container/mts: renamed audio_test.go to encoder_test.go

This file will now contain any tests pertinent to the mts encoder.

container/mts/encoder_test.go

@@ -0,0 +1,144 @@
+/*
+NAME
+  audio_test.go
+
+AUTHOR
+  Trek Hopton <trek@ausocean.org>
+
+LICENSE
+  audio_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
+  Free Software Foundation, either version 3 of the License, or (at your
+  option) any later version.
+
+  It is distributed in the hope that it will be useful, but WITHOUT
+  ANY WARRANTY; without even the implied warranty of MERCHANTABILITY or
+  FITNESS FOR A PARTICULAR PURPOSE. See the GNU General Public License
+ for more details.
+
+  You should have received a copy of the GNU General Public License in gpl.txt.
+  If not, see http://www.gnu.org/licenses.
+*/
+
+package mts
+
+import (
+	"bytes"
+	"io"
+	"io/ioutil"
+	"testing"
+
+	"github.com/Comcast/gots/packet"
+	"github.com/Comcast/gots/pes"
+
+	"bitbucket.org/ausocean/av/container/mts/meta"
+)
+
+type nopCloser struct{ io.Writer }
+
+func (nopCloser) Close() error { return nil }
+
+// 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) {
+	Meta = meta.New()
+
+	var buf bytes.Buffer
+	sampleRate := 48000
+	sampleSize := 2
+	blockSize := 16000
+	writeFreq := float64(sampleRate*sampleSize) / float64(blockSize)
+	e := NewEncoder(nopCloser{&buf}, writeFreq, Audio)
+
+	inPath := "../../../test/test-data/av/input/sweep_400Hz_20000Hz_-3dBFS_5s_48khz.pcm"
+	inPcm, err := ioutil.ReadFile(inPath)
+	if err != nil {
+		t.Errorf("unable to read file: %v", err)
+	}
+
+	// Break pcm into blocks and encode to mts and get the resulting bytes.
+	for i := 0; i < len(inPcm); i += blockSize {
+		if len(inPcm)-i < blockSize {
+			block := inPcm[i:]
+			_, err = e.Write(block)
+			if err != nil {
+				t.Errorf("unable to write block: %v", err)
+			}
+		} else {
+			block := inPcm[i : i+blockSize]
+			_, err = e.Write(block)
+			if err != nil {
+				t.Errorf("unable to write block: %v", err)
+			}
+		}
+	}
+	clip := buf.Bytes()
+
+	// Get the first MTS packet to check
+	var pkt packet.Packet
+	pesPacket := make([]byte, 0, blockSize)
+	got := make([]byte, 0, len(inPcm))
+	i := 0
+	if i+PacketSize <= len(clip) {
+		copy(pkt[:], clip[i:i+PacketSize])
+	}
+
+	// Loop through MTS packets until all the audio data from PES packets has been retrieved
+	for i+PacketSize <= len(clip) {
+
+		// Check MTS packet
+		if !(pkt.PID() == audioPid) {
+			i += PacketSize
+			if i+PacketSize <= len(clip) {
+				copy(pkt[:], clip[i:i+PacketSize])
+			}
+			continue
+		}
+		if !pkt.PayloadUnitStartIndicator() {
+			i += PacketSize
+			if i+PacketSize <= len(clip) {
+				copy(pkt[:], clip[i:i+PacketSize])
+			}
+		} else {
+			// Copy the first MTS payload
+			payload, err := pkt.Payload()
+			if err != nil {
+				t.Errorf("unable to get MTS payload: %v", err)
+			}
+			pesPacket = append(pesPacket, payload...)
+
+			i += PacketSize
+			if i+PacketSize <= len(clip) {
+				copy(pkt[:], clip[i:i+PacketSize])
+			}
+
+			// Copy the rest of the MTS payloads that are part of the same PES packet
+			for (!pkt.PayloadUnitStartIndicator()) && i+PacketSize <= len(clip) {
+				payload, err = pkt.Payload()
+				if err != nil {
+					t.Errorf("unable to get MTS payload: %v", err)
+				}
+				pesPacket = append(pesPacket, payload...)
+
+				i += PacketSize
+				if i+PacketSize <= len(clip) {
+					copy(pkt[:], clip[i:i+PacketSize])
+				}
+			}
+		}
+		// Get the audio data from the current PES packet
+		pesHeader, err := pes.NewPESHeader(pesPacket)
+		if err != nil {
+			t.Errorf("unable to read PES packet: %v", err)
+		}
+		got = append(got, pesHeader.Data()...)
+		pesPacket = pesPacket[:0]
+	}
+
+	// Compare data from MTS with original data.
+	if !bytes.Equal(got, inPcm) {
+		t.Error("data decoded from mts did not match input data")
+	}
+}