Midi audio timing

.gitignore

@@ -41,4 +41,9 @@ mscz/
 *.db
 
 *.zip
-dist/
+dist/
+
+# audio
+*.mp3
+*.mid
+*.midi

README.md

@@ -79,4 +79,6 @@ Development pauses occasionally when I research better automation approaches
 - https://www.musicca.com/dictionary/scales 
 - https://www.gkiharapanindah.org/download/rekap-kidung-jemaat/
 - https://mymusictheory.com/more-music-theory-topics/key-signatures-chart/
-- https://fontdrop.info/#/?darkmode=true 
+- https://fontdrop.info/#/?darkmode=true 
+- Original MIDI Audio Arrangement by GEMA/SABDA (sabda.org). Modified for single-verse playback.
+- Sound Effect by <a href="https://pixabay.com/users/freesound_community-46691455/?utm_source=link-attribution&utm_medium=referral&utm_campaign=music&utm_content=91643">freesound_community</a> from <a href="https://pixabay.com//?utm_source=link-attribution&utm_medium=referral&utm_campaign=music&utm_content=91643">Pixabay</a>

cmd/lab/audio-stream/stream/audio_stream.go

@@ -0,0 +1,174 @@
+package stream
+
+import (
+	"io"
+	"log"
+	"net/http"
+	"os"
+	"strconv"
+	"sync"
+	"time"
+
+	"github.com/hcl/audioduration"
+	"github.com/julienschmidt/httprouter"
+)
+
+type AudioStream struct {
+	Sig chan os.Signal
+}
+
+func (dh *AudioStream) ServeHTTP(w http.ResponseWriter, r *http.Request, ps httprouter.Params) {
+
+	paths := []string{
+		`/home/jodiivan/go/src/github.com/jodi-ivan/numbered-notation-xml/files/audio/kj-001-opening.mp3`,
+		`/home/jodiivan/go/src/github.com/jodi-ivan/numbered-notation-xml/files/audio/kj-001-core.mp3`,
+	}
+
+	openingFile, err := os.Open(paths[0])
+	if err != nil {
+		log.Println("Failed to open openingFile", err.Error())
+		w.WriteHeader(500)
+		w.Write([]byte(err.Error()))
+		return
+	}
+
+	defer openingFile.Close()
+
+	openingDuration, err := audioduration.Mp3(openingFile)
+	if err != nil {
+		log.Println("Failed to calculate mp3 opening duration", err.Error())
+		w.WriteHeader(500)
+		w.Write([]byte(err.Error()))
+		return
+	}
+
+	coreFile, err := os.Open(paths[1])
+	if err != nil {
+		log.Println("Failed to open coreFile", err.Error())
+		w.WriteHeader(500)
+		w.Write([]byte(err.Error()))
+		return
+	}
+
+	defer coreFile.Close()
+
+	repeatRaw := r.FormValue("repeat")
+
+	repeat, err := strconv.Atoi(repeatRaw)
+	if repeatRaw != "" && err != nil {
+		log.Printf("[ServeHTTP] invalid verse: %v", err.Error())
+		w.WriteHeader(http.StatusBadRequest)
+		w.Write([]byte("Invalid URL"))
+		return
+	}
+
+	if repeat == 1 {
+		repeat = 0
+	}
+
+	w.Header().Set("Connection", "Keep-Alive")
+	w.Header().Set("Access-Control-Allow-Origin", "*")
+	w.Header().Set("X-Content-Type-Options", "nosniff")
+	w.Header().Set("Transfer-Encoding", "chunked")
+	w.Header().Set("Content-Type", "audio/mpeg")
+
+	ctx := r.Context()
+	currRepeat := 1
+	measure := 0
+	measureMtx := sync.Mutex{}
+
+	songMeasure := 23.0
+	songTempo := 85.0
+	songDuration := ((songMeasure * 4) / songTempo) * 60.0
+	op := time.Duration(openingDuration * float64(time.Second))
+	core := time.Duration(songDuration * float64(time.Second)) // for 1 timesignature no changes
+	log.Println("wait for ", op.String())
+
+	files := []*os.File{
+		openingFile,
+		coreFile,
+	}
+	go func() {
+
+		<-time.After(op)
+		measure = 1
+		log.Println("Start: Measure ", measure)
+		ticker := time.NewTicker(core / 23)
+		defer ticker.Stop()
+
+		for {
+			select {
+			case <-ticker.C:
+				measureMtx.Lock()
+				measure++
+				measureMtx.Unlock()
+				log.Println("Measure ", measure)
+				if measure == 23 {
+					return
+				}
+			case <-dh.Sig:
+				log.Println("os signal interrupt")
+				return
+			}
+		}
+
+	}()
+
+	for i, file := range files {
+
+		buf := make([]byte, 4096) // 4KB chunks
+
+		// Loop core indefinitely
+		for {
+			select {
+			case <-ctx.Done():
+				log.Println("context timeout")
+
+				return
+			case <-dh.Sig:
+				log.Println("os signal interrupt")
+				return
+			default:
+			}
+
+			n, err := file.Read(buf)
+			if err != nil {
+				if err == io.EOF {
+					log.Println("Music ", file.Name(), " is finished")
+					// if i == 1 && currRepeat == repeat {
+					// 	break
+					// }
+					measureMtx.Lock()
+					measure = 0
+					measureMtx.Unlock()
+
+					if i == 0 || ((i == 1 && repeat == 0) || (i == 1 && currRepeat == repeat)) {
+						break
+					} else if currRepeat < repeat {
+						currRepeat++
+						file.Seek(0, 0)
+						continue
+					}
+				}
+				log.Println("Failed to ", err.Error())
+				return
+			}
+
+			_, werr := w.Write(buf[:n])
+			if werr != nil {
+				log.Println("Failed to ", werr.Error())
+				return
+			}
+
+			if f, ok := w.(http.Flusher); ok {
+				f.Flush()
+			}
+
+		}
+	}
+
+	// wg.Wait()
+
+	log.Println("It is done")
+
+}

cmd/rest/app.go

@@ -8,6 +8,7 @@ import (
 	"syscall"
 
 	"github.com/jodi-ivan/numbered-notation-xml/adapter"
+	strmadapter "github.com/jodi-ivan/numbered-notation-xml/cmd/lab/audio-stream/stream"
 	lab "github.com/jodi-ivan/numbered-notation-xml/cmd/rest/adapter"
 	"github.com/jodi-ivan/numbered-notation-xml/decorator"
 	"github.com/jodi-ivan/numbered-notation-xml/internal/renderer"
@@ -63,14 +64,18 @@ func main() {
 		Db:        db,
 	})
 
-	sigs := make(chan os.Signal, 1)
+	sigs := make(chan os.Signal, 2)
 
 	ws.Register("GET", "/internal/diagnostic/verse/:scope", &adapter.DiagnosticHTTP{
 		Usecase:   usecaseMod,
 		Interrupt: sigs,
 		Repo:      repo,
 	})
 
+	ws.Register("GET", "/internal/v1/lab", &strmadapter.AudioStream{
+		Sig: sigs,
+	})
+
 	err = ws.Serve(cfg.Webserver.Port)
 	if err != nil {
 		log.Printf("Failed to start the server. Err: %s", err.Error())

files/audio/.gitkeep

@@ -0,0 +1 @@
+put your *.mp3 file