sdp file parsing failed

[autoexpect]

What did you do?

Hi~
I took a sdp file from a webcam, but it failed to parse
[
v=0
o=NVR 1585015269 1585015269 IN IP4 0.0.0.0
s=3GPP Unicast SDP
c=IN IP4 0.0.0.0
t=0 0
a=range:npt=0-
a=control:*
m=video 0 RTP/AVP 96
a=control:video_0
a=rtpmap:96 H264/90000
a=fmtp:96 profile-level-id=42002a;sprop-parameter-sets=Z0IAKp2oHgCJ+WbgICAgQA==,aM48gA==;packetization-mode=0
m=audio 0 RTP/AVP 8
a=control:audio_0
a=rtpmap:8 PCMA/8000

]

[at-wat]

The SDP looks be able to be parsed by the following code:

package main

import (
  "fmt"

  "github.com/pion/sdp/v2"
)

func main() {
  s := &sdp.SessionDescription{}
  err := s.Unmarshal([]byte(`v=0
o=NVR 1585015269 1585015269 IN IP4 0.0.0.0
s=3GPP Unicast SDP
c=IN IP4 0.0.0.0
t=0 0
a=range:npt=0-
a=control:*
m=video 0 RTP/AVP 96
a=control:video_0
a=rtpmap:96 H264/90000
a=fmtp:96 profile-level-id=42002a;sprop-parameter-sets=Z0IAKp2oHgCJ+WbgICAgQA==,aM48gA==;packetization-mode=0
m=audio 0 RTP/AVP 8
a=control:audio_0
a=rtpmap:8 PCMA/8000`))
  if err != nil {
    panic(err)
  }
  fmt.Printf("parsed:\n%+#v\n\n", s)
  
  b, err := s.Marshal()
  fmt.Printf("roundtrip:\n%s\n", b)
} 

output:

parsed:
&sdp.SessionDescription{Version:0, Origin:sdp.Origin{Username:"NVR", SessionID:0x5e7969e5, SessionVersion:0x5e7969e5, NetworkType:"IN", AddressType:"IP4", UnicastAddress:"0.0.0.0"}, SessionName:"3GPP Unicast SDP", SessionInformation:(*sdp.Information)(nil), URI:(*url.URL)(nil), EmailAddress:(*sdp.EmailAddress)(nil), PhoneNumber:(*sdp.PhoneNumber)(nil), ConnectionInformation:(*sdp.ConnectionInformation)(0xc0001100c0), Bandwidth:[]sdp.Bandwidth(nil), TimeDescriptions:[]sdp.TimeDescription{sdp.TimeDescription{Timing:sdp.Timing{StartTime:0x0, StopTime:0x0}, RepeatTimes:[]sdp.RepeatTime(nil)}}, TimeZones:[]sdp.TimeZone(nil), EncryptionKey:(*sdp.EncryptionKey)(nil), Attributes:[]sdp.Attribute{sdp.Attribute{Key:"range", Value:"npt=0-"}, sdp.Attribute{Key:"control", Value:"*"}}, MediaDescriptions:[]*sdp.MediaDescription{(*sdp.MediaDescription)(0xc000120000), (*sdp.MediaDescription)(0xc0001200a0)}}

roundtrip:
v=0
o=NVR 1585015269 1585015269 IN IP4 0.0.0.0
s=3GPP Unicast SDP
c=IN IP4 0.0.0.0
t=0 0
a=range:npt=0-
a=control:*
m=video 0 RTP/AVP 96
a=control:video_0
a=rtpmap:96 H264/90000
a=fmtp:96 profile-level-id=42002a;sprop-parameter-sets=Z0IAKp2oHgCJ+WbgICAgQA==,aM48gA==;packetization-mode=0
m=audio 0 RTP/AVP 8
a=control:audio_0
a=rtpmap:8 PCMA/8000

Could you post your code and error log?

[autoexpect]

code:

package main

import (
  "fmt"

  "github.com/pion/sdp/v2"
)

func main() {
  s := &sdp.SessionDescription{}
  err := s.Unmarshal([]byte(`v=0
o=NVR 1585043154 1585043154 IN IP4 0.0.0.0
s=3GPP Unicast SDP
c=IN IP4 0.0.0.0
t=0 0
a=range:npt=0-
a=control:*
m=video 0 RTP/AVP 96
a=control:video_0
a=rtpmap:96 H264/90000
a=fmtp:96 profile-level-id=42002a;sprop-parameter-sets=Z0IAKp2oHgCJ+WbgICAgQA==,aM48gA==;packetization-mode=0
m=audio 0 RTP/AVP 8
a=control:audio_0
a=rtpmap:8 PCMA/8000

`))
  if err != nil {
    panic(err)
  }
  fmt.Printf("parsed:\n%+#v\n\n", s)

  b, err := s.Marshal()
  fmt.Printf("roundtrip:\n%s\n", b)
}

output:

go run main.go
panic: EOF

goroutine 1 [running]:
main.main()
	/Users/harry/Downloads/test/main.go:28 +0x1d4
exit status 2

there are several newline bytes after sdp..

[at-wat]

I'm not very sure SDP allows empty lines.
I'll check the RFC and BNF definition of SDP.

[at-wat]

In my understanding, extra newlines in SDP is not fully adapting the specification. (I'm not 100% sure.)
But other SDP parsers, for example one in VLC media player, allow to have extra newlines.

#46 will fix the issue.

[autoexpect]

OK thanks！

[at-wat]

@umbrellary the master branch support SDP with extra newlines now. Please check it out!

[autoexpect]

it works!