From c437a98c9300db3bef001edbe357795b1c0dd8e9 Mon Sep 17 00:00:00 2001
From: nareix <hi.nareix@gmail.com>
Date: Sun, 12 Jun 2016 08:53:06 +0800
Subject: [PATCH] change Streams()

---
 av.go                  |  2 +-
 transcode/transcode.go | 21 ++++++++++++++++-----
 2 files changed, 17 insertions(+), 6 deletions(-)

diff --git a/av.go b/av.go
index 77a54d6..e0cc1e4 100644
--- a/av.go
+++ b/av.go
@@ -140,7 +140,7 @@ type Muxer interface {
 
 type Demuxer interface {
 	ReadPacket() (int, Packet, error)
-	Streams() []CodecData
+	Streams() ([]CodecData, error)
 }
 
 type Packet struct {
diff --git a/transcode/transcode.go b/transcode/transcode.go
index 52e47d4..c7246d3 100644
--- a/transcode/transcode.go
+++ b/transcode/transcode.go
@@ -45,7 +45,10 @@ func (self *Transcoder) Setup(streams []av.CodecData) (err error) {
 	}
 
 	self.queue = &pktreorder.Queue{}
-	self.queue.Alloc(self.Streams())
+
+	var newstreams []av.CodecData
+	newstreams, _ = self.Streams()
+	self.queue.Alloc(newstreams)
 	return
 }
 
@@ -105,7 +108,7 @@ func (self *Transcoder) ReadPacket() (i int, pkt av.Packet, err error) {
 	return self.queue.ReadPacket()
 }
 
-func (self *Transcoder) Streams() (streams []av.CodecData) {
+func (self *Transcoder) Streams() (streams []av.CodecData, err error) {
 	for _, stream := range self.streams {
 		streams = append(streams, stream.CodecData)
 	}
@@ -133,7 +136,11 @@ func (self *Muxer) WriteHeader(streams []av.CodecData) (err error) {
 	if err = self.Transcoder.Setup(streams); err != nil {
 		return
 	}
-	if err = self.Muxer.WriteHeader(self.Transcoder.Streams()); err != nil {
+	var newstreams []av.CodecData
+	if newstreams, err = self.Transcoder.Streams(); err != nil {
+		return
+	}
+	if err = self.Muxer.WriteHeader(newstreams); err != nil {
 		return
 	}
 	return
@@ -178,7 +185,11 @@ type Demuxer struct {
 }
 
 func (self *Demuxer) Setup() (err error) {
-	if err = self.Transcoder.Setup(self.Demuxer.Streams()); err != nil {
+	var streams []av.CodecData
+	if streams, err = self.Demuxer.Streams(); err != nil {
+		return
+	}
+	if err = self.Transcoder.Setup(streams); err != nil {
 		return
 	}
 	return
@@ -201,7 +212,7 @@ func (self *Demuxer) ReadPacket() (i int, pkt av.Packet, err error) {
 	}
 }
 
-func (self *Demuxer) Streams() []av.CodecData {
+func (self *Demuxer) Streams() ([]av.CodecData, error) {
 	return self.Transcoder.Streams()
 }