mts: removed readme reference, added comments to test

container/mts/audio_test.go

@@ -2,9 +2,6 @@
 NAME
   audio_test.go
 
-DESCRIPTION
-  See Readme.md
-
 AUTHOR
   Trek Hopton <trek@ausocean.org>
 
@@ -21,8 +18,8 @@ LICENSE
   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
-  along with revid in gpl.txt. If not, see http://www.gnu.org/licenses.
+  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
@@ -30,7 +27,6 @@ package mts
 import (
 	"bytes"
 	"io/ioutil"
-	"log"
 	"testing"
 
 	"bitbucket.org/ausocean/av/container/mts/meta"
@@ -39,7 +35,7 @@ import (
 )
 
 // 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 compares the result to the input pcm.
+// 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()
 
@@ -54,28 +50,28 @@ func TestEncodePcm(t *testing.T) {
 	inPath := "../../../test/test-data/av/input/sweep_400Hz_20000Hz_-3dBFS_5s_48khz.pcm"
 	inPcm, err := ioutil.ReadFile(inPath)
 	if err != nil {
-		log.Fatal(err)
+		t.Errorf("unable to read file: %v", err)
 	}
 
-	// Encode pcm to mts and get the resulting bytes.
+	// 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 {
-				log.Fatal(err)
+				t.Errorf("unable to write block: %v", err)
 			}
 		} else {
 			block := inPcm[i : i+blockSize]
 			_, err = e.Write(block)
 			if err != nil {
-				log.Fatal(err)
+				t.Errorf("unable to write block: %v", err)
 			}
 		}
 	}
 	clip := buf.Bytes()
 
-	// Decode the mts packets to extract the original data
+	// Get the first MTS packet to check
 	var pkt packet.Packet
 	pesPacket := make([]byte, 0, blockSize)
 	got := make([]byte, 0, len(inPcm))
@@ -84,12 +80,17 @@ func TestEncodePcm(t *testing.T) {
 		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 {
 			if pkt.PayloadUnitStartIndicator() {
+
+				// Copy the first MTS payload
 				payload, err := pkt.Payload()
 				if err != nil {
-					t.Fatalf("Unexpected err: %v\n", err)
+					t.Errorf("unable to get MTS payload: %v", err)
 				}
 				pesPacket = append(pesPacket, payload...)
 
@@ -98,10 +99,11 @@ func TestEncodePcm(t *testing.T) {
 					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.Fatalf("Unexpected err: %v\n", err)
+						t.Errorf("unable to get MTS payload: %v", err)
 					}
 					pesPacket = append(pesPacket, payload...)
 
@@ -116,9 +118,10 @@ func TestEncodePcm(t *testing.T) {
 					copy(pkt[:], clip[i:i+PacketSize])
 				}
 			}
+			// Get the audio data from the current PES packet
 			pesHeader, err := pes.NewPESHeader(pesPacket)
 			if err != nil {
-				t.Fatalf("Unexpected err: %v\n", err)
+				t.Errorf("unable to read PES packet: %v", err)
 			}
 			got = append(got, pesHeader.Data()...)
 			pesPacket = pesPacket[:0]
@@ -130,8 +133,8 @@ func TestEncodePcm(t *testing.T) {
 		}
 	}
 
-	// Compare encoded data with original data.
+	// Compare data from MTS with original data.
 	if !bytes.Equal(got, inPcm) {
-		t.Error("Error, unexpected output")
+		t.Error("data decoded from mts did not match input data")
 	}
 }

container/mts/encoder.go

@@ -2,9 +2,6 @@
 NAME
   encoder.go
 
-DESCRIPTION
-  See Readme.md
-
 AUTHOR
   Dan Kortschak <dan@ausocean.org>
   Saxon Nelson-Milton <saxon@ausocean.org>