hls: move fMP4 generator into dedicated folder

internal/hls/fmp4/audiosample.go

@@ -0,0 +1,17 @@
+package fmp4
+
+import (
+	"time"
+)
+
+// AudioSample is an audio sample.
+type AudioSample struct {
+	AU   []byte
+	PTS  time.Duration
+	Next *AudioSample
+}
+
+// Duration returns the sample duration.
+func (s AudioSample) Duration() time.Duration {
+	return s.Next.PTS - s.PTS
+}

internal/hls/fmp4/init.go

@@ -1,11 +1,9 @@
-package hls
+package fmp4
 
 import (
 	gomp4 "github.com/abema/go-mp4"
 	"github.com/aler9/gortsplib"
 	"github.com/aler9/gortsplib/pkg/h264"
-
-	"github.com/aler9/rtsp-simple-server/internal/mp4"
 )
 
 type myEsds struct {
@@ -21,7 +19,7 @@ func init() { //nolint:gochecknoinits
 	gomp4.AddBoxDef(&myEsds{}, 0)
 }
 
-func mp4InitGenerateVideoTrack(w *mp4.Writer, trackID int, videoTrack *gortsplib.TrackH264) error {
+func generateInitVideoTrack(w *mp4Writer, trackID int, videoTrack *gortsplib.TrackH264) error {
 	/*
 		trak
 		- tkhd
@@ -81,7 +79,7 @@ func mp4InitGenerateVideoTrack(w *mp4.Writer, trackID int, videoTrack *gortsplib
 	}
 
 	_, err = w.WriteBox(&gomp4.Mdhd{ // <mdhd/>
-		Timescale: fmp4VideoTimescale, // the number of time units that pass per second
+		Timescale: videoTimescale, // the number of time units that pass per second
 		Language:  [3]byte{'u', 'n', 'd'},
 	})
 	if err != nil {
@@ -265,7 +263,7 @@ func mp4InitGenerateVideoTrack(w *mp4.Writer, trackID int, videoTrack *gortsplib
 	return nil
 }
 
-func mp4InitGenerateAudioTrack(w *mp4.Writer, trackID int, audioTrack *gortsplib.TrackMPEG4Audio) error {
+func generateInitAudioTrack(w *mp4Writer, trackID int, audioTrack *gortsplib.TrackMPEG4Audio) error {
 	/*
 		trak
 		- tkhd
@@ -511,7 +509,8 @@ func mp4InitGenerateAudioTrack(w *mp4.Writer, trackID int, audioTrack *gortsplib
 	return nil
 }
 
-func mp4InitGenerate(videoTrack *gortsplib.TrackH264, audioTrack *gortsplib.TrackMPEG4Audio) ([]byte, error) {
+// GenerateInit generates a FMP4 initialization file.
+func GenerateInit(videoTrack *gortsplib.TrackH264, audioTrack *gortsplib.TrackMPEG4Audio) ([]byte, error) {
 	/*
 		- ftyp
 		- moov
@@ -523,7 +522,7 @@ func mp4InitGenerate(videoTrack *gortsplib.TrackH264, audioTrack *gortsplib.Trac
 		  - trex (audio)
 	*/
 
-	w := mp4.NewWriter()
+	w := newMP4Writer()
 
 	_, err := w.WriteBox(&gomp4.Ftyp{ // <ftyp/>
 		MajorBrand:   [4]byte{'m', 'p', '4', '2'},
@@ -558,7 +557,7 @@ func mp4InitGenerate(videoTrack *gortsplib.TrackH264, audioTrack *gortsplib.Trac
 	trackID := 1
 
 	if videoTrack != nil {
-		err := mp4InitGenerateVideoTrack(w, trackID, videoTrack)
+		err := generateInitVideoTrack(w, trackID, videoTrack)
 		if err != nil {
 			return nil, err
 		}
@@ -567,7 +566,7 @@ func mp4InitGenerate(videoTrack *gortsplib.TrackH264, audioTrack *gortsplib.Trac
 	}
 
 	if audioTrack != nil {
-		err := mp4InitGenerateAudioTrack(w, trackID, audioTrack)
+		err := generateInitAudioTrack(w, trackID, audioTrack)
 		if err != nil {
 			return nil, err
 		}

internal/hls/fmp4/mp4writer.go

@@ -1,4 +1,4 @@
-package mp4
+package fmp4
 
 import (
 	"io"
@@ -7,15 +7,15 @@ import (
 	"github.com/orcaman/writerseeker"
 )
 
-// Writer is a MP4 writer.
-type Writer struct {
+// mp4Writer is a MP4 writer.
+type mp4Writer struct {
 	buf *writerseeker.WriterSeeker
 	w   *gomp4.Writer
 }
 
-// NewWriter allocates a Writer.
-func NewWriter() *Writer {
-	w := &Writer{
+// newMP4Writer allocates a mp4Writer.
+func newMP4Writer() *mp4Writer {
+	w := &mp4Writer{
 		buf: &writerseeker.WriterSeeker{},
 	}
 
@@ -25,7 +25,7 @@ func NewWriter() *Writer {
 }
 
 // WriteBoxStart writes a box start.
-func (w *Writer) WriteBoxStart(box gomp4.IImmutableBox) (int, error) {
+func (w *mp4Writer) WriteBoxStart(box gomp4.IImmutableBox) (int, error) {
 	bi := &gomp4.BoxInfo{
 		Type: box.GetType(),
 	}
@@ -44,13 +44,13 @@ func (w *Writer) WriteBoxStart(box gomp4.IImmutableBox) (int, error) {
 }
 
 // WriteBoxEnd writes a box end.
-func (w *Writer) WriteBoxEnd() error {
+func (w *mp4Writer) WriteBoxEnd() error {
 	_, err := w.w.EndBox()
 	return err
 }
 
 // WriteBox writes a self-closing box.
-func (w *Writer) WriteBox(box gomp4.IImmutableBox) (int, error) {
+func (w *mp4Writer) WriteBox(box gomp4.IImmutableBox) (int, error) {
 	off, err := w.WriteBoxStart(box)
 	if err != nil {
 		return 0, err
@@ -65,7 +65,7 @@ func (w *Writer) WriteBox(box gomp4.IImmutableBox) (int, error) {
 }
 
 // RewriteBox rewrites a box.
-func (w *Writer) RewriteBox(off int, box gomp4.IImmutableBox) error {
+func (w *mp4Writer) RewriteBox(off int, box gomp4.IImmutableBox) error {
 	prevOff, err := w.w.Seek(0, io.SeekCurrent)
 	if err != nil {
 		return err
@@ -95,6 +95,6 @@ func (w *Writer) RewriteBox(off int, box gomp4.IImmutableBox) error {
 }
 
 // Bytes returns the MP4 content.
-func (w *Writer) Bytes() []byte {
+func (w *mp4Writer) Bytes() []byte {
 	return w.buf.Bytes()
 }

internal/hls/fmp4/part.go

@@ -0,0 +1,291 @@
+package fmp4
+
+import (
+	"math"
+	"time"
+
+	gomp4 "github.com/abema/go-mp4"
+	"github.com/aler9/gortsplib"
+)
+
+func durationGoToMp4(v time.Duration, timescale time.Duration) int64 {
+	return int64(math.Round(float64(v*timescale) / float64(time.Second)))
+}
+
+func generatePartVideoTraf(
+	w *mp4Writer,
+	trackID int,
+	videoSamples []*VideoSample,
+) (*gomp4.Trun, int, error) {
+	/*
+		traf
+		- tfhd
+		- tfdt
+		- trun
+	*/
+
+	_, err := w.WriteBoxStart(&gomp4.Traf{}) // <traf>
+	if err != nil {
+		return nil, 0, err
+	}
+
+	flags := 0
+
+	_, err = w.WriteBox(&gomp4.Tfhd{ // <tfhd/>
+		FullBox: gomp4.FullBox{
+			Flags: [3]byte{2, byte(flags >> 8), byte(flags)},
+		},
+		TrackID: uint32(trackID),
+	})
+	if err != nil {
+		return nil, 0, err
+	}
+
+	_, err = w.WriteBox(&gomp4.Tfdt{ // <tfdt/>
+		FullBox: gomp4.FullBox{
+			Version: 1,
+		},
+		// sum of decode durations of all earlier samples
+		BaseMediaDecodeTimeV1: uint64(durationGoToMp4(videoSamples[0].DTS, videoTimescale)),
+	})
+	if err != nil {
+		return nil, 0, err
+	}
+
+	flags = 0
+	flags |= 0x01  // data offset present
+	flags |= 0x100 // sample duration present
+	flags |= 0x200 // sample size present
+	flags |= 0x400 // sample flags present
+	flags |= 0x800 // sample composition time offset present or v1
+
+	trun := &gomp4.Trun{ // <trun/>
+		FullBox: gomp4.FullBox{
+			Version: 1,
+			Flags:   [3]byte{0, byte(flags >> 8), byte(flags)},
+		},
+		SampleCount: uint32(len(videoSamples)),
+	}
+
+	for _, e := range videoSamples {
+		off := e.PTS - e.DTS
+
+		flags := uint32(0)
+		if !e.IDRPresent {
+			flags |= 1 << 16 // sample_is_non_sync_sample
+		}
+
+		trun.Entries = append(trun.Entries, gomp4.TrunEntry{
+			SampleDuration:                uint32(durationGoToMp4(e.Duration(), videoTimescale)),
+			SampleSize:                    uint32(len(e.AVCC)),
+			SampleFlags:                   flags,
+			SampleCompositionTimeOffsetV1: int32(durationGoToMp4(off, videoTimescale)),
+		})
+	}
+
+	trunOffset, err := w.WriteBox(trun)
+	if err != nil {
+		return nil, 0, err
+	}
+
+	err = w.WriteBoxEnd() // </traf>
+	if err != nil {
+		return nil, 0, err
+	}
+
+	return trun, trunOffset, nil
+}
+
+func generatePartAudioTraf(
+	w *mp4Writer,
+	trackID int,
+	audioTrack *gortsplib.TrackMPEG4Audio,
+	audioSamples []*AudioSample,
+) (*gomp4.Trun, int, error) {
+	/*
+		traf
+		- tfhd
+		- tfdt
+		- trun
+	*/
+
+	if len(audioSamples) == 0 {
+		return nil, 0, nil
+	}
+
+	_, err := w.WriteBoxStart(&gomp4.Traf{}) // <traf>
+	if err != nil {
+		return nil, 0, err
+	}
+
+	flags := 0
+
+	_, err = w.WriteBox(&gomp4.Tfhd{ // <tfhd/>
+		FullBox: gomp4.FullBox{
+			Flags: [3]byte{2, byte(flags >> 8), byte(flags)},
+		},
+		TrackID: uint32(trackID),
+	})
+	if err != nil {
+		return nil, 0, err
+	}
+
+	_, err = w.WriteBox(&gomp4.Tfdt{ // <tfdt/>
+		FullBox: gomp4.FullBox{
+			Version: 1,
+		},
+		// sum of decode durations of all earlier samples
+		BaseMediaDecodeTimeV1: uint64(durationGoToMp4(audioSamples[0].PTS, time.Duration(audioTrack.ClockRate()))),
+	})
+	if err != nil {
+		return nil, 0, err
+	}
+
+	flags = 0
+	flags |= 0x01  // data offset present
+	flags |= 0x100 // sample duration present
+	flags |= 0x200 // sample size present
+
+	trun := &gomp4.Trun{ // <trun/>
+		FullBox: gomp4.FullBox{
+			Version: 0,
+			Flags:   [3]byte{0, byte(flags >> 8), byte(flags)},
+		},
+		SampleCount: uint32(len(audioSamples)),
+	}
+
+	for _, e := range audioSamples {
+		trun.Entries = append(trun.Entries, gomp4.TrunEntry{
+			SampleDuration: uint32(durationGoToMp4(e.Duration(), time.Duration(audioTrack.ClockRate()))),
+			SampleSize:     uint32(len(e.AU)),
+		})
+	}
+
+	trunOffset, err := w.WriteBox(trun)
+	if err != nil {
+		return nil, 0, err
+	}
+
+	err = w.WriteBoxEnd() // </traf>
+	if err != nil {
+		return nil, 0, err
+	}
+
+	return trun, trunOffset, nil
+}
+
+// GeneratePart generates a FMP4 part file.
+func GeneratePart(
+	videoTrack *gortsplib.TrackH264,
+	audioTrack *gortsplib.TrackMPEG4Audio,
+	videoSamples []*VideoSample,
+	audioSamples []*AudioSample,
+) ([]byte, error) {
+	/*
+		moof
+		- mfhd
+		- traf (video)
+		- traf (audio)
+		mdat
+	*/
+
+	w := newMP4Writer()
+
+	moofOffset, err := w.WriteBoxStart(&gomp4.Moof{}) // <moof>
+	if err != nil {
+		return nil, err
+	}
+
+	_, err = w.WriteBox(&gomp4.Mfhd{ // <mfhd/>
+		SequenceNumber: 0,
+	})
+	if err != nil {
+		return nil, err
+	}
+
+	trackID := 1
+
+	var videoTrun *gomp4.Trun
+	var videoTrunOffset int
+	if videoTrack != nil {
+		var err error
+		videoTrun, videoTrunOffset, err = generatePartVideoTraf(
+			w, trackID, videoSamples)
+		if err != nil {
+			return nil, err
+		}
+
+		trackID++
+	}
+
+	var audioTrun *gomp4.Trun
+	var audioTrunOffset int
+	if audioTrack != nil {
+		var err error
+		audioTrun, audioTrunOffset, err = generatePartAudioTraf(w, trackID, audioTrack, audioSamples)
+		if err != nil {
+			return nil, err
+		}
+	}
+
+	err = w.WriteBoxEnd() // </moof>
+	if err != nil {
+		return nil, err
+	}
+
+	mdat := &gomp4.Mdat{} // <mdat/>
+
+	dataSize := 0
+	videoDataSize := 0
+
+	if videoTrack != nil {
+		for _, e := range videoSamples {
+			dataSize += len(e.AVCC)
+		}
+		videoDataSize = dataSize
+	}
+
+	if audioTrack != nil {
+		for _, e := range audioSamples {
+			dataSize += len(e.AU)
+		}
+	}
+
+	mdat.Data = make([]byte, dataSize)
+	pos := 0
+
+	if videoTrack != nil {
+		for _, e := range videoSamples {
+			pos += copy(mdat.Data[pos:], e.AVCC)
+		}
+	}
+
+	if audioTrack != nil {
+		for _, e := range audioSamples {
+			pos += copy(mdat.Data[pos:], e.AU)
+		}
+	}
+
+	mdatOffset, err := w.WriteBox(mdat)
+	if err != nil {
+		return nil, err
+	}
+
+	if videoTrack != nil {
+		videoTrun.DataOffset = int32(mdatOffset - moofOffset + 8)
+		err = w.RewriteBox(videoTrunOffset, videoTrun)
+		if err != nil {
+			return nil, err
+		}
+	}
+
+	if audioTrack != nil && audioTrun != nil {
+		audioTrun.DataOffset = int32(videoDataSize + mdatOffset - moofOffset + 8)
+		err = w.RewriteBox(audioTrunOffset, audioTrun)
+		if err != nil {
+			return nil, err
+		}
+	}
+
+	return w.Bytes(), nil
+}

internal/hls/fmp4/videosample.go

@@ -0,0 +1,24 @@
+package fmp4
+
+import (
+	"time"
+)
+
+const (
+	videoTimescale = 90000
+)
+
+// VideoSample is a video sample.
+type VideoSample struct {
+	NALUs      [][]byte
+	PTS        time.Duration
+	DTS        time.Duration
+	AVCC       []byte
+	IDRPresent bool
+	Next       *VideoSample
+}
+
+// Duration returns the sample duration.
+func (s VideoSample) Duration() time.Duration {
+	return s.Next.DTS - s.DTS
+}

internal/hls/muxer_variant_fmp4.go

@@ -7,35 +7,10 @@ import (
 	"time"
 
 	"github.com/aler9/gortsplib"
-)
 
-const (
-	fmp4VideoTimescale = 90000
+	"github.com/aler9/rtsp-simple-server/internal/hls/fmp4"
 )
 
-type fmp4VideoSample struct {
-	nalus      [][]byte
-	pts        time.Duration
-	dts        time.Duration
-	avcc       []byte
-	idrPresent bool
-	next       *fmp4VideoSample
-}
-
-func (s fmp4VideoSample) duration() time.Duration {
-	return s.next.dts - s.dts
-}
-
-type fmp4AudioSample struct {
-	au   []byte
-	pts  time.Duration
-	next *fmp4AudioSample
-}
-
-func (s fmp4AudioSample) duration() time.Duration {
-	return s.next.pts - s.pts
-}
-
 type muxerVariantFMP4 struct {
 	playlist   *muxerVariantFMP4Playlist
 	segmenter  *muxerVariantFMP4Segmenter
@@ -110,7 +85,7 @@ func (v *muxerVariantFMP4) file(name string, msn string, part string, skip strin
 
 		if v.initContent == nil ||
 			(v.videoTrack != nil && (!bytes.Equal(v.videoLastSPS, sps) || !bytes.Equal(v.videoLastPPS, pps))) {
-			initContent, err := mp4InitGenerate(v.videoTrack, v.audioTrack)
+			initContent, err := fmp4.GenerateInit(v.videoTrack, v.audioTrack)
 			if err != nil {
 				return &MuxerFileResponse{Status: http.StatusInternalServerError}
 			}

internal/hls/muxer_variant_fmp4_part.go

@@ -3,298 +3,15 @@ package hls
 import (
 	"bytes"
 	"io"
-	"math"
 	"strconv"
 	"time"
 
-	gomp4 "github.com/abema/go-mp4"
 	"github.com/aler9/gortsplib"
 	"github.com/aler9/gortsplib/pkg/mpeg4audio"
 
-	"github.com/aler9/rtsp-simple-server/internal/mp4"
+	"github.com/aler9/rtsp-simple-server/internal/hls/fmp4"
 )
 
-func durationGoToMp4(v time.Duration, timescale time.Duration) int64 {
-	return int64(math.Round(float64(v*timescale) / float64(time.Second)))
-}
-
-func mp4PartGenerateVideoTraf(
-	w *mp4.Writer,
-	trackID int,
-	videoSamples []*fmp4VideoSample,
-) (*gomp4.Trun, int, error) {
-	/*
-		traf
-		- tfhd
-		- tfdt
-		- trun
-	*/
-
-	_, err := w.WriteBoxStart(&gomp4.Traf{}) // <traf>
-	if err != nil {
-		return nil, 0, err
-	}
-
-	flags := 0
-
-	_, err = w.WriteBox(&gomp4.Tfhd{ // <tfhd/>
-		FullBox: gomp4.FullBox{
-			Flags: [3]byte{2, byte(flags >> 8), byte(flags)},
-		},
-		TrackID: uint32(trackID),
-	})
-	if err != nil {
-		return nil, 0, err
-	}
-
-	_, err = w.WriteBox(&gomp4.Tfdt{ // <tfdt/>
-		FullBox: gomp4.FullBox{
-			Version: 1,
-		},
-		// sum of decode durations of all earlier samples
-		BaseMediaDecodeTimeV1: uint64(durationGoToMp4(videoSamples[0].dts, fmp4VideoTimescale)),
-	})
-	if err != nil {
-		return nil, 0, err
-	}
-
-	flags = 0
-	flags |= 0x01  // data offset present
-	flags |= 0x100 // sample duration present
-	flags |= 0x200 // sample size present
-	flags |= 0x400 // sample flags present
-	flags |= 0x800 // sample composition time offset present or v1
-
-	trun := &gomp4.Trun{ // <trun/>
-		FullBox: gomp4.FullBox{
-			Version: 1,
-			Flags:   [3]byte{0, byte(flags >> 8), byte(flags)},
-		},
-		SampleCount: uint32(len(videoSamples)),
-	}
-
-	for _, e := range videoSamples {
-		off := e.pts - e.dts
-
-		flags := uint32(0)
-		if !e.idrPresent {
-			flags |= 1 << 16 // sample_is_non_sync_sample
-		}
-
-		trun.Entries = append(trun.Entries, gomp4.TrunEntry{
-			SampleDuration:                uint32(durationGoToMp4(e.duration(), fmp4VideoTimescale)),
-			SampleSize:                    uint32(len(e.avcc)),
-			SampleFlags:                   flags,
-			SampleCompositionTimeOffsetV1: int32(durationGoToMp4(off, fmp4VideoTimescale)),
-		})
-	}
-
-	trunOffset, err := w.WriteBox(trun)
-	if err != nil {
-		return nil, 0, err
-	}
-
-	err = w.WriteBoxEnd() // </traf>
-	if err != nil {
-		return nil, 0, err
-	}
-
-	return trun, trunOffset, nil
-}
-
-func mp4PartGenerateAudioTraf(
-	w *mp4.Writer,
-	trackID int,
-	audioTrack *gortsplib.TrackMPEG4Audio,
-	audioSamples []*fmp4AudioSample,
-) (*gomp4.Trun, int, error) {
-	/*
-		traf
-		- tfhd
-		- tfdt
-		- trun
-	*/
-
-	if len(audioSamples) == 0 {
-		return nil, 0, nil
-	}
-
-	_, err := w.WriteBoxStart(&gomp4.Traf{}) // <traf>
-	if err != nil {
-		return nil, 0, err
-	}
-
-	flags := 0
-
-	_, err = w.WriteBox(&gomp4.Tfhd{ // <tfhd/>
-		FullBox: gomp4.FullBox{
-			Flags: [3]byte{2, byte(flags >> 8), byte(flags)},
-		},
-		TrackID: uint32(trackID),
-	})
-	if err != nil {
-		return nil, 0, err
-	}
-
-	_, err = w.WriteBox(&gomp4.Tfdt{ // <tfdt/>
-		FullBox: gomp4.FullBox{
-			Version: 1,
-		},
-		// sum of decode durations of all earlier samples
-		BaseMediaDecodeTimeV1: uint64(durationGoToMp4(audioSamples[0].pts, time.Duration(audioTrack.ClockRate()))),
-	})
-	if err != nil {
-		return nil, 0, err
-	}
-
-	flags = 0
-	flags |= 0x01  // data offset present
-	flags |= 0x100 // sample duration present
-	flags |= 0x200 // sample size present
-
-	trun := &gomp4.Trun{ // <trun/>
-		FullBox: gomp4.FullBox{
-			Version: 0,
-			Flags:   [3]byte{0, byte(flags >> 8), byte(flags)},
-		},
-		SampleCount: uint32(len(audioSamples)),
-	}
-
-	for _, e := range audioSamples {
-		trun.Entries = append(trun.Entries, gomp4.TrunEntry{
-			SampleDuration: uint32(durationGoToMp4(e.duration(), time.Duration(audioTrack.ClockRate()))),
-			SampleSize:     uint32(len(e.au)),
-		})
-	}
-
-	trunOffset, err := w.WriteBox(trun)
-	if err != nil {
-		return nil, 0, err
-	}
-
-	err = w.WriteBoxEnd() // </traf>
-	if err != nil {
-		return nil, 0, err
-	}
-
-	return trun, trunOffset, nil
-}
-
-func mp4PartGenerate(
-	videoTrack *gortsplib.TrackH264,
-	audioTrack *gortsplib.TrackMPEG4Audio,
-	videoSamples []*fmp4VideoSample,
-	audioSamples []*fmp4AudioSample,
-) ([]byte, error) {
-	/*
-		moof
-		- mfhd
-		- traf (video)
-		- traf (audio)
-		mdat
-	*/
-
-	w := mp4.NewWriter()
-
-	moofOffset, err := w.WriteBoxStart(&gomp4.Moof{}) // <moof>
-	if err != nil {
-		return nil, err
-	}
-
-	_, err = w.WriteBox(&gomp4.Mfhd{ // <mfhd/>
-		SequenceNumber: 0,
-	})
-	if err != nil {
-		return nil, err
-	}
-
-	trackID := 1
-
-	var videoTrun *gomp4.Trun
-	var videoTrunOffset int
-	if videoTrack != nil {
-		var err error
-		videoTrun, videoTrunOffset, err = mp4PartGenerateVideoTraf(
-			w, trackID, videoSamples)
-		if err != nil {
-			return nil, err
-		}
-
-		trackID++
-	}
-
-	var audioTrun *gomp4.Trun
-	var audioTrunOffset int
-	if audioTrack != nil {
-		var err error
-		audioTrun, audioTrunOffset, err = mp4PartGenerateAudioTraf(w, trackID, audioTrack, audioSamples)
-		if err != nil {
-			return nil, err
-		}
-	}
-
-	err = w.WriteBoxEnd() // </moof>
-	if err != nil {
-		return nil, err
-	}
-
-	mdat := &gomp4.Mdat{} // <mdat/>
-
-	dataSize := 0
-	videoDataSize := 0
-
-	if videoTrack != nil {
-		for _, e := range videoSamples {
-			dataSize += len(e.avcc)
-		}
-		videoDataSize = dataSize
-	}
-
-	if audioTrack != nil {
-		for _, e := range audioSamples {
-			dataSize += len(e.au)
-		}
-	}
-
-	mdat.Data = make([]byte, dataSize)
-	pos := 0
-
-	if videoTrack != nil {
-		for _, e := range videoSamples {
-			pos += copy(mdat.Data[pos:], e.avcc)
-		}
-	}
-
-	if audioTrack != nil {
-		for _, e := range audioSamples {
-			pos += copy(mdat.Data[pos:], e.au)
-		}
-	}
-
-	mdatOffset, err := w.WriteBox(mdat)
-	if err != nil {
-		return nil, err
-	}
-
-	if videoTrack != nil {
-		videoTrun.DataOffset = int32(mdatOffset - moofOffset + 8)
-		err = w.RewriteBox(videoTrunOffset, videoTrun)
-		if err != nil {
-			return nil, err
-		}
-	}
-
-	if audioTrack != nil && audioTrun != nil {
-		audioTrun.DataOffset = int32(videoDataSize + mdatOffset - moofOffset + 8)
-		err = w.RewriteBox(audioTrunOffset, audioTrun)
-		if err != nil {
-			return nil, err
-		}
-	}
-
-	return w.Bytes(), nil
-}
-
 func fmp4PartName(id uint64) string {
 	return "part" + strconv.FormatUint(id, 10)
 }
@@ -305,8 +22,8 @@ type muxerVariantFMP4Part struct {
 	id         uint64
 
 	isIndependent    bool
-	videoSamples     []*fmp4VideoSample
-	audioSamples     []*fmp4AudioSample
+	videoSamples     []*fmp4.VideoSample
+	audioSamples     []*fmp4.AudioSample
 	renderedContent  []byte
 	renderedDuration time.Duration
 }
@@ -341,7 +58,7 @@ func (p *muxerVariantFMP4Part) duration() time.Duration {
 	if p.videoTrack != nil {
 		ret := time.Duration(0)
 		for _, e := range p.videoSamples {
-			ret += e.duration()
+			ret += e.Duration()
 		}
 		return ret
 	}
@@ -356,7 +73,7 @@ func (p *muxerVariantFMP4Part) duration() time.Duration {
 func (p *muxerVariantFMP4Part) finalize() error {
 	if len(p.videoSamples) > 0 || len(p.audioSamples) > 0 {
 		var err error
-		p.renderedContent, err = mp4PartGenerate(
+		p.renderedContent, err = fmp4.GeneratePart(
 			p.videoTrack,
 			p.audioTrack,
 			p.videoSamples,
@@ -374,13 +91,13 @@ func (p *muxerVariantFMP4Part) finalize() error {
 	return nil
 }
 
-func (p *muxerVariantFMP4Part) writeH264(sample *fmp4VideoSample) {
-	if sample.idrPresent {
+func (p *muxerVariantFMP4Part) writeH264(sample *fmp4.VideoSample) {
+	if sample.IDRPresent {
 		p.isIndependent = true
 	}
 	p.videoSamples = append(p.videoSamples, sample)
 }
 
-func (p *muxerVariantFMP4Part) writeAAC(sample *fmp4AudioSample) {
+func (p *muxerVariantFMP4Part) writeAAC(sample *fmp4.AudioSample) {
 	p.audioSamples = append(p.audioSamples, sample)
 }

internal/hls/muxer_variant_fmp4_segment.go

@@ -7,6 +7,8 @@ import (
 	"time"
 
 	"github.com/aler9/gortsplib"
+
+	"github.com/aler9/rtsp-simple-server/internal/hls/fmp4"
 )
 
 type partsReader struct {
@@ -101,8 +103,8 @@ func (s *muxerVariantFMP4Segment) getRenderedDuration() time.Duration {
 }
 
 func (s *muxerVariantFMP4Segment) finalize(
-	nextVideoSample *fmp4VideoSample,
-	nextAudioSample *fmp4AudioSample,
+	nextVideoSample *fmp4.VideoSample,
+	nextAudioSample *fmp4.AudioSample,
 ) error {
 	err := s.currentPart.finalize()
 	if err != nil {
@@ -117,7 +119,7 @@ func (s *muxerVariantFMP4Segment) finalize(
 	s.currentPart = nil
 
 	if s.videoTrack != nil {
-		s.renderedDuration = nextVideoSample.dts - s.startDTS
+		s.renderedDuration = nextVideoSample.DTS - s.startDTS
 	} else {
 		s.renderedDuration = 0
 		for _, pa := range s.parts {
@@ -128,8 +130,8 @@ func (s *muxerVariantFMP4Segment) finalize(
 	return nil
 }
 
-func (s *muxerVariantFMP4Segment) writeH264(sample *fmp4VideoSample, adjustedPartDuration time.Duration) error {
-	size := uint64(len(sample.avcc))
+func (s *muxerVariantFMP4Segment) writeH264(sample *fmp4.VideoSample, adjustedPartDuration time.Duration) error {
+	size := uint64(len(sample.AVCC))
 
 	if (s.size + size) > s.segmentMaxSize {
 		return fmt.Errorf("reached maximum segment size")
@@ -160,8 +162,8 @@ func (s *muxerVariantFMP4Segment) writeH264(sample *fmp4VideoSample, adjustedPar
 	return nil
 }
 
-func (s *muxerVariantFMP4Segment) writeAAC(sample *fmp4AudioSample, adjustedPartDuration time.Duration) error {
-	size := uint64(len(sample.au))
+func (s *muxerVariantFMP4Segment) writeAAC(sample *fmp4.AudioSample, adjustedPartDuration time.Duration) error {
+	size := uint64(len(sample.AU))
 
 	if (s.size + size) > s.segmentMaxSize {
 		return fmt.Errorf("reached maximum segment size")

internal/hls/muxer_variant_fmp4_segmenter.go

@@ -6,6 +6,8 @@ import (
 
 	"github.com/aler9/gortsplib"
 	"github.com/aler9/gortsplib/pkg/h264"
+
+	"github.com/aler9/rtsp-simple-server/internal/hls/fmp4"
 )
 
 func partDurationIsCompatible(partDuration time.Duration, sampleDuration time.Duration) bool {
@@ -60,8 +62,8 @@ type muxerVariantFMP4Segmenter struct {
 	currentSegment        *muxerVariantFMP4Segment
 	nextSegmentID         uint64
 	nextPartID            uint64
-	nextVideoSample       *fmp4VideoSample
-	nextAudioSample       *fmp4AudioSample
+	nextVideoSample       *fmp4.VideoSample
+	nextAudioSample       *fmp4.AudioSample
 	firstSegmentFinalized bool
 	sampleDurations       map[time.Duration]struct{}
 	adjustedPartDuration  time.Duration
@@ -144,18 +146,18 @@ func (m *muxerVariantFMP4Segmenter) writeH264(pts time.Duration, nalus [][]byte)
 		return err
 	}
 
-	return m.writeH264Entry(&fmp4VideoSample{
-		pts:        pts,
-		nalus:      nalus,
-		avcc:       avcc,
-		idrPresent: idrPresent,
+	return m.writeH264Entry(&fmp4.VideoSample{
+		PTS:        pts,
+		NALUs:      nalus,
+		AVCC:       avcc,
+		IDRPresent: idrPresent,
 	})
 }
 
-func (m *muxerVariantFMP4Segmenter) writeH264Entry(sample *fmp4VideoSample) error {
+func (m *muxerVariantFMP4Segmenter) writeH264Entry(sample *fmp4.VideoSample) error {
 	if !m.videoFirstIDRReceived {
 		// skip sample silently until we find one with an IDR
-		if !sample.idrPresent {
+		if !sample.IDRPresent {
 			return nil
 		}
 
@@ -164,25 +166,25 @@ func (m *muxerVariantFMP4Segmenter) writeH264Entry(sample *fmp4VideoSample) erro
 		m.videoSPS = append([]byte(nil), m.videoTrack.SafeSPS()...)
 
 		var err error
-		sample.dts, err = m.videoDTSExtractor.Extract(sample.nalus, sample.pts)
+		sample.DTS, err = m.videoDTSExtractor.Extract(sample.NALUs, sample.PTS)
 		if err != nil {
 			return err
 		}
-		sample.nalus = nil
+		sample.NALUs = nil
 
-		m.startDTS = sample.dts
-		sample.dts = 0
-		sample.pts -= m.startDTS
+		m.startDTS = sample.DTS
+		sample.DTS = 0
+		sample.PTS -= m.startDTS
 	} else {
 		var err error
-		sample.dts, err = m.videoDTSExtractor.Extract(sample.nalus, sample.pts)
+		sample.DTS, err = m.videoDTSExtractor.Extract(sample.NALUs, sample.PTS)
 		if err != nil {
 			return err
 		}
-		sample.nalus = nil
+		sample.NALUs = nil
 
-		sample.dts -= m.startDTS
-		sample.pts -= m.startDTS
+		sample.DTS -= m.startDTS
+		sample.PTS -= m.startDTS
 	}
 
 	// put samples into a queue in order to
@@ -192,7 +194,7 @@ func (m *muxerVariantFMP4Segmenter) writeH264Entry(sample *fmp4VideoSample) erro
 	if sample == nil {
 		return nil
 	}
-	sample.next = m.nextVideoSample
+	sample.Next = m.nextVideoSample
 
 	now := time.Now()
 
@@ -202,7 +204,7 @@ func (m *muxerVariantFMP4Segmenter) writeH264Entry(sample *fmp4VideoSample) erro
 			m.lowLatency,
 			m.genSegmentID(),
 			now,
-			sample.dts,
+			sample.DTS,
 			m.segmentMaxSize,
 			m.videoTrack,
 			m.audioTrack,
@@ -211,7 +213,7 @@ func (m *muxerVariantFMP4Segmenter) writeH264Entry(sample *fmp4VideoSample) erro
 		)
 	}
 
-	m.adjustPartDuration(sample.duration())
+	m.adjustPartDuration(sample.Duration())
 
 	err := m.currentSegment.writeH264(sample, m.adjustedPartDuration)
 	if err != nil {
@@ -219,13 +221,13 @@ func (m *muxerVariantFMP4Segmenter) writeH264Entry(sample *fmp4VideoSample) erro
 	}
 
 	// switch segment
-	if sample.next.idrPresent {
+	if sample.Next.IDRPresent {
 		sps := m.videoTrack.SafeSPS()
 		spsChanged := !bytes.Equal(m.videoSPS, sps)
 
-		if (sample.next.dts-m.currentSegment.startDTS) >= m.segmentDuration ||
+		if (sample.Next.DTS-m.currentSegment.startDTS) >= m.segmentDuration ||
 			spsChanged {
-			err := m.currentSegment.finalize(sample.next, nil)
+			err := m.currentSegment.finalize(sample.Next, nil)
 			if err != nil {
 				return err
 			}
@@ -237,7 +239,7 @@ func (m *muxerVariantFMP4Segmenter) writeH264Entry(sample *fmp4VideoSample) erro
 				m.lowLatency,
 				m.genSegmentID(),
 				now,
-				sample.next.dts,
+				sample.Next.DTS,
 				m.segmentMaxSize,
 				m.videoTrack,
 				m.audioTrack,
@@ -258,20 +260,20 @@ func (m *muxerVariantFMP4Segmenter) writeH264Entry(sample *fmp4VideoSample) erro
 }
 
 func (m *muxerVariantFMP4Segmenter) writeAAC(pts time.Duration, au []byte) error {
-	return m.writeAACEntry(&fmp4AudioSample{
-		pts: pts,
-		au:  au,
+	return m.writeAACEntry(&fmp4.AudioSample{
+		PTS: pts,
+		AU:  au,
 	})
 }
 
-func (m *muxerVariantFMP4Segmenter) writeAACEntry(sample *fmp4AudioSample) error {
+func (m *muxerVariantFMP4Segmenter) writeAACEntry(sample *fmp4.AudioSample) error {
 	if m.videoTrack != nil {
 		// wait for the video track
 		if !m.videoFirstIDRReceived {
 			return nil
 		}
 
-		sample.pts -= m.startDTS
+		sample.PTS -= m.startDTS
 	}
 
 	// put samples into a queue in order to
@@ -280,7 +282,7 @@ func (m *muxerVariantFMP4Segmenter) writeAACEntry(sample *fmp4AudioSample) error
 	if sample == nil {
 		return nil
 	}
-	sample.next = m.nextAudioSample
+	sample.Next = m.nextAudioSample
 
 	now := time.Now()
 
@@ -291,7 +293,7 @@ func (m *muxerVariantFMP4Segmenter) writeAACEntry(sample *fmp4AudioSample) error
 				m.lowLatency,
 				m.genSegmentID(),
 				now,
-				sample.pts,
+				sample.PTS,
 				m.segmentMaxSize,
 				m.videoTrack,
 				m.audioTrack,
@@ -313,8 +315,8 @@ func (m *muxerVariantFMP4Segmenter) writeAACEntry(sample *fmp4AudioSample) error
 
 	// switch segment
 	if m.videoTrack == nil &&
-		(sample.next.pts-m.currentSegment.startDTS) >= m.segmentDuration {
-		err := m.currentSegment.finalize(nil, sample.next)
+		(sample.Next.PTS-m.currentSegment.startDTS) >= m.segmentDuration {
+		err := m.currentSegment.finalize(nil, sample.Next)
 		if err != nil {
 			return err
 		}
@@ -326,7 +328,7 @@ func (m *muxerVariantFMP4Segmenter) writeAACEntry(sample *fmp4AudioSample) error
 			m.lowLatency,
 			m.genSegmentID(),
 			now,
-			sample.next.pts,
+			sample.Next.PTS,
 			m.segmentMaxSize,
 			m.videoTrack,
 			m.audioTrack,