rtc::RtcpNackResponder>();
-  h264Handler->addToChain(nackResponder);
-  track->setMediaHandler(h264Handler);
+  packetizer->addToChain(nackResponder);
+  track->setMediaHandler(packetizer);
   return std::shared_ptr<ClientTrackData>(new ClientTrackData{track, srReporter});
 }
 
diff --git a/third_party/libdatachannel b/third_party/libdatachannel
index 04cf4738..222529eb 160000
--- a/third_party/libdatachannel
+++ b/third_party/libdatachannel
@@ -1 +1 @@
-Subproject commit 04cf4738961f55ba3f0aa39b4a61342f66bb3781
+Subproject commit 222529eb2c8ae44f96462504ae38023f62809cec
diff --git a/util/ffmpeg/remuxer.c b/util/ffmpeg/remuxer.c
index 76b8c568..ca07544d 100644
--- a/util/ffmpeg/remuxer.c
+++ b/util/ffmpeg/remuxer.c
@@ -7,7 +7,13 @@
 static AVRational time_base = {1, 1000LL * 1000LL};
 static unsigned avio_ctx_buffer_size = 4096;
 
-static int ffmpeg_remuxer_init_avcontext(AVFormatContext **context, ffmpeg_remuxer_t *remuxer, int output, int (*packet)(void *opaque, uint8_t *buf, int buf_size))
+#if LIBAVFORMAT_VERSION_MAJOR < 61
+typedef int (*ffmpeg_write_nonconst_packet)(void *opaque, uint8_t *buf, int buf_size);
+#else // LIBAVFORMAT_VERSION_MAJOR < 61
+#define ffmpeg_write_nonconst_packet ffmpeg_write_packet
+#endif // LIBAVFORMAT_VERSION_MAJOR < 61
+
+static int ffmpeg_remuxer_init_avcontext(AVFormatContext **context, ffmpeg_remuxer_t *remuxer, int output, ffmpeg_write_packet packet_out, ffmpeg_read_packet packet_in)
 {
   uint8_t *buffer = NULL;
   AVIOContext *avio = NULL;
@@ -20,7 +26,7 @@ static int ffmpeg_remuxer_init_avcontext(AVFormatContext **context, ffmpeg_remux
   buffer = av_malloc(buffer_size);
   if (!buffer)
     return AVERROR(ENOMEM);
-  avio = avio_alloc_context(buffer, buffer_size, output, remuxer->opaque, output ? NULL : packet, output ? packet : NULL, NULL);
+  avio = avio_alloc_context(buffer, buffer_size, output, remuxer->opaque, packet_in, (ffmpeg_write_nonconst_packet)packet_out, NULL);
   if (!avio)
     goto error;
   if (output && (ret = avformat_alloc_output_context2(context, NULL, remuxer->video_format, NULL)) < 0)
@@ -106,9 +112,9 @@ int ffmpeg_remuxer_open(ffmpeg_remuxer_t *remuxer)
   remuxer->packet = av_packet_alloc();
   if (!remuxer->packet)
     return AVERROR(ENOMEM);
-  if ((ret = ffmpeg_remuxer_init_avcontext(&remuxer->input_context, remuxer, 0, remuxer->read_packet)) < 0)
+  if ((ret = ffmpeg_remuxer_init_avcontext(&remuxer->input_context, remuxer, 0, NULL, remuxer->read_packet)) < 0)
     return ret;
-  if ((ret = ffmpeg_remuxer_init_avcontext(&remuxer->output_context, remuxer, 1, remuxer->write_packet)) < 0)
+  if ((ret = ffmpeg_remuxer_init_avcontext(&remuxer->output_context, remuxer, 1, remuxer->write_packet, NULL)) < 0)
     return ret;
   if ((ret = avformat_open_input(&remuxer->input_context, NULL, input_format, &remuxer->input_opts)) < 0)
     return ret;
diff --git a/util/ffmpeg/remuxer.h b/util/ffmpeg/remuxer.h
index 4a5c5a9e..872d2bb7 100644
--- a/util/ffmpeg/remuxer.h
+++ b/util/ffmpeg/remuxer.h
@@ -10,15 +10,16 @@
 #define FFMPEG_DATA_PACKET_EOF -1
 #endif
 
-typedef int (*ffmpeg_data_packet)(void *opaque, uint8_t *buf, int buf_size);
+typedef int (*ffmpeg_read_packet)(void *opaque, uint8_t *buf, int buf_size);
+typedef int (*ffmpeg_write_packet)(void *opaque, const uint8_t *buf, int buf_size);
 
 typedef struct ffmpeg_remuxer_s {
   const char *name;
   const char *input_format;
   const char *video_format;
   void *opaque;
-  ffmpeg_data_packet read_packet;
-  ffmpeg_data_packet write_packet;
+  ffmpeg_read_packet read_packet;
+  ffmpeg_write_packet write_packet;
   unsigned read_buffer_size;
   unsigned write_buffer_size;