diff --git a/testdata/src/test/assets/muxerdumps/stsz_box.dump b/testdata/src/test/assets/muxerdumps/stsz_box.dump
new file mode 100644
index 0000000000..f6f8cfc6dc
--- /dev/null
+++ b/testdata/src/test/assets/muxerdumps/stsz_box.dump
@@ -0,0 +1,2 @@
+stsz (36 bytes):
+  Data = length 28, hash 2257E30F
diff --git a/testdata/src/test/assets/muxerdumps/stts_box_all_different_sample_durations.dump b/testdata/src/test/assets/muxerdumps/stts_box_all_different_sample_durations.dump
new file mode 100644
index 0000000000..ca9083f365
--- /dev/null
+++ b/testdata/src/test/assets/muxerdumps/stts_box_all_different_sample_durations.dump
@@ -0,0 +1,2 @@
+stts (48 bytes):
+  Data = length 40, hash 558A08D9
diff --git a/testdata/src/test/assets/muxerdumps/stts_box_few_same_sample_durations.dump b/testdata/src/test/assets/muxerdumps/stts_box_few_same_sample_durations.dump
new file mode 100644
index 0000000000..e1b4e58a53
--- /dev/null
+++ b/testdata/src/test/assets/muxerdumps/stts_box_few_same_sample_durations.dump
@@ -0,0 +1,2 @@
+stts (32 bytes):
+  Data = length 24, hash AA341F5
diff --git a/testdata/src/test/assets/muxerdumps/stts_box_single_sample_duration.dump b/testdata/src/test/assets/muxerdumps/stts_box_single_sample_duration.dump
new file mode 100644
index 0000000000..ffddef995b
--- /dev/null
+++ b/testdata/src/test/assets/muxerdumps/stts_box_single_sample_duration.dump
@@ -0,0 +1,2 @@
+stts (24 bytes):
+  Data = length 16, hash E4FC6496