add demuxer.go

This commit is contained in:
nareix 2016-03-18 19:57:00 +08:00
parent b69852c281
commit e060a3e79d
4 changed files with 238 additions and 230 deletions

212
demuxer.go Normal file
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@ -0,0 +1,212 @@
package mp4
import (
"github.com/nareix/mp4/atom"
_ "os"
"fmt"
"io"
_ "log"
)
type Demuxer struct {
R io.ReadSeeker
Tracks []*Track
TrackH264 *Track
TrackAAC *Track
MovieAtom *atom.Movie
}
func (self *Demuxer) ReadHeader() (err error) {
var N int64
var moov *atom.Movie
if N, err = self.R.Seek(0, 2); err != nil {
return
}
if _, err = self.R.Seek(0, 0); err != nil {
return
}
lr := &io.LimitedReader{R: self.R, N: N}
for lr.N > 0 {
var ar *io.LimitedReader
var cc4 string
if ar, cc4, err = atom.ReadAtomHeader(lr, ""); err != nil {
return
}
if cc4 == "moov" {
if moov, err = atom.ReadMovie(ar); err != nil {
return
}
}
if _, err = atom.ReadDummy(lr, int(ar.N)); err != nil {
return
}
}
if moov == nil {
err = fmt.Errorf("'moov' atom not found")
return
}
self.MovieAtom = moov
self.Tracks = []*Track{}
for _, atrack := range(moov.Tracks) {
track := &Track{
TrackAtom: atrack,
r: self.R,
}
if atrack.Media != nil && atrack.Media.Info != nil && atrack.Media.Info.Sample != nil {
track.sample = atrack.Media.Info.Sample
} else {
err = fmt.Errorf("sample table not found")
return
}
if record := atom.GetAVCDecoderConfRecordByTrack(atrack); record != nil {
track.Type = H264
self.TrackH264 = track
if len(record.PPS) > 0 {
track.PPS = record.PPS[0]
}
if len(record.SPS) > 0 {
track.SPS = record.SPS[0]
}
self.Tracks = append(self.Tracks, track)
} else if mp4a := atom.GetMp4aDescByTrack(atrack); mp4a != nil {
self.TrackAAC = track
track.Type = AAC
self.Tracks = append(self.Tracks, track)
}
}
return
}
func (self *Track) setSampleIndex(index int) (err error) {
found := false
start := 0
self.chunkGroupIndex = 0
for self.chunkIndex = range(self.sample.ChunkOffset.Entries) {
n := self.sample.SampleToChunk.Entries[self.chunkGroupIndex].SamplesPerChunk
if index >= start && index < start+n {
found = true
self.sampleIndexInChunk = index-start
break
}
start += n
if self.chunkGroupIndex+1 < len(self.sample.SampleToChunk.Entries) &&
self.chunkIndex+1 == self.sample.SampleToChunk.Entries[self.chunkGroupIndex+1].FirstChunk {
self.chunkGroupIndex++
}
}
if !found {
err = io.EOF
return
}
self.sampleIndex = index
return
}
func (self *Track) incSampleIndex() {
self.sampleIndexInChunk++
if self.sampleIndexInChunk == self.sample.SampleToChunk.Entries[self.chunkGroupIndex].SamplesPerChunk {
self.chunkIndex++
self.sampleIndexInChunk = 0
}
if self.chunkGroupIndex+1 < len(self.sample.SampleToChunk.Entries) &&
self.chunkIndex+1 == self.sample.SampleToChunk.Entries[self.chunkGroupIndex+1].FirstChunk {
self.chunkGroupIndex++
}
self.sampleIndex++
}
func (self *Track) SampleCount() int {
if self.sample.SampleSize.SampleSize == 0 {
chunkGroupIndex := 0
count := 0
for chunkIndex := range(self.sample.ChunkOffset.Entries) {
n := self.sample.SampleToChunk.Entries[chunkGroupIndex].SamplesPerChunk
count += n
if chunkGroupIndex+1 < len(self.sample.SampleToChunk.Entries) &&
chunkIndex+1 == self.sample.SampleToChunk.Entries[chunkGroupIndex+1].FirstChunk {
chunkGroupIndex++
}
}
return count
} else {
return len(self.sample.SampleSize.Entries)
}
}
func (self *Track) ReadSample() (pts int64, dts int64, isKeyFrame bool, data []byte, err error) {
return
}
func (self *Track) ReadSampleAtIndex(index int) (pts int64, dts int64, isKeyFrame bool, data []byte, err error) {
if self.sampleIndex+1 == index {
self.incSampleIndex()
} else if self.sampleIndex != index {
if err = self.setSampleIndex(index); err != nil {
return
}
}
if self.chunkIndex > len(self.sample.ChunkOffset.Entries) {
err = io.EOF
return
}
if self.chunkGroupIndex >= len(self.sample.SampleToChunk.Entries) {
err = io.EOF
return
}
chunkOffset := self.sample.ChunkOffset.Entries[self.chunkIndex]
sampleOffset := 0
sampleSize := 0
if self.sample.SampleSize.SampleSize != 0 {
sampleOffset = chunkOffset + self.sampleIndexInChunk*self.sample.SampleSize.SampleSize
} else {
sampleOffset = chunkOffset
for i := self.sampleIndex-self.sampleIndexInChunk; i < self.sampleIndex; i++ {
sampleOffset += self.sample.SampleSize.Entries[i]
}
}
if _, err = self.r.Seek(int64(sampleOffset), 0); err != nil {
return
}
data = make([]byte, sampleSize)
if _, err = self.r.Read(data); err != nil {
return
}
return
}
func (self *Track) Duration() float32 {
total := int64(0)
for _, entry := range(self.sample.TimeToSample.Entries) {
total += int64(entry.Duration*entry.Count)
}
return float32(total)/float32(self.TrackAtom.Media.Header.TimeScale)
}
func (self *Track) TimeToSampleIndex(second float32) int {
return 0
}
func (self *Track) TimeStampToTime(ts int64) float32 {
return 0.0
}
func (self *Track) WriteSample(pts int64, dts int64, data []byte) (err error) {
return
}

26
example/example.go Normal file
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package main
import (
"github.com/nareix/mp4"
"os"
"fmt"
)
func DemuxExample() {
file, _ := os.Open("test.mp4")
demuxer := &mp4.Demuxer{
R: file,
}
demuxer.ReadHeader()
fmt.Println("Duration: ", demuxer.TrackH264.Duration())
count := demuxer.TrackH264.SampleCount()
fmt.Println("SampleCount: ", count)
}
func main() {
DemuxExample()
}

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@ -1,30 +0,0 @@
package main
import (
mp4 "./.."
"flag"
"log"
)
func main() {
testconv := flag.Bool("testconv", false, "")
probe := flag.Bool("probe", false, "")
flag.Parse()
if *testconv {
if err := mp4.TestConvert(flag.Arg(0)); err != nil {
log.Println(err)
return
}
}
if *probe {
if err := mp4.ProbeFile(flag.Arg(0)); err != nil {
log.Println(err)
return
}
}
}

200
test.go
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@ -1,200 +0,0 @@
package mp4
import (
"github.com/nareix/mp4/atom"
"os"
"io"
"fmt"
"log"
"encoding/hex"
)
/*
func TestRewrite(filename string) (err error) {
var infile *os.File
if infile, err = os.Open(filename); err != nil {
return
}
var outfile *os.File
if outfile, err = os.Open(filename+".out.mp4"); err != nil {
return
}
return
}
*/
func getAVCDecoderConfRecordByTrack(track *atom.Track) (record *atom.AVCDecoderConfRecord) {
if media := track.Media; media != nil {
if info := media.Info; info != nil {
if sample := info.Sample; sample != nil {
if desc := sample.SampleDesc; desc != nil {
if avc1 := desc.Avc1Desc; avc1 != nil {
if conf := avc1.Conf; conf != nil {
return &conf.Record
}
}
}
}
}
}
return
}
func ProbeFile(filename string) (err error) {
var osfile *os.File
if osfile, err = os.Open(filename); err != nil {
return
}
var finfo os.FileInfo
if finfo, err = osfile.Stat(); err != nil {
return
}
dumper := &atom.Dumper{}
var moov *atom.Movie
lr := &io.LimitedReader{R: osfile, N: finfo.Size()}
for lr.N > 0 {
var ar *io.LimitedReader
var cc4 string
if ar, cc4, err = atom.ReadAtomHeader(lr, ""); err != nil {
log.Println("read atom failed")
return
}
if cc4 == "moov" {
if moov, err = atom.ReadMovie(ar); err != nil {
log.Println("read '%s' atom failed", cc4)
return
}
if false {
atom.WalkMovie(dumper, moov)
}
} else {
fmt.Println("atom:", cc4)
}
if _, err = atom.ReadDummy(lr, int(ar.N)); err != nil {
return
}
}
if moov == nil {
err = fmt.Errorf("'moov' atom not found")
log.Println("'moov' atom not found")
return
}
if len(moov.Tracks) > 0 {
track := moov.Tracks[0]
record := getAVCDecoderConfRecordByTrack(track)
if record != nil && len(record.SPS) > 0 {
sps := record.SPS[0]
if len(sps) > 1 {
sps = sps[1:]
log.Println(hex.Dump(sps))
var info *atom.H264SPSInfo
if info, err = atom.ParseH264SPS(sps); err != nil {
return
}
log.Println(info)
}
}
}
return
}
func TestConvert(filename string) (err error) {
var osfile *os.File
if osfile, err = os.Open(filename); err != nil {
return
}
var finfo os.FileInfo
if finfo, err = osfile.Stat(); err != nil {
return
}
log.Println("filesize", finfo.Size())
lr := &io.LimitedReader{R: osfile, N: finfo.Size()}
var outfile *os.File
if outfile, err = os.Create(filename+".out.mp4"); err != nil {
return
}
for lr.N > 0 {
var ar *io.LimitedReader
var cc4 string
if ar, cc4, err = atom.ReadAtomHeader(lr, ""); err != nil {
return
}
if cc4 == "moov" {
curPos, _ := outfile.Seek(0, 1)
origSize := ar.N+8
var moov *atom.Movie
if moov, err = atom.ReadMovie(ar); err != nil {
return
}
//log.Println(moov.Tracks[0].Media.Info.Data.Refer)
if err = atom.WriteMovie(outfile, moov); err != nil {
return
}
curPosAfterRead, _ := outfile.Seek(0, 1)
bytesWritten := curPosAfterRead - curPos
log.Println("regen moov", "tracks nr", len(moov.Tracks),
"origSize", origSize, "bytesWritten", bytesWritten,
)
padSize := origSize - bytesWritten - 8
aw, _ := atom.WriteAtomHeader(outfile, "free")
atom.WriteDummy(outfile, int(padSize))
aw.Close()
} else {
outcc4 := cc4
if outcc4 != "mdat" {
log.Println("omit", cc4)
outcc4 = "free"
} else {
log.Println("copy", cc4)
}
var aw *atom.Writer
if aw, err = atom.WriteAtomHeader(outfile, outcc4); err != nil {
return
}
if _, err = io.CopyN(aw, ar, ar.N); err != nil {
return
}
if err = aw.Close(); err != nil {
return
}
}
//log.Println("atom", cc4, "left", lr.N)
//atom.ReadDummy(ar, int(ar.N))
}
if err = outfile.Close(); err != nil {
return
}
return
}