# ffmpeg -i tmp.flv tmp.mkv
ffmpeg version N-85962-g164e277 Copyright (c) 2000-2017 the FFmpeg developers
  built with gcc 4.4.7 (GCC) 20120313 (Red Hat 4.4.7-11)
  configuration: --enable-gpl --enable-libx264 --enable-nonfree --enable-libfdk_aac --enable-libmp3lame --enable-libass
  libavutil      55. 62.100 / 55. 62.100
  libavcodec     57. 95.100 / 57. 95.100
  libavformat    57. 72.101 / 57. 72.101
  libavdevice    57.  7.100 / 57.  7.100
  libavfilter     6. 88.100 /  6. 88.100
  libswscale      4.  7.101 /  4.  7.101
  libswresample   2.  8.100 /  2.  8.100
  libpostproc    54.  6.100 / 54.  6.100
Input #0, flv, from 'tmp.flv':
  Duration: 00:42:59.94, start: 1258.836000, bitrate: 1430 kb/s
    Stream #0:0: Video: h264 (High), yuvj420p(pc, bt709, progressive), 1920x1080, 30.30 fps, 30 tbr, 1k tbn, 60 tbc
    Stream #0:1: Audio: aac, 44100 Hz, stereo, fltp
File 'tmp.mkv' already exists. Overwrite ? [y/N] y
Stream mapping:
  Stream #0:0 -> #0:0 (h264 (native) -> h264 (libx264))
  Stream #0:1 -> #0:1 (aac (native) -> ac3 (native))
Press [q] to stop, [?] for help
No pixel format specified, yuvj420p for H.264 encoding chosen.
Use -pix_fmt yuv420p for compatibility with outdated media players.
[libx264 @ 0x3e35680] using cpu capabilities: MMX2 SSE2Fast SSSE3 SSE4.2 AVX
[libx264 @ 0x3e35680] profile High, level 4.0
[libx264 @ 0x3e35680] 264 - core 142 - H.264/MPEG-4 AVC codec - Copyleft 2003-2014 - http://www.videolan.org/x264.html - options: cabac=1 ref=3 deblock=1:0:0 analyse=0x3:0x113 me=hex subme=7 psy=1 psy_rd=1.00:0.00 mixed_ref=1 me_range=16 chroma_me=1 trellis=1 8x8dct=1 cqm=0 deadzone=21,11 fast_pskip=1 chroma_qp_offset=-2 threads=12 lookahead_threads=2 sliced_threads=0 nr=0 decimate=1 interlaced=0 bluray_compat=0 constrained_intra=0 bframes=3 b_pyramid=2 b_adapt=1 b_bias=0 direct=1 weightb=1 open_gop=0 weightp=2 keyint=250 keyint_min=25 scenecut=40 intra_refresh=0 rc_lookahead=40 rc=crf mbtree=1 crf=23.0 qcomp=0.60 qpmin=0 qpmax=69 qpstep=4 ip_ratio=1.40 aq=1:1.00
Output #0, matroska, to 'tmp.mkv':
  Metadata:
    encoder         : Lavf57.72.101
    Stream #0:0: Video: h264 (libx264) (H264 / 0x34363248), yuvj420p(pc), 1920x1080, q=-1--1, 30 fps, 1k tbn, 30 tbc
    Metadata:
      encoder         : Lavc57.95.100 libx264
    Side data:
      cpb: bitrate max/min/avg: 0/0/0 buffer size: 0 vbv_delay: -1
    Stream #0:1: Audio: ac3 ([0] [0][0] / 0x2000), 44100 Hz, stereo, fltp, 192 kb/s
    Metadata:
      encoder         : Lavc57.95.100 ac3
frame= 1241 fps= 48 q=-1.0 Lsize=   11541kB time=00:00:41.65 bitrate=2270.0kbits/s speed=1.62x
video:10547kB audio:976kB subtitle:0kB other streams:0kB global headers:0kB muxing overhead: 0.159336%
[libx264 @ 0x3e35680] frame I:13    Avg QP:14.64  size: 55679
[libx264 @ 0x3e35680] frame P:616   Avg QP:20.08  size: 13384
[libx264 @ 0x3e35680] frame B:612   Avg QP:22.63  size:  2991
[libx264 @ 0x3e35680] consecutive B-frames: 26.8% 20.8%  5.1% 47.4%
[libx264 @ 0x3e35680] mb I  I16..4: 40.6% 46.2% 13.2%
[libx264 @ 0x3e35680] mb P  I16..4:  5.4% 10.3%  0.5%  P16..4: 21.2%  4.6%  1.7%  0.0%  0.0%    skip:56.3%
[libx264 @ 0x3e35680] mb B  I16..4:  0.3%  0.3%  0.0%  B16..8: 14.6%  1.1%  0.1%  direct: 1.5%  skip:82.0%  L0:45.9% L1:52.0% BI: 2.1%
[libx264 @ 0x3e35680] 8x8 transform intra:61.4% inter:80.5%
[libx264 @ 0x3e35680] coded y,uvDC,uvAC intra: 15.9% 43.2% 16.3% inter: 2.4% 8.6% 0.4%
[libx264 @ 0x3e35680] i16 v,h,dc,p: 37% 48%  8%  7%
[libx264 @ 0x3e35680] i8 v,h,dc,ddl,ddr,vr,hd,vl,hu: 24% 21% 47%  1%  1%  1%  1%  1%  1%
[libx264 @ 0x3e35680] i4 v,h,dc,ddl,ddr,vr,hd,vl,hu: 28% 27% 19%  4%  5%  5%  5%  3%  3%
[libx264 @ 0x3e35680] i8c dc,h,v,p: 49% 28% 20%  3%
[libx264 @ 0x3e35680] Weighted P-Frames: Y:3.1% UV:2.9%
[libx264 @ 0x3e35680] ref P L0: 78.8%  5.4% 11.6%  4.2%  0.0%
[libx264 @ 0x3e35680] ref B L0: 86.3% 12.0%  1.7%
[libx264 @ 0x3e35680] ref B L1: 96.6%  3.4%
[libx264 @ 0x3e35680] kb/s:2088.48
Exiting normally, received signal 2.



# ffmpeg -ss 30.5 -i tmp.mkv -vframes 1 out2.png
ffmpeg version N-85962-g164e277 Copyright (c) 2000-2017 the FFmpeg developers
  built with gcc 4.4.7 (GCC) 20120313 (Red Hat 4.4.7-11)
  configuration: --enable-gpl --enable-libx264 --enable-nonfree --enable-libfdk_aac --enable-libmp3lame --enable-libass
  libavutil      55. 62.100 / 55. 62.100
  libavcodec     57. 95.100 / 57. 95.100
  libavformat    57. 72.101 / 57. 72.101
  libavdevice    57.  7.100 / 57.  7.100
  libavfilter     6. 88.100 /  6. 88.100
  libswscale      4.  7.101 /  4.  7.101
  libswresample   2.  8.100 /  2.  8.100
  libpostproc    54.  6.100 / 54.  6.100
Input #0, matroska,webm, from 'tmp.mkv':
  Metadata:
    ENCODER         : Lavf57.72.101
  Duration: 00:00:41.66, start: 0.000000, bitrate: 2269 kb/s
    Stream #0:0: Video: h264 (High), yuvj420p(pc, progressive), 1920x1080, 30 fps, 30 tbr, 1k tbn, 60 tbc (default)
    Metadata:
      ENCODER         : Lavc57.95.100 libx264
      DURATION        : 00:00:41.406000000
    Stream #0:1: Audio: ac3, 44100 Hz, stereo, fltp, 192 kb/s (default)
    Metadata:
      ENCODER         : Lavc57.95.100 ac3
      DURATION        : 00:00:41.657000000
File 'out2.png' already exists. Overwrite ? [y/N] y
Stream mapping:
  Stream #0:0 -> #0:0 (h264 (native) -> png (native))
Press [q] to stop, [?] for help
[swscaler @ 0x425a280] deprecated pixel format used, make sure you did set range correctly
Output #0, image2, to 'out2.png':
  Metadata:
    encoder         : Lavf57.72.101
    Stream #0:0: Video: png, rgb24, 1920x1080, q=2-31, 200 kb/s, 30 fps, 30 tbn, 30 tbc (default)
    Metadata:
      DURATION        : 00:00:41.406000000
      encoder         : Lavc57.95.100 png
frame=    1 fps=0.0 q=-0.0 Lsize=N/A time=00:00:00.03 bitrate=N/A speed=0.199x
video:892kB audio:0kB subtitle:0kB other streams:0kB global headers:0kB muxing overhead: unknown