When reading Matroska files & splitting all packets were accidentally considered to be splitpoints. Same situation: the list of unique numbers was not cleaned, and therefore the second pass could not keep the UIDs.

src/cluster_helper.cpp

@@ -448,7 +448,7 @@ int cluster_helper_c::render() {
     // The next stuff is for splitting files.
     if (pass == 1) {            // first pass: find splitpoints
       if ((pack->bref == -1) && // this is a keyframe
-          ((video_fps == -1) || // either no video track present...
+          (!video_track_present || // either no video track present...
            // ...or this is the video track
            (source->get_track_type() == track_video))) { 
         sp = (splitpoint_t *)safemalloc(sizeof(splitpoint_t));

src/common.cpp

@@ -552,6 +552,10 @@ char *from_utf8(int handle, const char *utf8) {
 
 static vector<uint32_t> ru_numbers;
 
+void clear_list_of_unique_uint32() {
+  ru_numbers.clear();
+}
+
 bool is_unique_uint32(uint32_t number) {
   int i;
 

src/common.h

@@ -115,6 +115,7 @@ void utf8_done();
 char *to_utf8(int handle, const char *local);
 char *from_utf8(int handle, const char *utf8);
 
+void clear_list_of_unique_uint32();
 bool is_unique_uint32(uint32_t number);
 void add_unique_uint32(uint32_t number);
 uint32_t create_unique_uint32();

src/mkvmerge.cpp

@@ -1635,6 +1635,7 @@ static void init_globals() {
   default_tracks[2] = 0;
   display_counter = 1;
   display_reader = NULL;
+  clear_list_of_unique_uint32();
 }
 
 static void destroy_readers() {
@@ -1986,6 +1987,8 @@ void main_loop() {
 // {{{ FUNCTION main(int argc, char **argv)
 
 int main(int argc, char **argv) {
+  time_t start, end;
+
   init_globals();
 
   setup();
@@ -1995,6 +1998,8 @@ int main(int argc, char **argv) {
   if (split_after > 0) {
     mxinfo("Pass 1: finding split points. This may take a while.\n\n");
 
+    start = time(NULL);
+
     create_readers();
 
     if (packetizers.size() == 0)
@@ -2005,7 +2010,12 @@ int main(int argc, char **argv) {
     main_loop();
     finish_file();
 
-    mxinfo("\nPass 2: merging the files. This will take even longer.\n\n");
+    end = time(NULL);
+
+    mxinfo("\nPass 1 took %u seconds.\nPass 2: merging the files. This will "
+           "take even longer.\n\n", end - start);
+
+    start = time(NULL);
 
     delete cluster_helper;
     destroy_readers();
@@ -2021,8 +2031,13 @@ int main(int argc, char **argv) {
     main_loop();
     finish_file();
 
+    end = time(NULL);
+    mxinfo("Pass 2 took %u seconds.\n", end - start);
+
   } else {
 
+    start = time(NULL);
+
     create_readers();
 
     if (packetizers.size() == 0)
@@ -2032,6 +2047,9 @@ int main(int argc, char **argv) {
     create_next_output_file(true, true);
     main_loop();
     finish_file();
+
+    end = time(NULL);
+    mxinfo("Muxing took %u seconds.\n", end - start);
   }
 
   cleanup();