add 0.2.1 to changelog

improve the warning message on invalid bps value

.gitignore

@@ -4,6 +4,7 @@
 *.dll
 *.so
 *.dylib
+bin/
 
 # Test binary, built with `go test -c`
 *.test
@@ -13,5 +14,3 @@
 
 # Dependency directories (remove the comment below to include it)
 # vendor/
-
-*.txt

CHANGELOG.md

@@ -9,23 +9,44 @@ Before any major/minor/patch bump all unit tests will be run to verify they pass
 
 ## [Unreleased]
 
-- [x]
+-   [x]
+
+# [0.2.1] - 2024-11-07
+
+### Fixed
+
+-   {packet}.header() now uses a reusable buffer.
+
+# [0.2.0] - 2024-10-27
+
+### Added
+
+-   `config` flag (shorthand `C`), you may now specify a custom config directory. It defaults to `home directory / .config / vbantxt_cli /`.
+    -   please note, the default directory has changed from v0.1.0
+-   Functional options `WithRateLimit` and `WithBPSOpt` and `WithChannel` added. Use them to configure the vbantxt client. See the [included vbantxt cli][vbantxt-cli] for an example of usage.
+
+### Changed
+
+-   Behaviour change: if any one of `"host", "h", "port", "p", "streamname", "s"` flags are passed then the config file will be ignored.
+-   `delay` flag changed to `ratelimit` (shorthand `r`). It defaults to 20ms.
 
 # [0.1.0] - 2024-06-28
 
 ### Added
 
-- Matrix and Logging sections to README.
+-   Matrix and Logging sections to README.
 
 ### Changed
 
-- `host` flag now defaults to "localhost". Useful if sending VBAN-Text to Matrix
-- `loglevel` flag now expects values that correspond to the logrus package loglevels (0 up to 6). See README.
-- Config values are only applied if the corresponding flag was not passed on the command line.
+-   `host` flag now defaults to "localhost". Useful if sending VBAN-Text to Matrix
+-   `loglevel` flag now expects values that correspond to the logrus package loglevels (0 up to 6). See README.
+-   Config values are only applied if the corresponding flag was not passed on the command line.
 
 # [0.0.1] - 2022-09-23
 
 ### Added
 
-- Initial release, package implements VBAN PROTOCOL TXT with a basic CLI for configuring options.
-- Ability to load configuration settings from a config.toml.
+-   Initial release, package implements VBAN PROTOCOL TXT with a basic CLI for configuring options.
+-   Ability to load configuration settings from a config.toml.
+
+[vbantxt-cli]: https://github.com/onyx-and-iris/vbantxt/blob/main/cmd/vbantxt/main.go

README.md

@@ -1,48 +1,82 @@
 ![Windows](https://img.shields.io/badge/Windows-0078D6?style=for-the-badge&logo=windows&logoColor=white)
 ![Linux](https://img.shields.io/badge/Linux-FCC624?style=for-the-badge&logo=linux&logoColor=black)
 
-# VBAN Sendtext CLI Utility
+# VBAN Sendtext
 
-Send Voicemeeter string requests over a network or to Matrix
+Send Voicemeeter/Matrix vban requests.
 
 For an outline of past/future changes refer to: [CHANGELOG](CHANGELOG.md)
 
 ## Tested against
 
-- Basic 1.0.8.4
-- Banana 2.0.6.4
-- Potato 3.0.2.4
-- Matrix 1.0.0.3
+-   Basic 1.0.8.4
+-   Banana 2.0.6.4
+-   Potato 3.0.2.4
+-   Matrix 1.0.0.3
 
 ## Requirements
 
-- [Voicemeeter](https://voicemeeter.com/) or [Matrix](https://vb-audio.com/Matrix/)
-- Go 1.18 or greater (if you want to compile yourself, otherwise check `Releases`)
+-   [Voicemeeter](https://voicemeeter.com/) or [Matrix](https://vb-audio.com/Matrix/)
+-   Go 1.18 or greater (if you want to compile yourself, otherwise check `Releases`)
 
 ---
 
+## `Use`
+
+`go get github.com/onyx-and-iris/vbantxt`
+
+```go
+package main
+
+import (
+	"log"
+
+	"github.com/onyx-and-iris/vbantxt"
+)
+
+func main() {
+	var (
+		host       string = "vm.local"
+		port       int    = 6980
+		streamname string = "onyx"
+	)
+
+	client, err := vbantxt.New(host, port, streamname)
+	if err != nil {
+		log.Fatal(err)
+	}
+	defer client.Close()
+
+	err = client.Send("strip[0].mute=0")
+	if err != nil {
+		_, _ = fmt.Fprintf(os.Stderr, "Error: %s", err)
+		os.Exit(1)
+	}
+}
+```
+
 ## `Command Line`
 
 Pass `host`, `port` and `streamname` as flags, for example:
 
 ```
-vbantxt-cli -h="gamepc.local" -p=6980 -s=Command1 "strip[0].mute=1 strip[1].mono=1"
+vbantxt -h="gamepc.local" -p=6980 -s=Command1 "strip[0].mute=1 strip[1].mono=1"
 ```
 
-You may also store them in a `config.toml` located in `home directory / .vbantxt_cli /`
+You may also store them in a `config.toml` located in `home directory / .config / vbantxt /`
 
 A valid `config.toml` might look like this:
 
 ```toml
 [connection]
-Host="gamepc.local"
-Port=6980
-Streamname="Command1"
+host="gamepc.local"
+port=6980
+streamname="Command1"
 ```
 
-- `host` defaults to "localhost"
-- `port` defaults to 6980
-- `streamname` defaults to "Command1"
+-   `host` defaults to "localhost"
+-   `port` defaults to 6980
+-   `streamname` defaults to "Command1"
 
 Command line flags will override values in a config.toml.
 
@@ -54,7 +88,7 @@ The vbantxt-cli utility accepts a single string request or an array of string re
 
 For example, in Windows with Powershell you could:
 
-`vbantxt-cli $(Get-Content .\script.txt)`
+`vbantxt $(Get-Content .\script.txt)`
 
 Or with Bash:
 
@@ -75,7 +109,7 @@ bus[3].eq.On=0
 Sending commands to VB-Audio Matrix is also possible, for example:
 
 ```
-vbantxt-cli -s=streamname "Point(ASIO128.IN[2],ASIO128.OUT[1]).dBGain = -8"
+vbantxt -s=streamname "Point(ASIO128.IN[2],ASIO128.OUT[1]).dBGain = -8"
 ```
 
 ---

cmd/vbantxt/config.go

@@ -0,0 +1,42 @@
+package main
+
+import (
+	"fmt"
+	"os"
+
+	"github.com/BurntSushi/toml"
+	log "github.com/sirupsen/logrus"
+)
+
+type config struct {
+	Connection connection `toml:"connection"`
+}
+
+func (c config) String() string {
+	return fmt.Sprintf(
+		"host: %s port: %d streamname: %s",
+		c.Connection.Host, c.Connection.Port, c.Connection.Streamname)
+}
+
+type connection struct {
+	Host       string `toml:"host"`
+	Port       int    `toml:"port"`
+	Streamname string `toml:"streamname"`
+}
+
+func loadConfig(configPath string) (*connection, error) {
+	_, err := os.Stat(configPath)
+	if err != nil {
+		return nil, err
+	}
+
+	var config config
+
+	_, err = toml.DecodeFile(configPath, &config)
+	if err != nil {
+		return nil, err
+	}
+	log.Debug(config)
+
+	return &config.Connection, nil
+}

cmd/vbantxt/config_internal_test.go

@@ -0,0 +1,39 @@
+package main
+
+import (
+	"testing"
+
+	"github.com/stretchr/testify/assert"
+	"github.com/stretchr/testify/require"
+)
+
+func TestLoadConfig_Success(t *testing.T) {
+	conn, err := loadConfig("testdata/config.toml")
+	require.NoError(t, err)
+
+	assert.Equal(t, conn.Host, "localhost")
+	assert.Equal(t, conn.Port, 7000)
+	assert.Equal(t, conn.Streamname, "vbantxt")
+}
+
+func TestLoadConfig_Errors(t *testing.T) {
+	tt := map[string]struct {
+		input string
+		err   string
+	}{
+		"no such file": {
+			input: "/no/such/dir/config.toml",
+			err:   "no such file or directory",
+		},
+	}
+
+	for name, tc := range tt {
+		_, err := loadConfig("/no/such/dir/config.toml")
+
+		t.Run(name, func(t *testing.T) {
+			assert.Error(t, err)
+			assert.ErrorContains(t, err, tc.err)
+		})
+	}
+
+}

cmd/vbantxt/main.go

@@ -0,0 +1,97 @@
+package main
+
+import (
+	"flag"
+	"fmt"
+	"os"
+	"path/filepath"
+	"slices"
+	"time"
+
+	"github.com/onyx-and-iris/vbantxt"
+	log "github.com/sirupsen/logrus"
+)
+
+func exit(err error) {
+	_, _ = fmt.Fprintf(os.Stderr, "Error: %s", err)
+	os.Exit(1)
+}
+
+func main() {
+	var (
+		host       string
+		port       int
+		streamname string
+		loglevel   int
+		configPath string
+		bps        int
+		channel    int
+		ratelimit  int
+	)
+
+	flag.StringVar(&host, "host", "localhost", "vban host")
+	flag.StringVar(&host, "h", "localhost", "vban host (shorthand)")
+	flag.IntVar(&port, "port", 6980, "vban server port")
+	flag.IntVar(&port, "p", 6980, "vban server port (shorthand)")
+	flag.StringVar(&streamname, "streamname", "Command1", "stream name for text requests")
+	flag.StringVar(&streamname, "s", "Command1", "stream name for text requests (shorthand)")
+
+	flag.IntVar(&bps, "bps", 0, "vban bps")
+	flag.IntVar(&bps, "b", 0, "vban bps (shorthand)")
+	flag.IntVar(&channel, "channel", 0, "vban channel")
+	flag.IntVar(&channel, "c", 0, "vban channel (shorthand)")
+	flag.IntVar(&ratelimit, "ratelimit", 20, "request ratelimit in milliseconds")
+	flag.IntVar(&ratelimit, "r", 20, "request ratelimit in milliseconds (shorthand)")
+
+	homeDir, err := os.UserHomeDir()
+	if err != nil {
+		exit(err)
+	}
+	defaultConfigPath := filepath.Join(homeDir, ".config", "vbantxt", "config.toml")
+	flag.StringVar(&configPath, "config", defaultConfigPath, "config path")
+	flag.StringVar(&configPath, "C", defaultConfigPath, "config path (shorthand)")
+	flag.IntVar(&loglevel, "loglevel", int(log.WarnLevel), "log level")
+	flag.IntVar(&loglevel, "l", int(log.WarnLevel), "log level (shorthand)")
+	flag.Parse()
+
+	if slices.Contains(log.AllLevels, log.Level(loglevel)) {
+		log.SetLevel(log.Level(loglevel))
+	}
+
+	if !flagsPassed([]string{"host", "h", "port", "p", "streamname", "s"}) {
+		config, err := loadConfig(configPath)
+		if err != nil {
+			exit(err)
+		}
+		host = config.Host
+		port = config.Port
+		streamname = config.Streamname
+	}
+
+	client, err := createClient(host, port, streamname, bps, channel, ratelimit)
+	if err != nil {
+		exit(err)
+	}
+	defer client.Close()
+
+	for _, arg := range flag.Args() {
+		err := client.Send(arg)
+		if err != nil {
+			log.Error(err)
+		}
+	}
+}
+
+func createClient(host string, port int, streamname string, bps, channel, ratelimit int) (*vbantxt.VbanTxt, error) {
+	client, err := vbantxt.New(
+		host,
+		port,
+		streamname,
+		vbantxt.WithBPSOpt(bps),
+		vbantxt.WithChannel(channel),
+		vbantxt.WithRateLimit(time.Duration(ratelimit)*time.Millisecond))
+	if err != nil {
+		return nil, err
+	}
+	return client, err
+}

cmd/vbantxt/testdata/config.toml

@@ -0,0 +1,4 @@
+[connection]
+host = "localhost"
+port = 7000
+streamname = "vbantxt"

cmd/vbantxt/util.go

@@ -0,0 +1,17 @@
+package main
+
+import (
+	"flag"
+	"slices"
+)
+
+func flagsPassed(flags []string) bool {
+	found := false
+	flag.Visit(func(f *flag.Flag) {
+		if slices.Contains(flags, f.Name) {
+			found = true
+			return
+		}
+	})
+	return found
+}

errors.go

@@ -0,0 +1,9 @@
+package vbantxt
+
+// Error is used to define sentinel errors.
+type Error string
+
+// Error implements the error interface.
+func (r Error) Error() string {
+	return string(r)
+}

go.mod

@@ -1,10 +1,16 @@
-module github.com/onyx-and-iris/vbantxt-cli
+module github.com/onyx-and-iris/vbantxt
 
 go 1.19
 
 require (
 	github.com/BurntSushi/toml v1.2.1
 	github.com/sirupsen/logrus v1.9.0
+	github.com/stretchr/testify v1.9.0
 )
 
-require golang.org/x/sys v0.0.0-20220715151400-c0bba94af5f8 // indirect
+require (
+	github.com/davecgh/go-spew v1.1.1 // indirect
+	github.com/pmezard/go-difflib v1.0.0 // indirect
+	golang.org/x/sys v0.0.0-20220715151400-c0bba94af5f8 // indirect
+	gopkg.in/yaml.v3 v3.0.1 // indirect
+)

go.sum

@@ -8,10 +8,13 @@ github.com/pmezard/go-difflib v1.0.0/go.mod h1:iKH77koFhYxTK1pcRnkKkqfTogsbg7gZN
 github.com/sirupsen/logrus v1.9.0 h1:trlNQbNUG3OdDrDil03MCb1H2o9nJ1x4/5LYw7byDE0=
 github.com/sirupsen/logrus v1.9.0/go.mod h1:naHLuLoDiP4jHNo9R0sCBMtWGeIprob74mVsIT4qYEQ=
 github.com/stretchr/objx v0.1.0/go.mod h1:HFkY916IF+rwdDfMAkV7OtwuqBVzrE8GR6GFx+wExME=
-github.com/stretchr/testify v1.7.0 h1:nwc3DEeHmmLAfoZucVR881uASk0Mfjw8xYJ99tb5CcY=
 github.com/stretchr/testify v1.7.0/go.mod h1:6Fq8oRcR53rry900zMqJjRRixrwX3KX962/h/Wwjteg=
+github.com/stretchr/testify v1.9.0 h1:HtqpIVDClZ4nwg75+f6Lvsy/wHu+3BoSGCbBAcpTsTg=
+github.com/stretchr/testify v1.9.0/go.mod h1:r2ic/lqez/lEtzL7wO/rwa5dbSLXVDPFyf8C91i36aY=
 golang.org/x/sys v0.0.0-20220715151400-c0bba94af5f8 h1:0A+M6Uqn+Eje4kHMK80dtF3JCXC4ykBgQG4Fe06QRhQ=
 golang.org/x/sys v0.0.0-20220715151400-c0bba94af5f8/go.mod h1:oPkhp1MJrh7nUepCBck5+mAzfO9JrbApNNgaTdGDITg=
+gopkg.in/check.v1 v0.0.0-20161208181325-20d25e280405 h1:yhCVgyC4o1eVCa2tZl7eS0r+SDo693bJlVdllGtEeKM=
 gopkg.in/check.v1 v0.0.0-20161208181325-20d25e280405/go.mod h1:Co6ibVJAznAaIkqp8huTwlJQCZ016jof/cbN4VW5Yz0=
-gopkg.in/yaml.v3 v3.0.0-20200313102051-9f266ea9e77c h1:dUUwHk2QECo/6vqA44rthZ8ie2QXMNeKRTHCNY2nXvo=
 gopkg.in/yaml.v3 v3.0.0-20200313102051-9f266ea9e77c/go.mod h1:K4uyk7z7BCEPqu6E+C64Yfv1cQ7kz7rIZviUmN+EgEM=
+gopkg.in/yaml.v3 v3.0.1 h1:fxVm/GzAzEWqLHuvctI91KS9hhNmmWOoWu0XTYJS7CA=
+gopkg.in/yaml.v3 v3.0.1/go.mod h1:K4uyk7z7BCEPqu6E+C64Yfv1cQ7kz7rIZviUmN+EgEM=

main.go

@@ -1,142 +0,0 @@
-package main
-
-import (
-	"bytes"
-	"encoding/binary"
-	"flag"
-	"fmt"
-	"net"
-	"os"
-	"path/filepath"
-	"time"
-
-	"github.com/BurntSushi/toml"
-
-	log "github.com/sirupsen/logrus"
-)
-
-var (
-	host       string
-	port       int
-	streamname string
-	bps        int
-	channel    int
-	delay      int
-	loglevel   int
-
-	bpsOpts = []int{0, 110, 150, 300, 600, 1200, 2400, 4800, 9600, 14400, 19200, 31250,
-		38400, 57600, 115200, 128000, 230400, 250000, 256000, 460800, 921600,
-		1000000, 1500000, 2000000, 3000000}
-)
-
-type (
-	// connection represents the configurable fields of a config.toml
-	connection struct {
-		Host       string
-		Port       int
-		Streamname string
-	}
-
-	// config maps toml headers
-	config struct {
-		Connection map[string]connection
-	}
-)
-
-func main() {
-	flag.StringVar(&host, "host", "localhost", "vban host")
-	flag.StringVar(&host, "h", "localhost", "vban host (shorthand)")
-	flag.IntVar(&port, "port", 6980, "vban server port")
-	flag.IntVar(&port, "p", 6980, "vban server port (shorthand)")
-	flag.StringVar(&streamname, "streamname", "Command1", "stream name for text requests")
-	flag.StringVar(&streamname, "s", "Command1", "stream name for text requests (shorthand)")
-	flag.IntVar(&bps, "bps", 0, "vban bps")
-	flag.IntVar(&bps, "b", 0, "vban bps (shorthand)")
-	flag.IntVar(&channel, "channel", 0, "vban channel")
-	flag.IntVar(&channel, "c", 0, "vban channel (shorthand)")
-	flag.IntVar(&delay, "delay", 20, "delay between requests")
-	flag.IntVar(&delay, "d", 20, "delay between requests (shorthand)")
-	flag.IntVar(&loglevel, "loglevel", int(log.WarnLevel), "log level")
-	flag.IntVar(&loglevel, "l", int(log.WarnLevel), "log level (shorthand)")
-	flag.Parse()
-
-	if loglevel >= int(log.PanicLevel) && loglevel <= int(log.TraceLevel) {
-		log.SetLevel(log.Level(loglevel))
-	}
-
-	c, err := vbanConnect()
-	if err != nil {
-		log.Fatal(err)
-	}
-	defer c.Close()
-
-	header := newRequestHeader(streamname, indexOf(bpsOpts, bps), channel)
-	for _, arg := range flag.Args() {
-		err := send(c, header, arg)
-		if err != nil {
-			log.Error(err.Error())
-		}
-	}
-}
-
-// vbanConnect establishes a VBAN connection to remote host
-func vbanConnect() (*net.UDPConn, error) {
-	homeDir, err := os.UserHomeDir()
-	if err != nil {
-		return nil, err
-	}
-	f := filepath.Join(homeDir, ".vbantxt_cli", "config.toml")
-	if _, err := os.Stat(f); err == nil {
-		conn, err := connFromToml(f)
-		if err != nil {
-			return nil, err
-		}
-		if !isFlagPassed("h") && !isFlagPassed("host") {
-			host = conn.Host
-		}
-		if !isFlagPassed("p") && !isFlagPassed("port") {
-			port = conn.Port
-		}
-		if !isFlagPassed("s") && !isFlagPassed("streamname") {
-			streamname = conn.Streamname
-		}
-	}
-	log.Debugf("Using values host: %s port: %d streamname: %s", host, port, streamname)
-
-	s, _ := net.ResolveUDPAddr("udp4", fmt.Sprintf("%s:%d", host, port))
-	c, err := net.DialUDP("udp4", nil, s)
-	if err != nil {
-		return nil, err
-	}
-	log.Infof("Connected to %s", c.RemoteAddr())
-
-	return c, nil
-}
-
-// connFromToml parses connection info from config.toml
-func connFromToml(f string) (*connection, error) {
-	var c config
-	_, err := toml.DecodeFile(f, &c.Connection)
-	if err != nil {
-		return nil, err
-	}
-	conn := c.Connection["connection"]
-	return &conn, nil
-}
-
-// send sends a VBAN text request over UDP to remote host
-func send(c *net.UDPConn, h *requestHeader, msg string) error {
-	log.Debugf("Sending '%s' to: %s", msg, c.RemoteAddr())
-	data := []byte(msg)
-	_, err := c.Write(append(h.header(), data...))
-	if err != nil {
-		return err
-	}
-	var a uint32
-	_ = binary.Read(bytes.NewReader(h.framecounter[:]), binary.LittleEndian, &a)
-	binary.LittleEndian.PutUint32(h.framecounter[:], a+1)
-
-	time.Sleep(time.Duration(delay) * time.Millisecond)
-
-	return nil
-}

makefile

@@ -0,0 +1,40 @@
+program = vbantxt
+
+GO = go
+BIN_DIR := bin
+
+WINDOWS=$(BIN_DIR)/$(program)_windows_amd64.exe
+LINUX=$(BIN_DIR)/$(program)_linux_amd64
+VERSION=$(shell git describe --tags --always --long --dirty)
+
+.DEFAULT_GOAL := build
+
+.PHONY: fmt vet build windows linux test clean
+fmt:        
+	$(GO) fmt ./...
+
+vet: fmt        
+	$(GO) vet ./...
+
+build: vet windows linux | $(BIN_DIR)
+	@echo version: $(VERSION)
+
+windows: $(WINDOWS)
+
+linux: $(LINUX)
+
+
+$(WINDOWS):
+	env GOOS=windows GOARCH=amd64 go build -v -o $(WINDOWS) -ldflags="-s -w -X main.version=$(VERSION)"  ./cmd/vbantxt/
+
+$(LINUX):
+	env GOOS=linux GOARCH=amd64 go build -v -o $(LINUX) -ldflags="-s -w -X main.version=$(VERSION)"  ./cmd/vbantxt/
+
+test:
+	$(GO) test ./...
+
+$(BIN_DIR):
+	@mkdir -p $@
+
+clean:
+	@rm -rv $(BIN_DIR)

option.go

@@ -0,0 +1,36 @@
+package vbantxt
+
+import (
+	"time"
+
+	log "github.com/sirupsen/logrus"
+)
+
+// Option is a functional option type that allows us to configure the VbanTxt.
+type Option func(*VbanTxt)
+
+// WithRateLimit is a functional option to set the ratelimit for requests
+func WithRateLimit(ratelimit time.Duration) Option {
+	return func(vt *VbanTxt) {
+		vt.ratelimit = ratelimit
+	}
+}
+
+// WithBPSOpt is a functional option to set the bps index for {VbanTxt}.packet
+func WithBPSOpt(bps int) Option {
+	return func(vt *VbanTxt) {
+		bpsIndex := indexOf(BpsOpts, bps)
+		if bpsIndex == -1 {
+			log.Warnf("invalid bps value %d, expected one of %v, defaulting to 0", bps, BpsOpts)
+			return
+		}
+		vt.packet.bpsIndex = bpsIndex
+	}
+}
+
+// WithChannel is a functional option to set the channel for {VbanTxt}.packet
+func WithChannel(channel int) Option {
+	return func(vt *VbanTxt) {
+		vt.packet.channel = channel
+	}
+}

packet.go

@@ -1,50 +1,71 @@
-package main
+package vbantxt
 
-var r *requestHeader
+import (
+	"bytes"
+	"encoding/binary"
 
-const VBAN_PROTOCOL_TXT = 0x40
+	log "github.com/sirupsen/logrus"
+)
 
-// requestHeader represents a single request header
-type requestHeader struct {
-	name         string
+const (
+	vbanProtocolTxt = 0x40
+	streamNameSz    = 16
+	headerSz        = 4 + 1 + 1 + 1 + 1 + 16 + 4
+)
+
+var BpsOpts = []int{0, 110, 150, 300, 600, 1200, 2400, 4800, 9600, 14400, 19200, 31250,
+	38400, 57600, 115200, 128000, 230400, 250000, 256000, 460800, 921600,
+	1000000, 1500000, 2000000, 3000000}
+
+type packet struct {
+	streamname   []byte
 	bpsIndex     int
 	channel      int
 	framecounter []byte
+	hbuf         *bytes.Buffer
 }
 
-// newRequestHeader returns a pointer to a requestHeader struct as a singleton
-func newRequestHeader(streamname string, bpsI, channel int) *requestHeader {
-	if r != nil {
-		return r
+// newPacket returns a packet struct with default values, framecounter at 0.
+func newPacket(streamname string) packet {
+	streamnameBuf := make([]byte, streamNameSz)
+	copy(streamnameBuf, streamname)
+
+	return packet{
+		streamname:   streamnameBuf,
+		bpsIndex:     0,
+		channel:      0,
+		framecounter: make([]byte, 4),
+		hbuf:         bytes.NewBuffer(make([]byte, headerSz)),
 	}
-	return &requestHeader{streamname, bpsI, channel, make([]byte, 4)}
 }
 
 // sr defines the samplerate for the request
-func (r *requestHeader) sr() byte {
-	return byte(VBAN_PROTOCOL_TXT + r.bpsIndex)
+func (p *packet) sr() byte {
+	return byte(vbanProtocolTxt + p.bpsIndex)
 }
 
 // nbc defines the channel of the request
-func (r *requestHeader) nbc() byte {
-	return byte(r.channel)
+func (p *packet) nbc() byte {
+	return byte(p.channel)
 }
 
-// streamname defines the stream name of the text request
-func (r *requestHeader) streamname() []byte {
-	b := make([]byte, 16)
-	copy(b, r.name)
-	return b
+// header returns a fully formed packet header
+func (p *packet) header() []byte {
+	p.hbuf.Reset()
+	p.hbuf.WriteString("VBAN")
+	p.hbuf.WriteByte(p.sr())
+	p.hbuf.WriteByte(byte(0))
+	p.hbuf.WriteByte(p.nbc())
+	p.hbuf.WriteByte(byte(0x10))
+	p.hbuf.Write(p.streamname)
+	p.hbuf.Write(p.framecounter)
+	return p.hbuf.Bytes()
 }
 
-// header returns a fully formed text request packet header
-func (t *requestHeader) header() []byte {
-	h := []byte("VBAN")
-	h = append(h, t.sr())
-	h = append(h, byte(0))
-	h = append(h, t.nbc())
-	h = append(h, byte(0x10))
-	h = append(h, t.streamname()...)
-	h = append(h, t.framecounter...)
-	return h
+// bumpFrameCounter increments the frame counter by 1
+func (p *packet) bumpFrameCounter() {
+	x := binary.LittleEndian.Uint32(p.framecounter)
+	binary.LittleEndian.PutUint32(p.framecounter, x+1)
+
+	log.Tracef("framecounter: %d", x)
 }

testdata/matrix.txt

@@ -0,0 +1,4 @@
+Point(ASIO128.IN[1..4],ASIO128.OUT[1]).dBGain = -3
+Point(ASIO128.IN[1..4],ASIO128.OUT[2]).dBGain = -3
+Point(ASIO128.IN[1..4],ASIO128.OUT[1]).Mute = 1
+Point(ASIO128.IN[1..4],ASIO128.OUT[2]).Mute = 1

testdata/vm.txt

@@ -0,0 +1,3 @@
+strip[0].mute=1;strip[0].mono=0
+strip[1].mute=0;strip[1].mono=1
+bus[3].eq.On=0

udpconn.go

@@ -0,0 +1,48 @@
+package vbantxt
+
+import (
+	"fmt"
+	"net"
+
+	log "github.com/sirupsen/logrus"
+)
+
+// udpConn represents the UDP client
+type udpConn struct {
+	conn *net.UDPConn
+}
+
+// newUDPConn returns a UDP client
+func newUDPConn(host string, port int) (udpConn, error) {
+	udpAddr, err := net.ResolveUDPAddr("udp4", fmt.Sprintf("%s:%d", host, port))
+	if err != nil {
+		return udpConn{}, err
+	}
+	conn, err := net.DialUDP("udp4", nil, udpAddr)
+	if err != nil {
+		return udpConn{}, err
+	}
+	log.Infof("Outgoing address %s", conn.RemoteAddr())
+
+	return udpConn{conn: conn}, nil
+}
+
+// Write implements the io.WriteCloser interface
+func (u udpConn) Write(buf []byte) (int, error) {
+	n, err := u.conn.Write(buf)
+	if err != nil {
+		return 0, err
+	}
+	log.Debugf("Sending '%s' to: %s", string(buf), u.conn.RemoteAddr())
+
+	return n, nil
+}
+
+// Close implements the io.WriteCloser interface
+func (u udpConn) Close() error {
+	err := u.conn.Close()
+	if err != nil {
+		return err
+	}
+	return nil
+}

util.go

@@ -1,8 +1,5 @@
-package main
+package vbantxt
 
-import "flag"
-
-// indexOf returns the index of an element in an array
 func indexOf[T comparable](collection []T, e T) int {
 	for i, x := range collection {
 		if x == e {
@@ -11,13 +8,3 @@ func indexOf[T comparable](collection []T, e T) int {
 	}
 	return -1
 }
-
-func isFlagPassed(name string) bool {
-	found := false
-	flag.Visit(func(f *flag.Flag) {
-		if f.Name == name {
-			found = true
-		}
-	})
-	return found
-}

vbantxt.go

@@ -0,0 +1,59 @@
+package vbantxt
+
+import (
+	"fmt"
+	"io"
+	"time"
+)
+
+// VbanTxt is used to send VBAN-TXT requests to a distant Voicemeeter/Matrix.
+type VbanTxt struct {
+	udpConn   io.WriteCloser
+	packet    packet
+	ratelimit time.Duration
+}
+
+// New constructs a fully formed VbanTxt instance. This is the package's entry point.
+// It sets default values for it's fields and then runs the option functions.
+func New(host string, port int, streamname string, options ...Option) (*VbanTxt, error) {
+	udpConn, err := newUDPConn(host, port)
+	if err != nil {
+		return nil, fmt.Errorf("error creating UDP client for (%s:%d): %w", host, port, err)
+	}
+
+	vt := &VbanTxt{
+		udpConn:   udpConn,
+		packet:    newPacket(streamname),
+		ratelimit: time.Duration(20) * time.Millisecond,
+	}
+
+	for _, o := range options {
+		o(vt)
+	}
+
+	return vt, nil
+}
+
+// Send is resonsible for firing each VBAN-TXT request.
+// It waits for {vt.ratelimit} time before returning.
+func (vt VbanTxt) Send(cmd string) error {
+	_, err := vt.udpConn.Write(append(vt.packet.header(), []byte(cmd)...))
+	if err != nil {
+		return fmt.Errorf("error sending command (%s): %w", cmd, err)
+	}
+
+	vt.packet.bumpFrameCounter()
+
+	time.Sleep(vt.ratelimit)
+
+	return nil
+}
+
+// Close is responsible for closing the UDP Client connection
+func (vt VbanTxt) Close() error {
+	err := vt.udpConn.Close()
+	if err != nil {
+		return fmt.Errorf("error attempting to close UDP Client: %w", err)
+	}
+	return nil
+}

vbantxt_test.go

@@ -0,0 +1,42 @@
+package vbantxt_test
+
+import (
+	"bufio"
+	"bytes"
+	_ "embed"
+	"testing"
+
+	"github.com/onyx-and-iris/vbantxt"
+	"github.com/stretchr/testify/require"
+)
+
+//go:embed testdata/vm.txt
+var vm []byte
+
+//go:embed testdata/matrix.txt
+var matrix []byte
+
+func run(t *testing.T, client *vbantxt.VbanTxt, script []byte) {
+	t.Helper()
+
+	r := bytes.NewReader(script)
+	scanner := bufio.NewScanner(r)
+	for scanner.Scan() {
+		err := client.Send(scanner.Text())
+		require.NoError(t, err)
+	}
+}
+
+func TestSendVm(t *testing.T) {
+	client, err := vbantxt.New("vm.local", 6980, "onyx")
+	require.NoError(t, err)
+
+	run(t, client, vm)
+}
+
+func TestSendMatrix(t *testing.T) {
+	client, err := vbantxt.New("vm.local", 6990, "onyx")
+	require.NoError(t, err)
+
+	run(t, client, matrix)
+}