.gitignore

@@ -0,0 +1 @@
+/segmento

main.go

@@ -0,0 +1,120 @@
+package main
+
+import (
+	"flag"
+	"fmt"
+	"io"
+	"log"
+	"net/http"
+	"os"
+	"time"
+
+	"github.com/tcolgate/mp3"
+)
+
+// TODO what should be the behaviour when adding a Frame to a Segment causes it to over-shoot
+// the TargetDuration?
+// should the frame be partially added, or not added at all?
+// typical frame duration 36ms
+type Segment struct {
+	TargetDuration time.Duration
+	Duration       time.Duration
+	Data           []byte
+}
+
+func newSegment(capacity int) *Segment {
+	return &Segment{
+		Data: make([]byte, 0, capacity),
+	}
+}
+
+func (s *Segment) Write(p []byte) (n int, err error) {
+	fmt.Println("write", len(p), "bytes")
+	return len(p), nil
+}
+
+type MP3HTTPSegmenter struct {
+	decoder *mp3.Decoder
+}
+
+func (s *MP3HTTPSegmenter) Segment(r io.Reader) (chan Segment, error) {
+	c := make(chan Segment)
+
+	go func() {
+		d := mp3.NewDecoder(r)
+
+		var (
+			v       mp3.Frame
+			skipped int
+		)
+
+		for {
+			if err := d.Decode(&v, &skipped); err != nil {
+				log.Fatal(err)
+			}
+
+			fmt.Println("decoded frame of", v.Size(), "bytes, duration", v.Duration(), ", skipped", skipped, "bytes")
+		}
+	}()
+
+	return c, nil
+}
+
+func newMP3HTTPSegmenter() *MP3HTTPSegmenter {
+	return &MP3HTTPSegmenter{}
+}
+
+// TODO
+
+// A Segmenter class which allows the passing in of a Reader
+// i.e.
+// Segment(r io.Reader) (chan *Segment, error)
+// This will create an mp3.NewDecoder(r) and store the returned decoder.
+// As the Reader is read, the Segmenter will publish a stream of SegmentEvents
+
+func main() {
+	// TODO accept some flags with:
+	// URL - source of stream
+	// TargetLength - length of segments in seconds
+	// Output
+	//   -d some_dir/ => output playlist and chunks to this directory, cleaning up old files from time to time.
+	//   -b 0.0.0.0:3000 => serve playlist and chunks from an HTTP server bound to this address
+
+	var url string
+	flag.StringVar(&url, "url", "", "URL of MP3 stream")
+
+	flag.Parse()
+
+	if url == "" {
+		log.Println("Invalid arguments")
+		flag.PrintDefaults()
+		os.Exit(-1)
+	}
+
+	log.Println("Open URL:", url)
+
+	client := &http.Client{}
+	resp, err := client.Get(url)
+
+	if err != nil {
+		log.Fatal(err)
+	}
+
+	defer resp.Body.Close()
+
+	segmenter := newMP3HTTPSegmenter()
+	segments, err := segmenter.Segment(resp.Body)
+	if err != nil {
+		log.Fatal(err)
+	}
+
+	go func() {
+		for segment := range segments {
+			log.Println("got segment", segment)
+		}
+	}()
+
+	time.Sleep(10 * time.Second)
+
+	log.Println("exiting")
+}