ffmpeg task not ending: "Error with filtering" from ffmpeg 3.3

[Benjamin Ahsan]

Summary of the bug:
Since version 3.3 some ffmpeg command lines do not end anymore. So far I could only reproduce this issue the overlay filter. The same command lines (cf. below) are working properly with ffmpeg version 3.2 and older.

How to reproduce:

ffmpeg -y -i media.mp4 -loop 1 -i 720p.png -filter_complex "overlay=0:0:shortest=1" out.ts
ffmpeg version 6d7192b Copyright (c) 2000-2017 the FFmpeg developers
  built with gcc 5.4.0 (Ubuntu 5.4.0-6ubuntu1~16.04.4) 20160609
  configuration: 
  libavutil      55. 58.100 / 55. 58.100
  libavcodec     57. 89.100 / 57. 89.100
  libavformat    57. 71.100 / 57. 71.100
  libavdevice    57.  6.100 / 57.  6.100
  libavfilter     6. 82.100 /  6. 82.100
  libswscale      4.  6.100 /  4.  6.100
  libswresample   2.  7.100 /  2.  7.100
Input #0, mov,mp4,m4a,3gp,3g2,mj2, from 'media.mp4':
  Metadata:
    major_brand     : isom
    minor_version   : 512
    compatible_brands: isomiso2avc1mp41
    encoder         : Lavf57.72.101
  Duration: 00:00:58.97, start: 0.000000, bitrate: 2332 kb/s
    Stream #0:0(und): Video: h264 (Main) (avc1 / 0x31637661), yuv420p, 1280x720 [SAR 1:1 DAR 16:9], 2201 kb/s, 25 fps, 25 tbr, 90k tbn, 50 tbc (default)
    Metadata:
      handler_name    : VideoHandler
    Stream #0:1(und): Audio: aac (LC) (mp4a / 0x6134706D), 48000 Hz, stereo, fltp, 125 kb/s (default)
    Metadata:
      handler_name    : SoundHandler
Input #1, png_pipe, from '720p.png':
  Duration: N/A, bitrate: N/A
    Stream #1:0: Video: png, rgba(pc), 1280x720 [SAR 15748:15748 DAR 16:9], 25 fps, 25 tbr, 25 tbn, 25 tbc
Stream mapping:
  Stream #0:0 (h264) -> overlay:main (graph 0)
  Stream #1:0 (png) -> overlay:overlay (graph 0)
  overlay (graph 0) -> Stream #0:0 (mpeg2video)
  Stream #0:1 -> #0:1 (aac (native) -> mp2 (native))
Press [q] to stop, [?] for help
Output #0, mpegts, to 'out.ts':
  Metadata:
    major_brand     : isom
    minor_version   : 512
    compatible_brands: isomiso2avc1mp41
    encoder         : Lavf57.71.100
    Stream #0:0: Video: mpeg2video (Main), yuv420p, 1280x720 [SAR 1:1 DAR 16:9], q=2-31, 200 kb/s, 25 fps, 90k tbn, 25 tbc (default)
    Metadata:
      encoder         : Lavc57.89.100 mpeg2video
    Side data:
      cpb: bitrate max/min/avg: 0/0/200000 buffer size: 0 vbv_delay: -1
    Stream #0:1(und): Audio: mp2, 48000 Hz, stereo, s16, 384 kb/s (default)
    Metadata:
      handler_name    : SoundHandler
      encoder         : Lavc57.89.100 mp2
Error while filtering=24.8 size=    6782kB time=00:00:58.93 bitrate= 942.7kbits/s speed=1.92x    
frame= 1474 fps=5.5 q=31.0 size=    6805kB time=00:00:58.95 bitrate= 945.5kbits/s speed=0.221x

[Benjamin Ahsan]

Sample media.mp4 file has been cut down to 10 seconds to match the 2.5MB attachement limit.

[Carl Eugen Hoyos]

Please test current FFmpeg git head.

[Elon Musk]

Duplicate of #6292.