From b652f1bfba3a2e30494425b5c594e2483b5c77d4 Mon Sep 17 00:00:00 2001
From: Dimitrii Lopanov <sexykdi@gmail.com>
Date: Fri, 26 Jun 2020 08:30:43 +0300
Subject: [PATCH] find rtsp must have left > 0

---
 format/rtsp/client.go | 25 +++++++++++++++----------
 1 file changed, 15 insertions(+), 10 deletions(-)

diff --git a/format/rtsp/client.go b/format/rtsp/client.go
index 21854b8..907afbd 100644
--- a/format/rtsp/client.go
+++ b/format/rtsp/client.go
@@ -8,13 +8,6 @@ import (
 	"encoding/binary"
 	"encoding/hex"
 	"fmt"
-	"github.com/deepch/vdk/av"
-	"github.com/deepch/vdk/av/avutil"
-	"github.com/deepch/vdk/codec"
-	"github.com/deepch/vdk/codec/aacparser"
-	"github.com/deepch/vdk/codec/h264parser"
-	"github.com/deepch/vdk/format/rtsp/sdp"
-	"github.com/deepch/vdk/utils/bits/pio"
 	"io"
 	"log"
 	"net"
@@ -23,6 +16,14 @@ import (
 	"strconv"
 	"strings"
 	"time"
+
+	"github.com/deepch/vdk/av"
+	"github.com/deepch/vdk/av/avutil"
+	"github.com/deepch/vdk/codec"
+	"github.com/deepch/vdk/codec/aacparser"
+	"github.com/deepch/vdk/codec/h264parser"
+	"github.com/deepch/vdk/format/rtsp/sdp"
+	"github.com/deepch/vdk/utils/bits/pio"
 )
 
 var ErrCodecDataChange = fmt.Errorf("rtsp: codec data change, please call HandleCodecDataChange()")
@@ -440,11 +441,15 @@ func (self *Client) findRTSP() (block []byte, data []byte, err error) {
 			}
 			if blocklen, _, ok := self.parseBlockHeader(peek); ok {
 				left := blocklen + 4 - len(peek)
-				block = append(peek, make([]byte, left)...)
-				if _, err = io.ReadFull(self.brconn, block[len(peek):]); err != nil {
+				if left >= 0 {
+					block = append(peek, make([]byte, left)...)
+					if _, err = io.ReadFull(self.brconn, block[len(peek):]); err != nil {
+						return
+					}
 					return
+				} else {
+					fmt.Println("Left < 0 ", blocklen, len(peek), left)
 				}
-				return
 			}
 			stat = 0
 			peek = _peek[0:0]