You cannot select more than 25 topics Topics must start with a letter or number, can include dashes ('-') and can be up to 35 characters long.
joy4/format/mp4/demuxer.go

447 lines
11 KiB
Go

package mp4
import (
"errors"
"fmt"
"io"
"time"
"gitlab.com/ics_cinnamon/joy4/av"
"gitlab.com/ics_cinnamon/joy4/codec/aacparser"
"gitlab.com/ics_cinnamon/joy4/codec/h264parser"
"gitlab.com/ics_cinnamon/joy4/format/mp4/mp4io"
)
type Demuxer struct {
r io.ReadSeeker
streams []*Stream
movieAtom *mp4io.Movie
}
func NewDemuxer(r io.ReadSeeker) *Demuxer {
return &Demuxer{
r: r,
}
}
func (self *Demuxer) Streams() (streams []av.CodecData, err error) {
if err = self.probe(); err != nil {
return
}
for _, stream := range self.streams {
streams = append(streams, stream.CodecData)
}
return
}
func (self *Demuxer) readat(pos int64, b []byte) (err error) {
if _, err = self.r.Seek(pos, 0); err != nil {
return
}
if _, err = io.ReadFull(self.r, b); err != nil {
return
}
return
}
func (self *Demuxer) probe() (err error) {
if self.movieAtom != nil {
return
}
var moov *mp4io.Movie
var atoms []mp4io.Atom
if atoms, err = mp4io.ReadFileAtoms(self.r); err != nil {
return
}
if _, err = self.r.Seek(0, 0); err != nil {
return
}
for _, atom := range atoms {
if atom.Tag() == mp4io.MOOV {
moov = atom.(*mp4io.Movie)
}
}
if moov == nil {
err = fmt.Errorf("mp4: 'moov' atom not found")
return
}
self.streams = []*Stream{}
for i, atrack := range moov.Tracks {
stream := &Stream{
trackAtom: atrack,
demuxer: self,
idx: i,
}
if atrack.Media != nil && atrack.Media.Info != nil && atrack.Media.Info.Sample != nil {
stream.sample = atrack.Media.Info.Sample
stream.timeScale = int64(atrack.Media.Header.TimeScale)
} else {
err = fmt.Errorf("mp4: sample table not found")
return
}
if avc1 := atrack.GetAVC1Conf(); avc1 != nil {
if stream.CodecData, err = h264parser.NewCodecDataFromAVCDecoderConfRecord(avc1.Data); err != nil {
return
}
self.streams = append(self.streams, stream)
} else if esds := atrack.GetElemStreamDesc(); esds != nil {
if stream.CodecData, err = aacparser.NewCodecDataFromMPEG4AudioConfigBytes(esds.DecConfig); err != nil {
return
}
self.streams = append(self.streams, stream)
}
}
self.movieAtom = moov
return
}
func (self *Stream) setSampleIndex(index int) (err error) {
found := false
start := 0
self.chunkGroupIndex = 0
for self.chunkIndex = range self.sample.ChunkOffset.Entries {
if self.chunkGroupIndex+1 < len(self.sample.SampleToChunk.Entries) &&
uint32(self.chunkIndex+1) == self.sample.SampleToChunk.Entries[self.chunkGroupIndex+1].FirstChunk {
self.chunkGroupIndex++
}
n := int(self.sample.SampleToChunk.Entries[self.chunkGroupIndex].SamplesPerChunk)
if index >= start && index < start+n {
found = true
self.sampleIndexInChunk = index - start
break
}
start += n
}
if !found {
err = fmt.Errorf("mp4: stream[%d]: cannot locate sample index in chunk", self.idx)
return
}
if self.sample.SampleSize.SampleSize != 0 {
self.sampleOffsetInChunk = int64(self.sampleIndexInChunk) * int64(self.sample.SampleSize.SampleSize)
} else {
if index >= len(self.sample.SampleSize.Entries) {
err = fmt.Errorf("mp4: stream[%d]: sample index out of range", self.idx)
return
}
self.sampleOffsetInChunk = int64(0)
for i := index - self.sampleIndexInChunk; i < index; i++ {
self.sampleOffsetInChunk += int64(self.sample.SampleSize.Entries[i])
}
}
self.dts = int64(0)
start = 0
found = false
self.sttsEntryIndex = 0
for self.sttsEntryIndex < len(self.sample.TimeToSample.Entries) {
entry := self.sample.TimeToSample.Entries[self.sttsEntryIndex]
n := int(entry.Count)
if index >= start && index < start+n {
self.sampleIndexInSttsEntry = index - start
self.dts += int64(index-start) * int64(entry.Duration)
found = true
break
}
start += n
self.dts += int64(n) * int64(entry.Duration)
self.sttsEntryIndex++
}
if !found {
err = fmt.Errorf("mp4: stream[%d]: cannot locate sample index in stts entry", self.idx)
return
}
if self.sample.CompositionOffset != nil && len(self.sample.CompositionOffset.Entries) > 0 {
start = 0
found = false
self.cttsEntryIndex = 0
for self.cttsEntryIndex < len(self.sample.CompositionOffset.Entries) {
n := int(self.sample.CompositionOffset.Entries[self.cttsEntryIndex].Count)
if index >= start && index < start+n {
self.sampleIndexInCttsEntry = index - start
found = true
break
}
start += n
self.cttsEntryIndex++
}
if !found {
err = fmt.Errorf("mp4: stream[%d]: cannot locate sample index in ctts entry", self.idx)
return
}
}
if self.sample.SyncSample != nil {
self.syncSampleIndex = 0
for self.syncSampleIndex < len(self.sample.SyncSample.Entries)-1 {
if self.sample.SyncSample.Entries[self.syncSampleIndex+1]-1 > uint32(index) {
break
}
self.syncSampleIndex++
}
}
if false {
fmt.Printf("mp4: stream[%d]: setSampleIndex chunkGroupIndex=%d chunkIndex=%d sampleOffsetInChunk=%d\n",
self.idx, self.chunkGroupIndex, self.chunkIndex, self.sampleOffsetInChunk)
}
self.sampleIndex = index
return
}
func (self *Stream) isSampleValid() bool {
if self.chunkIndex >= len(self.sample.ChunkOffset.Entries) {
return false
}
if self.chunkGroupIndex >= len(self.sample.SampleToChunk.Entries) {
return false
}
if self.sttsEntryIndex >= len(self.sample.TimeToSample.Entries) {
return false
}
if self.sample.CompositionOffset != nil && len(self.sample.CompositionOffset.Entries) > 0 {
if self.cttsEntryIndex >= len(self.sample.CompositionOffset.Entries) {
return false
}
}
if self.sample.SyncSample != nil {
if self.syncSampleIndex >= len(self.sample.SyncSample.Entries) {
return false
}
}
if self.sample.SampleSize.SampleSize != 0 {
if self.sampleIndex >= len(self.sample.SampleSize.Entries) {
return false
}
}
return true
}
func (self *Stream) incSampleIndex() (duration int64) {
if false {
fmt.Printf("incSampleIndex sampleIndex=%d sampleOffsetInChunk=%d sampleIndexInChunk=%d chunkGroupIndex=%d chunkIndex=%d\n",
self.sampleIndex, self.sampleOffsetInChunk, self.sampleIndexInChunk, self.chunkGroupIndex, self.chunkIndex)
}
self.sampleIndexInChunk++
if uint32(self.sampleIndexInChunk) == self.sample.SampleToChunk.Entries[self.chunkGroupIndex].SamplesPerChunk {
self.chunkIndex++
self.sampleIndexInChunk = 0
self.sampleOffsetInChunk = int64(0)
} else {
if self.sample.SampleSize.SampleSize != 0 {
self.sampleOffsetInChunk += int64(self.sample.SampleSize.SampleSize)
} else {
self.sampleOffsetInChunk += int64(self.sample.SampleSize.Entries[self.sampleIndex])
}
}
if self.chunkGroupIndex+1 < len(self.sample.SampleToChunk.Entries) &&
uint32(self.chunkIndex+1) == self.sample.SampleToChunk.Entries[self.chunkGroupIndex+1].FirstChunk {
self.chunkGroupIndex++
}
sttsEntry := self.sample.TimeToSample.Entries[self.sttsEntryIndex]
duration = int64(sttsEntry.Duration)
self.sampleIndexInSttsEntry++
self.dts += duration
if uint32(self.sampleIndexInSttsEntry) == sttsEntry.Count {
self.sampleIndexInSttsEntry = 0
self.sttsEntryIndex++
}
if self.sample.CompositionOffset != nil && len(self.sample.CompositionOffset.Entries) > 0 {
self.sampleIndexInCttsEntry++
if uint32(self.sampleIndexInCttsEntry) == self.sample.CompositionOffset.Entries[self.cttsEntryIndex].Count {
self.sampleIndexInCttsEntry = 0
self.cttsEntryIndex++
}
}
if self.sample.SyncSample != nil {
entries := self.sample.SyncSample.Entries
if self.syncSampleIndex+1 < len(entries) && entries[self.syncSampleIndex+1]-1 == uint32(self.sampleIndex+1) {
self.syncSampleIndex++
}
}
self.sampleIndex++
return
}
func (self *Stream) sampleCount() int {
if self.sample.SampleSize.SampleSize == 0 {
chunkGroupIndex := 0
count := 0
for chunkIndex := range self.sample.ChunkOffset.Entries {
n := int(self.sample.SampleToChunk.Entries[chunkGroupIndex].SamplesPerChunk)
count += n
if chunkGroupIndex+1 < len(self.sample.SampleToChunk.Entries) &&
uint32(chunkIndex+1) == self.sample.SampleToChunk.Entries[chunkGroupIndex+1].FirstChunk {
chunkGroupIndex++
}
}
return count
} else {
return len(self.sample.SampleSize.Entries)
}
}
func (self *Demuxer) ReadPacket() (pkt av.Packet, err error) {
if err = self.probe(); err != nil {
return
}
if len(self.streams) == 0 {
err = errors.New("mp4: no streams available while trying to read a packet")
return
}
var chosen *Stream
var chosenidx int
for i, stream := range self.streams {
if chosen == nil || stream.tsToTime(stream.dts) < chosen.tsToTime(chosen.dts) {
chosen = stream
chosenidx = i
}
}
if false {
fmt.Printf("ReadPacket: chosen index=%v time=%v\n", chosen.idx, chosen.tsToTime(chosen.dts))
}
tm := chosen.tsToTime(chosen.dts)
if pkt, err = chosen.readPacket(); err != nil {
return
}
pkt.Time = tm
pkt.Idx = int8(chosenidx)
return
}
func (self *Demuxer) CurrentTime() (tm time.Duration) {
if len(self.streams) > 0 {
stream := self.streams[0]
tm = stream.tsToTime(stream.dts)
}
return
}
func (self *Demuxer) SeekToTime(tm time.Duration) (err error) {
for _, stream := range self.streams {
if stream.Type().IsVideo() {
if err = stream.seekToTime(tm); err != nil {
return
}
tm = stream.tsToTime(stream.dts)
break
}
}
for _, stream := range self.streams {
if !stream.Type().IsVideo() {
if err = stream.seekToTime(tm); err != nil {
return
}
}
}
return
}
func (self *Stream) readPacket() (pkt av.Packet, err error) {
if !self.isSampleValid() {
err = io.EOF
return
}
//fmt.Println("readPacket", self.sampleIndex)
chunkOffset := self.sample.ChunkOffset.Entries[self.chunkIndex]
sampleSize := uint32(0)
if self.sample.SampleSize.SampleSize != 0 {
sampleSize = self.sample.SampleSize.SampleSize
} else {
sampleSize = self.sample.SampleSize.Entries[self.sampleIndex]
}
sampleOffset := int64(chunkOffset) + self.sampleOffsetInChunk
pkt.Data = make([]byte, sampleSize)
if err = self.demuxer.readat(sampleOffset, pkt.Data); err != nil {
return
}
if self.sample.SyncSample != nil {
if self.sample.SyncSample.Entries[self.syncSampleIndex]-1 == uint32(self.sampleIndex) {
pkt.IsKeyFrame = true
}
}
//println("pts/dts", self.ptsEntryIndex, self.dtsEntryIndex)
if self.sample.CompositionOffset != nil && len(self.sample.CompositionOffset.Entries) > 0 {
cts := int64(self.sample.CompositionOffset.Entries[self.cttsEntryIndex].Offset)
pkt.CompositionTime = self.tsToTime(cts)
}
self.incSampleIndex()
return
}
func (self *Stream) seekToTime(tm time.Duration) (err error) {
index := self.timeToSampleIndex(tm)
if err = self.setSampleIndex(index); err != nil {
return
}
if false {
fmt.Printf("stream[%d]: seekToTime index=%v time=%v cur=%v\n", self.idx, index, tm, self.tsToTime(self.dts))
}
return
}
func (self *Stream) timeToSampleIndex(tm time.Duration) int {
targetTs := self.timeToTs(tm)
targetIndex := 0
startTs := int64(0)
endTs := int64(0)
startIndex := 0
endIndex := 0
found := false
for _, entry := range self.sample.TimeToSample.Entries {
endTs = startTs + int64(entry.Count*entry.Duration)
endIndex = startIndex + int(entry.Count)
if targetTs >= startTs && targetTs < endTs {
targetIndex = startIndex + int((targetTs-startTs)/int64(entry.Duration))
found = true
}
startTs = endTs
startIndex = endIndex
}
if !found {
if targetTs < 0 {
targetIndex = 0
} else {
targetIndex = endIndex - 1
}
}
if self.sample.SyncSample != nil {
entries := self.sample.SyncSample.Entries
for i := len(entries) - 1; i >= 0; i-- {
if entries[i]-1 < uint32(targetIndex) {
targetIndex = int(entries[i] - 1)
break
}
}
}
return targetIndex
}