pi@raspberrypi:~ $ gdb --args ffmpeg_g -v debug -max_streams 1 -f v4l2 -list_formats all -i /dev/video0
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Reading symbols from ffmpeg_g...done.
(gdb) run
Starting program: /home/pi/bin/ffmpeg_g -v debug -max_streams 1 -f v4l2 -list_formats all -i /dev/video0
[Thread debugging using libthread_db enabled]
Using host libthread_db library "/lib/arm-linux-gnueabihf/libthread_db.so.1".
ffmpeg version N-83027-g0ddc24d Copyright (c) 2000-2017 the FFmpeg developers
  built with gcc 5.2.0 (crosstool-NG crosstool-ng-1.22.0)
  configuration: --enable-cross-compile --cross-prefix=/opt/cross/x-tools/arm-unknown-linux-gnueabi/bin/arm-unknown-linux-gnueabi- --arch=armel --target-os=linux --prefix=/home/redacted/workspace/arm
  libavutil      55. 43.100 / 55. 43.100
  libavcodec     57. 71.100 / 57. 71.100
  libavformat    57. 62.100 / 57. 62.100
  libavdevice    57.  2.100 / 57.  2.100
  libavfilter     6. 68.100 /  6. 68.100
  libswscale      4.  3.101 /  4.  3.101
  libswresample   2.  4.100 /  2.  4.100
Splitting the commandline.
Reading option '-v' ... matched as option 'v' (set logging level) with argument 'debug'.
Reading option '-max_streams' ... matched as AVOption 'max_streams' with argument '1'.
Reading option '-f' ... matched as option 'f' (force format) with argument 'v4l2'.
Reading option '-list_formats' ... matched as AVOption 'list_formats' with argument 'all'.
Reading option '-i' ... matched as input url with argument '/dev/video0'.
Finished splitting the commandline.
Parsing a group of options: global .
Applying option v (set logging level) with argument debug.
Successfully parsed a group of options.
Parsing a group of options: input url /dev/video0.
Applying option f (force format) with argument v4l2.
Successfully parsed a group of options.
Opening an input file: /dev/video0.
[NULL @ 0x1761d60] Value 0.000000 for parameter 'flags' is not a valid set of 32bit integer flags
	num: 1.000000
	intnum: 0
	den: 1

Program received signal SIGSEGV, Segmentation fault.
__frexp (x=4503599627370497, eptr=0x0) at ../sysdeps/ieee754/dbl-64/s_frexp.c:39
39	../sysdeps/ieee754/dbl-64/s_frexp.c: No such file or directory.
(gdb) bt
#0  __frexp (x=4503599627370497, eptr=0x0) at ../sysdeps/ieee754/dbl-64/s_frexp.c:39
#1  0x00bb3728 in av_d2q (d=<optimized out>, max=max@entry=2147483647) at libavutil/rational.c:115
#2  0x00bac0f0 in av_opt_set_defaults2 (s=s@entry=0x1761d60, mask=0, flags=0)
    at libavutil/opt.c:1334
#3  0x00604214 in init_context_defaults (s=s@entry=0x1761d60, codec=codec@entry=0x0)
    at libavcodec/options.c:111
#4  0x00604444 in avcodec_alloc_context3 (codec=codec@entry=0x0) at libavcodec/options.c:163
#5  0x0030dac4 in avformat_new_stream (s=s@entry=0x17611d0, c=c@entry=0x0)
    at libavformat/utils.c:4242
#6  0x000ada4c in v4l2_read_header (ctx=0x17611d0) at libavdevice/v4l2.c:827
#7  0x0030d0e0 in avformat_open_input (ps=ps@entry=0xbeffee84,
    filename=filename@entry=0xefd688 <received_nb_signals> "",
    fmt=fmt@entry=0xedd8a0 <ff_v4l2_demuxer>, options=0x1761094) at libavformat/utils.c:594
#8  0x00097c6c in open_input_file (o=o@entry=0xbeffef80, filename=<optimized out>)
    at ffmpeg_opt.c:999
#9  0x00099720 in open_files (l=0xc, l=0xc, open_file=0x967dc <open_input_file>,
    inout=0xc69498 "input") at ffmpeg_opt.c:3222
#10 ffmpeg_parse_options (argc=argc@entry=11, argv=argv@entry=0xbefff754) at ffmpeg_opt.c:3262
#11 0x000894b8 in main (argc=11, argv=0xbefff754) at ffmpeg.c:4553
(gdb)