diff --git a/testdata/src/test/assets/muxerdumps/co64_box.dump b/testdata/src/test/assets/muxerdumps/co64_box.dump
new file mode 100644
index 0000000000..05bd62bf02
--- /dev/null
+++ b/testdata/src/test/assets/muxerdumps/co64_box.dump
@@ -0,0 +1,2 @@
+co64 (48 bytes):
+  Data = length 40, hash A77CAF85
diff --git a/testdata/src/test/assets/muxerdumps/stsc_box.dump b/testdata/src/test/assets/muxerdumps/stsc_box.dump
new file mode 100644
index 0000000000..5319dbe7dc
--- /dev/null
+++ b/testdata/src/test/assets/muxerdumps/stsc_box.dump
@@ -0,0 +1,2 @@
+stsc (64 bytes):
+  Data = length 56, hash 1719CF36
diff --git a/testdata/src/test/assets/muxerdumps/stss_box.dump b/testdata/src/test/assets/muxerdumps/stss_box.dump
new file mode 100644
index 0000000000..2a3b052a2f
--- /dev/null
+++ b/testdata/src/test/assets/muxerdumps/stss_box.dump
@@ -0,0 +1,2 @@
+stss (40 bytes):
+  Data = length 32, hash C9DD8D8