FFMPEG "Past duration 0.xxxxxx too large"

Question

I'm recording an HLS streaming and I would like to save in a FLV Container.

My ffmpeg's cmd is:

/.../recorder/class/ffmpeg-2.6.1-32bit-static/./ffmpeg  -i http://server/url/playlist.m3u8 -b:a 128K -acodec libmp3lame -ar 44100 -write_xing 0 -y -b:v 512K -vcodec flv -t 1860 /tmp/test.flv

It starts recording but in the console output I display a lot of: Past duration 0.XXXXXX too large

What this warning means? And how can I fix them?

This is console output of input information:

ffmpeg version 2.6.1-   http://johnvansickle.com/ffmpeg/    Copyright (c) 2000-2015 the FFmpeg developers
  built with gcc 4.9.2 (Debian 4.9.2-10)
  configuration: --enable-gpl --enable-version3 --disable-shared --disable-debug --enable-runtime-cpudetect --enable-libmp3lame --enable-libx264 --enable-libx265 --enable-libwebp --enable-libspeex --enable-libvorbis --enable-libvpx --enable-libfreetype --enable-fontconfig --enable-libxvid --enable-libopencore-amrnb --enable-libopencore-amrwb --enable-libtheora --enable-libvo-aacenc --enable-libvo-amrwbenc --enable-gray --enable-libopenjpeg --enable-libopus --enable-libass --enable-gnutls --enable-libvidstab --cc=gcc-4.9
  libavutil      54. 20.100 / 54. 20.100
  libavcodec     56. 26.100 / 56. 26.100
  libavformat    56. 25.101 / 56. 25.101
  libavdevice    56.  4.100 / 56.  4.100
  libavfilter     5. 11.102 /  5. 11.102
  libswscale      3.  1.101 /  3.  1.101
  libswresample   1.  1.100 /  1.  1.100
  libpostproc    53.  3.100 / 53.  3.100
Input #0, hls,applehttp, from 'http://server/url/playlist.m3u8':
  Duration: N/A, start: 35483.191100, bitrate: N/A
  Program 0 
    Metadata:
      variant_bitrate : 303609
    Stream #0:0: Video: h264 (Main) ([27][0][0][0] / 0x001B), yuv420p, 320x180 [SAR 1:1 DAR 16:9], 30 fps, 30 tbr, 90k tbn, 60 tbc
    Metadata:
      variant_bitrate : 303609
    Stream #0:1: Audio: aac (LC) ([15][0][0][0] / 0x000F), 44100 Hz, mono, fltp, 67 kb/s
    Metadata:
      variant_bitrate : 303609

How do I resolve this?

Solution 1

This post seems to have the answer: "FFMpeg versions after Jan 15 2015 often display this warning. It has been added to warn about possible rate control distortion, otherwise it does not cause any harm."

It appears to be triggered when "the presentation time (pts) in the input stream differs from the one in the output stream by more than a fixed limit set to 0.6"

Solution 2

It seems to be a new "feature": ffmpeg spams "Past duration x.y too large" messages

With ffmpeg version 2.6.2 they get written out once per frame information (frame=...) and with 2.6.git they occur mostly at the start of the recording and then at irregular intervals.