diff --git a/src/common/id_info.cpp b/src/common/id_info.cpp
new file mode 100644
index 000000000..ee0b95512
--- /dev/null
+++ b/src/common/id_info.cpp
@@ -0,0 +1,37 @@
+/*
+   mkvmerge -- utility for splicing together matroska files
+   from component media subtypes
+
+   Distributed under the GPL v2
+   see the file COPYING for details
+   or visit https://www.gnu.org/licenses/old-licenses/gpl-2.0.html
+
+   Written by Moritz Bunkus <moritz@bunkus.org>.
+*/
+
+#include "common/common_pch.h"
+
+#include "common/id_info.h"
+#include "common/strings/formatting.h"
+
+namespace mtx::id {
+
+info_c &
+info_c::add(std::string const &key,
+            memory_cptr const &value) {
+  if (value && value->get_size())
+    set(key, mtx::string::to_hex(value->get_buffer(), value->get_size(), true));
+
+  return *this;
+}
+
+info_c &
+info_c::add(std::string const &key,
+            memory_c const *value) {
+  if (value && value->get_size())
+    set(key, mtx::string::to_hex(value->get_buffer(), value->get_size(), true));
+
+  return *this;
+}
+
+} // namespace mtx::id
diff --git a/src/common/id_info.h b/src/common/id_info.h
index c7b35ec58..18c58210c 100644
--- a/src/common/id_info.h
+++ b/src/common/id_info.h
@@ -86,6 +86,29 @@ class info_c {
 protected:
   verbose_info_t m_info;
 
+private:
+  template<typename... Args>
+  bool
+  all(Args... args) {
+    return (... && args);
+  }
+
+  template<typename T>
+  std::string
+  join([[maybe_unused]] std::string const &separator,
+       T const &value) {
+    return fmt::to_string(value);
+  }
+
+  template<typename Tfirst,
+           typename... Trest>
+  std::string
+  join(std::string const &separator,
+       Tfirst const &first,
+       Trest... rest) {
+    return fmt::to_string(first) + separator + join(separator, rest...);
+  }
+
 public:
   template<typename T> info_c &
   set(std::string const &key,
@@ -103,6 +126,9 @@ public:
     return *this;
   }
 
+  info_c &add(std::string const &key, memory_c const *value);
+  info_c &add(std::string const &key, memory_cptr const &value);
+
   info_c &
   add(std::string const &key,
       char const *value,
@@ -112,14 +138,26 @@ public:
     return *this;
   }
 
+  template<typename T>
   info_c &
   add(std::string const &key,
-      std::optional<bool> const &value) {
+      std::optional<T> const &value) {
     if (value.has_value())
       set(key, *value);
     return *this;
   }
 
+  template<typename... Tvalues>
+  info_c &
+  add_joined(std::string const &key,
+             std::string const &separator,
+             Tvalues... values) {
+    if (!all(values...))
+      return *this;
+
+    return add(key, join(separator, values...));
+  }
+
   verbose_info_t const &get() const {
     return m_info;
   }
diff --git a/src/input/r_avc.cpp b/src/input/r_avc.cpp
index 88d5ee528..57b628de4 100644
--- a/src/input/r_avc.cpp
+++ b/src/input/r_avc.cpp
@@ -102,8 +102,8 @@ void
 avc_es_reader_c::identify() {
   auto info = mtx::id::info_c{};
   info.add(mtx::id::packetizer,       mtx::id::mpeg4_p10_es_video);
-  info.add(mtx::id::pixel_dimensions, fmt::format("{0}x{1}", m_width, m_height));
   info.add(mtx::id::default_duration, m_default_duration);
+  info.add_joined(mtx::id::pixel_dimensions, "x"s, m_width, m_height);
 
   id_result_container();
   id_result_track(0, ID_RESULT_TRACK_VIDEO, codec_c::get_name(codec_c::type_e::V_MPEG4_P10, "MPEG-4 part 10 ES"), info.get());
diff --git a/src/input/r_avi.cpp b/src/input/r_avi.cpp
index dc4c6c707..4eeb96484 100644
--- a/src/input/r_avi.cpp
+++ b/src/input/r_avi.cpp
@@ -866,7 +866,7 @@ avi_reader_c::extended_identify_mpeg4_l2(mtx::id::info_c &info) {
       disp_height = mtx::to_int_rounded(m_video_width / aspect_ratio);
     }
 
-    info.add(mtx::id::display_dimensions, fmt::format("{0}x{1}", disp_width, disp_height));
+    info.add_joined(mtx::id::display_dimensions, "x"s, disp_width, disp_height);
   }
 }
 
@@ -894,10 +894,8 @@ avi_reader_c::identify_video() {
   else if (codec.is(codec_c::type_e::V_MPEG4_P10))
     info.add(mtx::id::packetizer, mtx::id::mpeg4_p10_es_video);
 
-  info.add(mtx::id::pixel_dimensions, fmt::format("{0}x{1}", m_video_width, m_video_height));
-
-  if (m_video_display_width)
-    info.add(mtx::id::display_dimensions, fmt::format("{0}x{1}", m_video_display_width, m_video_display_height));
+  info.add_joined(mtx::id::pixel_dimensions,   "x"s, m_video_width, m_video_height);
+  info.add_joined(mtx::id::display_dimensions, "x"s, m_video_display_width, m_video_display_height);
 
   id_result_track(0, ID_RESULT_TRACK_VIDEO, codec.get_name(fourcc_str), info.get());
 }
diff --git a/src/input/r_dirac.cpp b/src/input/r_dirac.cpp
index 98f8e4c8b..074e9ea9c 100644
--- a/src/input/r_dirac.cpp
+++ b/src/input/r_dirac.cpp
@@ -96,7 +96,7 @@ dirac_es_reader_c::read(generic_packetizer_c *,
 void
 dirac_es_reader_c::identify() {
   auto info = mtx::id::info_c{};
-  info.add(mtx::id::pixel_dimensions, fmt::format("{0}x{1}", m_seqhdr.pixel_width, m_seqhdr.pixel_height));
+  info.add_joined(mtx::id::pixel_dimensions, "x"s, m_seqhdr.pixel_width, m_seqhdr.pixel_height);
 
   id_result_container();
   id_result_track(0, ID_RESULT_TRACK_VIDEO, codec_c::get_name(codec_c::type_e::V_DIRAC, "Dirac"), info.get());
diff --git a/src/input/r_flv.cpp b/src/input/r_flv.cpp
index 774569f03..048c7f456 100644
--- a/src/input/r_flv.cpp
+++ b/src/input/r_flv.cpp
@@ -308,7 +308,7 @@ flv_reader_c::identify() {
       info.add(mtx::id::packetizer, mtx::id::mpeg4_p10_video);
 
     if (track->is_video())
-      info.add(mtx::id::pixel_dimensions, fmt::format("{0}x{1}", track->m_v_width, track->m_v_height));
+      info.add_joined(mtx::id::pixel_dimensions, "x"s, track->m_v_width, track->m_v_height);
 
     else if (track->is_audio()) {
       info.add(mtx::id::audio_channels,           track->m_a_channels);
diff --git a/src/input/r_hevc.cpp b/src/input/r_hevc.cpp
index 09dd6e118..eea8b3524 100644
--- a/src/input/r_hevc.cpp
+++ b/src/input/r_hevc.cpp
@@ -123,8 +123,8 @@ void
 hevc_es_reader_c::identify() {
   auto info = mtx::id::info_c{};
   info.add(mtx::id::packetizer,       mtx::id::mpegh_p2_es_video);
-  info.add(mtx::id::pixel_dimensions, fmt::format("{0}x{1}", m_width, m_height));
   info.add(mtx::id::default_duration, m_default_duration);
+  info.add_joined(mtx::id::pixel_dimensions, "x"s, m_width, m_height);
 
   id_result_container();
   id_result_track(0, ID_RESULT_TRACK_VIDEO, codec_c::get_name(codec_c::type_e::V_MPEGH_P2, "HEVC"), info.get());
diff --git a/src/input/r_ivf.cpp b/src/input/r_ivf.cpp
index 260e4b102..fe6e46f1f 100644
--- a/src/input/r_ivf.cpp
+++ b/src/input/r_ivf.cpp
@@ -132,6 +132,6 @@ ivf_reader_c::identify() {
     return;
 
   auto info = mtx::id::info_c{};
-  info.add(mtx::id::pixel_dimensions, fmt::format("{0}x{1}", m_width, m_height));
+  info.add_joined(mtx::id::pixel_dimensions, "x"s, m_width, m_height);
   id_result_track(0, ID_RESULT_TRACK_VIDEO, m_codec.get_name(), info.get());
 }
diff --git a/src/input/r_matroska.cpp b/src/input/r_matroska.cpp
index b415358d9..a89f25680 100644
--- a/src/input/r_matroska.cpp
+++ b/src/input/r_matroska.cpp
@@ -2749,6 +2749,7 @@ kax_reader_c::identify() {
     info.add(mtx::id::uid,                    track->track_uid);
     info.add(mtx::id::codec_id,               track->codec_id);
     info.set(mtx::id::codec_private_length,   track->private_data ? track->private_data->get_size() : 0u);
+    info.add(mtx::id::codec_private_data,     track->private_data);
     info.add(mtx::id::codec_delay,            track->codec_delay.to_ns(0));
     info.add(mtx::id::codec_name,             track->codec_name);
     info.add(mtx::id::language,               track->language.get_iso639_alpha_3_code());
@@ -2764,21 +2765,11 @@ kax_reader_c::identify() {
     info.add(mtx::id::flag_text_descriptions, track->text_descriptions_flag);
     info.add(mtx::id::flag_original,          track->original_flag);
     info.add(mtx::id::flag_commentary,        track->commentary_flag);
+    info.add(mtx::id::display_unit,           track->v_dunit);
 
-    if (track->private_data && (0 != track->private_data->get_size()))
-      info.add(mtx::id::codec_private_data, mtx::string::to_hex(track->private_data->get_buffer(), track->private_data->get_size(), true));
-
-    if ((0 != track->v_width) && (0 != track->v_height))
-      info.add(mtx::id::pixel_dimensions, fmt::format("{0}x{1}", track->v_width, track->v_height));
-
-    if ((0 != track->v_dwidth) && (0 != track->v_dheight))
-      info.add(mtx::id::display_dimensions, fmt::format("{0}x{1}", track->v_dwidth, track->v_dheight));
-
-    if (track->v_dunit)
-      info.set(mtx::id::display_unit, *track->v_dunit);
-
-    if ((0 != track->v_pcleft) || (0 != track->v_pctop) || (0 != track->v_pcright) || (0 != track->v_pcbottom))
-      info.add(mtx::id::cropping, fmt::format("{0},{1},{2},{3}", track->v_pcleft, track->v_pctop, track->v_pcright, track->v_pcbottom));
+    info.add_joined(mtx::id::pixel_dimensions,   "x"s, track->v_width, track->v_height);
+    info.add_joined(mtx::id::display_dimensions, "x"s, track->v_dwidth, track->v_dheight);
+    info.add_joined(mtx::id::cropping,           ","s, track->v_pcleft, track->v_pctop, track->v_pcright, track->v_pcbottom);
 
     if (track->codec.is(codec_c::type_e::V_MPEG4_P10))
       info.add(mtx::id::packetizer, track->ms_compat ? mtx::id::mpeg4_p10_es_video : mtx::id::mpeg4_p10_video);
diff --git a/src/input/r_mpeg_es.cpp b/src/input/r_mpeg_es.cpp
index 24f2852a5..6c23ccd47 100644
--- a/src/input/r_mpeg_es.cpp
+++ b/src/input/r_mpeg_es.cpp
@@ -217,7 +217,7 @@ void
 mpeg_es_reader_c::identify() {
   auto codec = fmt::format("mpg{0}", version);
   auto info  = mtx::id::info_c{};
-  info.add(mtx::id::pixel_dimensions, fmt::format("{0}x{1}", width, height));
+  info.add_joined(mtx::id::pixel_dimensions, "x"s, width, height);
 
   id_result_container();
   id_result_track(0, ID_RESULT_TRACK_VIDEO, codec_c::get_name(codec, codec), info.get());
diff --git a/src/input/r_mpeg_ps.cpp b/src/input/r_mpeg_ps.cpp
index bd038cb08..8b22d8dec 100644
--- a/src/input/r_mpeg_ps.cpp
+++ b/src/input/r_mpeg_ps.cpp
@@ -1406,9 +1406,7 @@ mpeg_ps_reader_c::identify() {
     info.set(mtx::id::number,        (static_cast<uint64_t>(track->id.sub_id) << 32) | static_cast<uint64_t>(track->id.id));
     info.add(mtx::id::stream_id,     track->id.id);
     info.add(mtx::id::sub_stream_id, track->id.sub_id);
-
-    if ((0 != track->v_dwidth) && (0 != track->v_dheight))
-      info.add(mtx::id::display_dimensions, fmt::format("{0}x{1}", track->v_dwidth, track->v_dheight));
+    info.add_joined(mtx::id::display_dimensions, "x"s, track->v_dwidth, track->v_dheight);
 
     if ('a' == track->type) {
       info.add(mtx::id::audio_channels,           track->a_channels);
@@ -1416,7 +1414,7 @@ mpeg_ps_reader_c::identify() {
       info.add(mtx::id::audio_bits_per_sample,    track->a_bits_per_sample);
 
     } else if ('v' == track->type)
-      info.add(mtx::id::pixel_dimensions, fmt::format("{0}x{1}", track->v_width, track->v_height));
+      info.add_joined(mtx::id::pixel_dimensions, "x"s, track->v_width, track->v_height);
 
     id_result_track(i, 'a' == track->type ? ID_RESULT_TRACK_AUDIO : ID_RESULT_TRACK_VIDEO, track->codec.get_name(), info.get());
   }
diff --git a/src/input/r_mpeg_ts.cpp b/src/input/r_mpeg_ts.cpp
index 0e91ff4bd..6dbc0b5c7 100644
--- a/src/input/r_mpeg_ts.cpp
+++ b/src/input/r_mpeg_ts.cpp
@@ -1384,12 +1384,10 @@ reader_c::identify() {
 
   for (auto const &track : m_tracks) {
     info = mtx::id::info_c{};
-    info.add(mtx::id::language,  track->language.get_iso639_alpha_3_code());
-    info.set(mtx::id::stream_id, track->pid);
-    info.set(mtx::id::number,    track->pid);
-
-    if (track->program_number)
-      info.set(mtx::id::program_number, track->program_number.value());
+    info.add(mtx::id::language,       track->language.get_iso639_alpha_3_code());
+    info.set(mtx::id::stream_id,      track->pid);
+    info.set(mtx::id::number,         track->pid);
+    info.add(mtx::id::program_number, track->program_number);
 
     if (pid_type_e::audio == track->type) {
       info.add(mtx::id::audio_channels,           track->a_channels);
@@ -1397,12 +1395,11 @@ reader_c::identify() {
       info.add(mtx::id::audio_bits_per_sample,    track->a_bits_per_sample);
 
     } else if (pid_type_e::video == track->type)
-      info.add(mtx::id::pixel_dimensions, fmt::format("{0}x{1}", track->v_width, track->v_height));
+      info.add_joined(mtx::id::pixel_dimensions, "x"s, track->v_width, track->v_height);
 
     else if (pid_type_e::subtitles == track->type) {
       info.set(mtx::id::text_subtitles, track->codec.is(codec_c::type_e::S_SRT));
-      if (track->m_ttx_wanted_page)
-        info.set(mtx::id::teletext_page, *track->m_ttx_wanted_page);
+      info.add(mtx::id::teletext_page,  track->m_ttx_wanted_page);
     }
 
     auto multiplexed_track_ids = std::vector<uint64_t>{};
diff --git a/src/input/r_obu.cpp b/src/input/r_obu.cpp
index 4f7529566..a1dd18ada 100644
--- a/src/input/r_obu.cpp
+++ b/src/input/r_obu.cpp
@@ -84,7 +84,7 @@ obu_reader_c::read(generic_packetizer_c *,
 void
 obu_reader_c::identify() {
   auto info = mtx::id::info_c{};
-  info.add(mtx::id::pixel_dimensions, fmt::format("{0}x{1}", m_width, m_height));
+  info.add_joined(mtx::id::pixel_dimensions, "x"s, m_width, m_height);
 
   id_result_container();
   id_result_track(0, ID_RESULT_TRACK_VIDEO, codec_c::get_name(codec_c::type_e::V_AV1, {}), info.get());
diff --git a/src/input/r_ogm.cpp b/src/input/r_ogm.cpp
index ab0119e83..48b7977db 100644
--- a/src/input/r_ogm.cpp
+++ b/src/input/r_ogm.cpp
@@ -689,8 +689,7 @@ ogm_reader_c::identify() {
     if (!dmx->title.empty() && !dmx->ms_compat)
       info.add(mtx::id::track_name, dmx->title);
 
-    if ((0 != dmx->display_width) && (0 != dmx->display_height))
-      info.add(mtx::id::display_dimensions, fmt::format("{0}x{1}", dmx->display_width, dmx->display_height));
+    info.add_joined(mtx::id::display_dimensions, "x"s, dmx->display_width, dmx->display_height);
 
     if (dynamic_cast<ogm_s_text_demuxer_c *>(dmx.get()) || dynamic_cast<ogm_s_kate_demuxer_c *>(dmx.get())) {
       info.add(mtx::id::text_subtitles, true);
@@ -698,8 +697,7 @@ ogm_reader_c::identify() {
     }
 
     auto pixel_dimensions = dmx->get_pixel_dimensions();
-    if (pixel_dimensions.first && pixel_dimensions.second)
-      info.add(mtx::id::pixel_dimensions, fmt::format("{0}x{1}", pixel_dimensions.first, pixel_dimensions.second));
+    info.add_joined(mtx::id::pixel_dimensions, "x"s, pixel_dimensions.first, pixel_dimensions.second);
 
     info.add(mtx::id::audio_channels,           dmx->channels);
     info.add(mtx::id::audio_sampling_frequency, dmx->sample_rate);
diff --git a/src/input/r_qtmp4.cpp b/src/input/r_qtmp4.cpp
index 8ff983f2a..ca0a5d48f 100644
--- a/src/input/r_qtmp4.cpp
+++ b/src/input/r_qtmp4.cpp
@@ -2029,7 +2029,7 @@ qtmp4_reader_c::identify() {
     info.add(mtx::id::language, dmx.language.get_iso639_alpha_3_code());
 
     if (dmx.is_video())
-      info.add(mtx::id::pixel_dimensions, fmt::format("{0}x{1}", dmx.v_width, dmx.v_height));
+      info.add_joined(mtx::id::pixel_dimensions, "x"s, dmx.v_width, dmx.v_height);
 
     else if (dmx.is_audio()) {
       info.add(mtx::id::audio_channels,           dmx.a_channels);
diff --git a/src/input/r_real.cpp b/src/input/r_real.cpp
index 5e02f149f..667170cd4 100644
--- a/src/input/r_real.cpp
+++ b/src/input/r_real.cpp
@@ -566,7 +566,7 @@ real_reader_c::identify() {
     info.set(mtx::id::number, demuxer->track->id);
 
     if (RMFF_TRACK_TYPE_VIDEO == demuxer->track->type)
-      info.add(mtx::id::pixel_dimensions, fmt::format("{0}x{1}", demuxer->width, demuxer->height));
+      info.add_joined(mtx::id::pixel_dimensions, "x"s, demuxer->width, demuxer->height);
 
     else if (RMFF_TRACK_TYPE_AUDIO == demuxer->track->type) {
       info.add(mtx::id::audio_channels,           demuxer->channels);
diff --git a/src/input/r_vc1.cpp b/src/input/r_vc1.cpp
index 4d2c19ac1..f98d6463f 100644
--- a/src/input/r_vc1.cpp
+++ b/src/input/r_vc1.cpp
@@ -96,7 +96,7 @@ vc1_es_reader_c::read(generic_packetizer_c *,
 void
 vc1_es_reader_c::identify() {
   auto info = mtx::id::info_c{};
-  info.add(mtx::id::pixel_dimensions, fmt::format("{0}x{1}", m_seqhdr.pixel_width, m_seqhdr.pixel_height));
+  info.add_joined(mtx::id::pixel_dimensions, "x"s, m_seqhdr.pixel_width, m_seqhdr.pixel_height);
 
   id_result_container();
   id_result_track(0, ID_RESULT_TRACK_VIDEO, codec_c::get_name(codec_c::type_e::V_VC1, "VC1"), info.get());