[FFmpeg-devel] libavformat/rtsp.c: fix RTSP not setup the UDP stream in SDP

[Chiu, Yung-Hsiang]

Thanks for your review.

I don't have any standards or formal documents mentioned the proto
'udp' in SDP should be uppercase.

The only document I google for the video server 'orbit2x' is shown below
https://developer.samsung.com/smarttv/develop/legacy-platform-library/art00071/index.html#sdp-supported-feature
Apologize for our buggy video server...

Could you give me some suggestions I should write down in the commit message?

"zhilizhao(赵志立)" <quinkblack at foxmail.com> 於 2021年7月30日 週五 下午2:57寫道：

>
>
>
> > On Jul 30, 2021, at 10:55 AM, Chiu, Yung-Hsiang <mirror.tw at gmail.com> wrote:
> >
> > Hi,
> >
> > Our RTSP video server reply two streams in SDP are UDP and RTP/AVP/UDP.
> >>> m=video 0 UDP 33
> >>> m=video 0 RTP/AVP/UDP 33
> >
> > ffmpeg now setup twice with the same transport "RTP/AVP/UDP"
> >
> > The first time is
> >>> SETUP rtsp://192.168.1.100:554/MOV_000012353521.mpg RTSP/1.0
> >>> Transport: RTP/AVP/UDP;unicast;client_port=26972-26973
> >
> > And the second time is
> >>> SETUP rtsp://192.168.1.100:554/MOV_000012353521.mpg RTSP/1.0
> >>> Transport: RTP/AVP/UDP;unicast;client_port=26974-26975
> >
> > After reviewing the rtsp.c, I found the bug is caused by the
> > acceptable string in sdp_parse_line() is "udp" only.
>
> From RFC 4566, the protocol should be specified as “udp”:
>
> https://datatracker.ietf.org/doc/html/rfc4566#section-8.2.2
>
> From IANA, “UDP” is not a registered protocol field of SDP:
> https://www.iana.org/assignments/sdp-parameters/sdp-parameters.xhtml
>
> Is there any reference that the field can be uppercase? I want figure out
> whether it’s a bug of FFmpeg, or a bug of the server. I don’t object the
> patch, but the patch commit message should reflect the difference between
> ‘fix bug of FFmpeg’ vs ‘workaround buggy server'.
>
> >
> > The transport with "udp" or "UDP" should be acceptable in sdp_parse_line().
> >
> > The full rtsp negotiation is shown below.
> >
> > OPTIONS rtsp://192.168.1.100:554/MOV_000012353521.mpg RTSP/1.0
> > CSeq: 1
> > User-Agent: Lavf58.35.101
> >
> > RTSP/1.0 200 OK
> > Server: Orbit2x
> > CSeq: 1
> > Public: OPTIONS, DESCRIBE, SETUP, TEARDOWN, PLAY, PAUSE, GET_PARAMETER
> >
> >
> > DESCRIBE rtsp://192.168.1.100:554/MOV_000012353521.mpg RTSP/1.0
> > Accept: application/sdp
> > CSeq: 2
> > User-Agent: Lavf58.35.101
> >
> >
> > RTSP/1.0 200 OK
> > Server: Orbit2x
> > CSeq: 2
> > Public: OPTIONS, DESCRIBE, SETUP, TEARDOWN, PLAY, PAUSE, GET_PARAMETER
> > Content-Type: application/sdp
> > Content-Length: 179
> >
> > v=0
> > o=- 60596 0 IN IP4 192.168.1.100
> > s=RTSP Session
> > t=0 0
> > c=IN IP4 192.168.1.100
> > b=AS:7984.000
> > a=type:vod
> > a=range:npt=0-5313
> > m=video 0 UDP 33
> > m=video 0 RTP/AVP/UDP 33
> >
> > SETUP rtsp://192.168.1.100:554/MOV_000012353521.mpg RTSP/1.0
> > Transport: RTP/AVP/UDP;unicast;client_port=26972-26973
> > CSeq: 3
> > User-Agent: Lavf58.35.101
> >
> > RTSP/1.0 200 OK
> > Server: Orbit2x
> > CSeq: 3
> > Session: 728680355;timeout=60
> > Transport: RTP/AVP/UDP;unicast;destination=192.168.2.184;client_port=26972;source=192.168.1.100;server_port=10000-10001;ssrc=7b9507dd
> >
> > SETUP rtsp://192.168.1.100:554/MOV_000012353521.mpg RTSP/1.0
> > Transport: RTP/AVP/UDP;unicast;client_port=26974-26975
> > CSeq: 4
> > User-Agent: Lavf58.35.101
> > Session: 728680355
> >
> > RTSP/1.0 200 OK
> > Server: Orbit2x
> > CSeq: 4
> > Session: 728680355;timeout=60
> > Transport: RTP/AVP/UDP;unicast;destination=192.168.2.184;client_port=26974;source=192.168.1.100;server_port=10000-10001;ssrc=7b9507dd
> >
> > PLAY rtsp://192.168.1.100:554/MOV_000012353521.mpg RTSP/1.0
> > Range: npt=0.000-
> > CSeq: 5
> > User-Agent: Lavf58.35.101
> > Session: 728680355
> >
> > RTSP/1.0 200 OK
> > Server: Orbit2x
> > CSeq: 5
> > Session: 728680355
> > Scale: 1.00
> > Range: npt=0-
> >
> > <0001-libavformat-rtsp.c-fix-RTSP-not-setup-the-UDP-stream.patch>_______________________________________________
> > ffmpeg-devel mailing list
> > ffmpeg-devel at ffmpeg.org
> > https://ffmpeg.org/mailman/listinfo/ffmpeg-devel
> >
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> >
>
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