[FFmpeg-user] timeout error when reading RTSP/RTP incoming audio stream

[Yannick Barbeaux]

On Mon, 15 Jun 2020 at 09:37, Yannick Barbeaux
<yannick.barbeaux at keemotion.com> wrote:
>
> Hello
> I am struggling to read a multicast audio RTP stream controlled by RTSP. As
> soon as I launch the ffplay or ffmpeg command, the RTP traffic starts
> (tcpdump) on port 5004/UDP (as advertised in the SDP file), so it should
> read the stream correctly but I finally get a time-out instead (and empty
> out file). The very same RTSP URL can be read without any issue with VLC or
> with rtpdump+sox.
>
> $ ffmpeg -y -rtsp_transport udp_multicast -i "rtsp://
> 192.168.2.148:554/by-name/AES67-stream (on hasseb-AoE-F8-82)" -vn -f s24le
> -ar 48000 -c:a pcm_s24be out.raw
> ffmpeg version 4.2.2 Copyright (c) 2000-2019 the FFmpeg developers
>   built with gcc 7 (Ubuntu 7.4.0-1ubuntu1~18.04.1)
>   configuration: --extra-libs=-ldl --prefix=/opt/ffmpeg --disable-debug
> --enable-nonfree --enable-gpl --enable-version3 --enable-libopencore-amrnb
> --enable-libopencore-amrwb --disable-decoder=amrnb --disable-decoder=amrwb
> --enable-libpulse --enable-libfreetype --enable-gnutl
> s --enable-libdav1d --enable-libx264 --enable-libx265 --enable-libfdk-aac
> --enable-libvorbis --enable-libmp3lame --enable-libopus --enable-libvpx
> --enable-libspeex --enable-libass --enable-avisynth --enable-libsoxr
> --enable-libxvid --enable-libvidstab --enable-libtheora --en
> able-libwavpack --enable-libopenjpeg --enable-libgsm --enable-nvenc
> --enable-libzimg --enable-libaom
>   libavutil      56. 31.100 / 56. 31.100
>   libavcodec     58. 54.100 / 58. 54.100
>   libavformat    58. 29.100 / 58. 29.100
>   libavdevice    58.  8.100 / 58.  8.100
>   libavfilter     7. 57.100 /  7. 57.100
>   libswscale      5.  5.100 /  5.  5.100
>   libswresample   3.  5.100 /  3.  5.100
>   libpostproc    55.  5.100 / 55.  5.100
> Guessed Channel Layout for Input Stream #0.0 : stereo
> Input #0, rtsp, from 'rtsp://192.168.2.148:554/by-name/AES67-stream (on
> hasseb-AoE-F8-82)':
> Metadata:
>     title           : AES67-stream (on hasseb-AoE-F8-82) streamed by
> "hasseb"
>   Duration: N/A, bitrate: 2304 kb/s
>     Stream #0:0: Audio: pcm_s24be, 48000 Hz, stereo, s32 (24 bit), 2304 kb/s
> Stream mapping:
>   Stream #0:0 -> #0:0 (pcm_s24be (native) -> pcm_s24be (native))
> Press [q] to stop, [?] for help
> rtsp://192.168.2.148:554/by-name/AES67-stream (on hasseb-AoE-F8-82):
> Connection timed out
> Output #0, s24le, to 'out.raw':
>   Metadata:
>     title           : AES67-stream (on hasseb-AoE-F8-82) streamed by
> "hasseb"
>     encoder         : Lavf58.29.100
>     Stream #0:0: Audio: pcm_s24be, 48000 Hz, stereo, s32 (24 bit), 2304 kb/s
>     Metadata:
>       encoder         : Lavc58.54.100 pcm_s24be
> size=       0kB time=00:00:00.00 bitrate=N/A speed=   0x
> video:0kB audio:0kB subtitle:0kB other streams:0kB global headers:0kB
> muxing overhead: unknown
> Output file is empty, nothing was encoded (check -ss / -t / -frames
> parameters if used)
>
> The SDP file is :
>
> v=0
> o=- 254522267104 0 IN IP4 192.168.2.148
> s=AES67-stream (on hasseb-AoE-F8-82) streamed by "hasseb"
> t=0 0
> a=clock-domain:PTPv2 0
> a=recvonly
> m=audio 5004 RTP/AVP 98
> c=IN IP4 239.123.123.123/255
> a=rtpmap:98 L24/48000/2
> a=sync-time:0
> a=framecount:48
> a=source-filter: incl IN IP4 239.123.123.123 192.168.2.148
> a=ts-refclk:ptp=IEEE1588-2008:00-10-4b-ff-fe-2e-f8-82:domain-nmbr=0
> a=mediaclk:direct=0
> a=ptime:1
>
> Comparing those files, we see that ffmpeg detects the correct
> audio settings (pcm_s24be, 48000 Hz, stereo, s32 (24 bit)) so I cannot
> figure out why it can't read the data stream? I have tried to increase the
> timeout but that did not help.
>
> Any help would be appreciated. Thank you.
>
> Yannick
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My apologies to everyone for multi-posting this question. My question
did not appear in the list after two days so I tried multiple times,
thinking it had been considered as spam or something. Then I noticed
the question appeared three times in the ffmpeg-user archives, sorry.
(Strange thing though : "Receive your own posts to the list?" is set
to "Yes" in my subscription settings and I do not receive them).
Cheers