Приветствую!
Увы, не помогло (ни tcp, ни udp)...
В логе появляется:
.... avregd: cam[2]: capture (V) failed: Invalid data found when processing input
В avreg-gst-rtsp-proxy.log при rtsp-transports = tcp
---
2020-04-28 05:53:37 avreg-gst-rtsp-proxy-INFO: cam[2] add mount point "media" => "/avreg-media/2/media.amp"
2020-04-28 05:53:37 avreg-gst-rtsp-proxy-INFO: ready at rtsp://*:8554
0:00:01.000762907 9512 0x55dc7fc58b70 ERROR rtspclient rtsp-client.c:1012:find_media: client 0x55dc7fc83140: not authorized to see factory path /avreg-media/2/media.amp
0:00:01.000841104 9512 0x55dc7fc58b70 ERROR rtspclient rtsp-client.c:2899:handle_describe_request: client 0x55dc7fc83140: no media
2020-04-28 05:53:38 avreg-gst-rtsp-proxy-INFO: uridecodebin: setup "rtspsrc" source by gstprox_rtspsrc_opts = "latency=200 tcp-timeout=5000000 timeout=3000000"
0:00:21.012489274 9512 0x55dc7fc58b70 WARN rtspmedia rtsp-media.c:2991:wait_preroll: failed to preroll pipeline
0:00:21.012569981 9512 0x55dc7fc58b70 WARN rtspmedia rtsp-media.c:3295:gst_rtsp_media_prepare: failed to preroll pipeline
0:00:21.028092745 9512 0x55dc7fc58b70 ERROR rtspclient rtsp-client.c:1044:find_media: client 0x55dc7fc83140: can't prepare media
0:00:21.028249302 9512 0x55dc7fc58b70 ERROR rtspclient rtsp-client.c:2899:handle_describe_request: client 0x55dc7fc83140: no media
.......
0:02:50.566364741 9512 0x7f3b04003400 ERROR rtspclient rtsp-client.c:1012:find_media: client 0x7f3af0129880: not authorized to see factory path /avreg-media/2/media.amp
0:02:50.566428594 9512 0x7f3b04003400 ERROR rtspclient rtsp-client.c:2899:handle_describe_request: client 0x7f3af0129880: no media
2020-04-28 05:56:27 avreg-gst-rtsp-proxy-INFO: uridecodebin: setup "rtspsrc" source by gstprox_rtspsrc_opts = "latency=200 tcp-timeout=5000000 timeout=3000000"
0:03:10.567668056 9512 0x7f3b04003400 WARN rtspmedia rtsp-media.c:2991:wait_preroll: failed to preroll pipeline
0:03:10.567744712 9512 0x7f3b04003400 WARN rtspmedia rtsp-media.c:3295:gst_rtsp_media_prepare: failed to preroll pipeline
0:03:10.578259392 9512 0x7f3b04003400 ERROR rtspclient rtsp-client.c:1044:find_media: client 0x7f3af0129880: can't prepare media
0:03:10.579018303 9512 0x7f3b04003400 ERROR rtspclient rtsp-client.c:2899:handle_describe_request: client 0x7f3af0129880: no media
0:03:14.790041902 9512 0x7f3b04003450 ERROR rtspclient rtsp-client.c:1012:find_media: client 0x7f3af0129660: not authorized to see factory path /avreg-media/2/media.amp
0:03:14.790124620 9512 0x7f3b04003450 ERROR rtspclient rtsp-client.c:2899:handle_describe_request: client 0x7f3af0129660: no media
2020-04-28 05:56:51 avreg-gst-rtsp-proxy-INFO: uridecodebin: setup "rtspsrc" source by gstprox_rtspsrc_opts = "latency=200 tcp-timeout=5000000 timeout=3000000"
0:03:21.008626263 9512 0x7f3b0806f590 WARN rtpjitterbuffer rtpjitterbuffer.c:570:calculate_skew: delta - skew: 0:00:02.609619858 too big, reset skew
0:03:21.010421137 9512 0x7f3af8003c50 WARN uridecodebin gsturidecodebin.c:921:unknown_type_cb:<uribin> warning: No decoder available for type 'application/x-rtp, media=( string)application, payload=(int)106, clock-rate=(int)90000, encoding-name=(string)VND.ONVIF.METADATA, a-source-filter=(string)"\ incl\ IN\ IP4\ \*\ 192.168.1.123", a-sendonly=(stri ng)"", ssrc=(uint)673453824, npt-start=(guint64)0, play-speed=(double)1, play-scale=(double)1'.
0:03:21.010607338 9512 0x7f3af8003c50 WARN default descriptions.c:1229:gst_pb_utils_get_codec_description: No description available for media type: application/x-rt p
0:03:21.010664739 9512 0x7f3af8003c50 WARN decodebin gstdecodebin2.c:4640:gst_decode_bin_expose:<decodebin11> error: no suitable plugins found:
Missing decoder: application/x-rtp (application/x-rtp, media=(string)application, payload=(int)106, clock-rate=(int)90000, encoding-name=(string)VND.ONVIF.METADATA, a-source-filter= (string)"\ incl\ IN\ IP4\ \*\ 192.168.1.123", a-sendonly=(string)"", ssrc=(uint)673453824, npt-start=(guint64)0, play-speed=(double)1, play-scale=(double)1)
0:03:21.011464463 9512 0x7f3b0806f5e0 WARN rtspmedia rtsp-media.c:2735:default_handle_message: 0x7f3b080841d0: got warning No decoder available for type 'application/ x-rtp, media=(string)application, payload=(int)106, clock-rate=(int)90000, encoding-name=(string)VND.ONVIF.METADATA, a-source-filter=(string)"\ incl\ IN\ IP4\ \*\ 192.168.1.123", a- sendonly=(string)"", ssrc=(uint)673453824, npt-start=(guint64)0, play-speed=(double)1, play-scale=(double)1'. (gsturidecodebin.c(921): unknown_type_cb (): /GstPipeline:media-pipelin e/GstBin:GstRTSPMediaFactoryURI/GstBin:dynpay0/GstURIDecodeBin:uribin)
---
Кстати, если декодирование включено, последний блок лога (про "...warning: No decoder available for type..." и "... error: no suitable plugins found: Missing decoder...") появляется практически сразу. А если декодирование выключено - всё равно появится, но через какое-то время.
У rtsp-proxy свои режимы работы с декодерами, не используется avregd ?