diff --git a/.gitignore b/.gitignore
index b19b893..ee79665 100644
--- a/.gitignore
+++ b/.gitignore
@@ -1,3 +1,2 @@
 .DS_STORE
-coverage.out
-tmp
\ No newline at end of file
+coverage.out
\ No newline at end of file
diff --git a/format_context_test.go b/format_context_test.go
index a1e093e..bbe0616 100644
--- a/format_context_test.go
+++ b/format_context_test.go
@@ -35,7 +35,7 @@ func TestFormatContext(t *testing.T) {
 	require.NoError(t, err)
 	require.Equal(t, "v=0\r\no=- 0 0 IN IP4 127.0.0.1\r\ns=Big Buck Bunny\r\nt=0 0\r\na=tool:libavformat 61.1.100\r\nm=video 0 RTP/AVP 96\r\nb=AS:441\r\na=rtpmap:96 H264/90000\r\na=fmtp:96 packetization-mode=1; sprop-parameter-sets=Z0LADasgKDPz4CIAAAMAAgAAAwBhHihUkA==,aM48gA==; profile-level-id=42C00D\r\na=control:streamid=0\r\nm=audio 0 RTP/AVP 97\r\nb=AS:161\r\na=rtpmap:97 MPEG4-GENERIC/48000/2\r\na=fmtp:97 profile-level-id=1;mode=AAC-hbr;sizelength=13;indexlength=3;indexdeltalength=3; config=1190\r\na=control:streamid=1\r\n", sdp)
 
-	fc2, err := AllocOutputFormatContext(nil, "", "/tmp/test.mp4")
+	fc2, err := AllocOutputFormatContext(nil, "mp4", "")
 	require.NoError(t, err)
 	defer fc2.Free()
 	require.True(t, fc2.OutputFormat().Flags().Has(IOFormatFlagGlobalheader))
@@ -83,11 +83,57 @@ func TestFormatContext(t *testing.T) {
 	require.Equal(t, 1, len(ps))
 	require.Equal(t, 1, ps[0].ID())
 
-	// TODO Test ReadFrame
-	// TODO Test SeekFrame
-	// TODO Test Flush
-	// TODO Test WriteHeader
-	// TODO Test WriteFrame
-	// TODO Test WriteInterleavedFrame
-	// TODO Test WriteTrailer
+	fc6 := AllocFormatContext()
+	require.NotNil(t, fc6)
+	defer fc6.Free()
+	require.NoError(t, fc6.OpenInput("testdata/video.mp4", nil, nil))
+	require.NoError(t, fc6.FindStreamInfo(nil))
+	require.Equal(t, 2, fc6.NbStreams())
+	pkt1 := AllocPacket()
+	require.NotNil(t, pkt1)
+	defer pkt1.Free()
+	require.NoError(t, fc6.ReadFrame(pkt1))
+	require.Equal(t, int64(48), pkt1.Pos())
+	pkt2 := AllocPacket()
+	require.NotNil(t, pkt2)
+	defer pkt2.Free()
+	require.NoError(t, fc6.ReadFrame(pkt2))
+	require.Equal(t, int64(261), pkt2.Pos())
+	require.NoError(t, fc6.SeekFrame(0, 0, NewSeekFlags().Add(SeekFlagBackward)))
+	require.NoError(t, fc6.ReadFrame(pkt1))
+	require.Equal(t, int64(48), pkt1.Pos())
+
+	const outputPath = "tmp/test-format-context-output.mp4"
+	fc7, err := AllocOutputFormatContext(nil, "", outputPath)
+	require.NoError(t, err)
+	defer fc7.Free()
+	for _, is := range fc6.Streams() {
+		os := fc7.NewStream(nil)
+		require.NotNil(t, os)
+		require.NoError(t, is.CodecParameters().Copy(os.CodecParameters()))
+	}
+	ic, err := OpenIOContext(outputPath, NewIOContextFlags(IOContextFlagWrite))
+	require.NoError(t, err)
+	fc7.SetPb(ic)
+	require.NoError(t, fc7.WriteHeader(nil))
+	require.NoError(t, fc7.WriteFrame(pkt1))
+	require.NoError(t, fc7.WriteInterleavedFrame(pkt2))
+	require.NoError(t, fc7.WriteTrailer())
+	require.NoError(t, fc7.Flush())
+	fc8 := AllocFormatContext()
+	require.NotNil(t, fc8)
+	defer fc8.Free()
+	require.NoError(t, fc8.OpenInput(outputPath, nil, nil))
+	require.NoError(t, fc8.FindStreamInfo(nil))
+	require.Equal(t, 2, fc8.NbStreams())
+	pkt3 := AllocPacket()
+	require.NotNil(t, pkt3)
+	defer pkt3.Free()
+	require.NoError(t, fc8.ReadFrame(pkt3))
+	require.Equal(t, int64(48), pkt3.Pos())
+	pkt4 := AllocPacket()
+	require.NotNil(t, pkt4)
+	defer pkt4.Free()
+	require.NoError(t, fc8.ReadFrame(pkt4))
+	require.Equal(t, int64(261), pkt4.Pos())
 }
diff --git a/internal/benchmarks/.gitignore b/internal/benchmarks/.gitignore
new file mode 100644
index 0000000..1c2f433
--- /dev/null
+++ b/internal/benchmarks/.gitignore
@@ -0,0 +1 @@
+tmp
\ No newline at end of file
diff --git a/internal/test/arm/7/.gitignore b/internal/test/arm/7/.gitignore
new file mode 100644
index 0000000..1c2f433
--- /dev/null
+++ b/internal/test/arm/7/.gitignore
@@ -0,0 +1 @@
+tmp
\ No newline at end of file
diff --git a/tmp/.gitignore b/tmp/.gitignore
new file mode 100644
index 0000000..c96a04f
--- /dev/null
+++ b/tmp/.gitignore
@@ -0,0 +1,2 @@
+*
+!.gitignore
\ No newline at end of file