container/mts: wrote test TestEncodeVideo

Wrote a test to check mts encoding of video to validate packet creation etc. Test is failing because how I did mts
encoding is interesting, thinking about changing.

container/mts/encoder_test.go

@@ -1,12 +1,13 @@
 /*
 NAME
-  audio_test.go
+  encoder_test.go
 
 AUTHOR
   Trek Hopton <trek@ausocean.org>
+  Saxon A. Nelson-Milton <saxon@ausocean.org>
 
 LICENSE
-  audio_test.go is Copyright (C) 2017-2019 the Australian Ocean Lab (AusOcean)
+  encoder_test.go is Copyright (C) 2017-2019 the Australian Ocean Lab (AusOcean)
 
   It is free software: you can redistribute it and/or modify them
   under the terms of the GNU General Public License as published by the
@@ -26,6 +27,7 @@ package mts
 
 import (
 	"bytes"
+	"fmt"
 	"io"
 	"io/ioutil"
 	"testing"
@@ -40,6 +42,91 @@ type nopCloser struct{ io.Writer }
 
 func (nopCloser) Close() error { return nil }
 
+type destination struct {
+	packets [][]byte
+}
+
+func (d *destination) Write(p []byte) (int, error) {
+	tmp := make([]byte, PacketSize)
+	copy(tmp, p)
+	d.packets = append(d.packets, tmp)
+	return len(p), nil
+}
+
+func TestEncodeVideo(t *testing.T) {
+	Meta = meta.New()
+
+	const headAndAdaptLen = 12
+	const adaptNoStuffLen = 7
+	const dataLength = 440
+	const numOfPackets = 3
+	const stuffingLen = 88
+
+	// Generate test data.
+	data := make([]byte, 0, dataLength)
+	for i := 0; i < dataLength; i++ {
+		data = append(data, byte(i))
+	}
+
+	// Expect headers for PID 256 (video)
+	// NB: timing fieldsl ike PCR are neglected.
+	expectedHeaders := [][]byte{
+		{
+			0x47, // Sync byte.
+			0x41, // TEI=0, PUSI=1, TP=0, PID=00001 (256).
+			0x00, // PID(Cont)=00000000.
+			0x30, // TSC=00, AFC=11(adaptation followed by payload), CC=0000(0).
+			0x07, // AFL= 7.
+			0x50, // DI=0,RAI=1,ESPI=0,PCRF=1,OPCRF=0,SPF=0,TPDF=0, AFEF=0.
+		},
+		{
+			0x47, // Sync byte.
+			0x01, // TEI=0, PUSI=0, TP=0, PID=00001 (256).
+			0x00, // PID(Cont)=00000000.
+			0x31, // TSC=00, AFC=11(adaptation followed by payload), CC=0000(0).
+			0x07, // AFL= 7.
+			0x10, // DI=0,RAI=0,ESPI=0,PCRF=1,OPCRF=0,SPF=0,TPDF=0, AFEF=0.
+		},
+		{
+			0x47,                                // Sync byte.
+			0x01,                                // TEI=0, PUSI=0, TP=0, PID=00001 (256).
+			0x00,                                // PID(Cont)=00000000.
+			0x31,                                // TSC=00, AFC=11(adaptation followed by payload), CC=0000(0).
+			byte(adaptNoStuffLen + stuffingLen), // AFL= 7+stuffingLen.
+			0x10,                                // DI=0,RAI=0,ESPI=0,PCRF=1,OPCRF=0,SPF=0,TPDF=0, AFEF=0.
+		},
+	}
+
+	dst := &destination{}
+	e := NewEncoder(nopCloser{dst}, 25, Video)
+
+	// Write data.
+	_, err := e.Write(data)
+	if err != nil {
+		t.Fatalf("could not write data to encoder, failed with err: %v\n", err)
+	}
+
+	// Check headers.
+	var expectedIdx int
+	for _, p := range dst.packets {
+		// Get PID.
+		var _p packet.Packet
+		copy(_p[:], p)
+		pid := packet.Pid(&_p)
+		if pid == VideoPid {
+			// Get mts header, excluding PCR.
+			gotHeader := p[0:6]
+			fmt.Printf("got: %v\n", p)
+			wantHeader := expectedHeaders[expectedIdx]
+			fmt.Printf("want: %v\n", expectedHeaders[expectedIdx])
+			if !bytes.Equal(gotHeader, wantHeader) {
+				t.Errorf("did not get expected header.\n Got: %v\n Want: %v\n", gotHeader, wantHeader)
+			}
+			expectedIdx++
+		}
+	}
+}
+
 // TestEncodePcm tests the mpegts encoder's ability to encode pcm audio data.
 // It reads and encodes input pcm data into mpegts, then decodes the mpegts and compares the result to the input pcm.
 func TestEncodePcm(t *testing.T) {

container/mts/mpegts.go

@@ -196,6 +196,7 @@ func FindPid(d []byte, pid uint16) (pkt []byte, i int, err error) {
 func (p *Packet) FillPayload(data []byte) int {
 	currentPktLen := 6 + asInt(p.PCRF)*6 + asInt(p.OPCRF)*6 +
 		asInt(p.SPF)*1 + asInt(p.TPDF)*1 + len(p.TPD)
+	fmt.Printf("currentPktLen: %v\n", currentPktLen)
 	if len(data) > PayloadSize-currentPktLen {
 		p.Payload = make([]byte, PayloadSize-currentPktLen)
 	} else {