muxer: regenerate init.mp4 only when its content changes (#100)

bluenviron · Sep 27, 2023 · f228995 · f228995
1 parent 66221e4
commit f228995
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Showing 6 changed files with 63 additions and 10 deletions.
diff --git a/muxer_segment.go b/muxer_segment.go
@@ -19,6 +19,7 @@ type muxerSegment interface {
 	getName() string
 	getDuration() time.Duration
 	getSize() uint64
+	isForceSwitched() bool
 	reader() (io.ReadCloser, error)
 }
 
@@ -37,10 +38,14 @@ func (g muxerGap) getDuration() time.Duration {
 	return g.duration
 }
 
-func (g muxerGap) getSize() uint64 {
+func (muxerGap) getSize() uint64 {
 	return 0
 }
 
-func (g muxerGap) reader() (io.ReadCloser, error) {
+func (muxerGap) isForceSwitched() bool {
+	return false
+}
+
+func (muxerGap) reader() (io.ReadCloser, error) {
 	return nil, fmt.Errorf("unimplemented")
 }
diff --git a/muxer_segment_fmp4.go b/muxer_segment_fmp4.go
@@ -18,6 +18,7 @@ type muxerSegmentFMP4 struct {
 	audioTrack     *Track
 	audioTimeScale uint32
 	prefix         string
+	forceSwitched  bool
 	genPartID      func() uint64
 	publishPart    func(*muxerPart)
 
@@ -39,6 +40,7 @@ func newMuxerSegmentFMP4(
 	audioTrack *Track,
 	audioTimeScale uint32,
 	prefix string,
+	forceSwitched bool,
 	factory storage.Factory,
 	genPartID func() uint64,
 	publishPart func(*muxerPart),
@@ -53,6 +55,7 @@ func newMuxerSegmentFMP4(
 		audioTrack:     audioTrack,
 		audioTimeScale: audioTimeScale,
 		prefix:         prefix,
+		forceSwitched:  forceSwitched,
 		genPartID:      genPartID,
 		publishPart:    publishPart,
 		name:           segmentName(prefix, id, true),
@@ -93,6 +96,10 @@ func (s *muxerSegmentFMP4) getSize() uint64 {
 	return s.storage.Size()
 }
 
+func (s *muxerSegmentFMP4) isForceSwitched() bool {
+	return s.forceSwitched
+}
+
 func (s *muxerSegmentFMP4) reader() (io.ReadCloser, error) {
 	return s.storage.Reader()
 }

diff --git a/muxer_segment_mpegts.go b/muxer_segment_mpegts.go
@@ -83,6 +83,10 @@ func (t *muxerSegmentMPEGTS) getSize() uint64 {
 	return t.storage.Size()
 }
 
+func (*muxerSegmentMPEGTS) isForceSwitched() bool {
+	return false
+}
+
 func (t *muxerSegmentMPEGTS) reader() (io.ReadCloser, error) {
 	return t.storage.Reader()
 }

diff --git a/muxer_segmenter_fmp4.go b/muxer_segmenter_fmp4.go
@@ -330,6 +330,7 @@ func (m *muxerSegmenterFMP4) writeVideo(
 			m.audioTrack,
 			m.audioTimeScale,
 			m.prefix,
+			false,
 			m.factory,
 			m.genPartID,
 			m.publishPart,
@@ -372,6 +373,7 @@ func (m *muxerSegmenterFMP4) writeVideo(
 			m.audioTrack,
 			m.audioTimeScale,
 			m.prefix,
+			forceSwitch,
 			m.factory,
 			m.genPartID,
 			m.publishPart,
@@ -461,6 +463,7 @@ func (m *muxerSegmenterFMP4) writeAudio(ntp time.Time, dts time.Duration, au []b
 				m.audioTrack,
 				m.audioTimeScale,
 				m.prefix,
+				false,
 				m.factory,
 				m.genPartID,
 				m.publishPart,
@@ -506,6 +509,7 @@ func (m *muxerSegmenterFMP4) writeAudio(ntp time.Time, dts time.Duration, au []b
 			m.audioTrack,
 			m.audioTimeScale,
 			m.prefix,
+			false,
 			m.factory,
 			m.genPartID,
 			m.publishPart,

diff --git a/muxer_server.go b/muxer_server.go
@@ -819,13 +819,15 @@ func (s *muxerServer) publishSegment(segment muxerSegment) error {
 			s.segmentDeleteCount++
 		}
 
+		// always regenerate multivariant playlist since it contains bandwidth
 		buf, err := generateMultivariantPlaylist(s.variant, s.videoTrack, s.audioTrack, s.segments)
 		if err != nil {
 			return err
 		}
 		s.multivariantPlaylist = buf
 
-		if s.variant != MuxerVariantMPEGTS {
+		// regenerate init.mp4 only if missing or codec parameters have changed
+		if s.variant != MuxerVariantMPEGTS && (s.init == nil || segment.isForceSwitched()) {
 			if s.init != nil {
 				s.init.Remove()
 				s.init = nil
@@ -838,6 +840,8 @@ func (s *muxerServer) publishSegment(segment muxerSegment) error {
 			s.init = f
 		}
 
+		// do not pregenerate media playlist since it's too dynamic.
+
 		return nil
 	}()
 	if err != nil {

diff --git a/muxer_test.go b/muxer_test.go
@@ -12,6 +12,7 @@ import (
 	"time"
 
 	"github.com/bluenviron/mediacommon/pkg/codecs/mpeg4audio"
+	"github.com/bluenviron/mediacommon/pkg/formats/fmp4"
 	"github.com/stretchr/testify/require"
 
 	"github.com/bluenviron/gohlslib/pkg/codecs"
@@ -805,25 +806,53 @@ func TestMuxerDynamicParams(t *testing.T) {
 		"CODECS=\"avc1.42c028\",RESOLUTION=1920x1084,FRAME-RATE=30.000\n"+
 		"stream.m3u8\n", string(bu))
 
+	bu, _, err = doRequest(m, m.prefix+"_init.mp4", "", "", "")
+	require.NoError(t, err)
+
+	func() {
+		var init fmp4.Init
+		err = init.Unmarshal(bu)
+		require.NoError(t, err)
+		require.Equal(t, testSPS, init.Tracks[0].Codec.(*fmp4.CodecH264).SPS)
+	}()
+
+	// SPS (720p)
+	testSPS2 := []byte{
+		0x67, 0x64, 0x00, 0x1f, 0xac, 0xd9, 0x40, 0x50,
+		0x05, 0xbb, 0x01, 0x6c, 0x80, 0x00, 0x00, 0x03,
+		0x00, 0x80, 0x00, 0x00, 0x1e, 0x07, 0x8c, 0x18,
+		0xcb,
+	}
+
 	err = m.WriteH26x(testTime, 3*time.Second, [][]byte{
-		{ // SPS (720p)
-			0x67, 0x64, 0x00, 0x1f, 0xac, 0xd9, 0x40, 0x50,
-			0x05, 0xbb, 0x01, 0x6c, 0x80, 0x00, 0x00, 0x03,
-			0x00, 0x80, 0x00, 0x00, 0x1e, 0x07, 0x8c, 0x18,
-			0xcb,
-		},
+		testSPS2,
 		{5}, // IDR
 		{2},
 	})
 	require.NoError(t, err)
 
+	err = m.WriteH26x(testTime, 5*time.Second, [][]byte{
+		{5}, // IDR
+	})
+	require.NoError(t, err)
+
 	bu, _, err = doRequest(m, "index.m3u8", "", "", "")
 	require.NoError(t, err)
 	require.Equal(t, "#EXTM3U\n"+
 		"#EXT-X-VERSION:9\n"+
 		"#EXT-X-INDEPENDENT-SEGMENTS\n"+
 		"\n"+
-		"#EXT-X-STREAM-INF:BANDWIDTH=1144,AVERAGE-BANDWIDTH=989,"+
+		"#EXT-X-STREAM-INF:BANDWIDTH=912,AVERAGE-BANDWIDTH=742,"+
 		"CODECS=\"avc1.64001f\",RESOLUTION=1280x720,FRAME-RATE=30.000\n"+
 		"stream.m3u8\n", string(bu))
+
+	bu, _, err = doRequest(m, m.prefix+"_init.mp4", "", "", "")
+	require.NoError(t, err)
+
+	func() {
+		var init fmp4.Init
+		err = init.Unmarshal(bu)
+		require.NoError(t, err)
+		require.Equal(t, testSPS2, init.Tracks[0].Codec.(*fmp4.CodecH264).SPS)
+	}()
 }