Fixed segmenter bug

cmd/media/fingerprint.go

@@ -3,6 +3,7 @@ package main
 import (
 	"fmt"
 	"os"
+	"time"
 
 	// Packages
 	chromaprint "github.com/mutablelogic/go-media/pkg/chromaprint"
@@ -18,10 +19,11 @@ type FingerprintCommands struct {
 }
 
 type MatchMusic struct {
-	Path   string   `arg:"" type:"path" help:"File"`
-	APIKey string   `env:"CHROMAPRINT_KEY" help:"API key for the music matching service (https://acoustid.org/login)"`
-	Type   []string `cmd:"" help:"Type of match to perform" enum:"any,recording,release,releasegroup,track" default:"any"`
-	Score  float64  `cmd:"" help:"Minimum match scoreto perform" default:"0.9"`
+	Path     string        `arg:"" type:"path" help:"File"`
+	APIKey   string        `env:"CHROMAPRINT_KEY" help:"API key for the music matching service (https://acoustid.org/login)"`
+	Type     []string      `cmd:"" help:"Type of match to perform" enum:"any,recording,release,releasegroup,track" default:"any"`
+	Score    float64       `cmd:"" help:"Minimum match scoreto perform" default:"0.9"`
+	Duration time.Duration `cmd:"" help:"Length of audio to use for fingerprinting" default:"30s"`
 }
 
 ///////////////////////////////////////////////////////////////////////////////
@@ -62,7 +64,7 @@ func (cmd *MatchMusic) Run(app server.Cmd) error {
 	}
 
 	// Create the matches
-	matches, err := client.Match(app.Context(), r, meta)
+	matches, err := client.Match(app.Context(), r, cmd.Duration, meta)
 	if err != nil {
 		return err
 	}
@@ -78,17 +80,3 @@ func (cmd *MatchMusic) Run(app server.Cmd) error {
 	fmt.Println(result)
 	return nil
 }
-
-/*
-
-	META_RECORDING Meta = (1 << iota)
-	META_RECORDINGID
-	META_RELEASE
-	META_RELEASEID
-	META_RELEASEGROUP
-	META_RELEASEGROUPID
-	META_TRACK
-	META_COMPRESS
-	META_USERMETA
-	META_SOURCE
-*/

pkg/chromaprint/client.go

@@ -38,6 +38,9 @@ const (
 
 	// defaultQps rate limits number of requests per second
 	defaultQps = 3
+
+	// sample rate used for fingerprinting
+	sampleRate = 32000
 )
 
 ///////////////////////////////////////////////////////////////////////////////
@@ -94,10 +97,11 @@ func (c *Client) Lookup(fingerprint string, duration time.Duration, flags Meta)
 ////////////////////////////////////////////////////////////////////////////////
 // FINGERPRINT
 
-// Match a media file and lookup any matches
-func (c *Client) Match(ctx context.Context, r io.Reader, flags Meta) ([]*ResponseMatch, error) {
+// Match a media file and lookup any matches, using up to "dur" seconds
+// to fingerprint (or zero for no limit). The fingerprint is calculated
+func (c *Client) Match(ctx context.Context, r io.Reader, dur time.Duration, flags Meta) ([]*ResponseMatch, error) {
 	// Create a segmenter
-	segmenter, err := segmenter.NewReader(r, 0, 32000)
+	segmenter, err := segmenter.NewReader(r, dur, sampleRate)
 	if err != nil {
 		return nil, err
 	}
@@ -111,13 +115,17 @@ func (c *Client) Match(ctx context.Context, r io.Reader, flags Meta) ([]*Respons
 	defer fp.Free()
 
 	// Start the fingerprinting
-	if err := fp.Start(32000, 1); err != nil {
+	if err := fp.Start(sampleRate, 1); err != nil {
 		return nil, err
 	}
 
-	// Perform fingerprinting
+	// Perform fingerprinting. Segment the audio into 'dur' segments, only feed
+	// the fingerprinter when the timestamp is less than 'dur'
 	if err := segmenter.DecodeInt16(ctx, func(timestamp time.Duration, data []int16) error {
-		return fp.WritePtr(uintptr(unsafe.Pointer(&data[0])), len(data))
+		if dur == 0 || timestamp < dur {
+			return fp.WritePtr(uintptr(unsafe.Pointer(&data[0])), len(data))
+		}
+		return nil
 	}); err != nil {
 		return nil, err
 	}
@@ -127,6 +135,7 @@ func (c *Client) Match(ctx context.Context, r io.Reader, flags Meta) ([]*Respons
 		return nil, err
 	}
 
+	// Get fingerprint value
 	value, err := fp.GetFingerprint()
 	if err != nil {
 		return nil, err

pkg/chromaprint/client_test.go

@@ -89,7 +89,7 @@ func Test_client_004(t *testing.T) {
 	}
 	defer r.Close()
 
-	matches, err := client.Match(context.Background(), r, META_ALL)
+	matches, err := client.Match(context.Background(), r, 0, META_ALL)
 	assert.NoError(err)
 	t.Log(matches)
 }

pkg/segmenter/segmenter.go

@@ -87,7 +87,7 @@ func (s *Segmenter) Close() error {
 
 // Return current timestamp
 func (s *Segmenter) Duration() time.Duration {
-	return s.ts
+	return s.reader.Duration()
 }
 
 // Segments are output through a callback, with the samples and a timestamp
@@ -109,7 +109,7 @@ func (s *Segmenter) DecodeFloat32(ctx context.Context, fn SegmentFuncFloat32) er
 
 	// Allocate the buffer
 	if s.n > 0 {
-		s.buf_flt = make([]float32, s.n)
+		s.buf_flt = make([]float32, 0, s.n)
 	}
 
 	// Decode samples and segment
@@ -174,7 +174,7 @@ func (s *Segmenter) DecodeInt16(ctx context.Context, fn SegmentFuncInt16) error
 
 	// Allocate the buffer
 	if s.n > 0 {
-		s.buf_s16 = make([]int16, s.n)
+		s.buf_s16 = make([]int16, 0, s.n)
 	}
 
 	// Decode samples and segment