Skip to content

recorder: reset when absolute time drifts from stream time (#4778) #5239

New issue

Have a question about this project? Sign up for a free GitHub account to open an issue and contact its maintainers and the community.

Sign up for GitHub

By clicking “Sign up for GitHub”, you agree to our terms of service and privacy statement. We’ll occasionally send you account related emails.

Already on GitHub? Sign in to your account

Merged
merged 1 commit into from
Dec 2, 2025
Merged

recorder: reset when absolute time drifts from stream time (#4778) #5239

Show file tree
Hide file tree
Changes from all commits
Commits
Show all changes
1 commit
Select commit
File filter

Filter by extension

Filter by extension
Conversations
Failed to load comments.
Loading
Jump to
Jump to file
Failed to load files.
Loading
Diff view
Diff view
2 changes: 1 addition & 1 deletion docs/2-usage/14-route-absolute-timestamps.md
View file
Open in desktop
Original file line number Diff line number Diff line change
Expand Up @@ -13,7 +13,7 @@ and supports sending absolute timestamps with the following protocols:
- RTSP
- WebRTC

By default, absolute timestamps of incoming frames are not used, instead they are replaced with the current timestamp. This prevents users from arbitrarily changing recording dates, and also allows to support sources that do not send absolute timestamps. It is possible to preserve original absolute timestamps by toggling the `useAbsoluteTimestamp` parameter:
By default, absolute timestamps of incoming frames are not used, instead they are replaced with the system timestamp. This prevents users from arbitrarily changing recording dates, and also allows to support sources that do not send absolute timestamps. It is possible to preserve original absolute timestamps by toggling the `useAbsoluteTimestamp` parameter:

```yml
pathDefaults:
Expand Down
2 changes: 1 addition & 1 deletion go.mod
View file
Open in desktop
Original file line number Diff line number Diff line change
Expand Up @@ -13,7 +13,7 @@ require (
github.com/bluenviron/gohlslib/v2 v2.2.4
github.com/bluenviron/gortmplib v0.1.1
github.com/bluenviron/gortsplib/v5 v5.2.0
github.com/bluenviron/mediacommon/v2 v2.5.1
github.com/bluenviron/mediacommon/v2 v2.5.2-0.20251201152746-8d059e8616fb
github.com/datarhei/gosrt v0.9.0
github.com/fsnotify/fsnotify v1.9.0
github.com/gin-contrib/pprof v1.5.3
Expand Down
4 changes: 2 additions & 2 deletions go.sum
View file
Open in desktop
Original file line number Diff line number Diff line change
Expand Up @@ -39,8 +39,8 @@ github.com/bluenviron/gortmplib v0.1.1 h1:pmR6qfPcJJmE17lWQ/bpuBFZtgGnMrN8KdFj1G
github.com/bluenviron/gortmplib v0.1.1/go.mod h1:XWy2YzbTP1XEEZ8232OG7I1MSwubsbDRKDNhXGgS2kg=
github.com/bluenviron/gortsplib/v5 v5.2.0 h1:yk0H9Z1Z+H41/x5hDt84rKm6+MNA483NsRXPYe+or/A=
github.com/bluenviron/gortsplib/v5 v5.2.0/go.mod h1:UYCbHEb0T49kBDgIlTJaZOchD2f5g1JigFmmxQfW7vY=
github.com/bluenviron/mediacommon/v2 v2.5.1 h1:qB2fb5c0xyl5OB2gfSfulpEJn7Cdm3vI2n8wjiLMxKI=
github.com/bluenviron/mediacommon/v2 v2.5.1/go.mod h1:zy1fODPuS/kBd93ftgJS1Jhvjq7LFWfAo32KP7By9AE=
github.com/bluenviron/mediacommon/v2 v2.5.2-0.20251201152746-8d059e8616fb h1:42lRaSsrPXvwB9kLGIujU9yONrSPPp0j4Ohwg6zp/yw=
github.com/bluenviron/mediacommon/v2 v2.5.2-0.20251201152746-8d059e8616fb/go.mod h1:5V15TiOfeaNVmZPVuOqAwqQSWyvMV86/dijDKu5q9Zs=
github.com/bytedance/sonic v1.14.0 h1:/OfKt8HFw0kh2rj8N0F6C/qPGRESq0BbaNZgcNXXzQQ=
github.com/bytedance/sonic v1.14.0/go.mod h1:WoEbx8WTcFJfzCe0hbmyTGrfjt8PzNEBdxlNUO24NhA=
github.com/bytedance/sonic/loader v0.3.0 h1:dskwH8edlzNMctoruo8FPTJDF3vLtDT0sXZwvZJyqeA=
Expand Down
4 changes: 4 additions & 0 deletions internal/ntpestimator/estimator.go
View file
Open in desktop
Original file line number Diff line number Diff line change
Expand Up @@ -31,6 +31,10 @@ var zero = time.Time{}
func (e *Estimator) Estimate(pts int64) time.Time {
now := timeNow()

// do not store monotonic clock, in order to include
// system clock changes into time differences
now = now.Round(0)

if e.refNTP.Equal(zero) {
e.refNTP = now
e.refPTS = pts
Expand Down
47 changes: 25 additions & 22 deletions internal/recorder/format_fmp4.go
View file
Open in desktop
Original file line number Diff line number Diff line change
Expand Up @@ -98,6 +98,12 @@ func jpegExtractSize(image []byte) (int, int, error) {
}
}

type formatFMP4Sample struct {
*fmp4.Sample
dts int64
ntp time.Time
}

type formatFMP4 struct {
ri *recorderInstance

Expand All @@ -111,18 +117,15 @@ func (f *formatFMP4) initialize() bool {
nextID := 1

addTrack := func(format rtspformat.Format, codec mp4.Codec) *formatFMP4Track {
initTrack := &fmp4.InitTrack{
TimeScale: uint32(format.ClockRate()),
Codec: codec,
}
initTrack.ID = nextID
nextID++

track := &formatFMP4Track{
f: f,
initTrack: initTrack,
id: nextID,
clockRate: uint32(format.ClockRate()),
codec: codec,
}
track.initialize()

nextID++
f.tracks = append(f.tracks, track)
return track
}
Expand Down Expand Up @@ -180,7 +183,7 @@ func (f *formatFMP4) initialize() bool {
return err
}

return track.write(&sample{
return track.write(&formatFMP4Sample{
Sample: &sampl,
dts: u.PTS,
ntp: u.NTP,
Expand Down Expand Up @@ -257,7 +260,7 @@ func (f *formatFMP4) initialize() bool {
firstReceived = true
}

return track.write(&sample{
return track.write(&formatFMP4Sample{
Sample: &fmp4.Sample{
IsNonSyncSample: !randomAccess,
Payload: u.Payload.(unit.PayloadVP9),
Expand Down Expand Up @@ -348,7 +351,7 @@ func (f *formatFMP4) initialize() bool {
return err
}

return track.write(&sample{
return track.write(&formatFMP4Sample{
Sample: &sampl,
dts: dts,
ntp: u.NTP,
Expand Down Expand Up @@ -424,7 +427,7 @@ func (f *formatFMP4) initialize() bool {
return err
}

return track.write(&sample{
return track.write(&formatFMP4Sample{
Sample: &sampl,
dts: dts,
ntp: u.NTP,
Expand Down Expand Up @@ -481,7 +484,7 @@ func (f *formatFMP4) initialize() bool {
}
lastPTS = u.PTS

return track.write(&sample{
return track.write(&formatFMP4Sample{
Sample: &fmp4.Sample{
Payload: u.Payload.(unit.PayloadMPEG4Video),
IsNonSyncSample: !randomAccess,
Expand Down Expand Up @@ -532,7 +535,7 @@ func (f *formatFMP4) initialize() bool {
}
lastPTS = u.PTS

return track.write(&sample{
return track.write(&formatFMP4Sample{
Sample: &fmp4.Sample{
Payload: u.Payload.(unit.PayloadMPEG1Video),
IsNonSyncSample: !randomAccess,
Expand Down Expand Up @@ -570,7 +573,7 @@ func (f *formatFMP4) initialize() bool {
f.updateCodecParams()
}

return track.write(&sample{
return track.write(&formatFMP4Sample{
Sample: &fmp4.Sample{
Payload: u.Payload.(unit.PayloadMJPEG),
},
Expand All @@ -596,7 +599,7 @@ func (f *formatFMP4) initialize() bool {
pts := u.PTS

for _, packet := range u.Payload.(unit.PayloadOpus) {
err := track.write(&sample{
err := track.write(&formatFMP4Sample{
Sample: &fmp4.Sample{
Payload: packet,
},
Expand Down Expand Up @@ -630,7 +633,7 @@ func (f *formatFMP4) initialize() bool {
for i, au := range u.Payload.(unit.PayloadMPEG4Audio) {
pts := u.PTS + int64(i)*mpeg4audio.SamplesPerAccessUnit

err := track.write(&sample{
err := track.write(&formatFMP4Sample{
Sample: &fmp4.Sample{
Payload: au,
},
Expand Down Expand Up @@ -667,7 +670,7 @@ func (f *formatFMP4) initialize() bool {
return err
}

return track.write(&sample{
return track.write(&formatFMP4Sample{
Sample: &fmp4.Sample{
Payload: ame.Payloads[0][0][0],
},
Expand Down Expand Up @@ -710,7 +713,7 @@ func (f *formatFMP4) initialize() bool {
f.updateCodecParams()
}

err = track.write(&sample{
err = track.write(&formatFMP4Sample{
Sample: &fmp4.Sample{
Payload: frame,
},
Expand Down Expand Up @@ -779,7 +782,7 @@ func (f *formatFMP4) initialize() bool {

pts := u.PTS + int64(i)*ac3.SamplesPerFrame

err = track.write(&sample{
err = track.write(&formatFMP4Sample{
Sample: &fmp4.Sample{
Payload: frame,
},
Expand Down Expand Up @@ -825,7 +828,7 @@ func (f *formatFMP4) initialize() bool {
lpcm = al
}

return track.write(&sample{
return track.write(&formatFMP4Sample{
Sample: &fmp4.Sample{
Payload: lpcm,
},
Expand All @@ -851,7 +854,7 @@ func (f *formatFMP4) initialize() bool {
return nil
}

return track.write(&sample{
return track.write(&formatFMP4Sample{
Sample: &fmp4.Sample{
Payload: u.Payload.(unit.PayloadLPCM),
},
Expand Down
2 changes: 1 addition & 1 deletion internal/recorder/format_fmp4_part.go
View file
Open in desktop
Original file line number Diff line number Diff line change
Expand Up @@ -56,7 +56,7 @@ func (p *formatFMP4Part) close(w io.Writer) error {
return writePart(w, p.number, p.partTracks)
}

func (p *formatFMP4Part) write(track *formatFMP4Track, sample *sample, dts time.Duration) error {
func (p *formatFMP4Part) write(track *formatFMP4Track, sample *formatFMP4Sample, dts time.Duration) error {
size := uint64(len(sample.Payload))
if (p.size + size) > uint64(p.maxPartSize) {
return fmt.Errorf("reached maximum part size")
Expand Down
2 changes: 1 addition & 1 deletion internal/recorder/format_fmp4_segment.go
View file
Open in desktop
Original file line number Diff line number Diff line change
Expand Up @@ -201,7 +201,7 @@ func (s *formatFMP4Segment) closeCurPart() error {
return s.curPart.close(s.fi)
}

func (s *formatFMP4Segment) write(track *formatFMP4Track, sample *sample, dts time.Duration) error {
func (s *formatFMP4Segment) write(track *formatFMP4Track, sample *formatFMP4Sample, dts time.Duration) error {
endDTS := dts + timestampToDuration(int64(sample.Duration), int(track.initTrack.TimeScale))
if endDTS > s.endDTS {
s.endDTS = endDTS
Expand Down
33 changes: 30 additions & 3 deletions internal/recorder/format_fmp4_track.go
View file
Open in desktop
Original file line number Diff line number Diff line change
@@ -1,9 +1,11 @@
package recorder

import (
"fmt"
"time"

"github.com/bluenviron/mediacommon/v2/pkg/formats/fmp4"
"github.com/bluenviron/mediacommon/v2/pkg/formats/mp4"
"github.com/bluenviron/mediamtx/internal/logger"
)

Expand Down Expand Up @@ -43,12 +45,26 @@ func nextSegmentStartingPos(tracks []*formatFMP4Track) (time.Time, time.Duration

type formatFMP4Track struct {
f *formatFMP4
initTrack *fmp4.InitTrack
id int
clockRate uint32
codec mp4.Codec

initTrack *fmp4.InitTrack
nextSample *formatFMP4Sample
startInitialized bool
startDTS time.Duration
startNTP time.Time
}

nextSample *sample
func (t *formatFMP4Track) initialize() {
t.initTrack = &fmp4.InitTrack{
ID: t.id,
TimeScale: t.clockRate,
Codec: t.codec,
}
}

func (t *formatFMP4Track) write(sample *sample) error {
func (t *formatFMP4Track) write(sample *formatFMP4Sample) error {
// wait the first video sample before setting hasVideo
if t.initTrack.Codec.IsVideo() {
t.f.hasVideo = true
Expand All @@ -69,6 +85,17 @@ func (t *formatFMP4Track) write(sample *sample) error {

dts := timestampToDuration(sample.dts, int(t.initTrack.TimeScale))

if !t.startInitialized {
t.startDTS = dts
t.startNTP = sample.ntp
t.startInitialized = true
} else {
drift := sample.ntp.Sub(t.startNTP) - (dts - t.startDTS)
if drift < -ntpDriftTolerance || drift > ntpDriftTolerance {
return fmt.Errorf("detected drift between recording duration and absolute time, resetting")
}
}

if t.f.currentSegment == nil {
t.f.currentSegment = &formatFMP4Segment{
f: t.f,
Expand Down
Loading