From 32f5465ec993900cc7872d6a7ae6390ac75ab521 Mon Sep 17 00:00:00 2001
From: q191201771 <191201771@qq.com>
Date: Sun, 4 Jul 2021 20:25:28 +0800
Subject: [PATCH] =?UTF-8?q?(#82)=20[feat]=20sdp=E6=89=93=E5=8C=85?=
MIME-Version: 1.0
Content-Type: text/plain; charset=UTF-8
Content-Transfer-Encoding: 8bit

---
 pkg/base/version.go |  5 +++
 pkg/sdp/avconfig.go | 14 ++-------
 pkg/sdp/pack.go     | 75 +++++++++++++++++++++++++++++++++++++++++++++
 3 files changed, 82 insertions(+), 12 deletions(-)
 create mode 100644 pkg/sdp/pack.go

diff --git a/pkg/base/version.go b/pkg/base/version.go
index 671237f..ed351f9 100644
--- a/pkg/base/version.go
+++ b/pkg/base/version.go
@@ -73,6 +73,9 @@ var (
 
 	// e.g. lal/0.12.3
 	LalRtspPullSessionUa string
+
+	// e.g. lal 0.12.3
+	LalPackSdp string
 )
 
 // - rtmp handshake random buf
@@ -124,4 +127,6 @@ func init() {
 	LalRtspPullSessionUa = LalLibraryName + "/" + LalVersionDot
 
 	LalRtmpHandshakeWaterMark = LalFullInfo
+
+	LalPackSdp = LalLibraryName + " " + LalVersionDot
 }
diff --git a/pkg/sdp/avconfig.go b/pkg/sdp/avconfig.go
index f4ea13d..517d691 100644
--- a/pkg/sdp/avconfig.go
+++ b/pkg/sdp/avconfig.go
@@ -10,7 +10,7 @@ package sdp
 
 import (
 	"encoding/base64"
-	"strconv"
+	"encoding/hex"
 	"strings"
 
 	"github.com/q191201771/lal/pkg/base"
@@ -28,17 +28,7 @@ func ParseAsc(a *AFmtPBase) ([]byte, error) {
 	if len(v) < 4 || (len(v)%2) != 0 {
 		return nil, ErrSdp
 	}
-	l := len(v) / 2
-	r := make([]byte, l)
-	for i := 0; i < l; i++ {
-		b, err := strconv.ParseInt(v[i*2:i*2+2], 16, 0)
-		if err != nil {
-			return nil, ErrSdp
-		}
-		r[i] = uint8(b)
-	}
-
-	return r, nil
+	return hex.DecodeString(v)
 }
 
 func ParseVpsSpsPps(a *AFmtPBase) (vps, sps, pps []byte, err error) {
diff --git a/pkg/sdp/pack.go b/pkg/sdp/pack.go
new file mode 100644
index 0000000..87f0227
--- /dev/null
+++ b/pkg/sdp/pack.go
@@ -0,0 +1,75 @@
+// Copyright 2021, Chef.  All rights reserved.
+// https://github.com/q191201771/lal
+//
+// Use of this source code is governed by a MIT-style license
+// that can be found in the License file.
+//
+// Author: Chef (191201771@qq.com)
+
+package sdp
+
+import (
+	"encoding/base64"
+	"encoding/hex"
+	"fmt"
+
+	"github.com/q191201771/lal/pkg/base"
+)
+
+func Pack(vps, sps, pps, asc []byte) (ctx LogicContext, raw []byte, err error) {
+	var hasAudio, hasVideo, isHevc bool
+
+	if sps != nil && pps != nil {
+		hasVideo = true
+		if vps != nil {
+			isHevc = true
+		}
+	}
+	if asc != nil {
+		hasAudio = true
+	}
+
+	if !hasAudio && !hasVideo {
+		err = ErrSdp
+		return
+	}
+
+	sdpStr := fmt.Sprintf(`v=0
+	o=- 0 0 IN IP4 127.0.0.1
+	s=No Name
+	c=IN IP4 127.0.0.1
+	t=0 0
+	a=tool:%s
+`, base.LalPackSdp)
+
+	streamid := 0
+
+	if hasVideo {
+		if isHevc {
+
+		} else {
+			tmpl := `m=video 0 RTP/AVP 96
+	a=rtpmap:96 H264/90000
+	a=fmtp:96 packetization-mode=1; sprop-parameter-sets=%s,%s; profile-level-id=640016
+	a=control:streamid=%d
+`
+			sdpStr += fmt.Sprintf(tmpl, base64.StdEncoding.EncodeToString(sps), base64.StdEncoding.EncodeToString(pps), streamid)
+		}
+
+		streamid++
+	}
+
+	if hasAudio {
+		tmpl := `m=audio 0 RTP/AVP 97
+	b=AS:128
+	a=rtpmap:97 MPEG4-GENERIC/44100/2
+	a=fmtp:97 profile-level-id=1;mode=AAC-hbr;sizelength=13;indexlength=3;indexdeltalength=3; config=%s
+	a=control:streamid=%d
+`
+		sdpStr += fmt.Sprintf(tmpl, hex.EncodeToString(asc), streamid)
+	}
+
+	raw = []byte(sdpStr)
+	ctx, err = ParseSdp2LogicContext(raw)
+	return
+}