Add pulseaudio volume display

Signed-off-by: Knut Ahlers <knut@ahlers.me>

cmd/streamdeck/display_pulsevolume.go

@@ -0,0 +1,125 @@
+// +build linux
+
+package main
+
+import (
+	"context"
+	"fmt"
+	"image/color"
+	"time"
+
+	"github.com/pkg/errors"
+	log "github.com/sirupsen/logrus"
+)
+
+func init() {
+	registerDisplayElement("pulsevolume", &displayElementPulseVolume{})
+}
+
+type displayElementPulseVolume struct{}
+
+func (d displayElementPulseVolume) Display(ctx context.Context, idx int, attributes map[string]interface{}) error {
+	if pulseClient == nil {
+		return errors.New("PulseAudio client not initialized")
+	}
+
+	sinkMatch, sinkOK := attributes["sink"].(string)
+	sinkOK = sinkOK && sinkMatch != ""
+
+	sinkInputMatch, sinkInputOK := attributes["sink_input"].(string)
+	sinkInputOK = sinkInputOK && sinkInputMatch != ""
+
+	var (
+		err    error
+		volume float64
+	)
+
+	switch {
+
+	case (sinkInputOK && sinkOK) || (!sinkInputOK && !sinkOK):
+		return errors.New("Exactly one of 'sink' and 'sink_input' must be specified")
+
+	case sinkInputOK:
+		volume, err = pulseClient.GetSinkInputVolume(sinkInputMatch)
+
+	case sinkOK:
+		volume, err = pulseClient.GetSinkVolume(sinkMatch)
+
+	}
+
+	if err != nil {
+		return errors.Wrap(err, "Unable to get volume")
+	}
+
+	img := newTextOnImageRenderer()
+
+	// Initialize color
+	var textColor color.Color = color.RGBA{0xff, 0xff, 0xff, 0xff}
+	if rgba, ok := attributes["color"].([]interface{}); ok {
+		if len(rgba) != 4 {
+			return errors.New("RGBA color definition needs 4 hex values")
+		}
+
+		tmpCol := color.RGBA{}
+
+		for cidx, vp := range []*uint8{&tmpCol.R, &tmpCol.G, &tmpCol.B, &tmpCol.A} {
+			switch rgba[cidx].(type) {
+			case int:
+				*vp = uint8(rgba[cidx].(int))
+			case float64:
+				*vp = uint8(rgba[cidx].(float64))
+			}
+		}
+
+		textColor = tmpCol
+	}
+
+	// Initialize fontsize
+	var fontsize float64 = 120
+	if v, ok := attributes["font_size"].(float64); ok {
+		fontsize = v
+	}
+
+	var border = 10
+	if v, ok := attributes["border"].(int); ok {
+		border = v
+	}
+
+	if err = img.DrawBigText(fmt.Sprintf("%.0f%%", volume*100), fontsize, border, textColor); err != nil {
+		return errors.Wrap(err, "Unable to draw text")
+	}
+
+	if err = ctx.Err(); err != nil {
+		// Page context was cancelled, do not draw
+		return err
+	}
+
+	return errors.Wrap(sd.FillImage(idx, img.GetImage()), "Unable to set image")
+}
+
+func (d displayElementPulseVolume) NeedsLoop(attributes map[string]interface{}) bool { return true }
+
+func (d *displayElementPulseVolume) StartLoopDisplay(ctx context.Context, idx int, attributes map[string]interface{}) error {
+	var interval = time.Second
+	if v, ok := attributes["interval"].(int); ok {
+		interval = time.Duration(v) * time.Second
+	}
+
+	go func() {
+		for tick := time.NewTicker(interval); ; <-tick.C {
+			if ctx.Err() != nil {
+				return
+			}
+
+			if err := d.Display(ctx, idx, attributes); err != nil {
+				log.WithError(err).Error("Unable to refresh element")
+			}
+		}
+	}()
+
+	return nil
+}
+
+func (d *displayElementPulseVolume) StopLoopDisplay() error {
+	return nil
+}

cmd/streamdeck/go.mod

@@ -10,6 +10,7 @@ require (
 	github.com/Luzifer/streamdeck v0.0.0-20191122003228-a2f524a6b22c
 	github.com/fsnotify/fsnotify v1.4.7
 	github.com/golang/freetype v0.0.0-20170609003504-e2365dfdc4a0
+	github.com/jfreymuth/pulse v0.0.0-20200804114219-7d61c4938214
 	github.com/konsorten/go-windows-terminal-sequences v1.0.2 // indirect
 	github.com/nfnt/resize v0.0.0-20180221191011-83c6a9932646
 	github.com/pkg/errors v0.8.1

cmd/streamdeck/go.sum

@@ -11,6 +11,8 @@ github.com/fsnotify/fsnotify v1.4.7/go.mod h1:jwhsz4b93w/PPRr/qN1Yymfu8t87LnFCMo
 github.com/golang/freetype v0.0.0-20170609003504-e2365dfdc4a0 h1:DACJavvAHhabrF08vX0COfcOBJRhZ8lUbR+ZWIs0Y5g=
 github.com/golang/freetype v0.0.0-20170609003504-e2365dfdc4a0/go.mod h1:E/TSTwGwJL78qG/PmXZO1EjYhfJinVAhrmmHX6Z8B9k=
 github.com/inconshreveable/go-update v0.0.0-20160112193335-8152e7eb6ccf/go.mod h1:hyb9oH7vZsitZCiBt0ZvifOrB+qc8PS5IiilCIb87rg=
+github.com/jfreymuth/pulse v0.0.0-20200804114219-7d61c4938214 h1:2xVJKIumEUWeV3vczQwn61SHjNZ94Bwk+4CTjmcePxk=
+github.com/jfreymuth/pulse v0.0.0-20200804114219-7d61c4938214/go.mod h1:cpYspI6YljhkUf1WLXLLDmeaaPFc3CnGLjDZf9dZ4no=
 github.com/konsorten/go-windows-terminal-sequences v1.0.1 h1:mweAR1A6xJ3oS2pRaGiHgQ4OO8tzTaLawm8vnODuwDk=
 github.com/konsorten/go-windows-terminal-sequences v1.0.1/go.mod h1:T0+1ngSBFLxvqU3pZ+m/2kptfBszLMUkC4ZK/EgS/cQ=
 github.com/konsorten/go-windows-terminal-sequences v1.0.2 h1:DB17ag19krx9CFsz4o3enTrPXyIXCl+2iCXH/aMAp9s=

cmd/streamdeck/pulseaudio.go

@@ -0,0 +1,112 @@
+// +build linux
+
+package main
+
+import (
+	"math"
+	"regexp"
+
+	"github.com/jfreymuth/pulse"
+	"github.com/jfreymuth/pulse/proto"
+	"github.com/pkg/errors"
+	log "github.com/sirupsen/logrus"
+)
+
+var pulseClient *pulseAudioClient
+
+func init() {
+	var err error
+	if pulseClient, err = newPulseAudioClient(); err != nil {
+		log.WithError(err).Error("Unable to connect to PulseAudio, functionality will not work")
+	}
+}
+
+type pulseAudioClient struct {
+	client *pulse.Client
+}
+
+func newPulseAudioClient() (*pulseAudioClient, error) {
+	c, err := pulse.NewClient()
+	if err != nil {
+		return nil, errors.Wrap(err, "Unable to create pulse client")
+	}
+
+	return &pulseAudioClient{client: c}, nil
+}
+
+func (p pulseAudioClient) Close() { p.client.Close() }
+
+func (p pulseAudioClient) GetSinkInputVolume(match string) (float64, error) {
+	m, err := regexp.Compile(match)
+	if err != nil {
+		return 0, errors.Wrap(err, "Unable to compile given match RegEx")
+	}
+
+	var resp proto.GetSinkInputInfoListReply
+	if err := p.client.RawRequest(&proto.GetSinkInputInfoList{}, &resp); err != nil {
+		return 0, errors.Wrap(err, "Unable to list sink inputs")
+	}
+
+	for _, info := range resp {
+		if !m.MatchString(info.MediaName) && !m.Match(info.Properties["application.name"]) {
+			continue
+		}
+
+		sinkBase, err := p.getSinkBaseVolumeByIndex(info.SinkIndex)
+		if err != nil {
+			return 0, errors.Wrap(err, "Unable to get sink base volume")
+		}
+
+		return p.unifyChannelVolumes(info.ChannelVolumes) / sinkBase, nil
+	}
+
+	return 0, errors.New("No such sink")
+}
+
+func (p pulseAudioClient) GetSinkVolume(match string) (float64, error) {
+	m, err := regexp.Compile(match)
+	if err != nil {
+		return 0, errors.Wrap(err, "Unable to compile given match RegEx")
+	}
+
+	var resp proto.GetSinkInfoListReply
+	if err := p.client.RawRequest(&proto.GetSinkInfoList{}, &resp); err != nil {
+		return 0, errors.Wrap(err, "Unable to list sinks")
+	}
+
+	for _, info := range resp {
+		if !m.MatchString(info.SinkName) && !m.MatchString(info.Device) {
+			continue
+		}
+
+		return p.unifyChannelVolumes(info.ChannelVolumes) / float64(info.BaseVolume), nil
+	}
+
+	return 0, errors.New("No such sink")
+}
+
+func (p pulseAudioClient) getSinkBaseVolumeByIndex(idx uint32) (float64, error) {
+	var resp proto.GetSinkInfoReply
+	if err := p.client.RawRequest(&proto.GetSinkInfo{SinkIndex: idx}, &resp); err != nil {
+		return 0, errors.Wrap(err, "Unable to get sink")
+	}
+
+	return float64(resp.BaseVolume), nil
+}
+
+func (p pulseAudioClient) unifyChannelVolumes(v proto.ChannelVolumes) float64 {
+	if len(v) == 0 {
+		return 0
+	}
+
+	if len(v) == 1 {
+		return float64(v[0])
+	}
+
+	var vMin = float64(v[0])
+	for i := 1; i < len(v); i++ {
+		vMin = math.Min(vMin, float64(v[i]))
+	}
+
+	return vMin
+}