joy4/muxer.go
2016-05-26 20:14:36 +08:00

286 lines
7.3 KiB
Go

package mp4
import (
"bytes"
"fmt"
"github.com/nareix/av"
"github.com/nareix/codec/aacparser"
"github.com/nareix/codec/h264parser"
"github.com/nareix/mp4/atom"
"github.com/nareix/mp4/isom"
"io"
)
func Create(W io.WriteSeeker, streams []av.CodecData) (muxer *Muxer, err error) {
_muxer := &Muxer{W: W}
if err = _muxer.WriteHeader(streams); err != nil {
return
}
muxer = _muxer
return
}
type Muxer struct {
W io.WriteSeeker
streams []*Stream
mdatWriter *atom.Writer
}
func (self *Muxer) IsCodecSupported(codec av.CodecData) bool {
switch codec.Type() {
case av.H264, av.AAC:
return true
default:
return false
}
}
func (self *Muxer) NewStream(codec av.CodecData) (err error) {
if !self.IsCodecSupported(codec) {
err = fmt.Errorf("codec type=%x is not supported", codec.Type())
return
}
stream := &Stream{CodecData: codec}
stream.sample = &atom.SampleTable{
SampleDesc: &atom.SampleDesc{},
TimeToSample: &atom.TimeToSample{},
SampleToChunk: &atom.SampleToChunk{
Entries: []atom.SampleToChunkEntry{
{
FirstChunk: 1,
SampleDescId: 1,
SamplesPerChunk: 1,
},
},
},
SampleSize: &atom.SampleSize{},
ChunkOffset: &atom.ChunkOffset{},
}
stream.trackAtom = &atom.Track{
Header: &atom.TrackHeader{
TrackId: len(self.streams) + 1,
Flags: 0x0003, // Track enabled | Track in movie
Duration: 0, // fill later
Matrix: [9]int{0x10000, 0, 0, 0, 0x10000, 0, 0, 0, 0x40000000},
},
Media: &atom.Media{
Header: &atom.MediaHeader{
TimeScale: 0, // fill later
Duration: 0, // fill later
Language: 21956,
},
Info: &atom.MediaInfo{
Sample: stream.sample,
Data: &atom.DataInfo{
Refer: &atom.DataRefer{
Url: &atom.DataReferUrl{
Flags: 0x000001, // Self reference
},
},
},
},
},
}
stream.timeScale = 90000
stream.muxer = self
self.streams = append(self.streams, stream)
return
}
func (self *Stream) fillTrackAtom() (err error) {
self.trackAtom.Media.Header.TimeScale = int(self.timeScale)
self.trackAtom.Media.Header.Duration = int(self.duration)
if self.Type() == av.H264 {
codec := self.CodecData.(av.H264CodecData)
width, height := codec.Width(), codec.Height()
self.sample.SampleDesc.Avc1Desc = &atom.Avc1Desc{
DataRefIdx: 1,
HorizontalResolution: 72,
VorizontalResolution: 72,
Width: int(width),
Height: int(height),
FrameCount: 1,
Depth: 24,
ColorTableId: -1,
Conf: &atom.Avc1Conf{Data: codec.AVCDecoderConfRecordBytes()},
}
self.sample.SyncSample = &atom.SyncSample{}
self.trackAtom.Media.Handler = &atom.HandlerRefer{
SubType: "vide",
Name: "Video Media Handler",
}
self.trackAtom.Media.Info.Video = &atom.VideoMediaInfo{
Flags: 0x000001,
}
self.trackAtom.Header.TrackWidth = atom.IntToFixed(int(width))
self.trackAtom.Header.TrackHeight = atom.IntToFixed(int(height))
} else if self.Type() == av.AAC {
codec := self.CodecData.(av.AACCodecData)
buf := &bytes.Buffer{}
if err = isom.WriteElemStreamDesc(buf, codec.MPEG4AudioConfigBytes(), uint(self.trackAtom.Header.TrackId)); err != nil {
return
}
self.sample.SampleDesc.Mp4aDesc = &atom.Mp4aDesc{
DataRefIdx: 1,
NumberOfChannels: codec.ChannelCount(),
SampleSize: codec.ChannelCount() * 8,
SampleRate: atom.IntToFixed(codec.SampleRate()),
Conf: &atom.ElemStreamDesc{
Data: buf.Bytes(),
},
}
self.trackAtom.Header.Volume = atom.IntToFixed(1)
self.trackAtom.Header.AlternateGroup = 1
self.trackAtom.Media.Handler = &atom.HandlerRefer{
SubType: "soun",
Name: "Sound Handler",
}
self.trackAtom.Media.Info.Sound = &atom.SoundMediaInfo{}
} else {
err = fmt.Errorf("please specify stream type")
}
return
}
func (self *Muxer) WriteHeader(streams []av.CodecData) (err error) {
for _, stream := range streams {
if err = self.NewStream(stream); err != nil {
return
}
}
if self.mdatWriter, err = atom.WriteAtomHeader(self.W, "mdat"); err != nil {
return
}
for _, stream := range self.streams {
if stream.IsVideo() {
stream.sample.CompositionOffset = &atom.CompositionOffset{}
}
}
return
}
func (self *Muxer) WritePacket(streamIndex int, pkt av.Packet) (err error) {
stream := self.streams[streamIndex]
frame := pkt.Data
if stream.Type() == av.AAC && aacparser.IsADTSFrame(frame) {
sampleRate := stream.CodecData.(av.AudioCodecData).SampleRate()
for len(frame) > 0 {
var payload []byte
var samples int
var framelen int
if _, payload, samples, framelen, err = aacparser.ReadADTSFrame(frame); err != nil {
return
}
newpkt := pkt
newpkt.Data = payload
newpkt.Duration = float64(samples)/float64(sampleRate)
if err = stream.writePacket(newpkt); err != nil {
return
}
frame = frame[framelen:]
}
return
}
return stream.writePacket(pkt)
}
func (self *Stream) writePacket(pkt av.Packet) (err error) {
var filePos int64
var sampleSize int
if filePos, err = self.muxer.mdatWriter.Seek(0, 1); err != nil {
return
}
if self.Type() == av.H264 {
nalus, _ := h264parser.SplitNALUs(pkt.Data)
h264parser.WalkNALUsAVCC(nalus, func(b []byte) {
sampleSize += len(b)
_, err = self.muxer.mdatWriter.Write(b)
})
if err != nil {
return
}
} else {
sampleSize = len(pkt.Data)
if _, err = self.muxer.mdatWriter.Write(pkt.Data); err != nil {
return
}
}
if pkt.IsKeyFrame && self.sample.SyncSample != nil {
self.sample.SyncSample.Entries = append(self.sample.SyncSample.Entries, self.sampleIndex+1)
}
duration := int(self.timeToTs(pkt.Duration))
if self.sttsEntry == nil || duration != self.sttsEntry.Duration {
self.sample.TimeToSample.Entries = append(self.sample.TimeToSample.Entries, atom.TimeToSampleEntry{Duration: duration})
self.sttsEntry = &self.sample.TimeToSample.Entries[len(self.sample.TimeToSample.Entries)-1]
}
self.sttsEntry.Count++
if self.sample.CompositionOffset != nil {
offset := int(self.timeToTs(pkt.CompositionTime))
if self.cttsEntry == nil || offset != self.cttsEntry.Offset {
table := self.sample.CompositionOffset
table.Entries = append(table.Entries, atom.CompositionOffsetEntry{Offset: offset})
self.cttsEntry = &table.Entries[len(table.Entries)-1]
}
self.cttsEntry.Count++
}
self.duration += int64(duration)
self.sampleIndex++
self.sample.ChunkOffset.Entries = append(self.sample.ChunkOffset.Entries, int(filePos))
self.sample.SampleSize.Entries = append(self.sample.SampleSize.Entries, sampleSize)
return
}
func (self *Muxer) WriteTrailer() (err error) {
moov := &atom.Movie{}
moov.Header = &atom.MovieHeader{
PreferredRate: atom.IntToFixed(1),
PreferredVolume: atom.IntToFixed(1),
Matrix: [9]int{0x10000, 0, 0, 0, 0x10000, 0, 0, 0, 0x40000000},
NextTrackId: 2,
}
maxDur := float64(0)
timeScale := 10000
for _, stream := range self.streams {
if err = stream.fillTrackAtom(); err != nil {
return
}
dur := stream.tsToTime(stream.duration)
stream.trackAtom.Header.Duration = int(float64(timeScale) * dur)
if dur > maxDur {
maxDur = dur
}
moov.Tracks = append(moov.Tracks, stream.trackAtom)
}
moov.Header.TimeScale = timeScale
moov.Header.Duration = int(float64(timeScale) * maxDur)
if err = self.mdatWriter.Close(); err != nil {
return
}
if err = atom.WriteMovie(self.W, moov); err != nil {
return
}
return
}