Opened 3 weeks ago

Closed 4 days ago

#6852 closed defect (needs_more_info)

Encoding process gets stuck and cpu load goes to 100% on Linux (ffmpeg version 2.8.13)

Reported by: fcarvalho Owned by:
Priority: important Component: undetermined
Version: 2.8.11 Keywords: deadlock regression
Cc: Blocked By:
Blocking: Reproduced by developer: no
Analyzed by developer: no


I am having issues with ffmpeg version 2.8.13 while trying to encode a ulaw to mp4. For more than 95% of the files it works fine, but some of the encoding process simply get stuck and the cpu load goes up to 100% until i kill the process.


  • Command line: /bin/ffmpeg -f mulaw -ar 8000 -y -i /home/recording_outbound_394485.ulaw -strict -2 /home/recording_outbound_394485.mp4
  • I am running on CentOS Linux release 7.3.1611 (Core)
  • On version 2.8.11 and 2.8.13 the process gets stuck with 100% cpu load
  • On version 2.5.4 the same files that cause the ffmpeg encoding process to get stuck work as expected in a couple of seconds.
  • On windows version 2.2.2 it works too and the file is encoded to mp4 as expected.

Command ran with valgrind:

valgrind /bin/ffmpeg -f mulaw -ar 8000 -y -i /home/recording_outbound_394485.ulaw -strict -2 /home/recording_outbound_394485.mp4

==48708== Memcheck, a memory error detector
==48708== Copyright (C) 2002-2015, and GNU GPL'd, by Julian Seward et al.
==48708== Using Valgrind-3.11.0 and LibVEX; rerun with -h for copyright info
==48708== Command: /bin/ffmpeg -f mulaw -ar 8000 -y -i /home/recording_outbound_394485.ulaw -strict -2 /home/recording_outbound_394485.mp4
ffmpeg version 2.8.13 Copyright (c) 2000-2017 the FFmpeg developers

built with gcc 4.8.5 (GCC) 20150623 (Red Hat 4.8.5-11)
configuration: --prefix=/usr --bindir=/usr/bin --datadir=/usr/share/ffmpeg --incdir=/usr/include/ffmpeg --libdir=/usr/lib64 --mandir=/usr/share/man --arch=x86_64 --optflags='-O2 -g -pipe -Wall -Wp,-D_FORTIFY_SOURCE=2 -fexceptions -fstack-protector-strong --param=ssp-buffer-size=4 -grecord-gcc-switches -m64 -mtune=generic' --extra-ldflags='-Wl,-z,relro ' --enable-libopencore-amrnb --enable-libopencore-amrwb --enable-libvo-amrwbenc --enable-version3 --enable-bzlib --disable-crystalhd --enable-gnutls --enable-ladspa --enable-libass --enable-libcdio --enable-libdc1394 --disable-indev=jack --enable-libfreetype --enable-libgsm --enable-libmp3lame --enable-openal --enable-libopenjpeg --enable-libopus --enable-libpulse --enable-libschroedinger --enable-libsoxr --enable-libspeex --enable-libtheora --enable-libvorbis --enable-libv4l2 --enable-libx264 --enable-libx265 --enable-libxvid --enable-x11grab --enable-avfilter --enable-avresample --enable-postproc --enable-pthreads --disable-static --enable-shared --enable-gpl --disable-debug --disable-stripping --shlibdir=/usr/lib64 --enable-runtime-cpudetect
libavutil 54. 31.100 / 54. 31.100
libavcodec 56. 60.100 / 56. 60.100
libavformat 56. 40.101 / 56. 40.101
libavdevice 56. 4.100 / 56. 4.100
libavfilter 5. 40.101 / 5. 40.101
libavresample 2. 1. 0 / 2. 1. 0
libswscale 3. 1.101 / 3. 1.101
libswresample 1. 2.101 / 1. 2.101
libpostproc 53. 3.100 / 53. 3.100

[mulaw @ 0x162de840] Estimating duration from bitrate, this may be inaccurate
Guessed Channel Layout for Input Stream #0.0 : mono
Input #0, mulaw, from '/home/recording_outbound_394485.ulaw':

Duration: 00:04:17.12, bitrate: 64 kb/s

Stream #0:0: Audio: pcm_mulaw, 8000 Hz, 1 channels, s16, 64 kb/s

[aac @ 0x163093c0] Too many bits per frame requested, clamping to max
Output #0, mp4, to '/home/recording_outbound_394485.mp4':


encoder : Lavf56.40.101
Stream #0:0: Audio: aac ([64][0][0][0] / 0x0040), 8000 Hz, mono, fltp, 48 kb/s

encoder : Lavc56.60.100 aac

Stream mapping:

Stream #0:0 -> #0:0 (pcm_mulaw (native) -> aac (native))

Press [q] to stop, ? for help
size= 322kB time=00:01:04.51 bitrate= 40.9kbits/s

===>> And it gets stuck <<===

Unfortunatelly i can't attach the audio file (ulaw) due to client's privacy.

Change History (4)

comment:1 Changed 3 weeks ago by cehoyos

Please test current FFmpeg git head.

comment:2 Changed 3 weeks ago by cehoyos

  • Component changed from ffmpeg to undetermined
  • Keywords deadlock regression added; ffmpeg encoding mp4 process stuck removed
  • Reproduced by developer unset

comment:3 Changed 3 weeks ago by fcarvalho

Ok, I will try to reproduce the error with ffmpeg git head and i will give you a feedback

comment:4 Changed 4 days ago by cehoyos

  • Resolution set to needs_more_info
  • Status changed from new to closed

Please reopen this ticket if you can provide the sample or a backtrace for current FFmpeg git head.

Note: See TracTickets for help on using tickets.