FFmpeg RTP network issue in Ubuntu

[Ivan Kolesnikov]

I want to copy a bunch of SD sources from mpegts transported with RTP on local files. (VBR mpeg2video, mp2 audio). It works fine for one multicast source with the following command:

ffmpeg -i rtp://@IP1:PORT?sources=SourceIP1 -c copy video1.mpg

but when I run a second ffmpeg instance with the following command:

ffmpeg -i rtp://@IP2:PORT?sources=SourceIP2 -c copy video2.mpg

then I start to get errors from both FFmpeg instances ("RTP: dropping old packet received too late") and in both files (video1.mpg and video2.mpg) start recording video from the second source (rtp://@IP2:PORT).

This issue occurs only in Linux (Ubuntu 15.04). I have no problems in Windows and when I try the same actions from files to files. Under Ubuntu even two ffplay instances tuned to different sources play back the same content (from the source which was opened last). I tried playing back with VLC and there is no such problem.

I can resolve this issue when using FFmpeg with the -f option:
ffmpeg -f mpegts -i rtp://@IP1:PORT?sources=SourceIP1 -c copy video1.mpg
and
ffmpeg -f mpegts -i rtp://@IP2:PORT?sources=SourceIP2 -c copy video2.mpg, but then I'm getting the following errors: "[mpegts @ 0x306e240] PES packet size mismatch" and receive both files (video1.mpg and video2.mpg) with artifacts and freeze effects. This issue appears for both operating systems.

How can I record videos from multiple RTP streams simultaneously under Ubuntu without errors and artifacts?

ffmpeg version 2.7.1 Copyright (c) 2000-2015 the FFmpeg developers
built with gcc 4.9.2 (Ubuntu 4.9.2-10ubuntu13)
configuration: --prefix=/home/ivan/ffmpeg_build --pkg-config-flags=--static --extra-cflags=-I/home/ivan/ffmpeg_build/include --extra-ldflags=-L/home/ivan/ffmpeg_build/lib --bindir=/home/ivan/bin --enable-gpl --enable-libass --enable-libfdk-aac --enable-libfreetype --enable-libmp3lame --enable-libopus --enable-libtheora --enable-libvorbis --enable-libvpx --enable-libx264 --enable-nonfree
libavutil 54. 27.100 / 54. 27.100
libavcodec 56. 41.100 / 56. 41.100
libavformat 56. 36.100 / 56. 36.100
libavdevice 56. 4.100 / 56. 4.100
libavfilter 5. 16.101 / 5. 16.101
libswscale 3. 1.101 / 3. 1.101
libswresample 1. 2.100 / 1. 2.100
libpostproc 53. 3.100 / 53. 3.100

[Carl Eugen Hoyos]

Please test current FFmpeg git head and please post the command line that allows to reproduce the issue together with the complete, uncut console output to make this a valid ticket.