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 _______________________________________________ ffmpeg-user mailing list ffmpeg-user@ffmpeg.org https://ffmpeg.org/mailman/listinfo/ffmpeg-user To unsubscribe, visit link above, or email ffmpeg-user-requ...@ffmpeg.org with subject "unsubscribe".