From 734db122e4285f955297c6082dcf84ecc4372d19 Mon Sep 17 00:00:00 2001
From: Moritz Bunkus <mo@bunkus.online>
Date: Tue, 3 Sep 2024 22:09:18 +0200
Subject: [PATCH] MPEG TS reader: add hack for not combining Dolby Vision
 layers from separate tracks

---
 src/common/hacks.cpp    | 1 +
 src/common/hacks.h      | 3 ++-
 src/input/r_mpeg_ts.cpp | 4 ++++
 3 files changed, 7 insertions(+), 1 deletion(-)

diff --git a/src/common/hacks.cpp b/src/common/hacks.cpp
index 52795d2bd..cc0eec485 100644
--- a/src/common/hacks.cpp
+++ b/src/common/hacks.cpp
@@ -68,6 +68,7 @@ get_list() {
   hacks.emplace_back("keep_whitespaces_in_text_subtitles", svec{ Y("Normally spaces & tabs are removed from the beginning & the end of each line in text subtitles."),
                                                                  Y("If this hack is enabled, they won't be removed.") });
   hacks.emplace_back("always_write_block_add_ids",         svec{ Y("If enabled, the BlockAddID element will be written even if it's set to its default value of 1.") });
+  hacks.emplace_back("keep_dolby_vision_layers_separate",  svec{ Y("Prevents mkvmerge from looking for Dolby Vision Enhancement Layers stored in a separate track & combining them with the track containing the Dolby Vision Base Layer.") });
   hacks.emplace_back("cow",                                svec{ Y("No help available.") });
 
   return hacks;
diff --git a/src/common/hacks.h b/src/common/hacks.h
index 862cd0aeb..5592ef4b9 100644
--- a/src/common/hacks.h
+++ b/src/common/hacks.h
@@ -47,7 +47,8 @@ constexpr unsigned int APPEND_AND_SPLIT_FLAC              = 22;
 constexpr unsigned int DONT_NORMALIZE_PARAMETER_SETS      = 23;
 constexpr unsigned int KEEP_WHITESPACES_IN_TEXT_SUBTITLES = 24;
 constexpr unsigned int ALWAYS_WRITE_BLOCK_ADD_IDS         = 25;
-constexpr unsigned int MAX_IDX                            = 25;
+constexpr unsigned int KEEP_DOLBY_VISION_LAYERS_SEPARATE  = 26;
+constexpr unsigned int MAX_IDX                            = 26;
 }
 
 struct hack_t {
diff --git a/src/input/r_mpeg_ts.cpp b/src/input/r_mpeg_ts.cpp
index b34fc3482..7e82f51aa 100644
--- a/src/input/r_mpeg_ts.cpp
+++ b/src/input/r_mpeg_ts.cpp
@@ -32,6 +32,7 @@
 #include "common/checksums/base_fwd.h"
 #include "common/dovi_meta.h"
 #include "common/endian.h"
+#include "common/hacks.h"
 #include "common/hdmv_textst.h"
 #include "common/mm_io_x.h"
 #include "common/mp3.h"
@@ -1427,6 +1428,9 @@ reader_c::read_headers_for_file(std::size_t file_num) {
 
 void
 reader_c::pair_dovi_base_and_enhancement_layer_tracks() {
+  if (mtx::hacks::is_engaged(mtx::hacks::KEEP_DOLBY_VISION_LAYERS_SEPARATE))
+    return;
+
   for (std::size_t idx = 0, num_tracks = m_tracks.size(); idx < num_tracks; ++idx) {
     auto &track = *m_tracks[idx];