[FFmpeg-user] Question regarding ffmpeg

[Vukan]

I am merging an image sequence into a video using the following command:

ffmpeg -f image2 -i "input\image%09d.png" -framerate 60 output.mp4

However, the framerate of the output video is always 25, no matter what I
set as -framerate argument. What is going on?

Full output:
ffmpeg version N-91725-g3ad0e6724d Copyright (c) 2000-2018 the FFmpeg
developers
  built with gcc 8.2.1 (GCC) 20180813
  configuration: --enable-gpl --enable-version3 --enable-sdl2
--enable-fontconfig --enable-gnutls --enable-iconv --enable-libass
--enable-libbluray --enable-libfreetype --enable-libmp3lame
--enable-libopencore-amrnb --enable-libopencore-amrwb --enable-libopenjpeg
--enable-libopus --enable-libshine --enable-libsnappy --enable-libsoxr
--enable-libtheora --enable-libtwolame --enable-libvpx --enable-libwavpack
--enable-libwebp --enable-libx264 --enable-libx265 --enable-libxml2
--enable-libzimg --enable-lzma --enable-zlib --enable-gmp
--enable-libvidstab --enable-libvorbis --enable-libvo-amrwbenc
--enable-libmysofa --enable-libspeex --enable-libxvid --enable-libaom
--enable-libmfx --enable-amf --enable-ffnvcodec --enable-cuvid
--enable-d3d11va --enable-nvenc --enable-nvdec --enable-dxva2
--enable-avisynth
  libavutil      56. 19.100 / 56. 19.100
  libavcodec     58. 27.100 / 58. 27.100
  libavformat    58. 17.103 / 58. 17.103
  libavdevice    58.  4.101 / 58.  4.101
  libavfilter     7. 26.100 /  7. 26.100
  libswscale      5.  2.100 /  5.  2.100
  libswresample   3.  2.100 /  3.  2.100
  libpostproc    55.  2.100 / 55.  2.100
Input #0, image2, from 'input\image%09d.png':
  Duration: 00:00:04.00, start: 0.000000, bitrate: N/A
    Stream #0:0: Video: png, gray(pc), 800x888, 25 fps, 25 tbr, 25 tbn, 25
tbc
Stream mapping:
  Stream #0:0 -> #0:0 (png (native) -> h264 (libx264))
Press [q] to stop, [?] for help
[libx264 @ 000001e1986ad0c0] using cpu capabilities: MMX2 SSE2Fast SSSE3
SSE4.2 AVX FMA3 BMI2 AVX2
[libx264 @ 000001e1986ad0c0] profile High, level 3.1, 4:0:0, 8-bit
[libx264 @ 000001e1986ad0c0] 264 - core 157 r2932 303c484 - H.264/MPEG-4
AVC codec - Copyleft 2003-2018 - 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=0 trellis=1 8x8dct=1
cqm=0 deadzone=21,11 fast_pskip=1 chroma_qp_offset=-2 threads=6
lookahead_threads=1 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, mp4, to 'output.mp4':
  Metadata:
    encoder         : Lavf58.17.103
    Stream #0:0: Video: h264 (libx264) (avc1 / 0x31637661), gray, 800x888,
q=-1--1, 25 fps, 12800 tbn, 25 tbc
    Metadata:
      encoder         : Lavc58.27.100 libx264
    Side data:
      cpb: bitrate max/min/avg: 0/0/0 buffer size: 0 vbv_delay: -1
frame=  100 fps= 77 q=-1.0 Lsize=     605kB time=00:00:03.88
bitrate=1278.3kbits/s speed=2.99x
video:603kB audio:0kB subtitle:0kB other streams:0kB global headers:0kB
muxing overhead: 0.328185%
[libx264 @ 000001e1986ad0c0] frame I:1     Avg QP:25.65  size: 15824
[libx264 @ 000001e1986ad0c0] frame P:25    Avg QP:26.34  size: 11861
[libx264 @ 000001e1986ad0c0] frame B:74    Avg QP:32.83  size:  4120
[libx264 @ 000001e1986ad0c0] consecutive B-frames:  1.0%  0.0%  3.0% 96.0%
[libx264 @ 000001e1986ad0c0] mb I  I16..4: 95.9%  1.0%  3.0%
[libx264 @ 000001e1986ad0c0] mb P  I16..4:  0.1%  0.1%  0.5%  P16..4: 36.3%
25.4% 37.0%  0.0%  0.0%    skip: 0.6%
[libx264 @ 000001e1986ad0c0] mb B  I16..4:  0.0%  0.0%  0.0%  B16..8: 19.6%
15.0%  7.9%  direct:17.8%  skip:39.7%  L0:48.3% L1:41.9% BI: 9.9%
[libx264 @ 000001e1986ad0c0] 8x8 transform intra:4.2% inter:94.8%
[libx264 @ 000001e1986ad0c0] coded y intra: 15.4% inter: 41.5%
[libx264 @ 000001e1986ad0c0] i16 v,h,dc,p: 31% 27% 41%  0%
[libx264 @ 000001e1986ad0c0] i8 v,h,dc,ddl,ddr,vr,hd,vl,hu:  3%  3% 69%
9%  0%  0%  0%  0% 17%
[libx264 @ 000001e1986ad0c0] i4 v,h,dc,ddl,ddr,vr,hd,vl,hu: 61% 31%  6%
1%  0%  0%  0%  0%  0%
[libx264 @ 000001e1986ad0c0] i8c dc,h,v,p: 100%  0%  0%  0%
[libx264 @ 000001e1986ad0c0] Weighted P-Frames: Y:32.0%
[libx264 @ 000001e1986ad0c0] ref P L0: 39.9% 20.8% 15.9% 16.8%  6.7%
[libx264 @ 000001e1986ad0c0] ref B L0: 82.0% 12.9%  5.1%
[libx264 @ 000001e1986ad0c0] ref B L1: 93.0%  7.0%
[libx264 @ 000001e1986ad0c0] kb/s:1234.51