input/gvctrl: added Channel option function and started making changes

Added a field called ch to hold the channel. Ch can be set using Channel option function.
Created default channel const and setting ch field in newSettings. Started making changes
to other option functions, namely CodecOut, subsequently, wrote testing for it."

input/gvctrl/gvctrl.go

@@ -35,6 +35,7 @@ LICENSE
 package gvctrl
 
 import (
+	"errors"
 	"fmt"
 	"math/rand"
 	"net/http"
@@ -60,6 +61,7 @@ type Option func(s settings) (settings, error)
 // vbr bitrate: 250 kbps
 // cbr bitrate: 512 kbps
 // refresh: 2 seconds
+// channel: 2
 func Set(host string, options ...Option) error {
 	// Randomly generate an ID our client will use.
 	const (
@@ -109,6 +111,17 @@ func Set(host string, options ...Option) error {
 	return nil
 }
 
+// Channel will set the GeoVision channel we will be using.
+func Channel(c int) Option {
+	return func(s settings) (settings, error) {
+		if c != 1 && c != 2 {
+			return s, errors.New("invalid channel")
+		}
+		s.ch = c
+		return s, nil
+	}
+}
+
 // Codec is a video codec.
 type Codec string
 
@@ -123,13 +136,11 @@ const (
 // codec options are listed above as consts.
 func CodecOut(c Codec) Option {
 	return func(s settings) (settings, error) {
-		switch c {
+		if (c != CodecH265 && c != CodecH264) && (s.ch == 1 || (s.ch == 2 && c != CodecMJPEG)) {
-		case CodecH265, CodecH264, CodecMJPEG:
-			s.codec = c
-			return s, nil
-		default:
 			return s, fmt.Errorf("unknown Codec: %v", c)
 		}
+		s.codec = c
+		return s, nil
 	}
 }
 

input/gvctrl/gvctrl_test.go

@@ -113,6 +113,70 @@ func TestConvRate(t *testing.T) {
 	}
 }
 
+func TestCodecOut(t *testing.T) {
+	tests := []struct {
+		s    settings
+		c    Codec
+		want settings
+		err  bool
+	}{
+		{
+			s:    settings{ch: 1},
+			c:    CodecH264,
+			want: settings{ch: 1, codec: CodecH264},
+		},
+		{
+			s:    settings{ch: 1},
+			c:    CodecH265,
+			want: settings{ch: 1, codec: CodecH265},
+		},
+		{
+			s:    settings{ch: 1},
+			c:    CodecMJPEG,
+			want: settings{ch: 1},
+			err:  true,
+		},
+		{
+			s:    settings{ch: 2},
+			c:    CodecH264,
+			want: settings{ch: 2, codec: CodecH264},
+		},
+		{
+			s:    settings{ch: 2},
+			c:    CodecH265,
+			want: settings{ch: 2, codec: CodecH265},
+		},
+		{
+			s:    settings{ch: 2},
+			c:    CodecMJPEG,
+			want: settings{ch: 2, codec: CodecMJPEG},
+		},
+		{
+			s:    settings{ch: 1},
+			c:    Codec(500),
+			want: settings{ch: 1},
+			err:  true,
+		},
+		{
+			s:    settings{ch: 2},
+			c:    Codec(500),
+			want: settings{ch: 2},
+			err:  true,
+		},
+	}
+
+	for i, test := range tests {
+		got, err := CodecOut(test.c)(test.s)
+		if err != nil && test.err != true {
+			t.Errorf("did not expect error: %v for test: %d", err, i)
+		}
+
+		if got != test.want {
+			t.Errorf("did not get expected result for test: %d\nGot: %v\nWant: %v\n", i, got, test.want)
+		}
+	}
+}
+
 func TestHeight(t *testing.T) {
 	tests := []struct {
 		h    int

input/gvctrl/request.go

@@ -145,7 +145,7 @@ func submitSettings(c *http.Client, id, host string, s settings) error {
 	req.Header.Set("User-Agent", "Mozilla/5.0 (X11; Linux x86_64) AppleWebKit/537.36 (KHTML, like Gecko) Chrome/77.0.3865.90 Safari/537.36")
 	req.Header.Set("Content-Type", "application/x-www-form-urlencoded")
 	req.Header.Set("Accept", "text/html,application/xhtml+xml,application/xml;q=0.9,image/webp,image/apng,*/*;q=0.8,application/signed-exchange;v=b3")
-	req.Header.Set("Referer", "http://"+host+"/ssi.cgi/VideoSettingSub.htm?cam=2")
+	req.Header.Set("Referer", "http://"+host+"/ssi.cgi/VideoSettingSub.htm?cam="+strconv.Itoa(s.ch))
 	req.Header.Set("Accept-Encoding", "gzip, deflate")
 	req.Header.Set("Accept-Language", "en-GB,en-US;q=0.9,en;q=0.8")
 	req.Header.Set("Cookie", "CLIENT_ID="+id)

input/gvctrl/utils.go

@@ -52,6 +52,7 @@ const (
 	defaultVBRBitrate = "250000" // 512 kbps (lowest with 360p)
 	defaultCBRBitrate = "512000"
 	defaultRefresh    = "2000" // 2 seconds
+	defaultChan       = 2
 )
 
 // settings holds string representations required by the settings form for each
@@ -65,6 +66,7 @@ type settings struct {
 	vbrBitrate string
 	cbrBitrate string
 	refresh    string
+	ch         int
 }
 
 // newSetting will return a settings with default values.
@@ -78,6 +80,7 @@ func newSettings() settings {
 		vbrBitrate: defaultVBRBitrate,
 		cbrBitrate: defaultCBRBitrate,
 		refresh:    defaultRefresh,
+		ch:         defaultChan,
 	}
 }