Can you help me? I can't get the duration of a fragmented video

[ruohuaii]

package main

import (
"fmt"
"os"

"github.com/Eyevinn/mp4ff/mp4"

)

func main() {
filename := "aa.mp4"
f, err := os.Open(filename)
if err != nil {
panic(err)
}
defer f.Close()
d, err := mp4.DecodeFile(f)
if err != nil {
panic(err)
}

if !d.IsFragmented() {
	mvhd := d.Moov.Mvhd
	duration := mvhd.Duration
	timeScale := mvhd.Timescale
	fmt.Println("duration:", duration/uint64(timeScale))
	return
}

traks := d.Moov.Traks
timescale := uint32(0)
for _, trak := range traks {
	if trak.Mdia.Hdlr.HandlerType == "vide" {
		timescale = trak.Mdia.Mdhd.Timescale
	}
}
if timescale == 0 {
	return
}

var duration uint32
segments := d.Segments
for _, segment := range segments {
	fragments := segment.Fragments
	for _, fragment := range fragments {
		trafs := fragment.Moof.Trafs
		for _, traf := range trafs {
			defaultDur := traf.Tfhd.DefaultSampleDuration
			sampleCount := traf.Trun.SampleCount()
			samples := traf.Trun.Samples
			for _, sample := range samples {
				if sample.Dur > 0 {
					duration += sample.Dur
				} else {
					duration += defaultDur
				}
			}
			if len(traf.Trun.Samples) == 0 && defaultDur > 0 {
				duration += defaultDur * sampleCount
			}
		}
	}
}

fmt.Println(duration / timescale)

}

[tobbee]

@ruohuaii Thanks for using mp4ff.

If you get a duration of zero, it may be because the defaultSampleDuration is set in the trex box in the init segment, and that the other durations are not set.

You may also find an mehd box inside the mvex box in the init segment which provides the total duration of the track.

If you have the defaultDuration properly set from trex and tfhd, you can call the function

TrunBox.Duration(defaultSampleDuration uint32) uint64

to get the total duration of all samples in that box.

I hope this helps?