diff --git a/src/app.cpp b/src/app.cpp
index 2657b27..534cce4 100644
--- a/src/app.cpp
+++ b/src/app.cpp
@@ -471,6 +471,8 @@ void App::init()
 
     uirtt.create(width, height, -1, GL_RGBA8, true);
 
+    rec_start();
+
     if (!check_license())
     {
         message_box("License", "Could not validate this license, running in demo mode.");
@@ -695,10 +697,10 @@ void App::update_rec_frames()
 {
     if (auto txt = layout[main_id]->find<NodeText>("txt-rec"))
     {
-        if (rec_running)
+        if (rec_running && Canvas::I->m_encoder)
         {
             static char buffer[128];
-            sprintf(buffer, "Recorded %d frames", rec_count);
+            sprintf(buffer, "Recorded %d frames", Canvas::I->m_encoder->frames_count());
             txt->set_text(buffer);
         }
         else
@@ -779,7 +781,7 @@ void App::rec_export(std::string path)
     });
 #endif
 */
-    m_encoder->write_mp4(data_path + "/export.mp4");
+    Canvas::I->m_encoder->write_mp4(data_path + "/export.mp4");
     
     pb->destroy();
 }
@@ -788,11 +790,6 @@ void App::rec_loop()
 {
     BT_SetTerminate();
     rec_running = true;
-    if (!m_encoder)
-    {
-        m_encoder = std::make_unique<MP4Encoder>();
-        m_encoder->init(1024, 512, 30, 500 << 10);
-    }
     while(rec_running)
     {
         std::unique_ptr<Image> frame;
@@ -810,8 +807,8 @@ void App::rec_loop()
             rec_frames.pop_front();
         }
         lock.unlock();
-        if (frame)
-            m_encoder->encode(*frame);
+        if (frame && Canvas::I->m_encoder)
+            Canvas::I->m_encoder->encode(*frame);
         update_rec_frames();
     }
 }
diff --git a/src/app.h b/src/app.h
index 1186e74..c0c8d29 100644
--- a/src/app.h
+++ b/src/app.h
@@ -96,7 +96,6 @@ public:
     std::mutex rec_mutex;
     std::condition_variable rec_cv;
     std::deque<std::unique_ptr<Image>> rec_frames;
-    std::unique_ptr<MP4Encoder> m_encoder;
 
     RTT uirtt;
     Sampler sampler;
diff --git a/src/app_events.cpp b/src/app_events.cpp
index 685d126..7a1390c 100644
--- a/src/app_events.cpp
+++ b/src/app_events.cpp
@@ -89,8 +89,11 @@ void App::tick(float dt)
             canvas->m_canvas->m_dirty_stroke = false;
             LOG("rec tick");
 
-            Canvas::I->draw_merge(true);
-            Texture2D equirect = Canvas::I->m_layers_merge.gen_equirect({ 1024, 512 });
+            Texture2D equirect;
+            App::I->render_task([&] {
+                Canvas::I->draw_merge(true);
+                equirect = Canvas::I->m_layers_merge.gen_equirect({ 1024, 512 });
+            });
             auto img = std::make_unique<Image>(equirect.get_image());
             {
                 std::lock_guard<std::mutex> lock(rec_mutex);
diff --git a/src/canvas.cpp b/src/canvas.cpp
index da3b595..a5b7abb 100644
--- a/src/canvas.cpp
+++ b/src/canvas.cpp
@@ -1644,6 +1644,9 @@ bool Canvas::create(int width, int height)
     m_merge_rtt.create(width, height);
     m_merge_tex.create(width, height);
     m_unsaved = true;
+
+    timelapse_reset_encoder();
+
     return true;
 }
 
@@ -2213,7 +2216,27 @@ bool Canvas::project_save_thread(std::string file_path, bool show_progress)
             }
         }
     }
+
+    if (ppi_header.doc_version.minor >= 4)
+    {
+        BinaryStreamWriter sw;
+        sw.init(BinaryStream::ByteOrder::LittleEndian);
+
+        Serializer::Descriptor info;
+        info.class_id = "ppi_info";
+        info.name = L"info header";
+        info.props["has_encoder"] = std::make_shared<Serializer::Boolean>(m_encoder != nullptr);
+        sw << info;
+        if (m_encoder != nullptr)
+            sw << *m_encoder;
+
+        int bytes = sw.m_data.size();
+        fwrite(&bytes, sizeof(int), 1, fp);
+        fwrite((char*)sw.m_data.data(), sw.m_data.size(), 1, fp);
+    }
+
     fclose(fp);
+
     bool success = false;
     if (use_tmp)
     {
@@ -2415,6 +2438,33 @@ bool Canvas::project_open_thread(std::string file_path)
 
     std::swap(tmp_layers, m_layers);
 
+    if (ppi_header.doc_version.minor >= 4)
+    {
+        int bytes = 0;
+        fread(&bytes, sizeof(int), 1, fp);
+        std::vector<uint8_t> data(bytes);
+        fread(data.data(), bytes, 1, fp);
+        BinaryStreamReader sr;
+        sr.init(data.data(), data.size(), BinaryStream::ByteOrder::LittleEndian);
+        Serializer::Descriptor info;
+        sr >> info;
+
+        if (info.value<Serializer::Boolean>("has_encoder"))
+        {
+            m_encoder = std::make_unique<MP4Encoder>();
+            sr >> *m_encoder;
+            m_encoder->init();
+        }
+        else
+        {
+            timelapse_reset_encoder();
+        }
+    }
+    else
+    {
+        timelapse_reset_encoder();
+    }
+
     fclose(fp);
     LOG("project restore from %s", file_path.c_str());
     
@@ -2829,3 +2879,10 @@ void Canvas::set_camera(const CameraData& c)
     m_proj = c.m_proj;
     m_vp = c.m_vp;
 }
+
+void Canvas::timelapse_reset_encoder() noexcept
+{
+    m_encoder = std::make_unique<MP4Encoder>();
+    int res = glm::min<int>(m_width / 2, 1024);
+    m_encoder->init(res * 4, res * 2, 30, 2000 << 10);
+}
diff --git a/src/canvas.h b/src/canvas.h
index 110ff32..0fc2887 100644
--- a/src/canvas.h
+++ b/src/canvas.h
@@ -8,6 +8,7 @@
 #include "canvas_actions.h"
 #include "canvas_modes.h"
 #include <stack>
+#include "mp4enc.h"
 
 #if __WEB__
 #define CANVAS_RES 512
@@ -33,7 +34,8 @@ struct PPIDocVersion
     // version 1: initial
     // version 2: added blend mode, alpha and visibility
     // version 3: added animation frames
-    int minor = 3;
+    // version 4: (released in 0.2.3) add info struct
+    int minor = 4;
 };
 
 struct PPISoftVersion
@@ -92,6 +94,7 @@ public:
     bool m_dirty = false;
     bool m_commit_delayed = false;
     bool m_dirty_stroke = false;
+    std::unique_ptr<MP4Encoder> m_encoder;
     std::chrono::time_point<std::chrono::steady_clock> m_disrty_stroke_time;
     std::stack<CameraData> m_camera_stack;
 
@@ -251,4 +254,5 @@ public:
     void pop_camera();
     CameraData get_camera();
     void set_camera(const CameraData& c);
+    void timelapse_reset_encoder() noexcept;
 };
diff --git a/src/image.cpp b/src/image.cpp
index c8f9092..1a78f4f 100644
--- a/src/image.cpp
+++ b/src/image.cpp
@@ -209,7 +209,7 @@ bool Image::read(BinaryStreamReader& r)
     auto img_raw = d.get<Serializer::RawData>("data");
     int png_width, png_height, png_comp;
     m_data = std::unique_ptr<uint8_t[]>(stbi_load_from_memory(
-        img_raw->data.data(), img_raw->data.size(), &png_width, &png_height, &png_comp, 4));
+        img_raw->value.data(), img_raw->value.size(), &png_width, &png_height, &png_comp, 4));
     return true;
 }
 
diff --git a/src/mp4enc.cpp b/src/mp4enc.cpp
index 9078822..7a47fdd 100644
--- a/src/mp4enc.cpp
+++ b/src/mp4enc.cpp
@@ -12,6 +12,11 @@ static void encoder_trace_callback(void* context, int level, const char* message
     LOG("ENCODER: %s", message);
 }
 
+MP4Encoder::~MP4Encoder()
+{
+    destroy();
+}
+
 bool MP4Encoder::init(int width, int height, int fps, int bitrate) noexcept
 {
     if (WelsCreateSVCEncoder(&m_encoder) != 0)
@@ -75,6 +80,11 @@ bool MP4Encoder::init(int width, int height, int fps, int bitrate) noexcept
     return true;
 }
 
+bool MP4Encoder::init() noexcept
+{
+    return init(m_width, m_height, m_framerate, m_bitrate);
+}
+
 bool MP4Encoder::encode(const Image& rgba) noexcept
 {
     // lazy allocation of YUV buffer
@@ -167,7 +177,7 @@ bool MP4Encoder::write_mp4(const std::string& filename) const noexcept
     MP4SetTimeScale(mp4, 90000);
     MP4SetVideoProfileLevel(mp4, 1);
     MP4TrackId mp4_track = MP4AddH264VideoTrack(mp4, 90000, 90000 / m_framerate, m_width, m_height, 
-        m_header.avc_profile, m_header.avc_profile_compat, m_header.avc_level, 3);
+        m_header.avc_profile, m_header.avc_compat, m_header.avc_level, 3);
     MP4AddH264SequenceParameterSet(mp4, mp4_track, m_header.SPS_data.data(), m_header.SPS_data.size());
     MP4AddH264PictureParameterSet(mp4, mp4_track, m_header.PPS_data.data(), m_header.PPS_data.size());
     for (const auto& f : m_frames)
@@ -196,3 +206,54 @@ void MP4Encoder::destroy() noexcept
     m_header.PPS_data.clear();
     m_header.SPS_data.clear();
 }
+
+bool MP4Encoder::read(BinaryStreamReader& r)
+{
+    Serializer::Descriptor d;
+    r >> d;
+    d.value<Serializer::Integer>("width", m_width);
+    d.value<Serializer::Integer>("height", m_height);
+    d.value<Serializer::Integer>("bitrate", m_bitrate);
+    d.value<Serializer::Float>("framerate", m_framerate);
+    d.value<Serializer::RawData>("SPS", m_header.SPS_data);
+    d.value<Serializer::RawData>("PPS", m_header.PPS_data);
+    d.value<Serializer::Integer>("avc_profile", m_header.avc_profile);
+    d.value<Serializer::Integer>("avc_compat", m_header.avc_compat);
+    d.value<Serializer::Integer>("avc_level", m_header.avc_level);
+    auto frames = d.get<Serializer::List>("frames");
+    for (const auto& f : frames->items)
+    {
+        if (auto fd = std::dynamic_pointer_cast<Serializer::Descriptor>(f))
+        {
+            m_frames.emplace_back();
+            m_frames.back().type = (Frame::kType)fd->value<Serializer::Integer>("type");
+            m_frames.back().data = fd->value<Serializer::RawData>("data");
+        }
+    }
+    return true;
+}
+
+void MP4Encoder::write(BinaryStreamWriter& w) const
+{
+    Serializer::Descriptor d;
+    d.class_id = "mp4enc";
+    d.name = L"MP4 Encoder class";
+    d.props["width"] = std::make_shared<Serializer::Integer>(m_width);
+    d.props["height"] = std::make_shared<Serializer::Integer>(m_height);
+    d.props["bitrate"] = std::make_shared<Serializer::Integer>(m_bitrate);
+    d.props["framerate"] = std::make_shared<Serializer::Float>(m_framerate);
+    d.props["SPS"] = std::make_shared<Serializer::RawData>(m_header.SPS_data);
+    d.props["PPS"] = std::make_shared<Serializer::RawData>(m_header.PPS_data);
+    d.props["avc_profile"] = std::make_shared<Serializer::Integer>(m_header.avc_profile);
+    d.props["avc_compat"] = std::make_shared<Serializer::Integer>(m_header.avc_compat);
+    d.props["avc_level"] = std::make_shared<Serializer::Integer>(m_header.avc_level);
+    auto frames = std::make_shared<Serializer::List>();
+    for (const auto& f : m_frames)
+    {
+        auto fd = frames->add<Serializer::Descriptor>();
+        fd->props["type"] = std::make_shared<Serializer::Integer>((int)f.type);
+        fd->props["data"] = std::make_shared<Serializer::RawData>(f.data);
+    }
+    d.props["frames"] = frames;
+    w << d;
+}
diff --git a/src/mp4enc.h b/src/mp4enc.h
index 62f6f05..063aecc 100644
--- a/src/mp4enc.h
+++ b/src/mp4enc.h
@@ -1,7 +1,8 @@
 #pragma once
 #include "image.h"
+#include "serializer.h"
 
-class MP4Encoder
+class MP4Encoder : public Serializer::Type
 {
     struct Frame
     {
@@ -14,7 +15,7 @@ class MP4Encoder
         std::vector<uint8_t> SPS_data;
         std::vector<uint8_t> PPS_data;
         uint8_t avc_profile;
-        uint8_t avc_profile_compat;
+        uint8_t avc_compat;
         uint8_t avc_level;
     };
     class ISVCEncoder* m_encoder = nullptr;
@@ -26,8 +27,13 @@ class MP4Encoder
     std::vector<Frame> m_frames;
     std::vector<uint8_t> m_yuv_buffer;
 public:
+    ~MP4Encoder();
+    bool init() noexcept;
     bool init(int width, int height, int fps, int bitrate) noexcept;
     bool encode(const Image& rgba) noexcept;
     bool write_mp4(const std::string& filename) const noexcept;
     void destroy() noexcept;
+    int frames_count() const noexcept { return m_frames.size(); }
+    virtual bool read(BinaryStreamReader& r) override;
+    virtual void write(BinaryStreamWriter& w) const override;
 };
diff --git a/src/serializer.h b/src/serializer.h
index 0f386e7..dd9336e 100644
--- a/src/serializer.h
+++ b/src/serializer.h
@@ -414,23 +414,23 @@ public:
     };
     struct RawData : public Type
     {
-        std::vector<uint8_t> data;
+        std::vector<uint8_t> value;
         RawData() = default;
         //RawData(const RawData&) = delete;
-        RawData(std::vector<uint8_t> data) : data(data) { }
+        RawData(std::vector<uint8_t> data) : value(data) { }
         virtual std::string type_key() const override { return "tdta"; }
         virtual std::string str(int indent, const std::string& prefix) const override
         {
-            return std::string(indent, '-') + prefix + fmt::format("raw: {} bytes", data.size());
+            return std::string(indent, '-') + prefix + fmt::format("raw: {} bytes", value.size());
         }
         virtual bool read(BinaryStreamReader& r) override
         {
-            data = r.rraw();
+            value = r.rraw();
             return true;
         }
         virtual void write(BinaryStreamWriter& w) const override
         {
-            w.wraw(data);
+            w.wraw(value);
         }
     };
     struct Descriptor : public Type