From ea26f04c107e32732471dd2c3771636afaf71195 Mon Sep 17 00:00:00 2001
From: nareix <hi.nareix@gmail.com>
Date: Mon, 4 Jul 2016 23:04:55 +0800
Subject: [PATCH] add format aac.go

---
 format/aac/aac.go | 119 ++++++++++++++++++++++++++++++++++++++++++++++
 1 file changed, 119 insertions(+)
 create mode 100644 format/aac/aac.go

diff --git a/format/aac/aac.go b/format/aac/aac.go
new file mode 100644
index 0000000..7a31b1d
--- /dev/null
+++ b/format/aac/aac.go
@@ -0,0 +1,119 @@
+
+package aac
+
+import (
+	"github.com/nareix/joy4/av/avutil"
+	"github.com/nareix/joy4/av"
+	"github.com/nareix/joy4/codec/aacparser"
+	"time"
+	"fmt"
+	"io"
+	"bufio"
+)
+
+type Muxer struct {
+	w io.Writer
+	config aacparser.MPEG4AudioConfig
+	adtshdr []byte
+}
+
+func NewMuxer(w io.Writer) *Muxer {
+	return &Muxer{
+		adtshdr: make([]byte, aacparser.ADTSHeaderLength),
+		w: w,
+	}
+}
+
+func (self *Muxer) WriteHeader(streams []av.CodecData) (err error) {
+	if len(streams) > 1 || streams[0].Type() != av.AAC {
+		err = fmt.Errorf("aac: must be only one aac stream")
+		return
+	}
+	self.config = streams[0].(aacparser.CodecData).Config
+	return
+}
+
+func (self *Muxer) WritePacket(pkt av.Packet) (err error) {
+	aacparser.FillADTSHeader(self.adtshdr, self.config, 1024, len(pkt.Data))
+	if _, err = self.w.Write(self.adtshdr); err != nil {
+		return
+	}
+	if _, err = self.w.Write(pkt.Data); err != nil {
+		return
+	}
+	return
+}
+
+func (self *Muxer) WriteTrailer() (err error) {
+	return
+}
+
+type Demuxer struct {
+	r *bufio.Reader
+	config aacparser.MPEG4AudioConfig
+	codecdata av.CodecData
+	ts time.Duration
+}
+
+func NewDemuxer(r io.Reader) *Demuxer {
+	return &Demuxer{
+		r: bufio.NewReader(r),
+	}
+}
+
+func (self *Demuxer) Streams() (streams []av.CodecData, err error) {
+	if self.codecdata == nil {
+		var adtshdr []byte
+		var config aacparser.MPEG4AudioConfig
+		if adtshdr, err = self.r.Peek(9); err != nil {
+			return
+		}
+		if config, _, _, _, err = aacparser.ParseADTSHeader(adtshdr); err != nil {
+			return
+		}
+		if self.codecdata, err = aacparser.NewCodecDataFromMPEG4AudioConfig(config); err != nil {
+			return
+		}
+	}
+	streams = []av.CodecData{self.codecdata}
+	return
+}
+
+func (self *Demuxer) ReadPacket() (pkt av.Packet, err error) {
+	var adtshdr []byte
+	var config aacparser.MPEG4AudioConfig
+	var hdrlen, framelen, samples int
+	if adtshdr, err = self.r.Peek(9); err != nil {
+		return
+	}
+	if config, hdrlen, framelen, samples, err = aacparser.ParseADTSHeader(adtshdr); err != nil {
+		return
+	}
+
+	pkt.Data = make([]byte, framelen)
+	if _, err = io.ReadFull(self.r, pkt.Data); err != nil {
+		return
+	}
+	pkt.Data = pkt.Data[hdrlen:]
+
+	pkt.Time = self.ts
+	self.ts += time.Duration(samples) * time.Second / time.Duration(config.SampleRate)
+	return
+}
+
+func Handler(h *avutil.RegisterHandler) {
+	h.Ext = ".aac"
+
+	h.ReaderDemuxer = func(r io.Reader) av.Demuxer {
+		return NewDemuxer(r)
+	}
+
+	h.WriterMuxer = func(w io.Writer) av.Muxer {
+		return NewMuxer(w)
+	}
+
+	h.Probe = func(b []byte) bool {
+		_, _, _, _, err := aacparser.ParseADTSHeader(b)
+		return err == nil
+	}
+}